Don Terrill’s Speed-Talk

There are shelf pistons with dish and lower compression, but all the currently available pistons I've been able to find photos of just have a round dish machined over the whole thing, which throws away a really big part of the squish area provided by the head. The idea I'm pursuing is having a pist...

Again , "internet photos" can be tough to figure out versus having a piston in your hand. The information about the ring upside down did change the probable cause in my mind and likely would have changed the piston manufacturers as well. While that company has "only" been around ...

If the symptom is skirt scuffing , there are some "usual" causes. Scuff or "black death" as it is sometimes called is caused by metal to metal contact. Aluminum and iron must have lubrication to avoid scuff ans the friction induced heat causes the piston to begin melting. So if t...

Taranis, Pistons do not crack because of material surface imperfections / scratches. Aluminum cracks because of FLEX which causes "work hardening" and cracking . Shot peening would compact the surface to some degree and provide a nice surface for carbon build up as has been mentioned. I do...

'69 , first in the Boss 302

Dave, The number on the side of the casting ins 112 not 121. Yes these carbs have shot up in value especially those for the auto trans used on Hertz GT350s. This has in turn caused all of the manual choke Hi Po carbs to go up in "cost". "112" castings were typically used on 390 /...

Piston skirt shapes vary with EVERY piston manufacturer. They view them as closely guarded secrets. "Short skirt" piston stability can be enhanced with different ovality and barrel shapes as well and some specific changes to the ring land area. It's always best to go with a company that ha...

It's possible the OP's piston skirts could be coated and reused. Polydyn , Calico, Line to line and others can do it.

Maybe Racetec will help you out on the replacement set. Sounds like they have been trying all along to help you.

IF you have that much cylinder wear in that short of mileage and you say you see the start of some scuffing , there is something really wrong here. The 3.250x6.250 stroke and rod should keep the piston skirt safely in the bore at the bottom of the stroke. Racetec must have had a reason for telling y...

Every piston manufacturer has it's own proprietary piston "cam" profiles and methods of applying them. Some manufacturers also adjust the second ring land diameter to reduce rock. Piston to wall clearance is a huge factor in piston rock as well. With a high rod to stroke ratio like you cal...

The small block stuff was 106/108LSA and when the Big blocks hit the LSA went wide like Mike said. Teams used to outdo each other by having the slowest Idle speed.

I still have a 319D and 321D I got from Dyno Don ( rip) Both were from the Pinto days and tagged "valve spring killer" on both.

Air doesn't like to turn so it makes complete sense than the 45* angle would flow more air as the valve gets "out of the way" of air flow. Race engines use 55* seats for more flow yet. Changing a 428 Ford CJ to 45 intake valve/seat was worth 12 hp by itself for me. The trouble with a flow ...

He got the axe about the same time Knudson did. The money wasn't wasted as they actually produced parts to test. The projects simply got cancelled.