Jon Kaase SR71 Cylinder Heads

jonkaase wrote:OK, here is a little info:

we have been working on this head for 4 years
we have been tight lipped about it because I want to have a good supply of complete heads in stock before we advertise it
we have 100 castings here now, about 50 are completely machined
we do all the machining in house
we have valves and guide plates for them in stock
the valves are 2.375 x 5.7, and 1.76 x 5.32
the exhaust side of the head is same as P-51, the valve cover rail on the exhaust side is stock height
the intake side of the head is 1/2" higher than stock, but you can see the pictures, it's not very noticeable
the intake valve bowl is about 1/2" deeper
the exhaust valve bowl is about .300" deeper

We have done lots of dyno testing on a 598, 4.6 bore x 4.5, flat top pistons, 15 to 1, cam is 286-296-114, .460 lobe, Comp 1.73 steel stud mounted rockers with no stud girdle, wet sump, at times vacuum pump
the heads are unported but the chambers come cnc finished
the manifold is an unported Trick Flow for 4500 with big Dominator carb
the power has been 1080-1130HP, with the 1130 using a vacuum pump and port matched intake
some of the runs were never under 1060HP between 6100 and 7800 rpm

they are planned around a 4.5 to 4.625 bore
they will work on a 4.390 bore

I can answer any questions on this thread.... Kaase

dfree383 wrote:

enginetech wrote:Maybe (finally), a worthy competitor to the SR-20?  Though we will play hell getting it approved for use in those limited classes requiring “conventional” heads, whatever the hell that means.

How conventional can they be if the factory valve covers and intakes wont even fit????

http://brodix.com/heads-2/big-block-chevrolet-compatible-heads/sr-20-series-cylinder-heads20

dfree383 wrote:Jon,

Do your new heads require custom valve reliefs or will the regular SCJ/P-51 pistons work?

Have you figured out a price point on them yet?

Great work too, just when AFR thought they had corner on the market, Bam !    

jonkaase wrote:OK, here is a little info:

we have been working on this head for 4 years
we have been tight lipped about it because I want to have a good supply of complete heads in stock before we advertise it
we have 100 castings here now, about 50 are completely machined
we do all the machining in house
we have valves and guide plates for them in stock
the valves are 2.375 x 5.7, and 1.76 x 5.32
the exhaust side of the head is same as P-51, the valve cover rail on the exhaust side is stock height
the intake side of the head is 1/2" higher than stock, but you can see the pictures, it's not very noticeable
the intake valve bowl is about 1/2" deeper
the exhaust valve bowl is about .300" deeper

We have done lots of dyno testing on a 598, 4.6 bore x 4.5, flat top pistons, 15 to 1, cam is 286-296-114, .460 lobe, Comp 1.73 steel stud mounted rockers with no stud girdle, wet sump, at times vacuum pump
the heads are unported but the chambers come cnc finished
the manifold is an unported Trick Flow for 4500 with big Dominator carb
the power has been 1080-1130HP, with the 1130 using a vacuum pump and port matched intake
some of the runs were never under 1060HP between 6100 and 7800 rpm

they are planned around a 4.5 to 4.625 bore
they will work on a 4.390 bore

I can answer any questions on this thread.... Kaase

Lem Evans wrote:

dfree383 wrote:Jon,

Do your new heads require custom valve reliefs or will the regular SCJ/P-51 pistons work?

Have you figured out a price point on them yet?

Great work too, just when AFR thought they had corner on the market, Bam !    

I predict most pistons will need a bigger dia. intake valve relief. The valve is 1/8" bigger than the std. P51.

rmcomprandy wrote:

Lem Evans wrote:

dfree383 wrote:Jon,

Do your new heads require custom valve reliefs or will the regular SCJ/P-51 pistons work?

Have you figured out a price point on them yet?

Great work too, just when AFR thought they had corner on the market, Bam !    

I predict most pistons will need a bigger dia. intake valve relief. The valve is 1/8" bigger than the std. P51.

HOWEVER, it is moved away from the notch edge .050" more towards the exhaust side ... same angles but the pierce point is slightly different than the P-51.
So, maybe just slightly.

Lem Evans wrote:

rmcomprandy wrote:

Lem Evans wrote:

dfree383 wrote:Jon,

Do your new heads require custom valve reliefs or will the regular SCJ/P-51 pistons work?

Have you figured out a price point on them yet?

Great work too, just when AFR thought they had corner on the market, Bam !    

I predict most pistons will need a bigger dia. intake valve relief. The valve is 1/8" bigger than the std. P51.

HOWEVER, it is moved away from the notch edge .050" more towards the exhaust side ... same angles but the pierce point is slightly different than the P-51.
So, maybe just slightly.

HOWEVER, I guy damn sure needs to check the intake valve for radial clearance.

jonkaase wrote:the valve angles are the same as the SCJ and P-51. The ex valve is a little closer to the bore. The  intake valve is about the same place as P-51, just down toward the outside of the block about .050". It is possible they may clear a P-51 pocket but bigger diameter would be safer.

We are going to run these heads again this week on a 598 and a 521

The P-51 to me is a magic head and we are going to continue to make it. They have always been is short supply and I hope we have that issue resolved

The plan is to sell the SR-71 heads complete for $2995. That includes ARP rocker studs and guide plates. They use CHE bronze guides. The stainless valves are custom made just for these heads  The intake comes already back cut and the exhaust has a 30 degree back angle. The Roller cam valve springs are Manley NexTek, 221443. They sell for $456 on Summit's site. Retainers , 10 degree super locks and spring seat locators are from Comp Cams. I just don't want any parts failures.

jonkaase wrote:I don't remember how to put pictures on here, or videos. If someone can guide me I will start posting some stuff.

jonkaase wrote:OK, here is a little info:

we have been working on this head for 4 years
we have been tight lipped about it because I want to have a good supply of complete heads in stock before we advertise it
we have 100 castings here now, about 50 are completely machined
we do all the machining in house
we have valves and guide plates for them in stock
the valves are 2.375 x 5.7, and 1.76 x 5.32
the exhaust side of the head is same as P-51, the valve cover rail on the exhaust side is stock height
the intake side of the head is 1/2" higher than stock, but you can see the pictures, it's not very noticeable
the intake valve bowl is about 1/2" deeper
the exhaust valve bowl is about .300" deeper

We have done lots of dyno testing on a 598, 4.6 bore x 4.5, flat top pistons, 15 to 1, cam is 286-296-114, .460 lobe, Comp 1.73 steel stud mounted rockers with no stud girdle, wet sump, at times vacuum pump
the heads are unported but the chambers come cnc finished
the manifold is an unported Trick Flow for 4500 with big Dominator carb
the power has been 1080-1130HP, with the 1130 using a vacuum pump and port matched intake
some of the runs were never under 1060HP between 6100 and 7800 rpm

they are planned around a 4.5 to 4.625 bore
they will work on a 4.390 bore

I can answer any questions on this thread.... Kaase