1600 SC rebuild

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Al Zim
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Re: 1600 SC rebuild

#16 Post by Al Zim »

Building my own engines I have come to two conclusions. the first is that the normal engine is extremely durable and offers plenty of driving fun. If I were rebuilding one I would use a super cam and lifters. However most people want MORE HORSEPOWER, My suggestion would be to use C/SC/ 912 heads, Factory K-S or Mahle pistons and cylinders new. If you use a counterbalanced crank then you will have to cut 25mm off the bottom of the piston otherwise everything fits. Use the super cam and lifters. You may step the cam up a little if you regrind it. Do not lighten the flywheel! I like the Zenith super carburetors because the throttle plates are in a steel housing. Everything else stays stock. You can use either rocker arm style but the steel (early) will be cheap to find parts for. Balance it all.
This engine will cruse happily in the 3500-4,00 RPM range. I would also suggest converting to a 12 volt system in the car and to use a 12 volt alternator. 90 MM 12 volt armatures are not available now and 105mm Generators require a 1968/9 generator stand which are in short supply. Ask yourself how fast you intend to drive the car? I believe that once you get past 75 MPH you should be in a 911, The basic design for the 356 was in production in 1939 as a VW. Since this post Zim's has been inundated with repairing worn, broken and improperly assembled front end parts which equates to handling problems. For your safety alignment is essential (previously posted) and should be done with rolling compensation. In summation I would say that the Super engine that has been a mainstay for the 356 (zenith carburetors) is the best choice for a durable responsive street engine.
Blueprinting an engine is the way and assembly should be done! al zim 2018/11/27 added material 2018/02/19
Last edited by Al Zim on Tue Feb 19, 2019 11:05 am, edited 1 time in total.
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Lars Waldner
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Re: 1600 SC rebuild

#17 Post by Lars Waldner »

Valve-train/rocker hardware question. So I have a couple complete sets of the early steel rocker assemblies. I also have 3/4s of the later aluminum SC assemblies. I need parts to make my later set complete. I need...
"head nuts" (5 large and 6 small)
longest rocker w/ complete shaft hardware
hardware to secure all 6 rockers and shafts to heads
hardware to secure both aluminum "cradles" to the heads/nuts
I am also willing to trade a set of the steel sets I have for a complete SC set.

Thanks for looking.
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Re: 1600 SC rebuild

#18 Post by Lars Waldner »

Interchange-ability of pressure plates. It has been advised that I retain the original pressure plate that came off the chassis, vs using a different PP and having to retrofit the fork and TO bearing. Ok, I get that. Chassis is not with me right now so I can't ID the trannie. But I do have pics of the PP still mounted to the back of the engine I dropped from the car. Pics are not great, but maybe enough to identify and compare the PP I have extra that looks very similar. I had hoped to R and R the flywheel and PP on the bench I have...vs removing the flywheel and PP from the engine that was removed. Hopefully the experts can chime in...thanks. First pic is what was removed from chassis, second pic is what I have to work with on my bench. I have to say they both look questionable as compared to a later 200mm Sachs PP...pic number three.
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David Jones
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Re: 1600 SC rebuild

#19 Post by David Jones »

The first two pictures show the type of pressure plate used in the earlier transmissions which have the early TO bearing which must match the type of clutch PP with the collar. The last picture is the diaphragm spring clutch with the fingers that match the 741 trans in the T6 chassis as for the "B" and "C".
If you have two 356 cars from 58 and 59 they would have originally had 180mm flywheel and clutch with the early PP with the collar.
If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
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Re: 1600 SC rebuild...Plating and powder coating.

#20 Post by Lars Waldner »

I have a pretty good idea for my 911 engine builds, as to what looks correct (yellow or white zinc) for fuel lines, throttle linkages, brackets and clamps etc. Fiberglass shrouds are typically correct colors depending on the engine, and the engine tin is usually black. We sometimes take liberty when re-finishing fans and housings.
I would like a reference for the SC engine about to be built as to what gets plated what color, and what should be powder coated...and what color. On the parts I have organized, fan housing is "a shade of grey", oil reservoir is black, engine tin looks to be black, and straps and brackets are hard to tell. Air cleaner covers are oxidized so I have no idea there. If someone can point me to a thread with pictures/diagrams, that would be appreciated. I have a good plater (zinc) and a new powder coater to try. Always nice to have the parts done before the build is started.

Thanks in advance!
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Re: 1600 SC rebuild

#21 Post by Erik Thomas »

Lars:

If you are going to put this engine in a '58, I would make sure that all the plating is white zinc, and then detail the engine so it looks correct to a '58. My tastes run to Solex 40PII's rather than Webers. I hate Webers as the idle jets clog on me constantly. Folks say the Zenith is easier to tune for a street engine, and more likely to stay that way. I recently replaced the camshaft in my '60 T-5, which started life as a Super engine, 75HP. It is now putting out 94HP at the wheels, and is 1600cc using original cast iron cylinders, but with new custom machined pistons to match 912 heads. My new camshaft was made my Megacycle. Make sure you get lifters with the cam as if they are not properly matched, the cam will destroy itself in short order. I am running a 180mm clutch on a slightly lightened flywheel. The 180mm clutch is lighter making for better gear changes, me thinks.

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Re: 1600 SC rebuild

#22 Post by Harlan Halsey »

+1 on Vick's comment on thr rods above.

A little detail on the rods: I polish the roots of the cap studs and die check or mag them. If no cracks, then they are good. (There's a good reason 356 rods were built the way they were: clearance between a cam lobe and the rod. Carillo 356 rods are mainly held together by Carillo's reputation.)

