just doing some research.....got a few questions about LS1 heads

and YES...I am STILL going to use the iron heads but there were some points made about aluminum heads that have made me think about them as a viable option

here are my questions:

1. would they work on a 6.0 any better than the stock heads or is it kinda pointless to do the swap ??

2. what is the chamber size ??...67cc ??

3. how much of a CR bump would those provide on a 6.0 with a 9.4:1 stock CR

4. flow numbers ??.....how do they compare to the 6.0 iron heads ?? (similar I am assuming because of the same size runners and valves)

5. '97-'98 perimeter bolt heads...are there any differences compared to center bolt heads other than coil mounts and valve covers ??....and will the perimeter bolt heads work on the 6.0 block ??? (yes...I know they aren't as popular because of the different valve covers but those early valve covers are cheap enough on ebay that as long as the chamber and runner architecture is the same as later heads it would be worth using those heads)

Thanks for the info guys !!!

BTW...I posted this in External Engine and got no replies.....so it IS kinda a double post....sorry

 

I think internal engine would be a better place, but truck guys get [Rodney Dangerfield voice]no respect[/Rodney Dangerfield voice] over in the car forums.

 

I can answer all your questions, no need to go to internal engine. Give me a minute to calc out your CR.

 

Cool...thanks BigTex

 

Here are MY answers:

1. I think they would work slightly better than the iron heads. Cooler, lighter, more compression, and at least as good of flow in stock form.

2. Chamber size is 67cc. They come in several casting numbers. Its rumored that the 02+ years have a little less casting material in the runners, making them slightly "better" than the older models.

3. If you reuse the stock GM gaskets, you'd see right at 9.9:1 with stock LS1 heads. Use the felpro 1041 gasket, and youd have a 10.1:1 CR with no milling, plus you'd have a tighter quench to prevent detonation.

4. I'd think the iron 6L heads would flow almost EXACTLY like the LS1 head (which is less than the LS6 and aluminum 6L style heads). Sorry, I don't have any flow numbers, but those heads have very similar runners to the LS1 head and run the same valve. Probably very close.

5. You won't have any problems running the perimeter bolt heads on your block. Just make sure you have the correct gaskets for those heads (some of them had little notches that when used with the wrong gaset would leak coolant). Valve covers and coil packs would need to be swapped, but thats no big deal. I have a friend with an extra set of perimeter bolt heads, I'll get you his info if you are interested.

Hope that helps.

*** I estimated the volume of the pistons dish for my calculation. I backed it into 9.4:1 compression with roughly an 8cc dish.

 

Thanks !!!

I think I can get a set for around $100 shipped (not sure yet) but if you want't to find out what he wants for them (or just the valve-covers and coil-brackets) let me know

so...this would be considered an "upgrade" from what I have ??.....and those heads should work well with the 212/218 cam I have chosen ??

BTW...if I do buy these thay are getting ported (probably a Stage II job) so they should outflow a stock LS6 head when done...correct ??

 

Well, any stage II head should outflow any of GMs stock heads. You could run the iron heads and with a stage II job, they should outflow a stock LS6 head. But I think you'd get better porting results from a LS1 head. The final port work would be easier on an aluminum head.

You might want to check on a stage 1.5 port job. These have been making good power, and not as expensive as a full stage 2.

$100 is cheap, do it. I'll see if he has his valve covers and coil packs.

That 212/218 cam - Is it the higher lift version (.558 .563)? I hope so. That higher lift with the better flow of ported heads should really pay off. It would be hard to say, but I'm sure it would add another 10 HP.

 

Yeah that cam is ground on the XE High-Lift lobes (212/218 .558/.563 114lsa)...I figured that the larger displacement of the 6.0 could use the extra lobe lift.

I was looking at the stage 1.5 port jobs awhile back....seems pretty good as long as the stock valve size is enough to feed the motor (should do OK I would think)

As long as HE is willing to go for the $100 pricetag I will be snapping them up in a heartbeat

 

The 6.0 LOVES the higher lift. With that cam, you'll be pretty happy Al. The heads shouldn't need anything more than a 1.5 porting, and stock valves should be fine too. Just weigh the options - is the $$$ for getting new valves worth it to you?