Head Grooving Update ????

xntrik said:

Automotivebreath..... are you still out there buddy? :mwink:

www.readershotrods.com add your ride

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I have been busy with much of the same. Most of my work is with race cars and an occasional street driven hot rod. Here's an example of my involvement.

A good friend, Glenn was having problems with his super pro 66 Mustang. Some of you may recognize the car from Ford races in the Houston, New Orleans or Gulf Port areas. He runs a small flat tappet cam shaft in a high compression 351 Windsor. The car was running mid to low 10s but he was having problems with trace detonation at launch with a transbrake.

I cut grooves in his AFR heads and he opened the squish clearance. Normally I would expect the reduced squish to create detonation. The result was low RPM power that was too much for the car to handle. I was there for the first night out after the modification. The car ended up in the trailer because he couldn't control the wheel standing.

He has now softened the combination to allow launch with out excessive wheel standing. Needless to say he's convinced.

Here's some picture from his project and other recent activities.

Likely because the OEMs knew about Quench a long time ago, and they knew the benefit of it. Chevrolet could have easily made a D dish piston and with the deck height at .025 and the gasket thickness at .028 would have created a .053 quench, which is respectable, but they never did this during the emissions era from 1972 to present. It would have helped performance and would also have created lower emissions due to a more efficient burn of the mixture. But they always stayed with the tried and true full concave dish piston that didn`t create any quench at all. In many tests a tight quench only showed a 3 horse power gain so they likely figured it wasn`t worth it. But I never seen anyone do a emissions test between a non quench and a quench engine and check the results.
Chevy`s performance engines of the 50`s 60`s and early 70`s that had flat top and dome pistons had quench due to the thin head gasket and .025 deck clearence, so they were the only engines that benefitted from it. In the end, there was alot of things the OEMs knew about and never changed it, and likely is because of cost, whatevers cheaper to make stick with it, or it could be the same reason the company I work for goes by which is "if it makes perfect sense we don`t do it, if it makes no sense at all, we do it"