HELP-piston rings gaps on DD ?
#1
HELP-piston rings gaps on DD ?
hey guys what would be some good gaps to gap the piston rings for my daily driver im going to run 10 psi on the street and 15# in the track im building a 6.0-30 over with some -11cc Wiseco pistons with some wiseco moly rings file fit & I beam rods at 9.1 compression but i dont know what to file gap the rings its going to be my DD so if anybody knows what to file fit them please let me know i alredy serched but i didnt find anything and thanks for the help...................please anyone.
Last edited by mike06tork; 02-23-2008 at 09:27 PM.
#7
.025 top .026 bottom on mine, I think. Recommended by Diamond, but that would be for a max effort build. Build it for the max. you KNOW you'll eventually be at. I think you could go a little smaller if you're really planning to stay in the 600 range.
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#9
It's hard to tell. The car runs rich at wot, but the little bit of smoke is black. I'd guess no. I would think if I had any blow by it would be from the PTW clearance, which is a little loose. Got to give those Diamonds a place to swell. On the good side, the more boost I run, the happier the engine should be.
#12
Sorry, piston to wall clearance. I think diamond recommends .001 - .005 additional, to the clearance the pistons already have. .0035 I think. .001 being a lower boost and .005 extra being an all out. I went middle of the road with .005 or so total. I'd give the piston manufacturer a call and they can tell you what to do. I'm only running 14lb or so now 800hp, but I plan on turning it up at the track, in the 1000 or so range.
#14
The pistons will come with a guide for end gap. FI, usually the gap is .0055 per inch of bore for the top ring, and .0045 per inch for the second. Of course each piston manufacturer is a little different, and each builder has their own preference.
You def want to run them a little looser than a little tighter. I like to run em about .025 on the top, and around .018/.020 on the second.
You def want to run them a little looser than a little tighter. I like to run em about .025 on the top, and around .018/.020 on the second.
#15
Latest thoughts from many high end engine shops have been to open up the seconds a couple of thousands more than the tops. The thought on this is to relieve pressure build up between the rings, which will keep the rings from becoming unseated. I haven't switched to this convention yet, but with additional data, I could see this is quite likely going to happen in the future, especially on higher output applications. One of the gripes I have on "some" of the piston and ring manf is they have "adders" for nitrous or blown applications with out regard for how much nitrous or boost is being added. I'm going to open my ring gap considerably more for a 500 shot vs 100 or 5 psig vs 20 psig. Oh well, thats beside the point. The last couple of blown applications that I have built have been at 0.020 and 0.023, 2nd and top rings respectively. I would be very comfortable recomending this on a 500-600 HP engine. If it was closer to the 1000 HP level mentioned above, I would be comfortable with agreeing with the larger gaps mentioned above.
What I see a lot of on tear downs, is people putting high boost levels on stock engine with factory like end gaps (and stock piston to cylinder wall clearances). There are typically witness marks on the cylinder walls where the ring ends are butting, and taking out the cylinder wall. Individuals aren't the only ones I have seen do this, I have seen an OEM take out one engine after the next, during the developement of a boosted application. I won't say which manufacturer.
What I see a lot of on tear downs, is people putting high boost levels on stock engine with factory like end gaps (and stock piston to cylinder wall clearances). There are typically witness marks on the cylinder walls where the ring ends are butting, and taking out the cylinder wall. Individuals aren't the only ones I have seen do this, I have seen an OEM take out one engine after the next, during the developement of a boosted application. I won't say which manufacturer.