Don Terrill’s Speed-Talk

What do the rules say regarding floor pan modifications? Can you put some version of asphalt late model crossover headers in it and fabricate a raised floorpan on the passenger side to fit a muffler and still maintain legal ground clearance?

Back when I was working at a Chevy dealership and racing circle track late models, we'd build "claimer" engines for the lower division guys. When the PM rods came out and ample core engines were available, we figured what better place to check their durability. I never saw one fail. Period. Never ra...

You need more angles. Clean up the bowl with 60 and 75 deg cutters/stones and a 37 deg top cut. Check the contact point on the valve face. Back cut the intake valve at 30 deg to within about 0.020" of the contact point, then recheck the flow. I'm sure that others can add more to that, but that worke...

Re: carb studs and wingnuts. What we did (circle track racer forever) was use all-thread with loctite AND a jamb nut on the carb end of the stud, then put the air cleaner on, then put on a wing nut made of all nylon, no brass/steel insert, hard to screw on the whole way (some cheap aftermarket one w...

Was it just me, or did anyone else think nothing of the tick marks and immediately go to how the head needed a proper valve job?

No problem running that thing at all. Zero hesitation.

Gaerte is out of business and the assets auctioned, so no help there. Earl passed away years ago. But they were big in circle track racing, specifically sprint cars. If we go in knowing that, the 3.76" stroke with a 4.155" bore gets us 408 inches, pretty close to a 410 sprinter, with a tad left for ...

It's for the inboard ski boats. The MerCruiser Black Scorpion MX 6.2L MPI. Lower intake is part number 807352A12. Short of finding one on ebay, call Edelbrock and see if they have any more lying around. MerCruiser, afaik, quit that project years ago. Dunno if any of that helps or not.

The one that comes to mind is the early porsche 930 turbos. Same valve sizes as the NA cars, same valve spring and retainer, same valve length. The intake and exhaust valve spring installed height was 1mm less on the turbos. Difference was made up with a couple more 0.020" shims under the valve spri...

rebelyell wrote: ↑

Sun Nov 24, 2019 6:13 pm

OE Iron Vortec L31 heads have straight conventional springs but no dampers.
spring GM pn 10212811 ... 80 lbs on seat, retainer GM pn 10241744

You're right, I must have been thinking about the LS engines.

L03 & L05, in trucks, were called Vortec. I believe they were the first to use the name along with the TBI 4.3 of the same era. It didn't denote anything special or different from the same engines used in cars, it was just a truck badge-marketing thing. It wasn't pushed hard like in later years wit...

Expanding on what Kevin said regarding piston cooling, the Porsche 962's had pistons that were Mahle forged two piece welded affairs with a cooling channel just behind the ring package that was cooled with oil sprayed via a straight tube squirter into the hole drilled in the piston, along with the "...

What was the RPO on those vortec V8's, pre '96? V6, sure, the L35 vin code "W" CPI engine that had all of the injector poppet nozzle problems.

My memory might be slipping, but I don't remember any vortec V8's before 96.

When I say "Vortec," I'm referring to the L31, vin code "R" engine with either 906 or 062 casting number cylinder heads, with 4 intake manifold bolts on each cylinder head. The others (other than the V6 that said "vortec" on the plastic valve covers), were not "vortec" but did have high vortex swirl...

Vortec heads had beehive springs with smaller retainers. And didn't have valve rotators.

Do you have the cam retainer plate? Is the 94 block machined for it? Does the cam have the fuel pump lobe? I thought those cams were missing the fuel pump lobe since all of the vortecs had electric fuel pumps. Also, the blocks have the pad for the fuel pump but none of the holes were drilled. Make s...