Topic: CB750 1000cc RC Cobra Rebuild

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

[HavocTurbo]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

[michrobi]

The crank is definitely being replaced. Will I have an issue using a 77F case with this cylinder and head? I know I'll have to bore it.

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

Have you ever worked with an RC stroker crank? I wouldn't call it backpedal....

[HavocTurbo]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

Have you ever worked with an RC stroker crank? I wouldn't call it backpedal....

I have actually. And I was only poking fun. Every RC motor I have opened has things done to it that I had never thought of at the time. For one reason or another it worked for him. And really ONLY worked for him.

I cannot seem to find an engine or a builder using the same techniques to get them to perform like he did.

Granted people take a little here and a little there. But in this instance breaking rods is serious especially if it isn't the same rod twice. And while immediate signs point to the crank or the oil pump, sometimes it can be something simple like the wrong bearing were installed or someone forgot something during the rebuild like a torque setting.

Stranger things have happened.

Calm down Mr. Reick. I think you are a genius when it comes to port design and would and have recommended you to everyone I know.

[754]

I am not saying that RC, never built a welded up stroker, but I do know that they sold a lot of 1 pce forged strokers.

 Which are you saying had problems?


 

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

Have you ever worked with an RC stroker crank? I wouldn't call it backpedal....

I have actually. And I was only poking fun. Every RC motor I have opened has things done to it that I had never thought of at the time. For one reason or another it worked for him. And really ONLY worked for him.

I cannot seem to find an engine or a builder using the same techniques to get them to perform like he did.

Granted people take a little here and a little there. But in this instance breaking rods is serious especially if it isn't the same rod twice. And while immediate signs point to the crank or the oil pump, sometimes it can be something simple like the wrong bearing were installed or someone forgot something during the rebuild like a torque setting.

Stranger things have happened.

Calm down Mr. Reick. I think you are a genius when it comes to port design and would and have recommended you to everyone I know.

No problem sir....though everybody spells my last name wrong at some point.  I've just seen those strokers used and cracked all over the place....just reflection.

[MRieck]

I am not saying that RC, never built a welded up stroker, but I do know that they sold a lot of 1 pce forged strokers.

 Which are you saying had problems?


 

One piece....really?

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

Have you ever worked with an RC stroker crank? I wouldn't call it backpedal....

I have actually. And I was only poking fun. Every RC motor I have opened has things done to it that I had never thought of at the time. For one reason or another it worked for him. And really ONLY worked for him.

I cannot seem to find an engine or a builder using the same techniques to get them to perform like he did.

Granted people take a little here and a little there. But in this instance breaking rods is serious especially if it isn't the same rod twice. And while immediate signs point to the crank or the oil pump, sometimes it can be something simple like the wrong bearing were installed or someone forgot something during the rebuild like a torque setting.

Stranger things have happened.

Calm down Mr. Reick. I think you are a genius when it comes to port design and would and have recommended you to everyone I know.

[HavocTurbo]

I am not saying that RC, never built a welded up stroker, but I do know that they sold a lot of 1 pce forged strokers.

 Which are you saying had problems?


 

One piece....really?

Some of them yes.

Are you having posting problems too? My computer at work was doing that.

[MRieck]

There is either something wrong with the crank or the oil pump....or both.....unless it was stroked by RC Then it is the crank

Heh heh fastest backpedal I have EVER seen. 

Have you ever worked with an RC stroker crank? I wouldn't call it backpedal....

I have actually. And I was only poking fun. Every RC motor I have opened has things done to it that I had never thought of at the time. For one reason or another it worked for him. And really ONLY worked for him.

I cannot seem to find an engine or a builder using the same techniques to get them to perform like he did.

Granted people take a little here and a little there. But in this instance breaking rods is serious especially if it isn't the same rod twice. And while immediate signs point to the crank or the oil pump, sometimes it can be something simple like the wrong bearing were installed or someone forgot something during the rebuild like a torque setting.

