Restoring #151489 - building a faux cam carrera

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#331 Post by Bill Sargent »

Well as John's photos show, the Faux Cam project has taken a temporary turn toward a less faux state. Now for the "safe harbor" statement: 151489 was not a 4 cam Carrera from the factory, and I am not making any attempt to ever say it was. Hopefully this will keep SH happy.

That said, the car now has a 2 liter 4 cam motor installed. Many of you have probably guessed by my 4 cam related questions in the main forum that something was up. The motor will stay in the car for a couple of years and is then destined for another project, at which time the faux cam motor will be installed. A few photos are included below.
Here is the motor after we set the valves, figured out the jigsaw puzzle of repro sheet metal and installed new plug wires.  Ready to be installed.
Here is the motor after we set the valves, figured out the jigsaw puzzle of repro sheet metal and installed new plug wires. Ready to be installed.
And here is the motor in the car.
And here is the motor in the car.
I wish getting the motor installed was as easy as these two pictures make it look.......
This is how the factory supported the sport exhaust.  The springs are inner 4 cam valve springs....
This is how the factory supported the sport exhaust. The springs are inner 4 cam valve springs....
And this is the top of the strut.
And this is the top of the strut.
Gregory Campbell went way above the call by providing his shop, bedrooms, equipment, knowledge and assistance all last week. I can not thank him and his wife Marianne enough.
Gregory and Ralfy.jpg
Ralfy Quepons also was a driving force in the installation. Most of the time Ralfy worked hard:
Ralfy the 4 cam mechanic.jpg
But sometimes Ralfy worked too hard:
Ralfy Working hard.jpg
And one last photo of us going into the 356 Group NW Bull Session last weekend. We got the motor in at midnight Friday and the first time the car turned a wheel was 5:30am Saturday when we headed out from Vancouver to Sequim, WA where the Bull Session was held.
Sargent Car at Bull Session.jpg
Over the weekend I will do a post with a blow by blow of the trials and tribulations encountered in the install. Who know, it may help when Dave Seeland gets around to putting his 2 liter 4 cam into his Carrera speedster.
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

Max Handley
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Re: Restoring #151489 - building a faux cam carrera

#332 Post by Max Handley »

Bill

Please tell us about your impressions driving the 2 liter 4 cam compared to what you have been use too.

Thanks Max H
 Contact email Spyderwerks@comcast.net

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#333 Post by Bill Sargent »

Now for the blow by blow install:

Day 1 - Sunday 19 July

Ralfy and I drove up to Vancouver Sunday morning and after a nice lunch we started work about 2:00 pm. We decided to open up the cam covers and sump since the motor had been sitting since 2012. We wanted to adjust valve clearances and put some lube on the cams as they were likely to be dry. Almost immediately we encountered small problems. Upon removing the valve clearance locks (see photo below) we found 3 of the 8 on the motor had the hex shaft, that fits in the valve adjuster screw to lock it in place, too badly rounded to reuse. Gregory to the rescue with some spares he had.
You can also see the double O ring cam plugs Jacques Le Friant sells to help slow the oil leaks.
You can also see the double O ring cam plugs Jacques Le Friant sells to help slow the oil leaks.
After we had the adjuster locks removed we found 3 of the valve adjuster screws so hard to turn that we decided to remove them to investigate. This involved removing the cam. We then slowly removed the offending adjuster screws and cleaned them up with a die. We also cleaned up the shaft with a tap and that solved our problems. When the cam goes back all parts have to be in exactly the same place and the small paint dots on the gears, which ensure the valve timing will be as it was before disassembly, must match up. fortunately Gregory was there to guide us through this procedure.
Valve adjuster screw.jpg
By dinner time we had all the valves adjusted, had the valve cover gaskets replaced and did a general clean up.

Day 2 - Monday 20 July

Monday morning we resumed on the motor, working to replace the spark plug wires. Magencor supplies a nice set of wires pre cut and labeled for the Carrera motors. This part went fairly easy. We also replaced the crank pulley with a reproduction supplied by Jacques LeFriant as the one on the motor had a chip that was wearing the fan belt. Jacques also supplied the nice spark plug wire guides that fit near the cam covers.
New Plug Wires.jpg
Ralfy then started on the carbs. The motor came with a set of Weber 48 IDA carbs set up for racing. Inside we found corrosion on one butterfly shaft, light showing around all the butterflies and one shaft slightly bent. Ralfy did his best to repair them as we did not have a spare set. [post install note - we determined for the short term that purchase of a new set of 48 IDAs with the 3rd progression hole, better needle valves and custom jetting for our application was more cost effective than trying to rebuild the set that come with the motor. Longer term the plan is to go to Solex 44s. I have a set of the original Carrera II intake manifolds and carb linkage. Jim at 356 Carb Rescue is building me a set of his split shaft Solex 40s converted to solid shaft and bored to 44mm. We will use the 904 sport jetting which should result in a much more drivable motor].

