Hey guys,

My buddy has a set of 317s he is willing to give me for my vette. I know the combustion chamber is big so I have heard you can have the combustion chamber welded, then massaged to get the CC down to 59-61cc for a NA application.

Have you done this, and when done proffessionally is there any draw backs?

I was thinking about going this route because a set of 243s or 799 is going to cost me $400 before porting, and to have the 317's welded and machine is $200.

Any suggestions? AI would be doing the work.

 

I haven't done it, but there are really no draw backs at all if done right, and AI knows what they are doing, so I say go for it!

 

I would spend the cash and get heads that are for a LS1. Welding 317s may be risky. Whats your budget for ported heads at 59ccs?

I highly doubt AI will do that kind of work for only $150. I have researched their work and they are on the high side for labor.

 

Well to weld the chambers its 150, then they go through and port them and whatever else.

Budget....well I was wanting to stay under 2000.

 

But if I am going with gm castings I want to stay cheap as possible other than the port work price. I think its dumb to spend 500 on stock unported castings.

 

Buy some 243/799's. You cant just weld on aluminum heads without doing alot of work. Will probably need new seats/guides & heat treat at a minimum after that much welding and all the machine work that goes with that operation. Aluminum moves around alot while welding/putting alot of heat into it.

 

A set of stock ls1 heads has the chamber volume you are looking for and after AI gets done with them you will have a killer set of heads for 150 less than your welded 317's. And if they aren't welded right, they can start to crack.

 

So you think it's dumb to buy a set of proven stockers to get ported, yet you want to weld some cheap heads you got?

If your budget is under $2k there are a lot of better options than this welding idea.

 

The 317s are the same head, just a larger combustion chamber. So yes these heads are cheap, but with the welding of the combustion chamber I can be about $250-300 less in the same set of identically flowing heads, just required different work.

Yes the 243/799 is proven, however when you look into it, your going to have $1400-1600 in a quality ported set, when a set of as cast Trick flows are around $1,800.

So the question is, what is better, an as cast TFS or a set of fully worked over 243s.

 

if you hunt around you can get 243 heads cheap i bought a set has 21k on them for 275 there is a guy on a local forum that has a seto of 243 heads with i think 650 lift springs and he is only asking 550 for the

 

Found a set of TEA ported Trick Flow 215's. Guess I am going to go with them

 

150 is cheap for welded them up and decking. thats not finishing the chamber, but you can get better chamber then 799/243. they weld easy too.

 

Thanks Studderin,

This somewhat turned into a useful post for someone. I found a set of TEA/Trickflows I am going to get tomorrow.

 

I have welded 317s. Alunimum is so easy to weld the material into, it is basically like casting more aluminum into the chamber. Its not like it can break loose, it becomes part of the head casting. Anyone that suggests different, has not tried it or worked with it. It is not a really common thing, but it is done. If you look at the website for AI, this is how they achieve thier HCR 241 heads as well. The 317 is, a set of 243 runners and a chamber that closely matches the LS1 (really close to an 806) chamber, the 243 chamber is considerably different. I didn't measure them exactly, but make this observation from side by side comparison, having several sets of LS heads on my shelves. I believe a welded and ported 317 is exactly equivalent to a ported 243. The CNC cutting, using the same program will make them the exact same dimensions afterward.

I went this route because it made sense from a quality and value standpoint. I think the AI work is outstanding, they really know thier stuff. I bought an LQ9 with 30K on the odometer, and pulled the 317s off it. The rest of the LQ9 is being used for a turbo 370 build with rectangular port heads, for my '56 buick. I have 2 other cars which I have dropped over 6 figures into. I didn't do this because I coudn't afford better heads, but the welded 317's, from AI, I feel are as good a product as about anything else available at any price, considering my intended use(NA in a street/strip car with no spray). From ones I've looked at only a Mamofied AFR, or a Mast rectangular port small bore head were viable options. I have heard from 2 tuners, during my own research before buying, that they have seen better performance from the factory ported AI heads than pretty much all of the aftermarket castings, as cast. Only the worked aftermarket castings, like TEA ported TFS, mamofied AFR's, etc are outperforming the AI heads. Is there any negative feedback on any of the AI heads anywhere? There may be but I havn't seen it.

Other reasons to use these heads include, the powdered metal guides, I prefer them to bronze. The stock LS rocker is a great light strong design, upgrade the trunion, and they are awsome IMO. I would not want to swap them out for some heavy aftermarket piece, some aftermarket heads don't work well with the stock rockers. The stealth factor also appeals to me. Who is afraid of an Fbody with 317 heads on it? Its not like having TFS, AFR or Mast staring at you upon opening the hood. I've even thought about having one of those names milled off a set I have. They are nice for a grudge car.

This is a topic that will have many opinions, and I'm sure there are some that will disagree with me. Just giving you my 2 cents worth.

I don't intend to talk you out of the TEA TFS, they are top notch as well, I'm sure you will be happy. My point is that you probably would have been happy either way. The worst thing about AI is getting you heads back, they are in high demand, it is a quite a wait.

 

maybe it mite be easier to just mill the 317 heads to the need cc size.

 

I have had lt1 heads welded before. never had a problem with them afterword.
If Phil tells you that this is a viable option. Just do it. Ai does great work and has top notch customer service.
I have the lt1 200 cc heads on my camaro. I plan on having them do some ls1 castings for my ls motor.
jmo.
Kory

 

The reason why you just dont mill them is that you lose PTV clearance to mill them enough to hit nice high compression numbers. With welding, the material is added in areas required to reshape the combustion chamber to make it more effiecient, basically material is added to shape it more like a 243 chamber. Milling alone leaves the shape the same, and just makes it shallower, and reduces PTV. When they are welded, they are milled as well, its required to get rid of any heat distortion etc., just not nearly as much as you would mill them if thats your primary method of increasing compression.

 

Plus the more you mill off a head the flow drops....that's why a lot of times you see flow numbers listed for heads as "unmilled"

 

Yes and You mill very much from aluminum heads and they will warp/crack at a lower temp than factory unmilled castings will .

I am welding on My combustion chambers to add a little quench area opposite the factory flat quench area with the idea being that I should gain a little in efficiency/power as the fuel/air will be forced toward the center in part replicating the GDI concept ,,,,,,aluminum welds easy except that My aluminum wire keeps bunching just past the drive roll ,,,,,,,,,I'm running .030" al wire and I've modified the cable liner so it is about .015" away from the drive roll/bearing and it still bunches up about every 20-30 seconds of welding so I'm getting it done but slowly . I have checked the deck surfaces when cool and there has been no warpage . 1 time I repaired a neighbors 4 cyl cracked head by first removing valves and seals ......etc then putting it on the portable gas grill 4 30 or 40 min then welding , let cool and was burned in awesomely and was'nt any more warped than it already was ,,,,,,,,needed milled anyway .

 

pushing alum mig is not something I would do, even the alum spool guns suck. You need a good tig machine with high fq they weld up fine.