Author Topic: CB750 AHRMA Sportsman 750 Racer  (Read 171355 times)

0 Members and 1 Guest are viewing this topic.

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #600 on: February 13, 2018, 06:12:39 PM »
Nothing wrong with larger rollers. just add a ramp plate to help roll the wheel on if it's a problem.

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #601 on: February 13, 2018, 07:50:12 PM »
Nothing wrong with larger rollers. just add a ramp plate to help roll the wheel on if it's a problem.

Yep, definitely going to have a short ramp to get up there.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline napoleonb

  • Enthusiast
  • **
  • Posts: 193
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #602 on: February 17, 2018, 07:54:46 AM »
What's the idea behind the magic windows?
Is it easier and faster air displacement behind the pistons moving up/down on the other side thus "cancelling" over and under pressure?

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #603 on: February 17, 2018, 09:51:48 AM »
Yes that is the idea. Apparently a proven modification especially for high RPM applications. Not sure if it's measurable but can't hurt.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #604 on: February 26, 2018, 06:19:13 AM »
As we edge ever closer to my season opener (June 2nd) I am still getting lots done, but still lots to do. Cases are at vapor blasting now along with a few engine covers. I have made extremely good progress on my oil tank, and would say its 90% complete on the construction side, but will need lots of finishing once the welding is done. I am still anxiously awaiting a ton of items from Cycle X at which point I can get underway on the bottom end. In the meantime, I have been working on building my wheels, which are now done but to trued yet, so pictures after that. The wheels will actually be on the GPS racing website, so I need to get some really good pics of them which I will also post here. I also worked on getting foot pegs lightened up and ready, as well as a backup set for "just in case".







All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline gschuld

  • Master
  • *****
  • Posts: 2,346
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #605 on: February 26, 2018, 06:43:57 AM »
Looking good.  Aluminum oil tanks built that way are are real test of craftsmanship.  Good on you for giving it a go. ;)

George

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #606 on: February 26, 2018, 07:43:01 AM »
Looking good.  Aluminum oil tanks built that way are are real test of craftsmanship.  Good on you for giving it a go. ;)

George

It certainly is a piece of function origami. I certainly cannot take credit on the design as that was all Captain on his dry sump DOHC racer. I will do everything the old one could and more as air/oil separation will be paramount in the high-revving engine I am building. I definitely could have taken an easier route and had square edges, but I wanted something special, and I am pretty proud of how far it has come, especially for my first one!
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #607 on: February 26, 2018, 06:41:42 PM »
Very nice work..
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 kmb69

  • Master
  • *****
  • Posts: 2,041
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #608 on: February 26, 2018, 06:57:21 PM »
ALL of it looking REAL good!  8)
Anxious to see pictures of the "Magic Windows".

Keith


Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #609 on: February 27, 2018, 11:49:52 AM »
Nice job on the tank Matt, but haven't you heard, wet sumps are the real deal!

Offline bear

  • Vale Bill McIntosh ......"illegitimi non carborundum"
  • Old Timer
  • ******
  • Posts: 2,575
  • Leeton in Australia
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #610 on: February 27, 2018, 11:55:44 AM »
Nice job on the tank Matt, but haven't you heard, wet sumps are the real deal!

 ::) ::) ::) ::)

The older I get the faster I was.

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #611 on: February 27, 2018, 12:21:50 PM »
Nice job on the tank Matt, but haven't you heard, wet sumps are the real deal!

Ummmm, No. I really do not want to redo my brand new MotoGP Werks pipe to fit that beast. My oil tank probably weighs less and it will be a very race inspired and battle tested design. Ill wait for the full report from Voxonda, but I am far from convinced, especially after Captain weighed in. I have never met Brent, but I have tremendous respect for his opinion and knowledge, especially regarding oil cooling and air separation, both of which are factors in my new tank. With this new tank and the long oil lines, I will be able to run more oil than stock as well. Yes it weighs more but now can run a bit cooler. A Sunday drive for this bike is 8 laps in the hot sun living above 6k for 30 min. Nothing about a race bike is leisurely.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline voxonda

  • Master
  • *****
  • Posts: 2,231
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #612 on: February 27, 2018, 01:00:11 PM »
Great work on the oiltank! Lovely to see the detailing. And no do not redo anything for that matter. Follow your own path in this. But mind you there are more roads leading to Rome. Even with the oem oiltank there is no problem with air. The system works, but the reason behind the use of the dry sump is not clear. They, Honda, did not stop making models with it for no reason. And very few had any problems. But..........there are also people who wonder how it would look or work without the tank and lines . Some for looks, some for other reasons. Like me, I ran my 750's all with dry sump, tanks, lines, coolers and what not. Always looking for ways to improve the bike for use on track, with use of time specific parts. No USD forks, no Ohlin shocks, no wide tyres, just like in them ol'days. Build, or altered all my parts by myself and some parts, SMAC wheels, tank are all in my possession from new in '75. Long story, but my main reason for going to run and test the "Sumpthing" is that there is a lot of theoratical discussion without any practical backup. If I wonder about an issue I tend to do something about it, if interesting. And I think this is.
I have made an agreement with BJ, who has this produced and we are both interested to see how it copes with a bike build for the track, though designed for mainly caferacers who dislike the oiltank feature on the bike.