While Ralfy was working on the carbs I removed the 60 B super motor that came with the car and also the pushrod engine tray, which bolts in to A cars. I then fabricated the Carrera fuel line using some 8 mm stainless tubing from Multi Metric. Once bead blasted it looks a lot like white cad plating. Once the fuel line was in place the next step was to unhook the driver's side tail light and get all the wiring out of the way to allow the metal channel that carries the engine seal rubber to be welded to the body.
Carrera fuel line.jpg
Peter Hoffman of Classic parts in Germany supplied the metal channel that holds the engine seal rubber. Nice parts but they require a lot of hand forming to get them to match the shape of the lower Carrera engine tray.
Original part was one piece, but we ended up using 3 pieces.
Original part was one piece, but we ended up using 3 pieces.
Once the channels were shaped correctly 1/8 inch holes were drilled and Gregory gas welded the channel to the body.
Since we elected to gas weld the channel in place, all the wiring had to be out of the way.
Since we elected to gas weld the channel in place, all the wiring had to be out of the way.
Once this was done I installed the coil brackets. For now they are just bolted through the firewall, but eventually I will install weld nuts on the inside to allow easy remove/install.

Day 3 - Tuesday 21 July

Ralfy took on the task of fitting the reproduction Carrera II engine sheet metal purchased from Peter Hoffman at Classic Parts. It was a real jigsaw puzzle. We were greatly helped by Hennrichs new Carrera book which has many good photos. It took Ralfy all day Tuesday and part of the day Wednesday to get the sheet metal trimmed, holes drilled, weld nuts welded on and everything fit. Not for the faint hearted.
Repro 4 cam engine sheet metal - as delivered.jpeg
And here is the motor with all the new sheet metal installed.
And here is the motor with all the new sheet metal installed.
In the mean time I continued to prepare the wiring to accept the Carrera motor, installed the seal rubber into the metal channel around the engine compartment. The rubber seal can be installed with the seal lip aimed up or down. I chose up the first time and was wrong. Down is correct so I had to take it out and redo. I also installed the fuel lines on the motor. We had to silver solder the pipes into the banjos on the carbs as the motor did not come with these parts. Ralfy brought the banjos with him and we used some of the 8mm stainless tubing to make the parts.

Day 4 - Wednesday 22 July

Ralfy finished p the engine sheet metal install Wednesday morning and we then installed new rear transmission mounts. Carreras had rear mounts with harder rubber and some metal reinforcements due to the heavier motor weight. These are long NLA, but Mike Smith with PR Services in the UK has reproduced the mounts with the harder rubber, but not the metal reinforcements. We installed a set of these mounts. While Ralfy was installing the motor mounts I started making up the two new oil lines that would be required - tank to motor and motor to thermostat. I also had to put a new end on one of the short lines that runs from the thermostat to the hard piping going to the coolers. While test fitting parts I notice that the anti backflow valve purchased from John Wilhoit had threads that were too short on one end, so the nut that captures the oil line Argus fitting would not allow the fitting to seat and seal. Gregory came to the rescue with his lathe where we machined about 2 mm off the nut to allow things to seal properly. The backflow valve is fitted to the oil tank and prevents oil from flowing through the oil pump into the motor sump while the car is idle.
Machining Tank Oil Line Fitting.jpg
Each end on an oil line takes me about 30 minutes to complete. First the hose is cut and the stray wires trimmed, then the cap is placed over the hose. This part can be a real chore, as the original part ID is a little small for the current AN hose sizes. Fortunately Peter at Classic Parts and others have reproduced these parts with a slightly larger ID to accommodate current AN hose. I got the short hose completed and reinstalled between the thermostat and hard lines and one end on each of the other 2 hoses by quitting time Wednesday. The rest of the day we got things on the motor ready for installation.

Next post will pick up on Thursday morning.
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Joris Koning
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Re: Restoring #151489 - building a faux cam carrera

#334 Post by Joris Koning »

Hey Bill,

Great post, thanks for posting. Ralfy did a great job, it took me over a week to get all my metal fitted with consistent 1mm gaps. The 4-cam sheet metal is a real challenge, especially if you want it to look nice.

I recently spoke to a friend of mine who build these engines at the factory when they were new. He looked at my engine and the fit of the pieces and needles to say concluded that it was way better than anything they ever did. That being said, he did say that the fit and finish of the factory pieces when new was pretty nice.

Thanks for sharing,

J.
'56 Coupe
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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#335 Post by Bill Sargent »

Max - I will share driving impressions after the install posts. Suffice it to say that with over double the rear wheel horsepower it was ..... satisfying. When taking the car back to storage in Seattle Ralfy was following me in a rental car. He said he could not keep up when I accelerated. When was the last time you could say that in a stock 356?

