WindWalker

Can this be done AND still have a good flowing, decent head for 15-17#. What about the quench too, if worked? If so, I'll skip the worked on Trick Flows and save some $2k. I need a 70cc head to get my C/R down to 9.1.

BigBenz

iTrader: (7)

I never though about getting a stock motor down to lower compression. Will you be able to run more HP/boost?

sorry hijack.

98turbls1

iTrader: (17)

first of all 70cc wouldn't be a big enough combustion chamber to get you down to 9:1... Secondly people have had really good luck with the LQ9/LQ4 heads... they are 71.5cc and have the same flow characteristics as the LS6 heads... By far a better and cheaper option in my opinion... Also with the LQ9 head you're still at 9.5:1 compression with the stock flat top piston so if you want to go lower you have to get creative or go with a dished piston of some sort... Good luck..

WindWalker

Well...I guess I should have added this. I have a 370 iron block built and am gonna run a T70 on it to about 15#. That's why I need to get the CR down to about 9.1. I wanted to get the Trick Flows that can be worked to 70cc, getting me the desired CR. But if I can find a decent alternative on the heads, like some worked LS1/6 heads, I'll go that route and save a cupla grand.

ls1290

iTrader: (20)

9 times out of 10 the first solution leads to problems unless you know what you are doing.


It is going to be hard to run 15 pounds of boost with that combo unless you get new pistons to get the desired ratio or use a metric **** load of methanol.

Keith

WindWalker

I'll be using dished Wiseco pistons. I plan using meth too so I think I can obtain my goal on this motor. Anyway, can LS1/6 heads be worked up to 70cc without giving up much on the flow?

ddnspider

iTrader: (26)

whats the point of working ls1/ls6 heads to 70cc's when lq4/lq9 heads are 72cc heads(read lower CR) and flow what the ls6 heads do and you can pick up a pair for a couple hundred bucks

ls1290

iTrader: (20)

That is not entirely true. LQ4/9 heads flow the same as LS6 heads on the exhaust, but less on the intake side.

WindWalker,

I assume you have already bought the pistons and are trying the bigger head chamber route to lower the compression level? If you have not bought the pistons, do the right thing on size the pistons to the match 65cc heads and 0.054" gaskets for the 9.0:1 compression level. If you have bought the pistons and need to drop the compression level, use LQ4/9 heads rather than opening up the chambers on a set of LS6 heads.

Keith