Will keep you updated.

Rob
« Last Edit: February 28, 2018, 01:51:29 AM by voxonda »
Better sorry for failing then for the lack of trying.

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #613 on: February 27, 2018, 05:07:16 PM »
You guys are no bloody fun. I thought I might at least get a jovial FU, but nothing!  ;D

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,564
  • Big ideas....
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #614 on: February 27, 2018, 05:15:05 PM »
ALL of it looking REAL good!  8)
Anxious to see pictures of the "Magic Windows".

Keith
I think a video of Keith performing "Spirit Fingers" would be much more entertaining.
Owner of the "Million Dollar CB"

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #615 on: February 27, 2018, 05:25:44 PM »
You guys are no bloody fun. I thought I might at least get a jovial FU, but nothing!  ;D

F*ck you Brent. Haha :)
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #616 on: February 27, 2018, 06:18:47 PM »
Hahaha, thanks. That's better.  ;)

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #617 on: February 27, 2018, 07:06:38 PM »
Brent, do you ever pack your race gear in a picking bag.?.lol..
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 bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #618 on: February 27, 2018, 07:33:44 PM »
Apple picking bag? No sir.

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #619 on: February 27, 2018, 07:47:40 PM »
SorryBrent I had to say it, hey they adjust vertically, change the size easily.
My kid did a short stint grading or packing a few months back. I worked in several packing houses..
 Better get back on topic, sorry for the highjack.
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 slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #620 on: March 08, 2018, 05:15:38 PM »
Big order of bits and bobs came in today from Kenny at cycle x. Crank with alternator snout cut and shut, HD cryo chains, new tensioner, main studs, CX11 cam and sprocket, Ti rocker nuts and pro cut trans. Trans will go to ISF treatment locally next week. Still waiting on cylinder studs and trans bearings.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #621 on: March 19, 2018, 07:44:19 AM »
The rest of my goodies from Cycle X showed up Friday (cylinder studs/nuts and coated trans bearings). I now have all the parts on hand except pistons, which look like early April for delivery. I will send a cylinder to Ken to get bored then get the whole package back ready to install.

My trans was dropped off at a local place for ISF processing. I took the whole trans (both shafts and gears), the shift forks/shaft, shift drum, clutch basket, oil pump gear/shaft and the primary drive shaft. Couple with Ken's coated bearings, this should be one smooth spinning and happy transmission. Here it is as received from Kenny, with pro cut.





More welding on the oil tank which nears completion, albeit slowly, every day. I am also working out a catch can for the tank which will allow vapor to rise up to the tank, and oil to drain back down to the tank, but also have a filtered breather in the back. If it does what it is supposed to, there should hardly ever be a drop of oil in there.



I also mocked up the engine breather on my freshly vapor blasted cases. You can see the magic windows that were cut between cylinder pairs.





Last are the very nice, and super light (40g each vs 120g each for stockers) fork caps form GL forks. Devin at Cognito Moto did a killer job and really came through with a nice product.

All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline napoleonb

  • Enthusiast
  • **
  • Posts: 193
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #622 on: March 19, 2018, 03:13:40 PM »
That's looking nice!

Offline slikwilli420

  • Master of Disaster
  • Master
  • *****
  • Posts: 2,362
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #623 on: March 23, 2018, 05:37:55 AM »
The trans and some other pieces came back from the ISF process at a local shop yesterday and look great. I had the whole trans done, as well as shift forks/shaft, clutch basket, oil pump gear/shaft, final output shaft and the 4 rocker shafts.

Here is a before and after:






The process really smooths things out nicely giving a uniform finish and is very slick once oiled up. Everything was cleaned in my parts washer, rinsed with hot water, blown dry then put in the oil I use in my engine. Next up is installing the bearings that are press fit then assembling the trans in the cases.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
Rickman CR Parts Kit Refresh: http://forums.sohc4.net/index.php/topic,154837.0.html
AHRMA CB750 Racer: http://forums.sohc4.net/index.php/topic,158461.0.html
AHRMA Superbike Heavyweight Racer: http://forums.sohc4.net/index.php/topic,173120.0.html
'76F CB750 Patina Redemption: http://forums.sohc4.net/index.php/topic,174871.0.html

Offline Rocketman

  • Hot Shot
  • ***
  • Posts: 391
Re: CB750 AHRMA Sportsman 750 Racer
« Reply #624 on: March 23, 2018, 07:27:19 AM »
Those gears look nice.  Who is your source for the ISF process?  Do they charge by the piece?