Joris - yes, Ralfy did a great job. Where metal had to be trimmed he got it within the 1 to 2 mm area. There were, however, some areas where there was no metal to trim and we had a gap. At some point when I am living in Seattle the motor will come out and I will take the time to weld on metal where needed and trim things so they really look nice. Some of the sheet metal already on the motor needs to be worked and cleaned up as well.

At this point I am just glad the motor is in the car and running. We are in the process of procuring parts to address the carb issues so that I can take the car to Rennsport Reunion V in late September. Ralfy will be in Georgia for a school on later Porsche electronics and will stop in Seattle on the way back in Mid August for a couple of days to install the carbs and get the car on a rolling dyno to make sure we have the jetting right. Longer term the plan is for 356 Carb Rescue's Solex 44s - I managed to purchase a set of the original solex manifolds and throttle cross bar to enable this set up.
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#336 Post by Bill Sargent »

Finally got some time to continue the install post.

Day 5 - Thursday 23 July:

On Wednesday evening we decided to pressure test the hard and soft lines that go to the front coolers. They were installed 3+ years ago and had bounced around for 4,000 miles. Ralfy had replicated my pressure test rig since my original was in storage. We hooked things up with a cap on one hard line and shop air to the other at 90 psi and a valve to close things in over night. Thursday morning the gauge showed some pressure loss, but we could not detect a leak. Running short on time, we decided to hope the leak would not be large. Two days later after running the car for 2.5 hours on the way to the 356 Group NW Bull Session we had zero leaks from the cooler loop, so we figure that our Teflon tape job on the pressure test rig must not have been good. :D
Pressure test gauge for testing the front cooler loop.
Pressure test gauge for testing the front cooler loop.
On Thursday I finished up work on the oil lines ends that could be installed before the motor goes in the car. After Gregory fixed the one fitting so it would work with the Wilhoit anti backflow valve I then installed the new Behr thermostat purchased from Peter Hoffman at Classic parts. Four years ago at the LA Lit meet I purchased an oil filter console, lines and the thermostat from a 72 911S for $600 to get the thermostat as a cheaper alternative to the then $1600 real thing. Now with a real four cam, I decided I should go with the real thermostat. The stronger Dollar meant the real thing was more like $1100, and in the mean time with the skyrocketing values of early 911s the complete 72S oil filter, lines and thermostat is probably worth 3 to 4 times that. So the 911 part will probably get sold.
oil line parts and thermostat from Classic Parts
oil line parts and thermostat from Classic Parts
Before installing the motor in the car we did some measurements on the clutch and pressure plate to determine if the combination of the Carrera flywheel which had been machined to a non stock depth, with a late 356 200 mm pressure plate and disc would work with the recommended late 356 B throwout bearing. Measurements said it would and we later found it did. I had a new C/SC throw out bearing on had just in case. After determining that the clutch would work we were ready to install the motor in the car. Gregory's mid rise lift made the task almost a breeze. But then we encountered a problem - motor offered up with upper bolts installed but the upper bolts were too short :shock: Turns out the flange on the Carrera engine case is thicker than the pushrod and each of the upper motor bolts is 10mm longer. Gregory to the rescue - he pulled two bolts of the right length from his parts stock. By the end of the day we had the motor in the car and the clutch adjusted.
Motor in the car
Motor in the car
Day 6 - Friday 24 July:

Today was the make or break day. I got the rest of the oil lines made up and connected with no problem. In the mean time Ralfy started to install the exhaust system, with the short header pipes going on first. The first obstacle was a loose exhaust stud which Ralfy fixed in a somewhat inelegant way, but it worked.
Used Sport Exhaust 1, otherwise known as a peashooter (I think) purchased from Jacques
Used Sport Exhaust 1, otherwise known as a peashooter (I think) purchased from Jacques
We then offered up the exhaust and immediately hit a snag. The stock street lower valve covers are too tall and interfered with the exhaust. Jacques must have seen this coming and decided to be my guardian angel - when Ralfy and I visited him at his shop in March we also took a tour of several of his suppliers. At one shop there was a large cart full of raw castings for lower GT valve covers. Jacques asked me if I wanted a pair and I took him up - his price was very reasonable. Problem was the lower valve covers were raw - they needed to be surfaced, have the holes drilled and then the nut seating surface faced.
GT Lower Cam Covers - LeFriant Reproduction.jpeg
Gregory to the rescue again. Doesn't everyone have an industrial drill press and a CNC mill in their shop? Between me, Ralfy and Gregory we got the new valve covers surfaced, holes marked and drilled and nut faces surfaced, but the time all this was done it was about 2 pm. The next problem was that we needed shorter studs in the heads to install the GT valve covers. Gregory to the rescue again with a nice stud puller and 8 studs of about the right length. Another hour to get the studs changed out and the valve covers installed. Then we tried to fit the exhaust again, only to discover that some of the lower sheet metal was in the way. So there were some .... modifications.... made :wink: . Finally just before dinner we got the exhaust installed. We also made up the exhaust support strut, which was relatively easy to do. But it was not Friday evening and the motor had not run. But we thought we were close.....Little did we know.
Exhaust support strut.  Springs are 4 cam inner valve springs per the parts manual.  Thick dished washers keep things centered.
Exhaust support strut. Springs are 4 cam inner valve springs per the parts manual. Thick dished washers keep things centered.
After dinner we had to modify the position of the lever arm on the throttle cross bar that hooks to the rod going thru the shroud down to the bell crank on the transmission that. The motor had been in 904-006 and an RS 60 so the cross bar was set up for mid engine use, not a street car. Another hour gone. The we found some fuel leaks and had to work on our fuel lines and banjos.

