Author Topic: PISTONS (970cc? 1000cc?)  (Read 61591 times)

0 Members and 1 Guest are viewing this topic.

Offline Big Jay

  • Expert
  • ****
  • Posts: 1,252
    • CBRzone
Re: PISTONS
« Reply #25 on: October 29, 2008, 10:14:41 PM »
Going to do 10:1. Don't thing anyone would want higher than that.

Jay

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: PISTONS
« Reply #26 on: October 29, 2008, 10:33:17 PM »
Is not 10.5 what most kits were in the old days?

I was thinking if I could get 12:1, that I would modify to about 11:1, seeing as I never had any  problems even with regular gas..

Jay, any idea of pricing on these units?

Also, did APE ever make the main bearing studs for the CB 750 engines.. would like to run a set of them..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS
« Reply #27 on: October 30, 2008, 04:49:49 AM »
Is not 10.5 what most kits were in the old days?

I was thinking if I could get 12:1, that I would modify to about 11:1, seeing as I never had any  problems even with regular gas..

Jay, any idea of pricing on these units?

Also, did APE ever make the main bearing studs for the CB 750 engines.. would like to run a set of them..
Dynoman sells main bearing studs. I believe Jay makes them for him.
Owner of the "Million Dollar CB"

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS
« Reply #28 on: October 30, 2008, 05:05:56 AM »
Going to do 10:1. Don't thing anyone would want higher than that.

Jay
I think that is a good number. By the time you get done decking and milling you'll add 1/2 point.
 
Owner of the "Million Dollar CB"

Offline Sam Green Racing

  • Really Old Timer ...
  • *******
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: PISTONS (970cc? 1000cc?)
« Reply #29 on: October 30, 2008, 07:50:35 AM »
Thanks Steve ;) ;) ;)

Sam.  ;)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS (970cc? 1000cc?)
« Reply #30 on: October 30, 2008, 08:44:02 AM »
 OK. Who is in on a 1000cc kit? I'll be the first to say I'll take one (as long as it comes with a modern head gasket).
Owner of the "Million Dollar CB"

Offline Leino

  • Not much of an
  • Expert
  • ****
  • Posts: 1,264
  • in drag racing since 2005
Re: PISTONS (970cc? 1000cc?)
« Reply #31 on: October 30, 2008, 09:07:48 AM »
Can this be done with machining->welding->machining->resleeving->boring the stock block or what's the story?  ;D

Offline MCRider

  • Such is the life of a
  • Really Old Timer ...
  • *******
  • Posts: 14,376
  • Today's Lesson: One good turn deserves another.
Re: PISTONS (970cc? 1000cc?)
« Reply #32 on: October 30, 2008, 09:15:29 AM »
Can this be done with machining->welding->machining->resleeving->boring the stock block or what's the story?  ;D
It is to laugh, pardon me.  ;)  All giggling aside, its a process, but one which a motivated person can accomplish. One must press out the stock sleeves, bor the alum block, press in new sleeves, bore them to the pistons. Also, I'm guesing the cyl studs will be removed (you'll want to upgrade anyway) and bore the top crankcase to accept the new sleeves.

I have run and will run again an 888cc kit. Same process except the bottom of the sleeves are tapered bypassing the boring of the crankcase. I think 888cc is the largest that this will work on.

But at 1000cc you'll need / want rods, lightened crank, maybe tranny work, so its a complete teardown to the last nth, but oh what results. About on par with a mid range modern 600cc sportbike. But we love our CBs.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Leino

  • Not much of an
  • Expert
  • ****
  • Posts: 1,264
  • in drag racing since 2005
Re: PISTONS (970cc? 1000cc?)
« Reply #33 on: October 30, 2008, 09:20:39 AM »
It is to laugh, pardon me.  ;)  All giggling aside, its a process, but one which a motivated person can accomplish. One must press out the stock sleeves, bor the alum block, press in new sleeves, bore them to the pistons. Also, I'm guesing the cyl studs will be removed (you'll want to upgrade anyway) and bore the top crankcase to accept the new sleeves.

I have run and will run again an 888cc kit. Same process except the bottom of the sleeves are tapered bypassing the boring of the crankcase. I think 888cc is the largest that this will work on.

