Technical > Matt Shaff's Engine Shop

Piston ring end gap.

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George:
Matt, what would be your preference for piston ring gap? Our combination is a fully filled Dart LIL M with Dart 230 cast iron heads running with no coolant in a FED. It's a 6:71 with a Bug running alky thru hat nozzles only. It's wet sump system with a System One remotely mounted so I run 10 quarts and we will be adding a Accusump to add even more oil ( cooling ?). It's been together for 2 years and have had no ring or piston (Venolia) issues. They are a 16-16-316 ring package. It's time for a freshening . I'm thinking we can tighten up the gap that is now at .026 .
 We run almost all 1/8 mile and don't spin it more than +16%

Thanks . George

Frontenginedragsters:
  Hello George:
 All of your parts selection sounds great.
Is the engine 4.125 bore? Then .026 sounds right with a blower. I would not go much tighter.
I would run the Total Seal AP top ring. Its stainless and works great with hard aftermarket blocks.
We have been changing our procedure for honing the aftermarket blocks.
Call Total Seal if you have any questions. I call them and Sunnen from time to time to make sure we are doing the right thing.

Matt

Paul New:
I agree with Matt no tighter than .026! A little to much gap will not hurt your performance.... but a little to tight could ruin your day

George:
Thanks guys. The block measures 4.133 to give the piston .008 clearance. Can I buy just the top ring somewhere?

Paul New:
Alerly Child's can sale you what ever you need 1-661-702-1999
I would open up your ring gap a little 4.133 X .0065-.007= .0268645-.028931 I would do .027 if it was mine.

I think Matt is saying to call Total Seal and buy their rings though.

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