Schubeck Lifter Update

RocketBlock · 08-16-2007, 05:49 PM

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.

08-16-2007, 05:49 PM	#14
RocketBlock Junior Member Join Date: Jan 2003 Posts: 57 Likes: 0 Liked 0 Times in 0 Posts	Re: Schubeck Lifter Update 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.