X head milled to closed chamber ?

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Did this a dozen years ago--chambers came in at 45 cc I believe. Beware your piston valve reliefs will have to change to accommodate. J.Rob
 
Wouldn't it have been nice if they had made some like that?
 
66fs said:
Why, just buy good pistons?
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Yes! :cheers:

You will also have to mill the intake to match the heads, and then figure out pushrod length, and/or shim the rocker arms... One headache after another... :banghead:


I agree, just buy the proper set of pistons... :D
 
RAMM said:
Did this a dozen years ago--chambers came in at 45 cc I believe. Beware your piston valve reliefs will have to change to accommodate. J.Rob
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Got any test results? That head should help resisting detonation with it's closed chamber. Would
work well on a 318. Machining costs would be the downside.
 
I have been pondering this exact thing for a few days now, only for a big block. I may just spray weld the chambers then mill them to create a closed chamber 906 or what ever. Just changing pistons will not gain the desired quench you get from a closed chamber. I'm thinking my pistons are too far in the hole for good quench anyway, but I could gain a little in compression, which the cam may drain off anyway. And so goes the vicious cycle with it's myriad of variables. I shall persevere and overcome, or I will just build a 280hp 440 that will run forever. Skinny tires should get me the smoke I desire.
 
skrews said:
Just found it interesting. Kind of a fools endever these days.
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I always want the thickest decks, the thickest bores, thickest head surface, highest valve seats. By milling that much off the head surface, I was always afraid of blowing head gaskets or worse. 340 pistons are above block at 10.5 to 1. Those heads do look sweet.
 
magnumdart said:
I have been pondering this exact thing for a few days now, only for a big block. I may just spray weld the chambers then mill them to create a closed chamber 906 or what ever. Just changing pistons will not gain the desired quench you get from a closed chamber. I'm thinking my pistons are too far in the hole for good quench anyway, but I could gain a little in compression, which the cam may drain off anyway. And so goes the vicious cycle with it's myriad of variables. I shall persevere and overcome, or I will just build a 280hp 440 that will run forever. Skinny tires should get me the smoke I desire.
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Custom pistons would probably be cheaper. 1967 915 heads are closed chamber as are 516's. The 516's in stock form will loose to the better flowing 906's. Search IQ-52's low compression 440 build. If you know the right combination, you can get a lot more than 280 HP, open chambers and all.
 
Also, rest assured whoever milled that head up there ^^^^^ had to angle mill it. Technically, they angle milled it the wrong way. Angle milling is used to get the valves on a better angle with the pistons and chamber. The intake side would have had to take the heaviest mill there and that's goin slap the wrong way.
 
66fs said:
Custom pistons would probably be cheaper. 1967 915 heads are closed chamber as are 516's. The 516's in stock form will loose to the better flowing 906's. Search IQ-52's low compression 440 build. If you know the right combination, you can get a lot more than 280 HP, open chambers and all.
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I am aware of that build. And I do have a pair of 516's to work with. They would need porting and larger exhaust valves. I may copy the build. Only thing is I really would like to run stock hp exhaust manifolds and I'm guessing I will loose a significant amount of power. I do have a set of headers I can use if it doesn't satisfy me.
 
the 516 head has way smaller intake ports. even ported , they will not come close to a stock 906 head!!!!! 184 cc vs 203 cc. not worth the effort. seen them on flow bench!!!
 
perfacar said:
the 516 head has way smaller intake ports. even ported , they will not come close to a stock 906 head!!!!! 184 cc vs 203 cc. not worth the effort. seen them on flow bench!!!
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Probably true. Would be better suited for a 383, if at all.
 
krazykuda said:
yes! :cheers:

You will also have to mill the intake to match the heads, and then figure out pushrod length, and/or shim the rocker arms... One headache after another... :banghead:


I agree, just buy the proper set of pistons... :d
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^^^^^^^^this!!!^^^^^^^^^^^^
 
I don't like cutting heads a lot cuz u lower the ports - not good for power. my 340 has .050" quench with open chamber 3418915 J heads
 
I did this to my 894D x heads. I milled them .35 thou and got a 60cc chamber. They were still open chamber slightly
 
magnumdart said:
I have been pondering this exact thing for a few days now, only for a big block. I may just spray weld the chambers then mill them to create a closed chamber 906 or what ever. Just changing pistons will not gain the desired quench you get from a closed chamber. I'm thinking my pistons are too far in the hole for good quench anyway, but I could gain a little in compression, which the cam may drain off anyway. And so goes the vicious cycle with it's myriad of variables. I shall persevere and overcome, or I will just build a 280hp 440 that will run forever. Skinny tires should get me the smoke I desire.
Click to expand...


Could you explain this posses to me, in more detail...............
 
magnumdart said:
I have been pondering this exact thing for a few days now, only for a big block. I may just spray weld the chambers then mill them to create a closed chamber 906 or what ever. Just changing pistons will not gain the desired quench you get from a closed chamber. I'm thinking my pistons are too far in the hole for good quench anyway, but I could gain a little in compression, which the cam may drain off anyway. And so goes the vicious cycle with it's myriad of variables. I shall persevere and overcome, or I will just build a 280hp 440 that will run forever. Skinny tires should get me the smoke I desire.
Click to expand...

It will be much more budget friendly to simply find some 915 heads. Even perhaps to buy a set of aftermarket aluminum closed chamber heads.
 
RustyRatRod said:
Google spray weld.
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I did, just can't see how it would hold up in a high heat/pressure situation like a head live in.

just wounder if any on had done this on a actual head......and did it live................

Sorry Getting this thread of in the wrong direction.......just curious
 
I did it in a restricted racing class with flat top KB pistons ON A 368CUBE 500cfm carb rule. all the intake seats cracked to the spark plug hole in every cylinder, and I was using race gas for 12 to1 or higher. rich carb and never went over 180 degs. and 32 degs timing, they were the x heads,894 69 head. but they did go about 250 miles at full throttle before I found the cracks. might hold up a full season in 1/4 mile racing or on the street with limited fun time. also the rocker oiling hole had to be reworked to keep the oil flowing.
 
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