Some race shop pics

[AlNyhus]

What’s the design approach today regarding piston skirts… short or long?

Somewhere between a full and a 'slipper" skirt would be the best way to describe them. With the 2618-T61 material, the wall clearance has come down considerably from years past. This has allowed the use of thinner rings. In Stock, the ring grooves have to be OEM but you can use any ring width with a spacer. I'm not a big fan of the spacer setup due to ring land issues but some guys make them work. This is an area that NHRA doesn't police very well and many are running a .9 mm ring pack with no spacers. The .9 setup does get you backed into a corner for ring material and hone, though. With the .9 mm setup, the use of a profilometer to establish the cross hatch angle and final Ra number is mandatory.

 

[jackieschmidt]

Hearing all the chatter about carbs & how to tune them, takes me back to the switch to mechanical fuel injection, Hillborn 667 on to top of our hemis......spent lots of time at Kinsler Fuel Injection in Troy Michigan. Pushed lots of alcohol thru those hemis.....not great pictures, most where lost in a divorce.....View attachment 1548757View attachment 1548758

In our Boats, I ran the big 3” stagger tube Crower injectors when we ran K boat on Methanol.
However, I always ran a Hillborn Pump as the Crower Pumps of that time were pure junk. For some reason the front seals would fail,

Tell us more about that injected Hemi.

 

[55fairlane]

In our Boats, I ran the big 3” stagger tube Crower injectors when we ran K boat on Methanol.
However, I always ran a Hillborn Pump as the Crower Pumps of that time were pure junk. For some reason the front seals would fail,

Tell us more about that injected Hemi.

This hemi was I believe the 1st, the chromed factor value covers tell me that, so this engine is a factory 426 hemi block, sleeved (.060 over) to make 441CID (if memory serves),steel radiused crank (I don't remember if it's a Keith Black or a direct connection) stock stroke. TRW 14to 1 pistons , Keith Black rods, R-290 roller cam (I believe .890 lift on the intake side at 270 of duration) Chrysler cast iron heads.....I bought this engine as a "fresh" ready to be assembled from sea port automotive.........that engine made 950/1000 HP @ the flywheel (on methanolalcohol) , what's sad that WAS a race engine, street cars make that as daily drivers, & don't misbehave or die a miserable death.
Car was/is a 68 fast back Cuda. Advanced chassis in Antwerp Ohio did the chassis, mustang 2 front end on a tube chassis. Glass nose/fenders/hood/bumper/ deck lid .....
Best I pedaled that car was 8.93 in the ¼ .

 

[AlNyhus]

As an update...the 396 is going back together and we'll see if our hunch on the ring pack gives us anything.

 

[AlNyhus]

In the meantime, with the primary engine hurt (big time ), we put the back-up engine in this car....a 427-425 for A/SA. It's an older build and won't go to the top of the qualifying sheet but it's raceable. The sharp eyed will notice a couple things about the headers.

 

[jackieschmidt]

Al, the #5 overlapping #7, I assume to optimize runner length.. I never was much into header technology,

What heads are on the 427?

 

[Bob3700]

In the meantime, with the primary engine hurt (big time ), we put the back-up engine in this car....a 427-425 for A/SA. It's an older build and won't go to the top of the qualifying sheet but it's raceable. The sharp eyed will notice a couple things about the headers.


Small tube n ceramic coated?

 

[Walt Krafft]

Back in 74 I was at the GM Tech center as a GMI student and walked thrue a building full of all aluminum big and small bock engines. God would I love to have been able to take a few.

 

[AlNyhus]

Al, the #5 overlapping #7, I assume to optimize runner length.. I never was much into header technology,

What heads are on the 427?

Jackie, tube sizes are different for the cylinders with the shorter intake runners...1-7/8" versus 2". The #1 header tube has some dimples from the inside from pieces of an exhaust valve. This has the closed chamber rectangular port 840's for heads. The alum 401's can be used as a replacement with a horsepower penalty.

 

[cp generation]

Al, look here at the twins....

 

[PhilKeil]

@AlNyhus , Have you ever worked on the Pro Stock engines?. The tech you have shown is amazing i bet that is off the chart..

 

[AlNyhus]

Al, look here at the twins....
View attachment 1550977

Nice! How about some more info?

 

[AlNyhus]

@AlNyhus , Have you ever worked on the Pro Stock engines?. The tech you have shown is amazing i bet that is off the chart..

No. The technology of the Pro Stock stuff is amazing. It's a pretty closed club, for understandable reasons. There used to be a fair bit of technology trickle down that helped a lot of the sportsman classes. Much of that is now considered intellectual property of each team or engine builder and as such is covered under the employment contracts. Quite a few teams lease engines as the development costs are staggering.

 

[J.J. Coe]

No. The technology of the Pro Stock stuff is amazing. It's a pretty closed club, for understandable reasons. There used to be a fair bit of technology trickle down that helped a lot of the sportsman classes. Much of that is now considered intellectual property of each team or engine builder and as such is covered under the employment contracts. Quite a few teams lease engines as the development costs are staggering.

Yep, we've built a lot of pro stockers over the years and you have to be within a tight circle to get any meaningful information. The money it takes to make a run at the championship for just 1 car is mind-boggling. We currently build all the cars for Elite Motorsports...........it's quite the honor. Here's a pic of the latest 1 for the Cuadra's

 

[AlNyhus]

Yep, we've built a lot of pro stockers over the years and you have to be within a tight circle to get any meaningful information. The money it takes to make a run at the championship for just 1 car is mind-boggling. We currently build all the cars for Elite Motorsports...........it's quite the honor. Here's a pic of the latest 1 for the Cuadra'sView attachment 1551082

Are you with RJ Race Cars?

 

[J.J. Coe]

Are you with RJ Race Cars?

Yep, for the last 35 years.

 

[AlNyhus]

Very cool. The work you guys turn out is beautiful.

 

[J.J. Coe]

Very cool. The work you guys turn out is beautiful.

Thanks Al

 

[AlNyhus]

Thanks Al

You can identify with the tube chassis Comp car in these pics. It's for BB/A which now allows 'factory' style intercooling of the supercharger. The engine is basically a Factory Shootout engine with the later model Whipple supercharger where the intercooler is above the supercharger rather than below it. The car has to weigh 2,600 with driver and the index is 7.89. Given the power the Factory Shootout cars make, the math works out pretty well.

 

[jackieschmidt]

Jackie, tube sizes are different for the cylinders with the shorter intake runners...1-7/8" versus 2". The #1 header tube has some dimples from the inside from pieces of an exhaust valve. This has the closed chamber rectangular port 840's for heads. The alum 401's can be used as a replacement with a horsepower penalty.

Those are the same closed chamber heads that came on the 1970 LS-6.
Back in the day, those were considered to be not as good as the open chamber version.

But then, with the open chamber version with the 119 cc combustion chambers, you had to have that humongous dome on the piston to get the same compression.