So then we finally begin trying to start the car about 7pm Friday evening. And it will not start. We finally determined we had power to the coils and the distributors, but were not getting spark. After quite some time (about 2 hours) we finally found the problem. Jacques had fitted the distributors with a custom Pertronix set up for Stanley's use in the 904. The pertronix has a plus and minus wire coming out of the distributor. We had some nice double bullet connectors from YnZ and decided to use them...... without inspecting them closely enough. Turns out they are meant to be used in a Y configuration ..... so when we hooked things up and applied power we immediately shorted out both Pertronix modules - hence no spark. Ralfy and I thought we were dead in the water.
Pertronix module in the distributor
Pertronix module in the distributor
Turns out Jacques made his own custom installation.  Took me and a very helpful Bill Hoge at pertronix a week to determine what the original modules were.  All good now and I have 4 new modules (at $73 each) - 2 for the motor and 2 spare.
Turns out Jacques made his own custom installation. Took me and a very helpful Bill Hoge at pertronix a week to determine what the original modules were. All good now and I have 4 new modules (at $73 each) - 2 for the motor and 2 spare.
Meanwhile Gregory had left the room and a couple of minutes later he returns with two 4 cam distributors (with points) - his spare set for the Elva. Gregory has my undying gratitude! So we installed them and finally at about 10pm Friday night the motor started :D :D :D ! And boy was it LOUD!! Peashooter in a small garage. Fortunately I had purchased a supertrap that had a 2.5 inch pipe opening into a 4 inch pipe. Gregory cut off the 2.5 inch pipe where the flare met the 4 inch, made some slots, flattened it into an oval and low and behold it matched the exhaust tail pipe. A large industrial hose clamp secured it and the noise was actually less than the seabring exhaust on the pushrod motor.

But our trials were still not over. The fuel pressure was too high and one carb had a float level problem - leading to gas peeing into the 1-2 cylinder side. Ralfy did his best and the motor ran well a high rpm, but idle was a problem due to the way rich mixture. Finally at about midnight we went to bed, at least knowing the car would run. 5:30am was going to come early! So 5:30 comes and there was one last problem. The engine lid would not close :shock: :shock: ! The inner structure of the A engine lid hit the throttle cross bar. Gregory to the rescue again. The solution was some long M6 bolts and spacer tubes to space the latch on the lid down enough to latch with the lid open about an inch. I should have done my homework. A carreras with an engine lid like mine had the throttle cross bar in front of the shroud with a different throttle linkage than the Carrera IIs. And the Carrera II twin grill engine lid does not have the same inner structure. Something else learned.

The next morning we headed out in convoy with Gregory and Marianne in their 1960 roadster (in which Gregory had packed a large bag of tools). Fortunately the car ran very well and we had no problems, other than the idle problems due to the carbs. We made it to the Bull Session and had a great time!
Heading into the Bull Session.
Heading into the Bull Session.
Next post will give some driving impressions and also talk about follow on work to the not so faux cam. Thanks for following along!
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#337 Post by Bill Sargent »

And now for some driving impressions:

Power and Torque Obviously WAY more power. We were hindered a bit in evaluating this due to the sorry state of the carbs, but when you put your foot into it at 70 mph in 4th (about 3500 rpm with my tall 4th gear) it really squats and shoots forward! And we were likely down on power due to the carb problems. Engine dyno in Stanley Gold's RS60 said 144 hp at the rear wheels, which probably translates to about 170 hp at the crank. Motor received new 904 pistons and barrels when rebuilt in 2004. Torque was good from 3000 RPM up. More flexible than I had expected, but several 4 cam owners told me that the Carrera II motor with the modifications made to my motor would have a broad torque band, which was confirmed. Ralfy's comment when following me back up I5 thru Seattle after the 356 Group NW Bull Session was that I was continually outrunning him in the rental car he was driving. And we had a supertrap on the peashooter exhaust to moderate the noise a little. Not your normal stock pushrod 356 experience.