Stranger things have happened.

Calm down Mr. Reick. I think you are a genius when it comes to port design and would and have recommended you to everyone I know.

Thanks....I appreciate the compliment

[HavocTurbo]

Reick does not equal Rieck....

Oh wtf god dammit!!!

[MRieck]

Reick does not equal Rieck....

Oh wtf god dammit!!!

It's in the details sir...... Your a mate though

[754]

This is what I found so far.. The RC catalog lists them as 1 pce, in mid 70,s.

 I found one for sale, not sure who made it, but it is here in town and 1 pce.. it had aluminum rods with it but not RCs.. I suspect Super rods..

 I also  got someone to get a hold of a former employee of RC, and asked them about where they were made.. (did not ask about the welded ones& it was not brought up) It appears they were likely made in Japan, and finish machined over here...

[Big Jay]

I am not saying that RC, never built a welded up stroker, but I do know that they sold a lot of 1 pce forged strokers.

 Which are you saying had problems?


 

Are you sure about that? Have you ever seen a forged one piece RC Honda stroked crank?  Everyone I ever saw was a weld up.

Jay

[754]

This from the catalog, not sure of the year, but mentions  7 sec bike on the cover.

"This kit developed specifically for the 750 Honda, adds more torque and horsepower to your motor than any bigbore kit of same displacement increase. This is a brand new crank with a 1/4 inch longer stroke. It has a special hardchrome alloy on the road and main journals to improve wear andincrease bearing life."

[BLUE71TURBO]

DOESN'T sound like a welded up crank to me, does it old timer ?

[BLUE71TURBO]

Man i'd sure like to get a hold of that bigblock michrobi has so i could build my 1200cc supercharged cb honda.
I have everthing to build a 970cc motor but the new MTC 970CC kit is 10.5 compression. So i can not use it for
the supercharger. 

[MRieck]

I am not saying that RC, never built a welded up stroker, but I do know that they sold a lot of 1 pce forged strokers.

 Which are you saying had problems?


 

Are you sure about that? Have you ever seen a forged one piece RC Honda stroked crank?  Everyone I ever saw was a weld up.

Jay

Me too..... that's why I was questioning things. When they were run hard......in my experience with hill climbing....they cracked  pretty bad. All plain bearing cranks are "one piece".....maybe that's the catch.

[754]

 I got a question,
 Regardless of anyones opinion on RC Products, does anyone know of anyone, turning quicker times than they did. (with the same Honda motors). using "newer technology".. it should be easier to make horsepower now, than it ever was..

[HavocTurbo]

Might want to ask MEC. I think he has a few ideas.

As for times maybe not, but I'm sure power is easily breakable.

[DRMR]

"This kit developed specifically for the 750 Honda, adds more torque and horsepower to your motor than any bigbore kit of same displacement increase. This is a brand new crank with a 1/4 inch longer stroke. It has a special hardchrome alloy on the road and main journals to improve wear andincrease bearing life."

My RC catalog sirca '86 has that same description,but the last sentence it states,

"Not an exchange item - send us your crank."

[MRieck]

 I got a question,
 Regardless of anyones opinion on RC Products, does anyone know of anyone, turning quicker times than they did. (with the same Honda motors). using "newer technology".. it should be easier to make horsepower now, than it ever was..

It doesn't take a lot of tech to make big HP with turbo or supercharged engines. Keeping them together and building multi engined bikes takes some know how. Byron is a true genius but they weren't running NA engines. I know one guy who's CB was the the quickest and fastest NA bike with bars in the country and he is in Massachusetts. He was using CB450 valves, +.250 deck etc. Jay knows exactly who it is too though many of you guys have never heard of him.

[754]

I think by 75 ish, they set more records on normally aspirated Honda, than most care to remember..

 BTW, how many bike racers are in the NHRA Hall of Fame ?