But at 1000cc you'll need / want rods, lightened crank, maybe tranny work, so its a complete teardown to the last nth, but oh what results. About on par with a mid range modern 600cc sportbike. But we love our CBs.
Well... those are the facts I already knew, and I have the lightened/balanced crank, undercut transmission etc. etc. on my 836cc at the moment.
I was just curious about the cylinder block, and if this could be done with the stock block
re-sleeved etc.

Cheers,

Juha

Offline MCRider

  • Such is the life of a
  • Really Old Timer ...
  • *******
  • Posts: 14,376
  • Today's Lesson: One good turn deserves another.
Re: PISTONS (970cc? 1000cc?)
« Reply #34 on: October 30, 2008, 09:25:19 AM »
It is to laugh, pardon me.  ;)  All giggling aside, its a process, but one which a motivated person can accomplish. One must press out the stock sleeves, bor the alum block, press in new sleeves, bore them to the pistons. Also, I'm guesing the cyl studs will be removed (you'll want to upgrade anyway) and bore the top crankcase to accept the new sleeves.

I have run and will run again an 888cc kit. Same process except the bottom of the sleeves are tapered bypassing the boring of the crankcase. I think 888cc is the largest that this will work on.

But at 1000cc you'll need / want rods, lightened crank, maybe tranny work, so its a complete teardown to the last nth, but oh what results. About on par with a mid range modern 600cc sportbike. But we love our CBs.
Well... those are the facts I already knew, and I have the lightened/balanced crank, undercut transmission etc. etc. on my 836cc at the moment.
I was just curious about the cylinder block, and if this could be done with the stock block
re-sleeved etc.

Cheers,

Juha
Great, that's a cool motor!  And yes, you just resleeve the stock block and bore the crankcase. FYI: There is no aluminum left between 1-2 and 3-4 after the boring! But no welding or oddball machining need be done.
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Artfrombama

  • Card-carrying, board certified
  • Hot Shot
  • ***
  • Posts: 371
  • CB750 K2
Re: PISTONS (970cc? 1000cc?)
« Reply #35 on: October 30, 2008, 10:05:17 AM »
Rebalancing required with the new 1000cc pistons?
Halfassed machinist
Tinkerer/goof-off/Mr. Fix-it
CB750-2011594 Sunrise Flake Orange
CB750E2441103

Offline MCRider

  • Such is the life of a
  • Really Old Timer ...
  • *******
  • Posts: 14,376
  • Today's Lesson: One good turn deserves another.
Re: PISTONS (970cc? 1000cc?)
« Reply #36 on: October 30, 2008, 11:14:54 AM »
Rebalancing required with the new 1000cc pistons?
You may want to hear from a real engine builder, but my take is, the 4 cylinder crank config is "neutral" so any displacement does not "require" a rebalance. However, the crank is balanced at the factory to rather loose average specs. A stock motor would benefit from a better balance, and a bigger motor that much more in terms of smoothness. And smoothness goes to reliability etc. The psitons are balanced to each other as are the rods.

So while you're at it, take off some pounds on the crank itself and off the alternator. That weight is masking the loose tolerances on the factory balance, a cheap substitute for smoothness..  That will allow that extra displacement to really cook. And lightening would require rebalancing.

Comments?

Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,929
  • Bought her new 4/75
Re: PISTONS (970cc? 1000cc?)
« Reply #37 on: October 30, 2008, 12:55:25 PM »
OK. Who is in on a 1000cc kit? I'll be the first to say I'll take one (as long as it comes with a modern head gasket).

I can't let Mike out-do me so I'm in for the 1000 kit but we also need the base gasket too.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS (970cc? 1000cc?)
« Reply #38 on: October 30, 2008, 02:08:58 PM »
OK. Who is in on a 1000cc kit? I'll be the first to say I'll take one (as long as it comes with a modern head gasket).

I can't let Mike out-do me so I'm in for the 1000 kit but we also need the base gasket too.
Jerry....I don't think I could ever out-do you. ;) ;D Yes on the base gasket....preferably in .010 thickness.
Owner of the "Million Dollar CB"

fuzzybutt

  • Guest
Re: PISTONS (970cc? 1000cc?)
« Reply #39 on: October 30, 2008, 03:56:32 PM »
i was at Metalheads this past weekend and i know he'll be up for a 1000cc kit

Offline Sam Green Racing

  • Really Old Timer ...
  • *******
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: PISTONS (970cc? 1000cc?)
« Reply #40 on: October 30, 2008, 04:29:03 PM »
No one has mentioned the price yet, pistons apart, what price for the ready to go block?

