What you guys think about 9.1 compression?

[soyee7]

Im thinking about buying a motor, its a fully built 6bolt with

eagle rods
JE 9.1 pistons .020 over
5 angle valve job
titanium valve, springs, and retainers
HKS cams
and a machined crank(?)
ARP Everything
Metal head gasket

I have two questions,

im getting the motor for 1500, how does that price sound(everthing is new).

Is the 9.1 comp. to high or will it perform well, what are your experiences with any motor similar to this. (Pros, cons)

[kjewer1]

I'm runing 9:1, even at 30 psi. DSMers definitely dont seem to care for JE pistons though. I would try to read up on that on talk, tuners, and nabr. The price sounds great if its all new.

[Shpyder]

Im not sure if Im right, but isnt lower compression good for Turbo cars due to boost? Have too high a compression ratio, then squirt in more boost, could cause egine to blow? Just wondering.

[aaronh2005]

ive been told time and time again that the 9:1 compression ratio is the ideal ratio because it needs to balance with the boost put into the engine. the price on the engine is really great, but it sounds as if it is a rebuild with custom parts...you may want to double check and make sure that every part of the engine is brand new and not a remanufactured part. there are some high qualities out there, just be careful-its a lot of money

[JoeWagon]

Originally Posted by Shpyder

Im not sure if Im right, but isnt lower compression good for Turbo cars due to boost? Have too high a compression ratio, then squirt in more boost, could cause egine to blow? Just wondering.

You tune the motor for no knock, but both boost and compression make power, so you have to find the balance. You wouldn't be able to boost much on a high compression motor, which is why certain Hondas are better than others for it. stock is 8.5 on a 2g and 7.8 on a 1g. 9.1 sounds good.

[soyee7]

it is a rebuilt motor with custom parts, but all the parts are new, i was just stating that it wasnt a used built motor. The guy built it but never put it in his car.

[BoostedSpyder]

what are your goals out of it? that is the question i had to ask myself for this current tune i am doing. are you really going to make a full on racer out of it? you will have a pretty bulletproof engine, but is there a necessity for it, and can that $$ go for other mods that will properly support a fully built engine that you don't have now?

just wondering...

[kjewer1]

Lower compression and more boost make more power. But once you are on a very efficient setup and running 116-117 octane fuelwhen you use high boost, higher CR and high boost make awesome power. I'm at 9:1 and moving 65 lbs/min at 27-29 psi. No knock, even when AFR rises to 14:1 at 7500 rpm because the 255lph pump cant keep up. I'll be raising boost soon. After the new pump goes in (aeromotive A1000, using the 255 as a lift pump).

If the motor has 0 miles, thats a great price for sure. Just a matter of wether or not JEs are ok to use. I would just search that on tuners and see if you can come to some comculsions. I'm sure they are fine, but its not worth saving a couple hundred bucks if most poeple have problems with those pistons. It might just be the stroker JEs that suck though, I wish I could remeber and save you hte hassle

[aaronh2005]

if you are going to get JE pistons, just make sure they are forged! if they are i think you will be fine.

[2of9]

what is the stock compression ratio in a 4g63-T?

[JoeWagon]

Are you serious? You need to try a little harder. I already said that info IN THIS THREAD. If I didn't, it's all over the stickies.