Author Topic: cycle -x pistons (Read 13212 times)

Terry in Australia · « **Reply #50 on:** November 12, 2009, 05:44:58 PM »

How'd those thin sleeves look after the piston failure Bob? Do you run an oil cooler on your race bike? I'm keen to see what Sean's pistons look like, but either way, I'll stay away from the Cyclex 850 kit, two failures in such a short space of time are two more than I've heard of with any 836cc kit that I can think of over the last 30 years. Cheers, Terry.

kos · « **Reply #51 on:** November 12, 2009, 08:28:29 PM »

I know Ken wanted to have a "clean up" kit for all those 836cc kits out there that need a good overhaul, but the resulting thin sleeves was an area that concerned me when he was deciding what size to go to.

Again, I don't think that kit would be my first choice for an racing application...but they are rather low cost and as they say, "Speed costs Money"!

KOS
.

voxonda · « **Reply #52 on:** November 12, 2009, 09:14:16 PM »

I remember why I chose for CB900 sleeves for my 850 replica, even Wiseco's would crash if the wall is to thin. Makes you wonder why Wiseco stopped at 836, isn't it?

Rob

MRieck · « **Reply #53 on:** November 13, 2009, 04:29:25 AM »

Quote from: voxonda on November 12, 2009, 09:14:16 PM

I remember why I chose for CB900 sleeves for my 850 replica, even Wiseco's would crash if the wall is to thin. Makes you wonder why Wiseco stopped at 836, isn't it?Rob

Knowing Wiseco it was more than likely because those blank forgings fit a few applications Rob.

750essess · « **Reply #54 on:** November 13, 2009, 09:09:30 AM »

FWIW I had a set of 836 wiseco's die like this. Cracked from valve pocket to ring land. It was also only 2, IIrc is was the 2 center, maybe a clue that it a cooling problem. Clearance was on the tight side at 1.5 thousands. Replaced with JE's at 3 thou just to be safe. Ok after that.

754 · « **Reply #55 on:** November 13, 2009, 09:55:49 AM »

I think the 850 was really built to use up the worn 836 cylinders that are abundant..

If I were going roadracing, and hold the motor, at them higher rpms.. I would be thinking forged pistons anyway..

MRieck · « **Reply #56 on:** November 13, 2009, 08:15:29 PM »

Quote from: 750essess on November 13, 2009, 09:09:30 AM

FWIW I had a set of 836 wiseco's die like this. Cracked from valve pocket to ring land. It was also only 2, IIrc is was the 2 center, maybe a clue that it a cooling problem. Clearance was on the tight side at 1.5 thousands. Replaced with JE's at 3 thou just to be safe. Ok after that.

.015 is tight for me. .017,.018 is more my speed. Jay says he has run them that tight naked but I'd have coatings on the crown and skirt for that.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #57 on:** November 13, 2009, 08:20:16 PM »

jay cut my 900 Henry Abe at .020. Hope my cast pistons hold up better. That MRieck head is WAY too pretty to mess up.

Correction: I slandered Big Jay by placing my decimal point incorrectly. Should read .002"
Hope he doesn't take it out on the 1000 kit

Big Jay · « **Reply #58 on:** November 13, 2009, 09:59:53 PM »

When I was doing the 836 kits back in the 70s and 80s, I did the wide valve pockets to keep from having to have left and right hand pistons. Worked very well. We made many hundreds of those kits.

I them made a deal with Wiseco to get them to make four stroke pistons. I sent them samples of everything I had. They copied the 836 exactly like my sample and have made it like that ever since.

I also made a 915 kit, and Wiseco made that also for many years. Same dome. That style dome and valve pockets that require no head modifications, has been so sucessful that we used it on our new 1000cc kits.

We are also a warehouse distributor for JE pistons and they still make an 836 kit with a full dome that requires extensive combustion chamber modifications.We sell them to people who want max compression to run on alky.

The were designed by Honda Jim after the RC / Arias TQ piston.

Jay

Terry in Australia · « **Reply #59 on:** November 13, 2009, 10:28:55 PM »

Oooher, what are these "combustion chamber mods" of which you speak Big Jay? I'm running RC/Arias 836cc pistons in my K1 engine with Mike's Stage 3 head, without any special mods to accommodate the pistons, I'm thinking? Cheers, Terry.

mick7504 · « **Reply #60 on:** November 13, 2009, 10:52:17 PM »

What would be an acceptable/safe piston to cylinder wall clearance for these 850 kits?
Cycle X reccomend .002" clearance and additional clearance for highly modified motors.
With the problems that have come to light so far is .002" enough clearance?
Is there any evidence of sleeve distortion by taking another .010" plus from the sleeve wall thickness going from 836 to 850?

Big Bob · « **Reply #61 on:** November 14, 2009, 08:16:19 AM »

Quote from: kos on November 12, 2009, 08:28:29 PM

...but they are rather low cost and as they say, "Speed costs Money"!

By that logic I will never, ever, exceed 50mph.

I'll try to post pics of the cylinders later today.

They're for sale if anybody wants them. Also for sale, 3 Cycle-X 850cc pistons, lightly used. Make me an offer.

754 · « **Reply #62 on:** November 14, 2009, 08:40:13 AM »

You could put a new sleeve in , if you can get single piston and a ringset,, and probably use it on the street..

racing.. stuff breaks.. gotta live with it, or not go racing..

MRieck · « **Reply #63 on:** November 14, 2009, 08:59:25 AM »

How real pistons are made

bwaller · « **Reply #64 on:** November 14, 2009, 09:29:59 AM »

Quite good Mike. There sure isn't much to some of these new pistons... ring holders. Makes those I had done look antiquated.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #65 on:** November 14, 2009, 10:56:26 AM »

Michael,

Are you and your CNC friend setting his machine up to do your heads?

