2.2 litre high comp. p&cs on a 2.4 litre Question

Silver Surfer · 11:15 AM

Has anyone out there actually done one of these engines? I have seen this recommended a number of times. My question is: do the heads have to be machined? Are any other mods necessary to do this? Or do you just bolt those 2.2 suckers on?

gaijinda · 03-21-2002, 08:46 AM

I just picked up my baby - 2.4 case & crank, 2.2"S" P&Cs, 2.2"S" heads, Solex cams and "S" spec distributor. This thing is so much more powerful than it was, it is amazing. The 2.2"S" pistons will give a very high compression ratio, and I have been advised to run Sunoco 94 + some octane boost. A the track I will use 100 octane unleaded mixed with 93 or 94.

Due to world energy situation back in 1973, even the "S" cars have relitively low compression ratios.. Raising the compression a few points I think is an effective way to get more hp and performance. Neither the heads or the case need to be machined.

If you can find a set of high compression 2.2 pistons and barrels, I say go for it.

Silver Surfer · 03-21-2002, 09:32 AM

Thanks for the response. But, do I need 2.2 heads? I am going with my stock 2.4 heads. Also, I need to run on 92 octane premium pump gas. Have you tried your car on pump gas?

gaijinda · 03-21-2002, 10:57 AM

I am no expert, but you should talk to one if your car is MFI or CIS. I know these systems can be unbalanced by something like greatly increasing the compression ratio. My motor has carbs..

Otherwise the 2.2 & 2.4 heads are the same, with identical combustion chamber cc's. Only the port sizes are different.

Is your motor a "T", "E" or "S"?? In the Bruce Anderson book he talks about this being a popular upgrade to the 2.4"S", I do not know about the others. According to BA, the compression ratio for this conversion works out to be about 9.7 to 1 That is as high as you can go with pump gas. The additives on the street and race gas mix at the track is only for insurance...

I take back what I said in my last post, you want to do some real research before you make this up-grade...

Silver Surfer · 03-21-2002, 11:11 AM

Yes, I have a 2.4 S engine, and I love the stock MFI. Is yours formerly a T engine? S engines were about 8.5/1 CR in 73, so the 2.2 p&cs add a little over 1 compression point to an S. The Ts had a lower CR, I think, around 8/1. The difference would probably be a little more noticeable on a T.

gaijinda · 03-21-2002, 12:11 PM

I really think this can be done to a MFI 2.4 "S" motor! With this upgrade and a sport muffler you will be adding all kinds of horsepower..

Now the trick is finding a set of 2.2"S" P&Cs that are not worn out. The "S" cams you have should not be a problem, but you want to check with someone who really knows to make sure there are no other clearance problems, like in the case or somewhere..

Yes, mine was a "T" motor and my mechanic didn't think the 2.2"S" P&C up-grade was really a good idea. Now I am selling it as a complete motor.

If nobody else posts, wait a few days and add another post, but ask specifically about a 2.4"S" upgrade to 2.2"S" high compression P&Cs. Somebody out there has done this upgrade...