Hey guys, how’s it going? Does anyone know the piston ring groove to top of piston (top ring land) measurement on the Wiseco pistons? And the distance between the compression rings? Or, how much can I mill the Wiseco piston down to help get my target compression ratio?

Thank you
-noah

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1969 Plymouth valiant 225

I don't know off the top of my head, but I would not take it off the piston except to bring it down to zero deck if it was too high. I would plane the head less if I wanted lower compression.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

That is what im looking for is zero deck or close to it , Ive already milled the block and head when i rebuilt the engine for daily driving. Now i want to build for power and im forced to either run a short rod setup and mill the block and head excessively -.240 in total or long rod and mill the piston -.50/-.60 ish or i guess i could dish it in some way. Im looking for 9.5:1-10.5:1.

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1969 Plymouth valiant 225

My pistons were cut @ .015 to get a zero deck. You can also open up the valve reliefs larger to cut some compression. You will likely need to do this anyhow if you are running oversize valves. My son has .080 thick MLS head gaskets also, which would be another option.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Who makes .08 mls gaskets? That would fix alot of my problems. I would also have to ask if anyone has used them in nitrous motors.

Thank you for all your help.

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1969 Plymouth valiant 225

Found them thank you

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1969 Plymouth valiant 225

Yes my son had them special made. He has ran them in an over 13.5 to 1 race motor at 6700 rpm. I would think they would work fine in a nitrous engine but we have not run them in anything with nitrous.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I would get a thick gasket to allow for adjusting CR and not mill the piston more than about 0.020 or 0.030". Your milling on the head and block might not get you much past zero deck with the 7" rods and Wisecos.

If you're going to do big valves anyway, just get another head casting to start over with and save this one that is perfectly good for running. Otherwise, you'll be throwing away the work you did on this head. I'm sure we can find you another head for cheap or free.

Lou

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Home of Slant6-powered fun machines since 1988

Well after a night of looking i found the info i needed and did a shi* load of math. It looks like i can run mahles headgasket and mill .100 off the face of the piston and then a dish 2.9”x .07” past that and have a top ring land that is still .180 thick and the dish would still be .180 thick
see
https://www.slantsix.org/forum/viewtopic.php?t=31815
.180 seems to me thick enough for the nitrous id be using but idk what do yall think.
The thick head gaskets wouldn’t be a bad idea. They are just really expensive and I would buy multiples in case they go out of stock and if I’m doing that with the price of them plus the pistons, it’s about the same price as customs.
I still have time tell i buy it all, might just get custom pistons made for a short rod set up but thats alot of compression height and weight added to the piston. The 2.2 turbo pistons would help also but it looks like nobody is making forged anymore.

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1969 Plymouth valiant 225

How much nitrous are you planning on spraying?

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Official Cookie and Mater Tormentor.