Weight in the rear - I have heard estimates for the 2 liter 4 cam motor ranging from 50 to 100 lbs heavier than a pushrod motor. Use of the peashooter exhaust meant I did not have the stock pushrod or Carrera II exhaust so the total weight gain was not as high as it could have been. Car was a little nose down prior to the motor swap and still had a little forward rake after the motor swap, without any change to the rear suspension setting. Given the frantic nature of the final 2 days of the install any thought of resetting the rear suspension went out the window, and in hind sight I am not sure it will be needed. What was evident while driving however was that the rear shocks need to be firmed up some. The car bounced a little too much over certain types of bumps. The car has new Koni shocks set full soft, so I have room to adjust and adjusting the shocks is easy. The car would probably benefit from the Wilhoit 17mm front sway bar and Vic Skirmants rear camber compensator.

Noise - with the supertrap actually less than the Jim Constas Seabring on the pushrod motor. Without the supertrap the peashooter exhaust is LOUD!

Other impressions - motor revs way more easily than a pushrod. My bone stock 64C starts to lose steam about 5500 rpm. Not so with the 4 cam. At 6000 it is still ready to rev higher. Maybe later after we get the carbs sorted. Changing plugs with the motor in the car would be a large challenge. Setting valve clearances with the motor in the car would be impossible. On the plus side the engine tin and exhaust all stay on the motor when it goes in and comes out, so pulling the motor is actually a little easier than a pushrod motor.

Photos below are of the car at the 356 Group NW Bull Session at Sequim, WA.
DSC_2765.JPG
DSC_2765.JPG (109.94 KiB) Viewed 5296 times
Ralfy looking happy that we actually made it!
Ralfy looking happy that we actually made it!
DSC_2778.JPG (124.15 KiB) Viewed 5296 times
Short Term Work - Ralfy is stopping in Seattle Monday and Tuesday this week on his way back from a Porsche training school to install the new pertronix modules in the distributors, install the new Weber 48 IDA carbs jetted for street use, get the car on a dyno to confirm jetting, and sort out a couple of other small problems. That should get the car good to go for Rennsport Reunion V. We are also modifying the engine lid to allow it to close with the Carrera II throttle cross bar placement. At the same time the engine lid will get a coat of paint to match the light yellow on the rest of the car.

Longer Term Work - I have Jim at 356 Carb Rescue building a set of his Solex split shaft converted to solid shaft carbs. They will be bored to 44 mm and have jets and venturis to match the 904 sport specs that the motor is built to. To enable this I purchased a set of original Carrera II solex manifolds and throttle cross bar. This set up, with the solex carbs being shorter, will allow me to run proper air cleaners.

Thanks for following along. I hope to see many of you at Rennsport Reunion V at laguna Seca and the Registry Reunion gathering in Carmel in a few weeks.
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#338 Post by Bill Sargent »

Got a note from Ralfy Tuesday morning US time. The new Pertronix ignition modules are installed in the distributors and work great (and we have two spare). An expensive lesson on check twice, power up once - $75 per distributor, x 2 for spares. The new Weber 48IDA carbs are also installed and the car now idles perfectly as well as revving smoothly. Ralfy talked with Jacques LeFriant and got his advice on jetting and venturis for the carbs. I can not thank Jacques enough for all his help. We purchased a second set of jet stacks for the carbs from JayCee Inc in order to have a set for road driving vs more spirited track driving - the difference being high RPM enrichment. The new Webers also have the 3rd transition hole drilled to aid in part throttle response and make the motor a little less ON/OFF - the trashed set of carbs, in addition to all their other problems, were jetted and tuned for all out racing and did not have the 3rd transition hole.

While the car was on the lift Ralfy also removed the exhaust and the lower valve covers to fit the proper 30mm length studs for the GT valve covers. When we replaced the stock Carrera II lower valve covers with Jacques GT covers (to allow the peashooter exhaust to fit) we had a mix of studs, some 30 mm and some a shorter, some a little longer - remember that we were raiding Gregory's parts supply. Problem was that on the longer studs the cap nuts were bottoming out, not allowing the valve cover to seal properly. We did the "Billybob" ("Heinifritz" in German) fix to get to the Bull Session by inserting extra washers under the cap nuts, but then our doudy washers (special washers with a rubber seal) did not seal properly and the result was lots of oil leaks. Ralfy reports after installing the new studs there are a lot less leaks and they are smaller. The real proper fix will be to get the GT covers on a mill to surface the area around the O-ring channel flat. Then turn over and make sure the milled nut seating faces are parallel so the valve cover will torque down evenly. We did not have time at Gregory's place to do all these steps. Bottom line is good enough for now :) And there will not be as much of the pricy Motul 20W50 mineral oil leaking out on the floor (or blowing on the car behind me).

