IRNMADN

Not sure if this is in the right section but here goes. I have 2 sets of 706 heads. One is from the 5.3L I'm using in my 46' Harvester. I was given another set that I may end up using on my LS1 in my 97' C5 Corvette.
I'm gonna pay to have the larger valve/s installed. I can't afford to pay for someone to port and polish them or have one of the bigger company CNC port them.
I have searched and searched and came up with nothing as far as how to clean them up at home. I was hoping someone did a thread with pics of how they cleaned up theirs. I was thinking I could just clean up all the casting crap and maybe open up the exhaust ports some. I have the old exhaust gaskets that I could use as a guide to at least open them up some. I have never fooled with porting heads but want to give it a shot.
Anyone know of a good online guide/ thread whatever where it shows what needs to be cleaned up and the best way to do so. Maybe gives tips and warnings on areas that need to be carefull around. Would hate to ruin a set.

studderin

iTrader: (28)

I posted some stuff search my name.

IRNMADN

Is it a thread you started or just others you have posted in?

omc8

iTrader: (7)

706s ,before you start carving or whittle away . Have you had them checked, some 706s the Castech heads in particular, had cracking issues. Have them checked unless you just want to practice .

IRNMADN

You happen to know the years of the heads that had issues? This was out of an 04' GMC Yukon XL. Last year of the LM7. I would sure hope they resolved the issue by then!

IRNMADN

I read up on the Castech 706's. The set that came on my motor are not Castech heads. There is a different casting logo on them and I have yet to figure out who made them. The extra set of 706 heads that were given to me off a 4.8L are Castech castings. There is no signs they were leaking coolant into the oil though. The 4.8L was pulled due to high mileage and the owner complaining of piston slap at startup.
The guy who gave them to me just swapped in a used 5.3L and is gutting the 4.8L to use as a mockup block. He gave me the heads and now I'm trying to score the flattop pistons from him to maybe use in my 5.3L. Not sure if they will be any good but you never know. Either way, I will use the non Castech heads on my 5.3L.
Now the question is on the Castech heads. If they lasted a long service life without problems, will that indicate they are fine and won't crack? I could always clean these up, install the LS1/6 size intake valve, and use them on my 97' LS1 C5 Corvette. I plan to add headers, a cam, and then the 706 heads could help bump the compression up a bit and flow better than the early LS1 heads(not sure what head # they are). I know the 97' 98' heads are perimeter bolts for the covers.
Any thoughts? I did watch some videos of porting the 241 heads. I assume the 706 heads will require the same areas to be smoothed out. ??????

IRNMADN

Here's a shot of the heads. I know I can just go in and polish the casting bumpiness out 80 grit tootsie rolls. Then go back over them with 120 grit and so on to get them good and smooth. But what I don't know is where I can and should remove material and where I shouldn't remove material, but just smooth out. Would be pretty bummed to remove a bump only to find out there is a water jacket under it and I just ruined the head. Should I use the factory exhaust gaskets to use as a guide to open up the exhaust ports to their openings? If so, do I angle the head port edges to the gasket opening and then just smooth out the transition, or do I hog it out to match the gasket? Just not sure what areas are safe to really open up.

omc8

iTrader: (7)

I believe it was concentrated to 2006 model year. So you are probably all right. I would still have them checked, the cost of having checked is cheap insurance vs putting a lot of time and money in to them later to find out they are cracked and cause other problems. Did you clean those heads up yourself, what did you use.

IRNMADN

The ones pictured are not the Castech heads. I was hoping someone knew what the casting logo was. The Castech heads have yet to be cleaned. All I have used on this set of heads is Power Purple (Walmart Degreaser) and water. I have a few different nylon brushes I've been using to get the tough spots but pretty much just spray it down with the pwr purple, let it break down, then hose it off. Repeat. They are pretty much spotless other than a few sludge spots in the intake runners.
The Castech are the ones given to me. I had tossed them on my 5.3L so I could wash/clean up the block without getting water inside the block. I will clean those heads up later. And will have the shop check them for cracks. Although I don't think there is anything wrong with them. They show none of the signs that the cracked heads show.

omc8

iTrader: (7)

The Castech logo is in the same area but is a battery symbol .

showing the Castech manufacturing casting logo (1).

IRNMADN

I know what the Castech logo is. I was wondering what the logo I showed above is on my set of heads. Like I said, the free set someone gave me, has the Castech battery looking logo. Those I will have looked at. This set above I plan to have the work over.

IRNMADN

I'm going to circle spots in the above photos that point out areas that may or may not be able to be ground down. Not sure what can and can't be ground down or removed.
What I can't find is information on what areas to take material out and what areas you can't. Should I only smooth out the casting? Or can I simply take out all the humps and bumps, open the exhaust ports to match the gaskets...
Shocked there is no real guide out there where it shows what to open up and remove, where to only smooth and polish.
I just ordered a new electric die grinder with a long shaft. Will order a carbide burr set. I have and will get more of the tootsie roll type sanders with the long mandrels. just need to find out what areas to go ahead and open up and what areas to only remove the casting texture.

1FastBrick

iTrader: (16)

There have been a few threads on the DIY head porting.

https://ls1tech.com/forums/generatio...-can-help.html

https://ls1tech.com/forums/generatio...ted-heads.html

https://ls1tech.com/forums/generatio...6k-beware.html

Basically you want to smooth the casting walls and the transition between the valve seat and the bowl. A little work in the bowl around the valve guide will help as well.

You're not looking to hog anything out as the castings can be thin on the roof area.