Terry in Australia · « **Reply #66 on:** November 14, 2009, 06:30:44 PM »

Quote from: MRieck on November 14, 2009, 08:59:25 AM

How real pistons are made

Nice. Mahle pistons are standard fitment in BMW Motorcycles, I had to replace a set on my 1979 R100RS when I bought it, 500 bucks for 2 bare pistons hurt my pocket, but the bike had done well over 100,000 miles by several owners over it's first 14 years, so still pretty good value for money, considering the beating that bike had taken. Cheers, Terry.

mick7504 · « **Reply #67 on:** November 14, 2009, 07:38:23 PM »

Our German friends know how to do it well.
18 months ago I was there for a visit and took one of these for a run.
Soon found out the meaning of the word SCHNELL!!!

Volkswagen Touareg V10 TDI
6-speed semi-automatic
10-cylinder, 5.0L, 2-valve, 90° V10 twin turbo-diesel

MRieck · « **Reply #68 on:** November 14, 2009, 09:46:49 PM »

Quote from: Jerry Rxman Griffin on November 14, 2009, 10:56:26 AM

Michael,

Are you and your CNC friend setting his machine up to do your heads?

Maybe....in billet Jerry. I'll settle for the cylinders now. My friend is getting over the Swine Flu or whatever the F it is. I have faced several setbacks on the cylinders and want them done ASAP. I'm focusing on that.

MRieck · « **Reply #69 on:** November 14, 2009, 09:52:30 PM »

Quote from: bwaller on November 14, 2009, 09:29:59 AM

Quite good Mike. There sure isn't much to some of these new pistons... ring holders. Makes those I had done look antiquated.

I hear you Brent. Boy...do I hear you.

Those pistons probably have nice pins too.......you think???

Jerry Rxman Griffin aka MuthaF'er · « **Reply #70 on:** November 14, 2009, 11:00:29 PM »

Quote from: MRieck on November 14, 2009, 09:46:49 PM

Quote from: Jerry Rxman Griffin on November 14, 2009, 10:56:26 AM
Michael,

Are you and your CNC friend setting his machine up to do your heads?
Maybe....in billet Jerry. I'll settle for the cylinders now. My friend is getting over the Swine Flu or whatever the F it is. I have faced several setbacks on the cylinders and want them done ASAP. I'm focusing on that.

I thought maybe the 2 of you would be programming it to "clean up" the existing old heads

and make them look like mine while you watch football on Sundays. Head robot.

paulages · « **Reply #71 on:** November 15, 2009, 12:03:25 AM »

Quote from: MRieck on November 14, 2009, 08:59:25 AM

How real pistons are made

...or you could go about it Burt Monroe style (that is if you had half the ingenuity and talent he did):

"Burt began modifying his bike in 1926. His methods, to say the least, were unorthodox. He used an old spoke for a micrometer and cast parts in old tins although one American report has him casting pistons in holes in the sand at the local beach! He built his own four-cam design to replace the standard two-cam system and converted to overhead valves.

He made his own barrels, flywheels, pistons, cams and followers and lubrication system. In their final form he in effect hand-carved his con-rods from a Caterpillar tractor axle, and hardened and tempered them to 143 tons tensile strength. He built a seventeen plate, thousand pound pressure clutch and used a triple chain drive. He experimented with streamlining and, in its final form, the bike was completely enclosed in a streamlined shell. The leaf-sprung fork was dispensed with and what appears to be a girder fork from a 1925 - 1928 Prince substituted."

MRieck · « **Reply #72 on:** November 15, 2009, 06:05:38 AM »

Quote from: Jerry Rxman Griffin on November 14, 2009, 11:00:29 PM

Quote from: MRieck on November 14, 2009, 09:46:49 PM
Quote from: Jerry Rxman Griffin on November 14, 2009, 10:56:26 AM
Michael,

Are you and your CNC friend setting his machine up to do your heads?
Maybe....in billet Jerry. I'll settle for the cylinders now. My friend is getting over the Swine Flu or whatever the F it is. I have faced several setbacks on the cylinders and want them done ASAP. I'm focusing on that.

I thought maybe the 2 of you would be programming it to "clean up" the existing old heads and make them look like mine while you watch football on Sundays. Head robot.

We have talked about CNC chambers and ports Jerry. Anything is possible good buddy.

kos · « **Reply #73 on:** November 16, 2009, 07:30:13 AM »

I have found one of the most limiting factors in source custom pistons is finding the correct sets of rings. Secondly like Mike said, size of slugs (forgings) in stock at the piston manufactures facility when you call with design you want. I know that you can g to perfect Circle and companies like that for rings, but I am always in the hunt for thin upper rings and correctly designed three piece oil rings, IE: Honda. FYI: Cosworth is constantly calling a dealership I have a friend at in Colorado, when they need rings and asking him if HONDA has ring sets in they size they need! And to back up this point, if he can source them from Honda...they purchase in very large quantities!

Vintage/classic racers do not have the quantity for buying power, that the more modern sport bikes and Chevy racers have!

KOS

754 · « **Reply #74 on:** November 16, 2009, 09:21:08 AM »

I should mention this FWIW.
A fellow I worked with is a CNC programmer/toolmaker. He said he made 6 pistons for a guy trying to build a diesel lawnmower.

Prototypes, just to try it.
I said taper skirt no problem, what about oval.. he said yeah, I got that too..!. I would like to measure one. He used a CNC lathe, it could do the oval I suppose..

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Author Topic: cycle -x pistons (Read 13212 times)