erufle

I'm not new to hot rodding but that was a long time ago. The urge was awakened in me when I had the privilege and honor of buying a beautiful low mile yellow convertible from The Late Herb Hanson"s Estate. We're he not my father-in-law I would never have had the opportunity to own such a fine machine. Forgive my ignorance as I try to learn.

I've got a wonderful 2001 LS1 you've probably heard me talk about before. I've also got a great set of 2004 # 243 heads to have ported and put on it. I'm not here to talk about how much horsepower a 220/230 duration, 285 lift. Cam will get me. That was kind of the general consensus when it came ordering a new cam for the car(doubt I'll use that much duration).

I wish to discuss all of the changes Chevrolet made to bring the engine from a 10 to 1 to a 10.5 to one motor. Starting with the fact that I keep getting told that both engines have flat top piston so that compression changes are made by changing or altering heads. This is not a new idea, all Pontiac V8 heads from the mid 50s on up had exchangeable heads. This made it easy to pull the heads off of your low compression smog motor, refurbish a junk yard set for anywhere from $400 to $800, and you were back in hot rod heaven. BUT I DiGRESS. Did Chevrolet make any changes to the rotating assembly that would affect compression when they made the LS6. This is an important consideration when putting LS6 heads on an LS1 motor. How will it affect valve clearance? Finally, is there any truth to the rumor that from 2001 to 2004 all LS6s and all LS1s used the LS6 rotating assembly, which was deemed superior, but why? I also want to know if there were any valve relief changes over the years?

k24556

no the combustion chamber is smaller on the ls6 heads. That's what causes the increase in compression. The pistons are not fly cut for valve clearance. You should not need to flycut the pistons if you select a cam that has the right duration and LSA for your purpose. However, new valve springs are a must with a different cam, and the selection of the correct springs is important. A good idea to replace the lifters if you are camming and very important to replace the lifter trays. The lifter trays keep the lifters from rotating. They are roller lifters and if they rotate, very bad things happen.


No changes to the rotating assembly and they should just bolt on You need to replace the bolts as they are torque to yield bolts and must not be reused.

erufle

Thank you!