Re: Jon Kaase SR71 Cylinder Heads

68formalGT April 27th 2023, 12:22 am

G-Code wrote:
68formalGT wrote:G-Code, is that any better?

Much better.

Thanks

It says nothing about raising the port, or altering the floor on either of them to make for a better short turn. Rats
That would be helpful. Changing that push rod pinch is certainly a winner and that would eliminate the turn before the short turn, so the floor would be more balanced.

New A460 head progress.
Last night on the flow bench we saw 450 cfm with a 2.320" valve through a 3.47" CSA = 311 fps. 0n a 4.50" bore.

Got the flow to mellow out through it's rough section @ .750" - 800" lift where it wants to get unstable.

We hope to maintain the smoothness and flow percentages with a 2.380 valve. ... Work in progress

Raising the port would give the brand X guys a way to complain that it's no longer "conventional port" legal

supervel45 April 27th 2023, 1:39 am

^ $4,350 for steel rocker stands, Kha Ching. Looks like you could have 8-10K in those A460's pretty quick.

I surprized nobody snagged the Thor's for $2,500 yet. They look like Gen II's and you never see them up for sale.

You will make your goal with what you have G-Code and have plenty of money left over for gas.

G-Code April 27th 2023, 12:17 pm

supervel45 wrote:^ $4,350 for steel rocker stands, Kha Ching. Looks like you could have 8-10K in those A460's pretty quick.

I surprized nobody snagged the Thor's for $2,500 yet. They look like Gen II's and you never see them up for sale.

You will make your goal with what you have G-Code and have plenty of money left over for gas.

The Thor's - solid heads no water. And yes the Eliminators are going to be costly with those stands.

G-Code April 27th 2023, 12:18 pm

[quote="68formalGT"][quote="G-Code"]

68formalGT wrote:G-Code, is that any better?[url=https://servimg.com/view/18825961

Raising the port would give the brand X guys a way to complain that it's no longer "conventional port" legal

True .

supervel45 May 16th 2023, 12:36 pm

rmcomprandy wrote:
Lem Evans wrote:
nascar429 wrote:
Lem Evans wrote:It appears that the exh. side of the chamber is wider that the 4.562" bore. Is that the case?

Yes that is correct there is a slight over hang of the bore into the exh side of the chamber maybe about .020" or 0.30" or so.. i'd say a 4.600" bore would have little or no overhang into the chamber.. I did put the dowels in the deck to make sure the head was square.

when i get a chance out of curiosity i'll do a dummy up with cam, lifters, rocker etc..and see how much exhaust valve clearance there is from the bore when the valve is open..

That being the case, a guy needs to get a head gasket that fits the chamber rather than the bore. The TFS A460 heads are the same way in that regard.

Do you think .030" offset dowel holes would be enough for a 4.390" bore using the normal 4.500" bore gaskets...?

Did you ever get a chance to look into that?

It sure looks like it would unshroud the exhaust valve from the pictures here, even on the large bore block it's on, on page 10, and center the chamber better?

I could see where it would be a lot of hassle for little gain, and would affect intake valve radial clearance.

Any other issues do doing it?

Looks like they make offset dowel pins for BBC and none for BBF.

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