BME stroker pistons, only one compression ring?
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 800
Likes: 3
From: Port Orange FL
BME stroker pistons, only one compression ring?
I just picked up a set of Bill Miller Engineering 383 stroker pistons for a song. What a beautiful lightweight piece. I know these guys basically just build hard core race parts, and I have never before used a piston that only had one compression ring and an oil ring. One nice thing is that with only one compression ring the pin area doesnt protrude into the oil ring area, and the area above the compression ring land is still nice and thick. But are these suitable for building a street motor with only one compression ring? Is this common and I am just behind the times?
If not what is the specific purpose of building them this way?
Thanks
Roy
If not what is the specific purpose of building them this way?
Thanks
Roy
Melting Slicks
Joined: Mar 2002
Posts: 3,105
Likes: 126
From: S.L.C. UT
With one compression ring those are all out max effort race pistons. Eliminating one ring for less drag. Personally, I don't think they would make a good street piston... but I have never tried them.
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
I have run those type pistons before - in the NASCAR Late Model Stock engines (before the rules dictated 2 compression rings). It's about 8-10yr old outlawed technology.
I'm betting they are 1.125 compression height. They are intended for a 3.5 stroke with a 6.125 rod. Will also fit a 3.75 stroke with a 6" rod BUT.... Keep in mind we are forced to run Holley 350CFM 2bbl carb and at the time the strongest LMS engines only made about 460HP. Those pistons are very light and very thin on the deck. They wouldn't stand up to a high HP engine very long and the one compression ring wouldn't last a week in a street car. About 200 laps is all we could get out of them back then in a LMS engine.
Will
I'm betting they are 1.125 compression height. They are intended for a 3.5 stroke with a 6.125 rod. Will also fit a 3.75 stroke with a 6" rod BUT.... Keep in mind we are forced to run Holley 350CFM 2bbl carb and at the time the strongest LMS engines only made about 460HP. Those pistons are very light and very thin on the deck. They wouldn't stand up to a high HP engine very long and the one compression ring wouldn't last a week in a street car. About 200 laps is all we could get out of them back then in a LMS engine.
Will
Thread Starter
Burning Brakes
Joined: Nov 2004
Posts: 800
Likes: 3
From: Port Orange FL
Hmmm, Interesting. I just measured the compression height and came up with 1.0 If they are 383 pistons that would require a 6.125 rod correct? Or perhaps they are 396 pistons with a 6" rod?
They are 4.030 diameter.
Measuring the deck the thinnest spot I can come up with near the edge is about .2, most of it is quite a bit thicker than that.
Is that thin? I have no idea.
I bought these figuring if I couldnt use them I could put them on Ebay, but it would be nice to determine just what they are before before I do. Any more input?
Thanks
Roy
They are 4.030 diameter.
Measuring the deck the thinnest spot I can come up with near the edge is about .2, most of it is quite a bit thicker than that.
Is that thin? I have no idea.
I bought these figuring if I couldnt use them I could put them on Ebay, but it would be nice to determine just what they are before before I do. Any more input?
Thanks
Roy
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Hmmm, Interesting. I just measured the compression height and came up with 1.0 If they are 383 pistons that would require a 6.125 rod correct? Or perhaps they are 396 pistons with a 6" rod?
They are 4.030 diameter.
Measuring the deck the thinnest spot I can come up with near the edge is about .2, most of it is quite a bit thicker than that.
Is that thin? I have no idea.
I bought these figuring if I couldnt use them I could put them on Ebay, but it would be nice to determine just what they are before before I do. Any more input?
Thanks
Roy
They are 4.030 diameter.
Measuring the deck the thinnest spot I can come up with near the edge is about .2, most of it is quite a bit thicker than that.
Is that thin? I have no idea.
I bought these figuring if I couldnt use them I could put them on Ebay, but it would be nice to determine just what they are before before I do. Any more input?
Thanks
Roy
.200 is actually pretty thick on the deck.
For comparison Manley's ultra light 2bbl pistons are a min of .155 on the deck and they are at least a couple yr newer desgin than your BME's. Manley's 4bbl ultra lights pistons are a min .185 deck and their std weight LSX stuff is .200 deck thickness.
Even thou the deck is thick enough I still wouldn't recommed you try them in a street car. The one compresssion ring won't last and it'll pump oil like a SOB without a vacum pump or dry sump to pull down the crankcase pressure as the second compression ring is mostly a oil scraper in conventional 3 ring pistons.
As others have said you can always call BME.
Will
