Schubeck Lifter Update

[Aubrey N Bruneau]

Yes Rich, I agree, more clearance at the exhaust would be desireable.
However, the engine seems to have responded VERY well to the "late" cam. Above 6000 is a different animal all together. Also, it's of course a stick car, and never sees below 3500 at any time during a run... and still has a terrible traction problem.

Hans, I check piston-to-valve by the "light spring" method. My "close" spot,is about 10- degrees before TDC on the exhaust valve.

oh yeah... it was an intake lifter... hot clearance had been set to .014" ( .016" hot by the cam card from Comp )

[John Lang]

Can anyone tell me the correct lash on Shubecks Hyd, 70 Ply RR 440. 6 Pak Got 34 passes and alls well. The reason i'm asking is i set them at .004 which i was told on this board, and i'm just wondering if that is close to right . John

[Hans Olsson]

Originally Posted by NHRAstocker409

Yes Rich, I agree, more clearance at the exhaust would be desireable.
However, the engine seems to have responded VERY well to the "late" cam. Above 6000 is a different animal all together. Also, it's of course a stick car, and never sees below 3500 at any time during a run... and still has a terrible traction problem.

Hans, I check piston-to-valve by the "light spring" method. My "close" spot,is about 10- degrees before TDC on the exhaust valve.

oh yeah... it was an intake lifter... hot clearance had been set to .014" ( .016" hot by the cam card from Comp )

Thank you Aubrey.
What spring pressure do you use?
The "light spring" method shows the least amount of clearance does it not?

[Aubrey N Bruneau]

oh yes, spring pressure...
250-255 seat... around 470 open.

The valve clearance ?
just geometry... !
pre-assemble everything, and check the "lash" ( measure with a dial indicator, the distance you can push the valve to the piston, when the crank / cam is positioned near overlap ).
really, very easy to do. be sure to check in various postions.

[Hans Olsson]

My question was, does the "light spring" method give less clearance then the "clay and actual valve springs" method. Sorry for the confusion.

[Aubrey N Bruneau]

I don't like the "clay" method.
"less clearnce" ?
I suppose the light-spring method COULD possibly end up indicating .0015" less !

The spring method lets you actually "feel" what the parts are experiencing.

[Hans Olsson]

Thank you

[RocketBlock]

My engine had about 2 1/2 hours on it.

I THINK THAT IS A MAJOR PART OF THE PROBLEM. STREET OR STREET RACING IS NOT THE ENVIRONMENT THESE ENGINES ARE DESIGNED FOR. STOCK ELIMINATOR CAMS, VALVETRAIN AND RING PACKAGES ARE NOT DESIGNED AROUND EXCESS HEAT CYCLES OR CONTINUED OPERATION WHICH LEADS TO TOLERANCE INSTABILITY.


Really what they do, is tolerate the ridiculous ramps on Stocker-type flat tappet cams...

SEE ABOVE STATEMENT. THOSE "RIDICULOUS RAMPS" ARE NOT DESIGNED FOR LONG TERM USE. MY OPINION IS THE SCHUBECKS ARE IN THE SAME CATEGORY. TOLERANCES ARE CRITICAL IN THE LIFTER BORE AND MY OPINION IS CONTINUOUS OPERATION WILL UPSET THE TOLERANCES CAUSING FAILURE.

Because of course due to the Stock rules, piston-to-valve clearance is at a minimum.
Mine measured .070" on the intake, .045"+ exhauast ( cam is retarded 4 deg ).

MORE CLEARANCES ARE AVAILABLE. YOU MAY HAVE TO LOOK AT A WIDER LSA. THAT MAY COMPROMISE HP TO SOME DEGREE. YOU MIGHT ALSO WANT TO SINK &/OR SHAVE THE VALVES. SOMEWHERE YOU NEED TO DETERMINE WHAT BENEFIT YOU REQUIRE.



I still have never wiped out ( or even hurt ) a cam lobe, in any engine. ( knocking on my head right now ! )

I THINK THAT'S BECAUSE THIS IS YOUR FIRST STOCK ELIMINATOR (???) CAR.


My plan is to change to the products from Performance Research. IE, tool steel lifters, steel billet cam...
that's why no-rebuild anytime soon !

SOUNDS LIKE A PLAN. I WOULD STILL TRY TO OBTAIN MORE PISTON TO VALVE CLEARANSE. ESPECIALLY IF YOU INTEND TO STREET RACE THE CAR.

[Aubrey N Bruneau]

Street racing ?????????????
here's my "street":



I guess I have a problem, Rocket...
I will under NO CIRCUMSTANCES EVER pound a cold engine...... EVER
No, I do not drive for MILES. The above picture is taken 1 1/2 miles from my shop. I don't race against people out there. I don't take riders. I don't "show off" for the neighbours.
Simply, if acting responsibly, it's a SAFE environment to tune the car.

"Tolerances" in the lifter bore ?
I have to confess two things...
I was never made aware that lifter-to-bore clearances were required to be anything special with these things.
And, I am a low-life... 'cuz I didn't spend $8,000,000.00 to have the lifter bores in my $3000.00 409 passenger-car engine block, machined/indexed/bushed.

Already DID the sink and shave the valves !
This cam is on a 108. I may go back to 110

No, I never wiped out a cam. And with lifters like Schubecks, no one should in Stock Eliminator.

"Street race" this car ?
I don't think so !

[LNorton]

Originally Posted by RocketBlock

My engine had about 2 1/2 hours on it.

I THINK THAT IS A MAJOR PART OF THE PROBLEM. STREET OR STREET RACING IS NOT THE ENVIRONMENT THESE ENGINES ARE DESIGNED FOR. STOCK ELIMINATOR CAMS, VALVETRAIN AND RING PACKAGES ARE NOT DESIGNED AROUND EXCESS HEAT CYCLES OR CONTINUED OPERATION WHICH LEADS TO TOLERANCE INSTABILITY.


Really what they do, is tolerate the ridiculous ramps on Stocker-type flat tappet cams...

SEE ABOVE STATEMENT. THOSE "RIDICULOUS RAMPS" ARE NOT DESIGNED FOR LONG TERM USE. MY OPINION IS THE SCHUBECKS ARE IN THE SAME CATEGORY. TOLERANCES ARE CRITICAL IN THE LIFTER BORE AND MY OPINION IS CONTINUOUS OPERATION WILL UPSET THE TOLERANCES CAUSING FAILURE.

So what you are saying is that race car parts shouldnt have to put up with some street abuse... I would think that if I spent $800 on a set of lifters like Aubrey did, I would be upset when they came apart like this as well.