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Title: dishing mahle 94mm pistons Post by: JIMP on July 03, 2018, 17:35:14 pm I have a street engine, n.a. going to 1914cc from 1.6, , I have the 94mm mahles, std comp height (K70401), as I need cc to lower the compression, how deep can I cut a dish on the crown without being dangerous? Comp will be just below 9:1, I suggest a 70mm circle dish on the crown?, but how much deep would be OK?
Thanks in advance Dimitrios Title: Re: dishing mahle 94mm pistons Post by: dragvw2180 on July 03, 2018, 18:20:56 pm A suggestion would be to add a copper head gasket like we use on turbo engines . They make them in different thicknesses .
Title: Re: dishing mahle 94mm pistons Post by: Martin S. on July 03, 2018, 20:36:10 pm Why such low compression? I have 9.4:1 in a 1776 with stock 34pict and muffler, which runs great on regular crappy gas. ???
Title: Re: dishing mahle 94mm pistons Post by: JIMP on July 04, 2018, 08:11:42 am Hello, thanks for inputs, i know that shims would be the easy option, but I just need to maintain something from that squish area, so I need to do it the harder way,
Martin I'm with you actually, you're right, but this specific one will go on a heavy car -bus T2- and the owner also has a heavy foot, so I\m thinking to give it some extra chances to survive! anyway was thinking for a dish at 70mm x2mm depth, if just someone can verify that this is good or let us with a pretty thin crown, as I measure it the crown will end in like 3mm thick after dishing, Friendly Dimitrios Title: Re: dishing mahle 94mm pistons Post by: Martin S. on July 04, 2018, 15:41:18 pm I still wouldn't do it. Simply back off the timing until it doesn't ping for the gas you're using and it won't be a problem.
Regardless, my turbo needed a dish and I believe it was cut .070" (1.8mm) using AA slipper skirt (the cheap ones). Title: Re: dishing mahle 94mm pistons Post by: RaptorLou on July 04, 2018, 22:36:52 pm [attachment=1] most pistons are made thicker on top to allow valve relief. Measure the thickness. These are 94 compression with hi wrist pin CP's
Back in the day I routinely took .100 off Mahle pistons.[attachment=1] Lou Title: Re: dishing mahle 94mm pistons Post by: Joel Mohr on July 04, 2018, 23:26:43 pm Hemi cut....
Title: Re: dishing mahle 94mm pistons Post by: JIMP on July 05, 2018, 21:44:49 pm Ok thanks a lot for inputs and pics, I made finally a 2mm deep dish, I hope it holds and will not have problems, the compression came to 9,1:1, that's with an fk8, so I think it wont be a problem,
again thanks a lot for helping Friendly Dimitrios |