Re: Jon Kaase SR71 Cylinder Heads

jonkaase November 8th 2018, 9:02 pm

Jon Kaase SR71 Cylinder Heads - Page 6 Ggg10

Jon Kaase SR71 Cylinder Heads - Page 6 Fff10

I know this is pretty much unbelievable, but this went past our goal. First sheet is with cam at 113, second is at 116. Timing at 28. It took 5 runs before these sheets to get the carbs right. 6 cylinders were way rich and the front two needed fuel. It would be hard to figure out without all 8 O2 sensors on the primary pipes. Special thanks to Billy Godbold at Comp Cams for making 2 new lobes for me. This engine has 179 gram steel intake valves, stud rockers with no stud girdle, and Manley Nextek dual springs with 250# on the seat and 750# open. Trend 3/8 pushrods, .135 wall. It still sounds like it wants more at 8100. Since we were going over 8000 rpm I started it a little higher than the other runs. Peak torque was below the starting RPM.

BBF552 November 8th 2018, 9:26 pm

What fuel are you using for the 598 tests?

jbozzelle November 8th 2018, 10:17 pm

Dave De wrote:The stud bosses on these heads seem to be higher than the P-51's. This makes the rocker trunnion closer to the base of the stud where its going to be stronger from side loading. Push rod lengths are much longer at 9.400 and 9.450.

Piston valve relief clearance
My Diamond piston reliefs were cut for modified P-51's with 2.300" diameter intake valves. The valves on the SR-71's are 2.375" where I expected interference. I checked the clearance to find that it has .160" radial clearance in the relief. This tells me that the valve centerline is closer to the piston center than the P-51 head. Those of you that have pistons with reliefs for SCJ/P-51's with 2.25" valves should have less clearance to something around .130" which is acceptable clearance where you wont have to cut the pistons. But you need to check it to make sure.

Thanks for the info. Been pondering a set of the SR-71s and a cam swap on my 514 here soon... Good to know the pistons may be able to stay in the block...

jbozzelle November 8th 2018, 10:18 pm

2 horsepower per cubic inch is nothing to sneeze at from the 598 test mule!

stanger68 November 8th 2018, 11:54 pm

BBF552 wrote:What fuel are you using for the 598 tests?

X2- I was wondering the same thing. Is this with alcohol or gas?

jonkaase November 9th 2018, 9:43 am

This is a maximum effort for sure. So the fuel is VP, Q-16. It's the best fuel I've ever seen for not hurting parts. Too much timing? just less power. Too lean, like over 16 to 1 air/fuel? no problem. C-16 VP is about the same power. But on this engine with 16 to 1 compression, C-12 or C-14 VP would probably hurt the rings

STR-LGL-70 November 9th 2018, 10:19 am

Jon,
I read through all of the posts for some idea of the cam specs you used but didn't see anything. Could you give us some specifics w/o going too much in detail? I just picked up some C heads and am almost kicking myself for the cost diff vs hp gain compared to the sr71 heads with being able to use the manifolds, headers, etc I already own.
Thanks, Sheldon

jonkaase November 9th 2018, 10:23 am

The C heads ported right are a good 100 better. so don't worry. the cam is Comp, 287-312 at .050 115 CL, .483" lobe lift.

jonkaase November 9th 2018, 10:49 am

Jon Kaase SR71 Cylinder Heads - Page 6 A13

It's not very often that you can make over 1200 HP, N.A. with $450 rockers

Lem Evans November 9th 2018, 10:56 am

Comp 1830-16?

jbozzelle November 9th 2018, 11:03 am

Looks like them...

jonkaase November 9th 2018, 11:15 am

yes.... Comp 1830-16

nuclearcobra November 9th 2018, 1:29 pm

Your ideas are incredible , Even your P38's , I put them on a 86 junk yard 5.0 short block with a small flat hyd cam 244@.050 and 534 lift and ran 10.80 at 121 mph with a 125 shot at 3050lb tripping the 60' box on the rear tires , and have been equally impressed with the SCJ's outta the box on a solid flat tappet flat top piston 472 and the P51's on a solid flat tappet 552 So thanks for all the killer creations you offer us , I think i might have to get a set of these SR71's to help with my hoarding hobby Very Happy

IDT-572 November 9th 2018, 5:01 pm

Jon, will you have a stud girdle in time to test on this engine. Be a great one to see if there is some power to be had with one.

jbozzelle November 9th 2018, 6:55 pm

IDT-572 wrote:Jon, will you have a stud girdle in time to test on this engine. Be a great one to see if there is some power to be had with one.

Curious about this too...

68galaxie November 9th 2018, 7:36 pm

Fantastic results John.

The AFR 315 heads have a 3.44 square inch CSA minimum (published)
How do the P51 and SR-71 heads compare.

Doing some PipeMax work and am curious about port sizing.

Cheers!

jonkaase November 9th 2018, 7:49 pm

I will try to do some measuring for you.

terryk105 November 10th 2018, 4:53 am

jonkaase wrote:The C heads ported right are a good 100 better.

Hi Jon

Where will the SR71 be with porting? and what about your A460?

Cheers
Terry

jonkaase November 10th 2018, 7:54 pm

i checked some sizes of intake ports. The areas figured in the corner radius’s. The P-51 and SR-71 heads have more corner radius in the roof than the AFR ‘s and that is figured in. Overall the sq in area is hard to measure but these are close

AFR. Pushrod pinch, 2.12 x 1.73, 3.45 sq in. Short turn, 1.9 x 2.16, 3.8 sq in. (Height x width)

P-51. 2.1 x 1.78 3.45. 1.9 x 2.15. 3.63

SR-71. 2.3 x 1.85. 4.04. 2.15 x 2.3. 4.41

jonkaase November 10th 2018, 8:00 pm

Sorry but listing this at home on my Ipad, it scooted all the numbers together and I can’t edit it back

68galaxie November 10th 2018, 9:42 pm

jonkaase wrote:i checked some sizes of intake ports. The areas figured in the corner radius’s. The P-51 and SR-71 heads have more corner radius in the roof than the AFR ‘s and that is figured in. Overall the sq in area is hard to measure but these are close

AFR. Pushrod pinch, 2.12 x 1.73, 3.45 sq in. Short turn, 1.9 x 2.16, 3.8 sq in. (Height x width)

P-51. 2.1 x 1.78 3.45. 1.9 x 2.15. 3.63

SR-71. 2.3 x 1.85. 4.04. 2.15 x 2.3. 4.41

Thank you!!

res0rli9 November 11th 2018, 2:34 am

I see more engine masters victory's

c.evans November 12th 2018, 3:22 pm

To Blake and J. Bozelle,

I sent an assembled SR-71 head to Jon Best at Jomar a couple of weeks ago. They are making the stud girdles now and have a P/N assigned for the SR-71 heads.

jbozzelle November 12th 2018, 3:51 pm

I saw that on Facebook Charlie.

IDT-572 November 12th 2018, 5:07 pm

Charlie,

I did too , just hoping jon will get them in time to make a pull or two with them on the engine.

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