Its cold and i'm thinking of the 360 i may build in the spring. Its flat top piston .005 in the hole and .030 over. I have a set of ported W-2 heads and would like to know how much i can safely mill them. Anyone with experience? I don't believe they have ever been milled on the chamber side.
Milling of a 810 casing W-2 head
- Thread starter mopfried
- Start date
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Locomotion
Well-Known Member
I've seen W-2 heads milled to the point of being closed chamber, but I don't know how that worked out or what durability problems it may have caused. Personally, I wouldn't be comfortable with it. You would have to mill the intake side a certain proportionate amount to fit the intake manifold, possibly the front & rear rails and it might cause some pushrod clearance issues. Needless to say, you would need custom pushrods.
I'm guessing that you are looking for more than a true 11.0 compression ratio with the flattops? You can get around that with roughly 65 cc chambers & a .039" Fel-Pro 1008. Much higher and you may need to consider additional sealing options.
I'm guessing that you are looking for more than a true 11.0 compression ratio with the flattops? You can get around that with roughly 65 cc chambers & a .039" Fel-Pro 1008. Much higher and you may need to consider additional sealing options.
yellow rose
Overnight Sensation
Deck the block instead. Stick the piston out of the hole. If you take that much off the head they don't seal very well.
They look thin around some of the cooling holes. I cc'ed them a while back and it seemed that they had not been cut. Decking the block makes since, dollar wise much cheaper than pistons. How much should the pistons stick out?
If i remember correctly the open area was about .070"-.075" deep. If the pistons stuck out .070 with a .035 gasket that should be good quench. I have access to machine pockets in the pistons to drop the compression down if need be. I want to run pump gas.
yellow rose
Overnight Sensation
Some of it depends on where the rings are. You can only get the piston up in the bore as far as the rings lest you. But .060-.080 usually isn't an issue.
Measure the recess in the heads before you start. About the deepest I've seen them is .110 but most by now if they've been surfaced will be in the .080-.090 range.
Get the heads flat and equal first, then decide how far you need to get out to the hole. I wouldn't be afraid to call Cometic and get some gaskets that are .027 thick and use them. It will take less milling of everything.
Duane
Well-Known Member
810 castings are early heads. I would not mill those. IMHO
Excerpt from the stroker small block book.
yellow rose
Overnight Sensation
If you mill any head that much they are prone to fracture. And the head gaskets take a beating.
It's much better to get the CR up other ways than milling the hell out of them.
Duane
Well-Known Member
Easy to get compression with a stroker crank imho.
I do plan on stroking it. Considered a 426 kit.. don't know if the heads will support that. Anyway i was trying to get some quench from the setup.
i have milled a 456 BB mopar head casting to a closed chamber and not had problems with it. i did use stock pistons with it.
i have milled a 456 BB mopar head casting to a closed chamber and not had problems with it. i did use stock pistons with it.
Ported W2’s will support that for the most part. A lot depends on how far your taking it. (Up the RPM scale and still making power.)
The math equation is available. You’ll need to measure up the head to know what it can do and about where your going to run short.
(CSA)
The math equation is available. You’ll need to measure up the head to know what it can do and about where your going to run short.
(CSA)
yellow rose
Overnight Sensation
First things first. If you mill the head that far, you'll kill flow. Hard. Don't mill the head that far for that reason all by itself. It's a bad deal.
Second, if you are worried about quench, you can fix that by sticking the piston out of the deck. This is the preferred method and the method Chrylser calls out. You can have quench with that head and not kill flow. BTW, if you mill that head that far, not only does it kill flow, it actually makes reverse flow go way, way up. That's a big power killer.
Third, and I'll say this until my teeth wear out, quench is a band aid for a crap spark plug location/chamber and emissions just as much as it is anything else. I've typed out a long, LONG post on this. As an example, a Hemi uses very little total timing, is about as detonation resistant as anything and yet has virtually zero quench. You can give the Hemi some SQUISH but not quench. And yet and still, you have to work hard to drive a Hemi into detonation.
Same thing with a small block dodge. Or the W2. Usually 35 total, damn hard to drive it into detonation unless you are just wreckless or stupid (not saying you as in YOU, saying you as a general term).
That head will feed bigger inches if it's done correctly. If not a W2 head, what other options do you have?
When you are doing that many inches, you need to make sure you consider the details. Because you will be induction limited, every little detail like reverse flow, throat area, valve shape, cross section and the valve job become critical. Big displacement, induction limited engines explore flaws because the actual air speed is much higher because the air demand is much greater.
You've also given up a HUGE amount of Rod ratio, and regardless of all the bull crap David Reher and some other engine builders love to publish Rod ratio matters, especially in induction limited applications. Even Chrysler admits this. When you are David Reher and most everything you build is NOT induction limited, then Rod ratio isn't that important.
Whatever intake manifold you use, I highly doubt you'll get by without at least some welding. You won't have enough area to feed that many inches, unless you have an operating range of a diesel. I weld on a Strip Dominator for 340 inches. Not because I love TIG welding so much, but because you can't get the shape and size you'll need without it.
I hope this helps. To do what you want and do it correctly, it will be likely you'll need a custom piston. You'll have to fight the piston guys because they just don't get that a positive deck isn't a bad thing, or criminally wrong. To keep the CR where you want or need it, and get some quench if you want it you'll probably need a piston with a positive deck and a reverse come on it.
pishta
I know I'm right....
I think custom pistons would be cheapest route. W2's dont grow on trees and your gonna need a special piston for the 4.125 stroke crank anyway. Get everything needed then order the pancake pistons.
The W2 should make more power than the Trick Flow heads due to a larger cross sectional area moving a larger volume of air and fuel. This is one of the reasons the MoPar W head line was so nice.
yellow rose
Overnight Sensation
The TF heads are beautiful to say the least. But they are a step back from the W2.
Don't fall in love with flow numbers. Get the CSA correct and the W2 will out horsepower most anything else that isn't a raised runner head.
There are guys making 800 HP on small block Chevy 23 degree heads. I'd have to go look it up, but those may be a raised runner deal, but that's where a W5 or the Indy head would compete.
The W2 is by far your best choice, especially since you have most of it.
yellow rose
Overnight Sensation
AKA, how tall and wide the port is at the smallest point.
yellow rose
Overnight Sensation
And the bowl and throat etc. On the W2 you don't really have a pushrod pinch but it's worth measuring all the stuff so you know what you have.
Duane
Well-Known Member
Good post. I agree. I remember when Ryan J ported my w2 he had 2 sets of Indy heads in the shop. He explained to me that the main reason that the 360-1 out performed the 360-2 is the open chamber on the 360-1 versus the closed type on the 2.
I agree on the custom piston especially if it's a stroker build.
My w2 have a 67 cc typical chamber. I had Ross make me a semi flat top piston. It has a dome, but it is flat and only .100 tall.
4.00 stroke. Stock length rod. I did not care about quench for my application, but that small dome gives me 12.7:1 compression.
A total flat top was 11.5:1 without milling the head and killing the flow as you have said. The cost of a custom piston was partially offset in my build by the weight accuracy of the Pistons from Ross.
My local builder cannot get them as close as Ross does. We only had to balance the crank and nothing else. Something to keep in mind.
Duane
Well-Known Member
Guys want the quench for pump gas.
Duane
Well-Known Member
The chamber in the Indy 360-1 looks more like the open chamber
W2. I guess it's a trade off. The W2 will still make some pretty good power with less compression. I always heard though that compression makes torque. But then you have fuel expenses.
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