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CVO Technical => Twin Cam => Topic started by: JoeVibe on March 04, 2019, 12:19:54 PM
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Any opinions or experiences with the Revolution 131" piston/cylinder set? http://revperf.com/131bigbore.php
Asking for a friend.
Thanks - Joe
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Hi Joe,
Is it the nikasil? 131? If so, heard they revamped that whole program. No personal exp though haven’t ventured into the Nikasil realm. Might check with FLaHeatwave he had decent mileage 37k? on the first 117 build, but far less in the rebuild.
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Hi Harry,
Their website says "NSC plated" (Nickel/Silicon/Carbide) so I guess. Unless the carbide is a new addition to the formula.
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The only thing they changed was ring package and piston design.....same manufacturer
I'd pass
Some live long happy lives....some don't
You/your builder can do not repairs or mods
Must be sent back to rev performance
Of the three builders that used to push them hard
Including tman all have went back to iron lined cylinders
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Back in the early 70's Chevy launched the New Vega with its 2.3L all aluminium block and iron head.
Reynolds Metal Co. developed a eutectic aluminum alloy called A-390, composed of 77 percent aluminum, 17 percent silicon, 4 percent copper, 1 percent iron, and traces of phosphorus, zinc, manganese, and titanium.
I guess I don't have to tell some of you older guys how that turned out for GM.
Back in the mid 60's we sold Bridgestone motorcycles and their motors used aluminium bores with industrial hard chrome plating. It worked okay, but there were no options for re-boring or honing the bore when replacing pistons.
I hope the new 131" system has the bugs worked out of it.
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Thanks guys! I'll pass this info along.
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I had 1 come in here a while back. Looked like the builder never checked rear piston clearance to front cylinder spigot. You find out rather quickly what goes on with that issue. Check everything during assembly.
John
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We experimented with nikasil cylinders on performance Two-strokes years ago. From my experience,
they didn't hold up all that well. Once that plating (which if very very thin) wears, the ring seal is gone
and so is the compression (It goes right out the window). Two-strokes burn oil by design so that wasn't
an issue. The loss of compression was the problem.
Unless your budget is unlimited and you can afford to go into it on a regular basis, I'd shy away from
nikasil. It works until it doesn't, if you get what I'm saying.
But what do I know...
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We used these guys to plate them. They held up ok, but for longevity, I'll take an iron sleeve
any day.
www.millennium-tech.net
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I understand why the rings would be different but why would pistons be only good for these types of cylinders? I see revolution performance stuff all over eBay and they have decent 117” pistons with a small dome which are hard to find at a good price.
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Hey Joe you need to update your picture. I keep looking at the roadking and wondering why no Fat tire?
BigLew
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Hey Joe you need to update your picture. I keep looking at the roadking and wondering why no Fat tire?
BigLew
Hi Lew. I was just talking to Janet about that last night. I don't even have the Ultra anymore. I'll see what I can do.
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Thanks for all the great feedback guys. So, is 124" as big as you can go with iron sleeved cylinders?
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I cannot address really any of the questions, but I do remember back in the mid to late 60's on the Bridgestones, the piston clearance was .0015". If you weren't careful, you couldn't even fit the piston into the cylinder without the rings. This was a VERY tight clearance.
The reasoning was that with the aluminium piston and the same composition for the cylinders, the expansion rate was the same. So they started off with their "hot" running clearance. We used to score lots of cylinders back then and you could maybe run a hone through once, but never twice.
They were all rotary valve induction so there were a less holes cut in the cylinder walls.
I'd think that's part of the Revolution upgrade concept on the new cylinder/piston combination.
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A 4.25 bore on a stock case doesn't leave a lot of room for gasket material between bore and stud hole or dowel pin holes. I might feel better with a .040 hg? 140 /150 are good numbers and isn't to hard to hit with a 124.
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4.250 bore head gasket. Not a whole lot of sealing area where it counts. Base gaskets are just as scary. I built 2 of these over the years on stock cases.
John
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That looks scary
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we wont use any nikasil cylinders here.no reason for it,too many reasons not to.go 124" with proven S&S cylinders
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Hey Joe you need to update your picture. I keep looking at the roadking and wondering why no Fat tire?
BigLew
Working on my profile pic.
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Back in the early 70's Chevy launched the New Vega with its 2.3L all aluminium block and iron head.
Reynolds Metal Co. developed a eutectic aluminum alloy called A-390, composed of 77 percent aluminum, 17 percent silicon, 4 percent copper, 1 percent iron, and traces of phosphorus, zinc, manganese, and titanium.
I guess I don't have to tell some of you older guys how that turned out for GM.
Back in the mid 60's we sold Bridgestone motorcycles and their motors used aluminium bores with industrial hard chrome plating. It worked okay, but there were no options for re-boring or honing the bore when replacing pistons.
I hope the new 131" system has the bugs worked out of it.
At the risk of dating myself, I won a “non running” Vega GT in a poker game.
Since it was scheduled to rain over the weekend, I went and bout a resleeved steel lined motor from a Machine shop on a Friday at lunch, went home and over the weekend pulled to old worn out one, put in the new one and put the core in the hatch to be returned Monday for the core deposit refund. It gave me great service as a commuter car for several years until I sold it.