Engine building parts?

[Juha Vane]

I bought an engine "project". Previous owner planned to build a race engine but changed
his mind and I ended up buying these parts. What I got are these and a lightened flywheel +
clutch and some other parts, like new oil cooler, bearings etc.:
- 616.104.901.02 Heads reconditioned with new valves and springs
- 616.108.104.03 Solex 40PII-4 carbs, new w/manifolds
- 616.102.015.01 Crankshaft new
- R616.103.101.01 Connecting rods, new
- Shasta? pistons w/rings
- Bosch VJR 4 BR 18 distributor
- Norris 356S camshaft
- Straight gear camshaft drive
- 616/36 block
- Stock used cast iron cylinders for the pistons, need to be bored.

Unfortunately I'm not sure if the con rods can be used. They are brand new, but someone "balanced" them.
They all weight the same, but the top and bottom end weight are not equal. Not sure if there is enough material
to balance them correctly.

I'm planning to build a little more powerful street engine and wonder if these parts would end up to that?
Our gasoline here have max 5% ethanol and have min. RON 95.0 and MON 85.0
Mainly concerned about the pistons and the cam shaft. Is the cam too "hot"?
Could I use the straight gear cam drive, is it too noisy and should use stock gears?

[David Jones]

Juha, the use of a straight cut camshaft gear is in my opinion a waste of time. The increase in power will not be noticeable even in a race engine except maybe on a dyno, though in a race engine it would be just one of a number of small improvements that may add up to a ft/lb or so of torque. The whine from the gear would offset any presumed advantage in a street car. 95 RON gas is what was specified for an SC or S90 back in the day but todays gas also burns better so I would stay with a 9.5 to 1 CR.
I would suggest that if the rods are all balanced correctly not to worry too much about end for end as it is after all a flat four which is inherently in balance. On my F Vee race engines I would get all the rods to be the same weight overall and end for end the same but not worry about balancing big to small end as once you add in the weight of the piston and wrist pin it was always more than the big end anyway. Worked for me and my engines lived even though they ran between 6 and 7K rpm at every race.
Hopefully Vic/CJ/Craig or one of the other 356 racers will chime in here and correct me if I am blowing smoke.

[Doug McDonnell]

Back in the mid 80's I Bought an SC prepared for short track use. It had an NPR 1720 kit and a Norris 356S cam. Ran very well and you could feel it come "on Cam".

[Paul Lima]

I agree with David re straight cut cam gears; the original helically cut gears are quieter and probably a bit easier on the cam as well. I think your Shasta/JE pistons may be a bit higher compression than you'd like for RON 95 fuel, although it also depends on the head volume.

[C J Murray]

Some people like the sound of straight gears. They are not excessively loud but that is a personal opinion thing.

Your pistons are not lightened under the dome so you may be able to shave the top of the dome to reduce the CR to work with a street cam. You need to see how thick the dome is now.

The camshaft duration at .050" lift stock is 230*(redline 5800) and full race is 280*(redline 7500). How fast do you want to go and how bad do you want it to drive in town? What is the .050" duration of your cam?

[Doug McDonnell]

Looks like it should be 248: http://www.willhoitautorestoration.com/CamSpecs.php

[C J Murray]

That, 248, shouldn't be too horrible. You could do a CR around 10:1 or so. You will lose power around town but the higher CR will help that a bit.

[Craig Richter]

Nix the straight gears. If you like to rev it up a little, that should be a fun cam. You made quite a score!

By the way, if you put all those parts together properly, you should be able to get close to 120HP, which is a heck of a lot more fun than less.

[Jim Liberty]

Way above my pay grade. Once Vic chimes in, All the right people had been heard from. .............Jim.

[David Baugh]

Depending upon how much the flywheel has been lightened, you may not like it for street use. Under the right conditions, a lightweight flywheel can "buck" you right out of the seat.
Dave

[Craig Richter]

What? I've never experienced exactly that, David. Light flywheels are... lighter, so physics says it needs to rotate a little faster to get enough inertia (help me Neil) for a smooth getaway. Give the throttle a little blip and you should be able to get away from that stop just fine. I don't wish SoCal freeway traffic on anyone driving a stick-shift!

[Ron LaDow]

My two pfennigs:
Those pistons are pure racing parts, needing 110octane gas to work. The dome (even with a tight quench, and I hope you know what that means) are going to require tons of ignition lead for the flame to find its way over the top of the Mt. Everest you've got there. Which chases you down the rabbit hole of adding shims to get an acceptable CR, making the quench even wider, requiring more ignition lead, needing lower compression, adding shims which makes the quench wider, requiring more ignition lead, (rinse and repeat).
Cams, I bow to Cliff or Dema.
Straight gears go in the classifieds; like wire-mesh air filters and 'extractor' exhausts, there are no lack of folks willing to trade real power for a lot of noise.
Rods, I still want end-to-end; that inherent balance tends to be more theoretical when there's a couple of grams hanging on the wrong end of the rotating/recip assembly.
Light 'wheel? You're trying to push a Coupe. I took 3# or so off the 'wheel fitted to the Speedster I owned at the time (early '70s). Getting that thing off the line on SF hills meant enough revs that the other folks in traffic were looking at me as if it was the start of Le Mans. I could deal with a light 'wheel in the Lusso; that thing made torque low enough to get it moving. 1720ccs won't do that. That 'wheel is probably in the stash someplace; it got replaced in a month or so.

[Craig Richter]

...or anyone living in SF.

[David Baugh]

Constant speed, 1st gear, 3400 rpm, and hit a small bump in the road. Suddenly, I'm in the bronc-bustin' event at the rodeo! Things really get exciting if my right foot joins the rhythm on the gas pedal, before I can stab the clutch to put her out of her misery. But, I sure love how it lets the engine "bark"!

Dave

[Martin Benade]

That sounds like a rough ride. It doesn't sound like a light flywheel problem however.