Topic: New (old) CB750 engine.

[sparty]

Hey guys,

I am picking up another CB750 engine over the weekend.  I have to drive 3 hours one way to get it, but it is free.  I plan to build this engine into a high performance/high horsepower streetfighter.  I’ll begin work on it once the snow hits the ground. 

First, I need to draw up a plan of attack and decide how big I want to go and what I can afford to put into it.  I was talking to the Cycle Exchange boys and some Honda Chopper guys and they have some great ideas.  I want to keep it normally aspirated, so a turbo is out.  I was told that it could be built as large as a 1061CC.  But I was thinking of something in the 900CC range.

I am building the engine for the pure fun of it and once it is completed I’ll put it into my café project.  Oh, my projected engine budget is $4K.

Has anyone on this forum built an engine like this?  Any ideas or recommendations are welcome.

Sparty

[SteveD CB500F]

Talk to Mike Rieck and Sam Green (samcr750).  They'll start you off.

[Jerry Rxman Griffin aka MuthaF'er]

Sparty,

It's very difficult to find piston kits larger than 836. The 836 are readily available. I found a NOS complete Henry Abe 900 kit this spring but was damn lucky. $700. I had to do a lot of digging to come up with it. It wasn't listed anywhere. PM me. I might have a lead for you.

Jerry

[tmht]

There is some good basic info on Axl's site about going big bore with a 750.

[ttr400]

On ebay Germany theres a guy selling a nos 970 kit with the barrels by the look of it, item # 170032261443.  Check out the other parts he's selling!! NOS cyl head, NOS full race cyl head, a russ collins cam and more.   better hurry theres plenty of bids on all his items.

Kevin

[sparty]

On ebay Germany theres a guy selling a nos 970 kit with the barrels by the look of it, item # 170032261443.  Check out the other parts he's selling!! NOS cyl head, NOS full race cyl head, a russ collins cam and more.   better hurry theres plenty of bids on all his items.

Kevin

Kevin,

Thanks for the info.  I wish that I was ready for something like that, but I don't want to just throw my money at it and hope it works out.  I guess that I need to find someone like Sam and Mike who are familiar with race engines to help me build a street reliable bad ass engine.  My current engine is a 836CC.  It is powerful, but since I have a chance to build another, I want to see what else I could do.

Here is what I was thinking:

836cc piston kit or larger if avaliable, light high quality race pistons
port and bore the head
light and race proven connecting rods
Heavy-duty valve springs
Racing top valve spring collars
HP race Camshaft
Amco 45 valve guides
Exhaust valves
Intake valves
a multi-angle valve job
a lightened and balance crankshaft
Heavy-duty cam chain
All cam chain rollers and slider
Connecting rod bearings
Main crankshaft bearings
heavy duty Primary chains
Heavy-duty clutch plates
Heavy-duty clutch springs
a lightened alternator rotor
undercut the transmission gears
race clutch
digital ignition
CR carbs

Sparty

[Jerry Rxman Griffin aka MuthaF'er]

On ebay Germany theres a guy selling a nos 970 kit with the barrels by the look of it, item # 170032261443.  Check out the other parts he's selling!! NOS cyl head, NOS full race cyl head, a russ collins cam and more.   better hurry theres plenty of bids on all his items.

Kevin

Can anyone translate? The only thing I understand is the euros. Multiply that by almost 2 for US$.

[Sam Green Racing]

Your wish list is good apart from one important component, a super dooper cam chain tensioner.

Tell me, have you won the lottery  

You should'nt need anything more for the clutch other than heavy duty springs and new plates.

For all your head work valves ect, speak to Mike Rieck.

Mike will also tell you where to get the rest of the machine work done, crank ect.
Posibly Jay at APE in Willow Springs, Jay can also suply 836 Wiseco pistons at a good price.

Sam.

[MRieck]

On ebay Germany theres a guy selling a nos 970 kit with the barrels by the look of it, item # 170032261443.  Check out the other parts he's selling!! NOS cyl head, NOS full race cyl head, a russ collins cam and more.   better hurry theres plenty of bids on all his items.

Kevin

Kevin,

Thanks for the info.  I wish that I was ready for something like that, but I don't want to just throw my money at it and hope it works out.  I guess that I need to find someone like Sam and Mike who are familiar with race engines to help me build a street reliable bad ass engine.  My current engine is a 836CC.  It is powerful, but since I have a chance to build another, I want to see what else I could do.

Here is what I was thinking:

836cc piston kit or larger if avaliable, light high quality race pistons
port and bore the head
light and race proven connecting rods
Heavy-duty valve springs
Racing top valve spring collars
HP race Camshaft
Amco 45 valve guides
Exhaust valves
Intake valves
a multi-angle valve job
a lightened and balance crankshaft
Heavy-duty cam chain
All cam chain rollers and slider
Connecting rod bearings
Main crankshaft bearings
heavy duty Primary chains
Heavy-duty clutch plates
Heavy-duty clutch springs
a lightened alternator rotor
undercut the transmission gears
race clutch
digital ignition
CR carbs

Sparty

A great start. Sam is right about the tensioner but that aside....a great start. If you are serious contact me but please....if you are serious. If you knew all the emails I get.... and answer, for nothing. I'd love to help and can point in all the right directions.
  Mike

[sparty]

Your wish list is good apart from one important component, a super dooper cam chain tensioner.

Tell me, have you won the lottery 

You should'nt need anything more for the clutch other than heavy duty springs and new plates.

For all your head work valves ect, speak to Mike Rieck.

Mike will also tell you where to get the rest of the machine work done, crank ect.
Posibly Jay at APE in Willow Springs, Jay can also suply 836 Wiseco pistons at a good price.

Sam.

I haven't won the lottery.  I could spend 10 or 15 grand on a new bike, but I'd rather put the money into something classic, something that is worthy, something cool like a SOHC Four.

Sparty

[sparty]

A great start. Sam is right about the tensioner but that aside....a great start. If you are serious contact me but please....if you are serious. If you knew all the emails I get.... and answer, for nothing. I'd love to help and can point in all the right directions.
 Mike

Mike,
I'd love to talk turkey with you.  I have contacted two engine builders and they have expressed their ideas.  I don't want to go too crazy with the build and sacrifice reliability and future repairs.  What I have laid out seems like it will work well.  I could have a entire CR style race engine built for around $10K, but then it would have to be rebuilt too often.  I am looking for a compromise.

Sparty