Tuesday morning the car will go to a rolling dyno in Bellevue to check jetting, optimize tune and air/fuel ratio. Brad is taking his 62 notch with a Jack Morris built 2 liter twin plug pushrod motor. Before the carb replacement on the 4 cam motor Brad was thinking he would win the horsepower contest. Now he is not so sure. Will be interesting to see the dyno results.

Back here in China I got on line a little before 9:00am eastern time (9:00pm same day in Beijing) Tuesday to see if I could snag some parade laps of Laguna Seca while at Rennsport Reunion V. Sales were only on line at the PCA site starting at 9:00am EST. I was done by 9:03am and was car 52 out of the 100 allowed for Saturday. Price of $25 was a bonus. There are 100 slots for parade laps each day for cars parked in one of the Porsche parking corrals. I suspect that as I write this at 10am EST they are all gone.

Hope to see you all at Rennsport. look for the loud, ugly, yellow faux cam on the track between 12:20 to 12:40 pm on Saturday the 26th of September. I turn 60 on 24 September and this is going to be a good birthday! I would love to receive photos anyone might happen to take. Thanks for following along!
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#339 Post by Bill Sargent »

Ralfy and Brad had my car and Brad's 62 notch at the rolling road dyno in Kirkland, WA on Tuesday and I thought I would share some of the data. I have dyno info on my 2 liter 4 cam motor from September 2009 after a major tear down inspection where fresh bearings were installed. I also have dyno info from Tuesday 18 August 2015 and for comparison I pulled Cliff Murray's dyno data for his Wilhoit 2133 pushrod motor from a post he put on the forum in 2013. The September 2009 dyno of my motor had it set up for all out racing but using dot 2 intake and dot 1 exhaust cams rather than the more aggressive dot 3 cams on intake and exhaust that a full race 904 motor would use. The factory estimated this would lose about 20 to 25 horsepower at higher RPMs. Otherwise my motor has 904 P&C etc. The carbs had jets and venturis (42 mm) for max power at high RPM at the expense of both power and torque at lower RPM. For the August 2015 dyno we had a new set of 48 IDA Webers with 40 mm venturis. We also had slightly different jetting to improve torque lower in the range. The other major difference was we are using a peashooter exhaust in the 2015 runs. The 2009 runs were done with a RS 60 exhaust. The graph for horsepower is shown below. Note that Cliff's data was motor and mine was rear wheel. I have used a 15% loss factor to get Cliff's data comparable to my rear wheel data. If a 20% loss factor were used then Cliff's data would overlay and be very similar to the 4 cam data.
P97290 Dyno comparisons - Horsepower - 20Aug15.jpg
Of note is that the change in venturi and jetting on the 4 cam picked up significant horsepower below 4500 RPM while losing about 10 horsepower above 6000 RPM. Max rear wheel horsepower in 2009 was 144 vs 134 last week. The 4 cam motor is probably performing about the same as 2009 except for the carb and exhaust change. Good to know. We still need to look at rebuilding the distributors as one does not appear to be advancing smoothly.

For those wondering if a 4 cam is worth it on horsepower - I guess the answer for any non racing application is no if you look at the power Cliff Murray's 2133 motor makes. My 4 cam only edges ahead over 5900 RPM. A full race 2 liter 4 cam would probably look similar to the 2133 pushrod up to about 5100 RPM but would then keep going up to about 160 to 165 rear wheel horsepower.

Now have a look at the Torque graph.
P97290 Dyno comparisons - Torque - 20Aug15.jpg
On my 4 cam motor the change of carbs and jetting and the different exhaust really flattened the torque curve below 4700 RPM, giving usable torque all the way down to about 2700 RPM. A big change for the better at the expense of 5 ft lbs above 4700 RMP. Ralfy thinks if we go down to a 38 mm venturi we can gain some torque in the 2700 to 3500 RPM range, but at the expense of top end horsepower. But again the 2311 pushrod wins big in the torque department until you get above 6000 RPM. Of course a full race 2 liter 4 cam motor would get to the same torque Cliff's motor makes by about 5500 RPM and then go up a little more to about 6000 RPM before falling off. Again the 15% loss factor was applied to Cliff's motor data to compare to my rear wheel data. Even if you went to a 20% loss, Cliff's motor makes a lot more torque at lower RPMs.

So conclusion is 4 cam motors are cool, but if you want everyday drivable horsepower for a lot less $$ then the Wilhoit 2133 motor is the way to go. But no, I am not going to sell the 4 cam motor and build a 2133 :)!

