stankinlancoln

I'm in the process of building a lq4 and l92(with double valve springs) engine for my 86 Monte Carlo S.S. I've been doing a lot of researching for different tips on my build. I read that my compression will be low with this set-up which will cause low torque and poor bottom end performance, but great top end performance. Well I plan on mostly weekend street racing, drag strip and hot ******* with this car. So bottom end and torque is what I Need allot of!!! Most races are over before top speed is reached. So my question is HOW do I rise compression Economically(cheap). I plan on running a medium to large cam and ls3 or fast intake.

87silverbullet

iTrader: (11)

You will have to shave the heads and run a thinner gasket to raise compression. In doing so you will have to watch your cam selection with the ls3 heads because of the large intake valve you could run into piston to valve clearance issues.

anheuserbusch08

iTrader: (11)

231 239 cam, heads milled .030 you'll be set

stankinlancoln

Ok 231 239 cam and mill heads .030. What should the compression ratio be then? Can you refer a cam company? About how much HP am I looking at?

Brian Tooley Racing

iTrader: (13)

You can also consider the Wiseco Junkyard dog 9cc dome pistons that uses the stock rods.

These pistons will give you tons of P to V and raise your compression at the same time, P/N K0044XS.

The crank would need to be rebalanced when changing pistons.

87silverbullet

iTrader: (11)

Milling the heads .030 will raise it to about 9.9:1 with a couple of other factors it might be a lil more or a lil less. Texas speed sells a few cams for ls3 headed motors. Check out EPS or contact PatG on here, they can spec you a cam for your setup.Hell, the man who posted above me can spec you a cam and get you setup with springs and pushrods too.

armyboyatc

iTrader: (29)

It wouldn't be more than 9.9:1 really? I figured it would be like 10.3 or so... Hhhmmmm

stankinlancoln

I was on Texas speed looking at Cams an noticed the magic stick 4 and the torque v3 cam. Can I use either of these cams with my set-up?

87silverbullet

iTrader: (11)

If all you do is mill the heads it's .006 per cc so .030 would reduce the chamber to 65 cc. A stock lq4 has 9.4:1 compression with the 70 cc 317 head which happens to be the same cc as an l92 head. Each cc is equal to a tenth of compression. Hence 5 cc is going to raise it to 9.9:1. Putting a thinner gasket will raise it more.

87silverbullet

iTrader: (11)

Those cams are for cathedral head setups. You need a cam for a rectangular port head. Can they be used? Yes but they are not optimal.

http://texas-speed.com/c-233-camshaf...al-tranny.aspx

A good number of years back, a tech member used the TSP 233/239 cam in an LQ9 with L92 heads and ran 10.80's in a cutlass. His screen name on here was burgers. That cam is meant for cathedral heads but it worked very well with the L92 heads and a carb.