85Iroc

iTrader: (12)

Just curious if there's anything different that needs to be done. I didn't come up with anything in a search. I'm gonna have a local shop do a valve job & mill my heads & I'm gonna clean them up a little myself. The shop isn't very experienced with LS1 heads & I want to make sure they wont be doing more harm than good.

Also, should I get new valves? I'm going to a 4.03 bore iron block.

Thanks,

Old SStroker

There is power in a valve job (VJ), but you have to go to the right people to find it. Obviously a local machine shop isn't that source, but if your heads need a valve seat touch up that is an economic choice. I would instruct them to duplicate the OEM valve angles rather than some "competition" VJ they might be selling even if you have to pay the "competition" VJ price.

IMO, more power is lost with incorrect valve jobs than is ever gained by getting fancy. You wouldn't want to know what the best VJs cost.

My $.02

KCS

iTrader: (20)

Like Old SStroker said, there is a lot of power to be made in the valvejob. There is also a lot of power lost in the valvejob.

The SBC ports and the LS1 ports are two different animals. The air behaves differently between these two ports. I don't know what this local shop has for a valvejob, but assuming it's a standard 30-45-60, I would suggest to them to go much steeper on the top cut and slightly more shallow on the bottom cut. That should get ya pretty close to some really popular, and effective, LSx valvejobs.

Old SStroker

Or not!

I have noticed that "really popular" and "effective" do not often apply to VJs.

As a wise (read that as successful) head porter once told me: "If you are not absolutely sure you are going to improve it, leave it the f### alone!"

KCS

iTrader: (20)

With all due respect, that was a suggestion passed down by a VERY, VERY wise and succesful symmetrical port cylinder head guy.

Old SStroker

VERY, VERY yes, but on many different port configurations. Hint, his initials are not DV.

DISCLAIMER: NOTHING IN THE ABOVE POST IS MEANT TO DISCREDIT ANYONE WITH THE INITIALS DV WHO HAS EVER PORTED HEADS FOR FUN OR PROFIT.

KCS

iTrader: (20)

Haha, no sir. His work is not published, except in blueprints and timeslips. I'd rather not make him the subject of this thread either.