l29 heads

[Franksmith]

@454cid I was planning on having them checked. I am just trying to get a little ahead of the game incase I need to replace heads due to cracks.

The truck is sitting in storage for another month. Once I get it home I have a month to get it tidied up before the first camping trip. She is a beast and doesn't fit in my garage so it will be a driveway job when the weather allows it.

 

[John Cunningham]

Actually the L29 is a pretty good head for low rpm. I have been an engine builder for many years and understand head technology. When Gm went to the 8.1 LS cathedral port head for a few reasons and none of them real good. The L29 is the best of both worlds.It is much better than the Peanut port head it replaced. Its a traditional oval port with a small swirl combustion chamber, a great exhaust port and a pretty good intake that is not too big or too small. Should make good power up to 5000 rpm. If your trying to build power after that then you need a different head. I am building a 496 for a towing engine and all the aftermarket heads are too big. You do not even want a 265 cc runner in a tow engine and you want more than 200 such as the peanut head. This head falls in the right spot at 230 cc's.
I would purchase some used heads off of ebay as they are pretty cheap. Install new seats and guides and valves. Get rid of the rotators and use an adjustable valve train. You can also clean up the ridge in the combustion chamber and put a good 3 angle valve job on the heads and your good to go and have something even better than the factory offered.

 

[Franksmith]

@John Cunningham Thanks for the advise.

It is a towing setup.

Would it be possible or worth it to deck the heads a few thousandths to try to bump compression a bit?

 

[Christian Steffen]

I did upgrade the injectors to ebay "upgrade" yellow top injectors. Are you saying I should put bigger ones in if I eventually do a cam upgrade?

If they're 19 lb @ 3 bar then yes, they are on the small end. Like i said, they'll barely support stock horsepower.

 

[John Cunningham]

Sure..depends

@John Cunningham Thanks for the advise.

It is a towing setup.

Would it be possible or worth it to deck the heads a few thousandths to try to bump compression a bit?

On the cubic inches..you would want to stay close to the 100 cc in the stock CC..otherwise you will be burning 93 octane..that's stock pistons and a 454..cut to clean them and you will be goof

 

[John Cunningham]

Sure..depends

On the cubic inches..you would want to stay close to the 100 cc in the stock CC..otherwise you will be burning 93 octane..that's stock pistons and a 454..cut to clean them and you will be goof

Comp stock is 9 to 1..anymore and look at 93 octane..spend your money on a 0411 box so you can tune it properly

 

[Franksmith]

I usually run 93 octane because that is what is non-ethanol around this area.

This is what I have planned so far.
411 swap
coolant loss repair (hope its only head gaskets)
electric fan swap controlled by 411 pcm
tow/haul mode turned on in pcm
ceramic headers and replace the rotted out flowmaster muffler (already have 2.25" dual tail pipes)
pcm tune

debating on:
even bigger injectors than the Bosch upgrade one I installed already
Cam
which tune software EFILive or HPTuners

 

[Christian Steffen]

Here's a suggestion on injectors, if you're going to tune yourself then swapping injectors is fairly easy. Try what you have, and see what the DC goes to while tuning. Also throw a wideband on your list for tuning.

 

[Supercharged111]

If they're 19 lb @ 3 bar then yes, they are on the small end. Like i said, they'll barely support stock horsepower.

This may be, but I believe they are 24# at the 4 bar they run at on the 454.

Don't horse with compression, the motor is already fairly knock-prone. Just get a decent tune instead, way more power on the table there. I don't think the 454 heads crack like the 350 vortecs, but correct me if I'm wrong here. The lower intake gaskets are hugely prone to leaking, mine were as have a number of other forum members' here.

 

[Crookedaxle]

Actually the L29 is a pretty good head for low rpm. I have been an engine builder for many years and understand head technology. When Gm went to the 8.1 LS cathedral port head for a few reasons and none of them real good. The L29 is the best of both worlds.It is much better than the Peanut port head it replaced. Its a traditional oval port with a small swirl combustion chamber, a great exhaust port and a pretty good intake that is not too big or too small. Should make good power up to 5000 rpm. If your trying to build power after that then you need a different head. I am building a 496 for a towing engine and all the aftermarket heads are too big. You do not even want a 265 cc runner in a tow engine and you want more than 200 such as the peanut head. This head falls in the right spot at 230 cc's.
I would purchase some used heads off of ebay as they are pretty cheap. Install new seats and guides and valves. Get rid of the rotators and use an adjustable valve train. You can also clean up the ridge in the combustion chamber and put a good 3 angle valve job on the heads and your good to go and have something even better than the factory offered.

I have been an engine builder for many years and understand head technology.

You would think that you'd know that an 8.1L Vortec isn't a LS motor then.