A little note on "taking liberties" and specifications. 356s were very good cars as built. I have had '63 SC since 1977. I rebuilt the engine at about 135.000 miles and it now is pushing 200,000. I like the SC cam the best of all, because of the way it drives. I had a muffled Burch exhaust system on it for years until I got tired of the noise and weighed it and the original. The 6 lb. it saved and maybe 2HP at the top end, wasn't worth it. Small things like balancing tighter than the spec won't be noticeable in a street engine.

The Stoddard catalogue, and the Porsche Workshop Manual are excellent starting places.

Hope this helps.

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Re: 1600 SC rebuild

#23 Post by Lars Waldner »

[quote/]

My new camshaft was made my Megacycle. [quote?]

Erik, this is all I found when I searched for Megacycle...and a motorcycle cam shop. Did you grind your own?
https://www.google.com/search?q=Megacyc ... e&ie=UTF-8

[quote/] Make sure you get lifters with the cam as if they are not properly matched, the cam will destroy itself in short order.[/quote]

Special grind cams need their own modified lifters?
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Re: 1600 SC rebuild

#24 Post by Erik Thomas »

Lars:

Camshafts are made of various materials, and so are lifters. The materials need to be compatible. Also, the shape of lifter where it contacts the camshaft is also a variable. On my engine, we sent the lifters to some place in Belgium for a special coating. Megacycle can advise on that. I have looked at the website too and see nothing related to 356 cams, but if you call them you may find more info. I only mention Megacycle for two reasons: 1) the SC cam that "everyone uses" failed on me, and the Megacycle cam clearly has very good drivability.
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Re: 1600 SC rebuild

#25 Post by Erik Thomas »

Here is the chart - hopefully
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Re: 1600 SC rebuild

#26 Post by Dick Weiss »

The rusty P/plates shown are not the same; The upper one is a 9-spring heavy duty and the lower one is a 6-spring common to VW..

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Re: 1600 SC rebuild

#27 Post by Harlan Halsey »

Original 356 cam lobes are slightly tapered and original followers are slightly crowned. This is done so that the contact point is a bit off center, causing the follower to rotate, spreading the wear. After many miles of use, both cam and follower have worn to mate, and many more miles of use follows. You can disassemble and reassemble a 356 engine as long as you keep the followers in their original places.
If you replace the cam without resurfacing the followers, there's no telling how or where the initial contact will take place. And "cam" failure may happen. This is why Dema Elgin always recommends resurfacing the followers with a cam grind.
Good luck.

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Re: 1600 SC rebuild

#28 Post by Harlan Halsey »

Diaphragm clutches supplanted the multiple spring type decades ago. The original pp/tb geometry was such that the center of gravity of the tb was in line with the clutch forks and the fork opening faced the pp. When Porsche went to the diaphragm pp they added a spacer ring to the diaphragm fingers to maintain the geometry. Later on they dropped the ring and lengthened to tb to bear directly on the fingers. This moved the CG of the tb toward the pp and would have allowed the tb to droop rather than staying roughly perpendicular to the pp. To prevent the tb from drooping they added a guide sleeve around the input shaft. Now the tb moves in a line back and forth. But the throw out arms swing in an arc. So Porsche changed the opening in the arms to point down, allowing the tb trunnions to move up and down slightly as the clutch is depressed. So you can see that here are two setups which will work: short tb forward facing arm openings and spacer ring on the clutch fingers; or long tb, guide tube, downward facing arm openings and no spacer ring. I think the 200 mm pp s are all the later type.
I cannot see any difference in practice between the 356A 180mm diaphragm set up and the last 200 mm SC set up. Both types of pp s are available quite cheaply from China these days, with or without the ring, and in my opinion, have a better design than the original Sachs pp s. For what it's worth if one of my flywheels needs work, I always have it balanced, have the crank mating area remachined to the proper taper and depth, and lighten it to 17 lb. The balancing and lightening are done in such a way that there are no holes in angled surfaces.

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Re: 1600 SC rebuild

#29 Post by ryan base »

lars , I was touched by your reference to your mentor neighbor. I wish my dad was still around

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Al Zim
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Re: 1600 SC rebuild

#30 Post by Al Zim »

Your best success will be with the 'C' engine. More than likely it has not been pushed hard and the lower end will be in better shape. Ask yourself if you are going to drive at 5000+ RPM's if not then you do not need the counterbalanced crank and the main bearings will not need to be line bored. The best part is that you can use the Zenith carburetors. No $+++ rebuild necessary because the throttle shafts are carried in a steel base. If your budget permits a set of 'C' malhe or klobenschmidt pistons and cylinders should be a must. The 4 rings give better oil control, the longer skirt on the piston keeps it from rocking at the tip of the stroke and the rings are wider making them more durable. Your head work should include new valves, valve guides and springs. Touching the manifold and head to smooth the air flow into the cylinder is helpful and can usually be done in the home workshop. I think the super/S-90 cam is an excellent choice. Porsche engineers designed it to cover all the aspects of engine operation. Rocker arms, pick the rockers that have the nicest tips. The intakes are the same for both styles of rockers, the exhaust is better with the later rockers, remember the piston is pushing the exhaust out of the cylinder at a lower RPM this will not be critical. The flywheel should remain stock so the car will accelerate smoothly from a standstill. Switch the car to 12 volts, It is my guess that 6 volt stuff will not be available in the near future. Your car should run on regular gas. Regarding your pictures. The flywheel with the A/VW clutch indicates to me that this engine was used in a Dun Buggy. You implied that you have Porsche engine experience. In my estimation it would be prudent to pulley the oil galley plugs clean and remove and bumps in the galley then reseal them with threaded plugs. We can do head service, rod service, cleaning the oil galleys and measuring the crankshaft bore in the case. al zim 2018/01/19.
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