Rebuild and Upgrade a 2.2s

[Scott Clarke]

James-
What crank are you running? Of course, if you use the 2.2 crank the compression ratio will not be 8.5, but quite a bit lower.
-Scott

[red-beard]

2.4/2.7 crank and rods. Wayne had an excellent set of the rods and I picked up a 2.7 crank on ebay for relatively low money.

My intention was to just stroke the 2.2 to 2.4 and increase CR, but when the cylinder's came back marginal, I decided to move up.

I guess I'm going from about 140 to 210 HP. I expect I should notice the difference.

Anyone have carb tuning rec's for this combo? The Bruce Anderson book talks about the E-cam version of this engine and suggests:

34 mm venturi
135 mains and 145 air correctors with an F3 emulsion tube.

Any suggestions moving from this to an S cam?

James

[campbellcj]

Originally posted by jluetjen
ChrisC;
Before I can offer an opinion on your situation, I have a couple of questions...

1) Do you race your car at all or just DE? The reason that I ask is because if you race, the rules will often define your path.

2) How fast do you want to rev your motor? In broad terms, there seem to be 2 categories of race engines. Actually there are more, but if you're already running S cams, we can ignore the slower options which are based on stock T or E engines.

a) Engines running S or similar cams and rev'ing to about 7500-7800 RPM redline. Peak torque is above 4500 RPM and peak HP around 6800 -7000 RPM. Basically modified S engines. In general, if well built these engines should last as long as a factory S engine.

b) What I would call "Full Race" engines running 906 or GE80 type cams. These have a redline at 8000 RPM or above, peak torque at 5000 RPM or above and peak HP above 7000 RPM. These are more analogous to an RSR or IMSA GT engine. The top end (heads and valves) life of one of these engines will generally be measured in events (actually hours) with the bottom end good for 1 or 2 seasons.

How wild do you want to go?

Thanks for the reply John. I didn't mean to hijack the thread, but it seems relevant.

I am currently doing (competitive) time-trials, mainly with POC, and next year I will be working towards a race license with potentially several different groups. I am very much aware of the rules and the car is currently set up for a tight "spec" class with POC. I am very limited on additional mods but am already taking classification points for the cams, compression etc. so going farther down that road will be "free" (haha).

Head work will cost me some points but I think I can fit it into my points-budget and stay in this class.

I can't afford to build an 8-9000 short-lived screamer, which would probably require a different crank, rods, case mods, etc. I would be happy with a hot-rodded "S" configuration and a 7200-7500 redline. With the short gears I can keep the revs between 4500-7500 at all times.

I'm interested in sticking with the <2.5L displacement so I have the option to run with various groups including some of the vintage organizations (HSR West for instance). Obviously dropping a 3.0 in the car would be "easy" power, but it would knock me completely into new classification territories...then I would need to do a wide-body conversion, bigger wheels/tires, yada yada yada. Not this year...

Cheers,

[red-beard]

Just picked up the engine!!!!!

Whew! Looks excellent. Now I just need to get the rest of it cleaned up and ready to re-assemble....

I'll post pics later.

James

[jluetjen]

campbellcj;
Given that you want to stay with an "S-Type" motor, I'd suggest that you have your heads ported to S spec's with 36 mm intake ports at the manifold face and have them open up about 1 mm for every 1/4 inch that you move in from the manifold face. This will result in the intake ports being about 40 mm in diameter just before the bowl above the valve. There are a number of cams to chose from such as the early S cams, GE60's and others. I've posted a comparison of cam specs as well as some predicted rev ranges based on a regression analysis elsewhere on this BBS. You can also influence the rev range by advancing and retarding the cam timing. People have posted information on this too.

If you were to run a 74 mm crank, 85 mm pistons and cylinders (a 1 mm overbore) like the factory did with the 2.5 ST's with a 10.5:1 CR, S spec heads and S type cams, I would expect that you should be able to get a something more then 200 HP if you tune it carefully. I bet you it would be a fun motor that would sound great!

[campbellcj]

Amen John...a 2.5 high-comp short-stroke is kind of my "holy grail" configuration for this car. If I can squeeze it into this class and squeeze the rebuild out of my wallet, I'll go for it! Thanks for the tips re. the ports etc. too.

[red-beard]