One last interesting comparison. Brad's 62 notch has a 2 liter stroker pushrod motor built by Jack Morris. It is twin plugged and has (I think) 10.0 to 1 compression. Not sure about the carbs but likely either Solex or Weber 40s. It topped out at 110 horsepower at about the same 5500 RPM that the 2133 pushrod motor did.

So there you have it. Thanks for following along!
Last edited by Bill Sargent on Tue Aug 25, 2015 10:37 am, edited 1 time in total.
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

Justin Rio
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Re: Restoring #151489 - building a faux cam carrera

#340 Post by Justin Rio »

Congratulations on acquiring and getting that motor up and running in your car Bill! You have done just an outstanding job of both researching and executing all the 4-cam carrera details. I've certainly learned a thing or two and I thank you for taking the time to share your experience. Looking forward to your next installment. Justin

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#341 Post by Bill Sargent »

Remembered another issue we encountered with 4 cam motor install. Earlier in this thread you will have seen the Eberspacher B2 gas heater installation. The B2 was used in the pushrod cars while the B3 was used in Carreras. I had always wondered why the difference. Visibly the B3 is about 5 inches longer than the B2 and has two relays mounted on the heater to control certain functions. Well just before installing the motor I measured clearances and we determined that the thermo probe cover on the B2 heater would interfere with one of the two distributors on the 4 cam motor. So the gas heater is no longer in the car, at least until the faux cam pushrod motor goes in. The B3 heater, being longer, places the thermo probe cover a few inches more toward the passenger side of the car and thus clears the distributors. That said however it appears that the only way to install the motor, even with the B3 heater, is for the distributors to be installed after the motor is in the car since the motor has to be offered up a few inches to the rear of where it will eventually sit in order to insert the lower studs into the transmission.

Ralfy also sent a few photos of the dyno testing.
Bill Car on Dyno - 18Aug14.jpg
Bill Car on Dyno 2 - 18Aug14.jpg
Apparently Ralfy has reached the age where help is needed to read the jets.......
Apparently Ralfy has reached the age where help is needed to read the jets.......
Ralfy's selection of Carb jets
Ralfy's selection of Carb jets
And now a "what is this part from" photo. Hint - it is for a Porsche car made in the 356 era. Vic - you are not eligible to answer:
Suspension part CAD - 21Aug15.JPG
Thanks for following along!
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Re: Restoring #151489 - building a faux cam carrera

#342 Post by Brad Ripley »

For one the 904 , here's a drawing below. I will check a type 804 tomorrow and get some photos.
Attachments
904 front suspension.jpg

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#343 Post by Bill Sargent »

Brad Wins! :D As usual he is spot on. Guess I should have excluded both Vic and Brad :) . Learning the CAD program to make the distributor V drive has given me the skills to assist friends at times, and the 904 Front Suspension Upright is one of those activities. Earlier in this thread you will have heard that Gregory is having M&W in the UK build him a 904 reproduction. He was very persuasive, so I have ordered one as well, and that will be the eventual home of the 2L four cam motor. The faux cam motor will then go in the 59A. In any event we would both like to get FIA papers for the 904s which means, among other things, period correct suspension parts. Since Brad and Stoddard NLA do not stock these parts what's a guy to do? Find a factory drawing and get it into CAD.
Still some work to do on the spindle dimensions.  Then likely 3D print a male part to make a mold for sand casting, but we are also looking at CNC machining from 4340 steel.
Still some work to do on the spindle dimensions. Then likely 3D print a male part to make a mold for sand casting, but we are also looking at CNC machining from 4340 steel.
So now after that diversion, back to the cars. Brad Green was kind enough to send the dyno graph for his 2 liter pushrod motor. It was on the dyno same day as my car, with Ralfy managing both tests. Brad's car is a 2 liter stroker motor using the LN 90 mm pistons and cylinders, twin plugs, stock heads and Solex 40 carbs. I have added a purple line to the graphs shown earlier for Brad's motor. Notice the difference between it and the 2133 motor, which is single plug - a large part of the advantage is in the redesign of the combustion chamber in the heads by John Wilhoit.
P97290 Dyno comparisons - Horsepower w 2L - 20Aug15.jpg
P97290 Dyno comparisons - Torque w 2L- 20Aug15.jpg
Thanks for following along!
Regards,

Bill Sargent
#151489 59A Cab - Faux Cam
#159176 64C Cab
#460603 67 912
904 clone in the works

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Alex Mestas
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Re: Restoring #151489 - building a faux cam carrera

#344 Post by Alex Mestas »

Hi Bill:
I have followed your Restoring 151489- Building a Faux Cam Carrera from the very beginning. It's been such a great thread. Congratulations to you and Ralfy and all those on the forum that have contributed to your success. I will be cheering you on at Rennsport V on Saturday, September 26 at 12:20 pm at turn 4. Looking forward to seeing you there.


