NXSLT1

As some of you might know I've been working on a roots blower setup for my car. The intake manifold and everything else I have fabbed up is working flawlessly but I've come to the conclusion that it just aint gonna run on the stock compression ratio. I've gotta get it lower. I know the easiest way would be to put thicker head gaskets on it but that will open up the squish area quite a bit and might make the detonation problem even worse. My only option other than that (with the exception of pulling the motor) is to hog out the combustion chambers. I was using a CR calculator and according to it I need to hog them out to about 73 cc to get it down to an 8.5:1. I know some aftermarket heads are 76cc, I'm just curious if I have enough material there to hog it out that much. Any of you guys that have had head work know what yer cc's were or know how far the stock heads can be taken to??

96capricemgr

iTrader: (1)

Have you tried alky injection? I think that is a better solution at this point. I honestly can not see you being able to remove that much material without hitting a lot of water or haveing it find water once it is running.

NXSLT1

I'm running it on E85. I'm in the process of rigging up E85 injection above the blower to see if it will cool it down and cool the incoming air down too. I'd rather lower compression. How far can you take the stock heads?? If I could get it down to say 9:1 it would probably be ok. I'd do it with thicker head gaskets but I'm afraid opening up the squish area will just make things worse.

vtec

iTrader: (1)

i would yank the motor, buy some reverse dome STD. bore forged pistons, get the rotating assembly balanced to them and put it all back together. oh and rod bolts too.

plaf713

iTrader: (8)

trickflow heads, i believe the chamber is bigger than the stock head and its made for supercharger application, someone correct me if im wrong but i believe they are 62cc combustion chamber. not really sure about it though, but iw ould look into it

NXSLT1

62 cc chambers won't lower it enough. I'm trying to avoid pulling the motor and rebuilding but that might be my only option.

Red97Z

iTrader: (22)

Increasing CC size, bigg head gasket, and some diamond racing -31cc dished pistons will get ya there.

plaf713

iTrader: (8)

if you pull it you pull it, it will pay off in the end because if you dont do it now you will be pulling it out later.

97Formy

When it comes to FI I'm a firm believer in rebuilding the bottom end for it. Do it right or don't do it at all. Just my .02

NXSLT1

The bottom end is fine for no more boost than I'm running. I'm not an idiot, I know stock parts have their limits. If anything goes it will be the stock cast pistons.

97Formy

Like I said, it's just my opinion on the subject. If there's a possible weak point then there's a weak point that needs to be upgraded. JMO.