Sam. ;) ;)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,929
  • Bought her new 4/75
Re: PISTONS (970cc? 1000cc?)
« Reply #41 on: October 30, 2008, 07:24:41 PM »
OK. Who is in on a 1000cc kit? I'll be the first to say I'll take one (as long as it comes with a modern head gasket).

I can't let Mike out-do me so I'm in for the 1000 kit but we also need the base gasket too.
Jerry....I don't think I could ever out-do you. ;) ;D Yes on the base gasket....preferably in .010 thickness.

I'd bet that your head will yield 2 or 3 hp more than the one you will have to build for me  ;)  :D
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS (970cc? 1000cc?)
« Reply #42 on: October 30, 2008, 07:26:30 PM »
OK. Who is in on a 1000cc kit? I'll be the first to say I'll take one (as long as it comes with a modern head gasket).

I can't let Mike out-do me so I'm in for the 1000 kit but we also need the base gasket too.
Jerry....I don't think I could ever out-do you. ;) ;D Yes on the base gasket....preferably in .010 thickness.

I'd bet that your head will yield 2 or 3 hp more than the one you will have to build for me  ;)  :D
The gauntlet has been thrown.....you are on bro!
Owner of the "Million Dollar CB"

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS (970cc? 1000cc?)
« Reply #43 on: October 30, 2008, 07:31:27 PM »
OK.....2 sets of 1000cc. Who else is in?
Owner of the "Million Dollar CB"

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: PISTONS (970cc? 1000cc?)
« Reply #44 on: October 30, 2008, 08:07:10 PM »
Need price.. and shipping costs...
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,577
  • Big ideas....
Re: PISTONS (970cc? 1000cc?)
« Reply #45 on: October 30, 2008, 08:16:49 PM »
Need price.. and shipping costs...
I understand that. I wonder......could something else be worked out. ;) ;)
Owner of the "Million Dollar CB"

Offline Big Jay

  • Expert
  • ****
  • Posts: 1,252
    • CBRzone
Re: PISTONS (970cc? 1000cc?)
« Reply #46 on: October 30, 2008, 09:21:30 PM »
I will get the tentative pricing worked out and posted.

As for rebalancing the crank, not necessary. Inline four cylinder cranks are "self canceling", so as long as the components all weigh the same, it doesn't effect the balance..

Jay

P.S. Thanks to whoever got the sticky done.

Offline Sam Green Racing

  • Really Old Timer ...
  • *******
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: PISTONS (970cc? 1000cc?)
« Reply #47 on: October 30, 2008, 09:49:23 PM »
Twas I that pushed it but, we can talk big discounts at a later date,  :D :D :D hope your contingency pay outs apply to bracket racers as well

Sam ;)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline mec

  • Hot Shot
  • ***
  • Posts: 503
Re: PISTONS (970cc? 1000cc?)
« Reply #48 on: October 31, 2008, 01:52:18 AM »
hi,

I did my experience with 1000ccm pistons (rc eng) in the late 70ies.
I remember there had been issues with oilleakage using the stock cyl-block.
boring the block, there will be huge "windows" between 1/2 and 3/4 and the sleeves become visible. those days I sealed these holes with "devcon". that solved the proble. however, there had been other "invisible" oilleakages round the sleeves cause of the very thin cylinder wall (during riding my boots took a hot oil bath :))

curious how will you solve these problems?

mec
Honda Monkey
Takeuchi TB 070
Massey Ferguson

Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
Re: PISTONS (970cc? 1000cc?)
« Reply #49 on: October 31, 2008, 05:19:30 AM »
OK.....2 sets of 1000cc. Who else is in?

Mike, you are like a kid in a candy store.   ;D ;D ;D ;D ;D

I'd love one, but I've gt to get my 850 together and ridable before I can even think about another engine.

...

...

okay, that's not true... I've been thinking, I just can't do anything about it yet.  :-[ ;)
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"