Topic: MTC rods and Pistons

[aggiepike]

Hey Guys,

Bought a 71 CB750 from a buddy which I knew had a motor issue but got a good deal on it so I said what the heck. Well low and behold the engine is pretty sweet! The bad news is I have a broken piston and one of the sleeves is broken so I have to replace that. The good news, this thing has some pretty sweet stuff, high performance cam, HUGE MTC rods, and I'm not sure about the pistons but they are 67mm either RC engineering or maybe MTC I'm guessing here off of what I have found from pics and some other guys help. Plus this being a southern California bike near where RC engineering was back in the day. There may be some more high end old hot rod stuff in it but we have just started tearing into it to get it back to running solid again.

My question is do any of you guys know if MTC made 67mm honda pistions back in the day? Or can you shed any light on what all the goodies in this may be? From what the shop guy told me he said this is some pretty cool stuff.

Also, I'm going to go to  w/ an 836 kit I would like to get some of your thoughts on what would be good for this set up? I found an old vintage RC engineering 836 kit that is brand new that I'm considering and still keeping it old school.  my concern is w/ it being old technology is it just as good as what is available today or should I pony up for some of the newer stuff that is available? Any thoughts on what brand may be a solid trusted one??

Any help or thoughts on this is greatly appreciated. If I need to move this elsewhere fine but considering it was old high end hot rod stuff some of the guys that have been around a while may be able to shed some light. 

Here is a pic of the bike and the piston.

Thanks,

Richard

[cbr954]

If you are going to go with 836 sized engine I would look at the 850cc Cycle X piston set.  Last time I checked they cost less than the Wiseco 836 kit, they also offer these pistons with a coating on the skirt but costs a little more.  They still use the stock cylinders and only require boring.  They also offer some bigger bore stuff if you have the cash.

[Retro Rocket]

If you are going to go with 836 sized engine I would look at the 850cc Cycle X piston set.  Last time I checked they cost less than the Wiseco 836 kit, they also offer these pistons with a coating on the skirt but costs a little more.  They still use the stock cylinders and only require boring.  They also offer some bigger bore stuff if you have the cash.

As far as i know, the cyclex kit are cast and the Weisco are forged, that accounts for the difference in price. Personally i would go with forged every time...Just saying....

[MRieck]

Why not use the 915 kit that CycleX sells? You need a sleeve anyway and you do not have to bore the upper case with the sleeves that come with the kit.

[Doctor_D]

Why not use the 915 kit that CycleX sells? You need a sleeve anyway and you do not have to bore the upper case with the sleeves that come with the kit.

+1  If it had been available when I built my motor, that's the way I would have gone. (and might still if I get bored)

[Retro Rocket]

Why not use the 915 kit that CycleX sells? You need a sleeve anyway and you do not have to bore the upper case with the sleeves that come with the kit.

+1  If it had been available when I built my motor, that's the way I would have gone. (and might still if I get bored)

Nice pun Doc, you'll definitely need a bore for the 915.....

[dragracer]

Why not use the 915 kit that CycleX sells? You need a sleeve anyway and you do not have to bore the upper case with the sleeves that come with the kit.

Mike, is the bottom of the sleeve turned down?? I haven't seen one of their 915 kits.

[BLUE71TURBO]

Any pics of the MTC rods ?   Steel or aluminum ?

[cbr954]

Yes the cycle x 915 kits have the turned down sleeves at the bottom, they are supposed to fit the stock 750 case without machining.

[aggiepike]

No pics of the rods yet but will some when we start putting it back together. I'll post some when I get them. Not sure if they are aluminum or steel will find that out too. What would be the difference in them other than the obvious of that I can think of being weight and strength. Once better than the other?

[BLUE71TURBO]

 Way easy to tell the difference, the aluminum rods will be a dull or shiny silver.  Steel rods will be a iron grey color.  If they are r.c.engineering aluminum rods then they will be gold in color.

  Here's M.T.C.  aluminum rods .........

         


  Here's R.C. ENGINEERING  aluminum rods .........

         
   

[cbr954]

An unopened package of Golden Rods!!! Thats sweet.

[BLUE71TURBO]

Yea,  I just wish they were mine !   

[754]

nobody will assure you of reliability on a USED Forged aluminum rod.. The RC ones are billet aluminum, should be safer. Where ever the rods are get someone to check them wioth a magnet if they dont know what they are seeing..
 There are at least 4 types of Aluminum rods..

[dragracer]

How much rod stretch should be accounted for when setting the deck height using those MTC aluminum rods?? It wouldn't be nice to break a piston, rod or crank due to insufficient deck height on a brand new motor.. Or even split a head in two.

[Jerry Rxman Griffin aka MuthaF'er]

Don't think I'd account for any stretch. If there is stretch I'd say they are on their way out and unsafe to use.

I have 2 spare sleeves I got from CycleX for my 900 kit if you need one. PM me with an offer. Maybe someone has a spare piston.

[Big Jay]

Those MTC pistons were good stuff in their day. The rods were forged and probably the best you could get.

[754]

 Dont order/buy a sleeve without pulling what you got. I bought a set of unfinished for a 970 kit, they were 25 thou smaller than the existing ones, so I got to do up a new cylinder.... just saying not all sleeves fit..