Alex D. Mestas
1963 356 T-6 Coupe Signal Red.
1973.5 911 T Coupe Ivory.
1989 911 Carrera Targa Grd Prix White.

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Bill Sargent
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Re: Restoring #151489 - building a faux cam carrera

#345 Post by Bill Sargent »

Now that the real 4 cam motor is in the car, Gregory and I had time to get back to faux cam motor building. Gregory and I have been working for about 18 months to design a V drive that would bolt onto a late pushrod motor and use pushrod distributors and components. One reproduction 4 cam distributor with cap and rotor will set you back over $2,500, hence the desire to use more affordable components. Shown below is the final version of the design in the CAD world:
Round V Drive Mount Frame Design 4.jpg
The first step for us was to make the V drive body so we could assemble the internal parts with distributors and test things for "proof of concept". Gregory spoke with many people knowledgeable about prototyping about 3D printing a plastic version versus making an aluminum prototype. The consensus was the we needed closer tolerances than could be had with a plastic print, hence we decided to go with a CNC machined aluminum prototype. Another advantage of the aluminium prototype, provided I got everything right, is it will make a fully working V drive. Gregory had a friend working for a prototyping firm called Omnitech in Bellingham, WA and they checked my CAD model for "machinability" and did a general clean up on the Parasolid V14 CAD file I exported to them for the actual CNC work. Omnitech in turn used a firm called Trulife, also in Bellingham, for the CNC work. The first aluminum CNC machined prototype was completed earlier this week and looks pretty good!
Front of V drive body.  Small tube on side of one of the distributor shaft tubes is for lube oil out.  The small tube on the other side on the V drive body is for lube oil in.
Front of V drive body. Small tube on side of one of the distributor shaft tubes is for lube oil out. The small tube on the other side on the V drive body is for lube oil in.
Rear of V drive body.  The V drive attaches to the mount frame with 3 x M8 hex bolts.  The mount frame in turn mounts to the 3rd piece of the push rod motor. The two bosses that are not drilled are for dowel pins that will be drilled after the V drive is centered on the crank.  It has to be dead on center with the crank for the T drive to work properly.
Rear of V drive body. The V drive attaches to the mount frame with 3 x M8 hex bolts. The mount frame in turn mounts to the 3rd piece of the push rod motor. The two bosses that are not drilled are for dowel pins that will be drilled after the V drive is centered on the crank. It has to be dead on center with the crank for the T drive to work properly.
Once we have proof of concept we may choose to bead blast the exterior of the V drive and mount frame to make them look more like cast parts so that they will look at home in a car. We may also investigate clear anodizing for corrosion protection - but these are down the road decisions. The design will work great for Gregory's 904 and also in 151489, since it is a 59 A that has the removable pushrod engine tray. The V drive will protrude far enough back off the pushrod motor that it is unlikely to fit without the pushrod rear engine tray being modified. Not a problem in an A where you can purchase a reproduction rear engine tray to modify, while saving the original.

To do the testing work Gregory will make a dummy internal shaft that will carry the oil seals, bearings, pushrod distributor drive gear and large C clip from a pushrod crank. The shaft is basically like a short piece of the crank that has been necked down on each end for the bearings and oil seals. The dummy shaft will have a rod out one end for a drill or lathe to turn and drive the distributors for testing. The Autodesk Inventor software allows me to produce fabrication drawings fairly easily, so that is what Gregory will use to make the internal shaft as well as the inner and outer end caps to the V drive body. An example of the shaft drawing is shown below:
The dummy shaft will be solid, without the internal splines.  The final version will have internal splines like the 4 cam part in order to use a T drive like the 4 cam part, just a different length.  The internally splined bar stock to make the shafts is expensive - about $2800 for enough to make 7 shafts!  Hence a solid dummy shaft for testing.
The dummy shaft will be solid, without the internal splines. The final version will have internal splines like the 4 cam part in order to use a T drive like the 4 cam part, just a different length. The internally splined bar stock to make the shafts is expensive - about $2800 for enough to make 7 shafts! Hence a solid dummy shaft for testing.
Work on making the internal shaft as well as inner and outer covers for the V drive body will start after Rennsport Reunion V. If the "proof of concept" is successful the next step will be to get the mount frame CNC machined, bite the bullet and purchase the expensive internally splined rod to make the internal shafts, purchase externally splined rod for the T drive, make all the parts and fit a prototype on Gregory's motor for dyno testing.

Thanks for following along!
_________________
Regards,

Bill Sargent
#151489 59A Cab
#159176 64C Cab

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