Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties CLASS C RACE NOTES

CLASS C RACE NOTES

Post Tue Nov 06, 2018 3:29 pm

Posts: 794
Location: Victoria, Australia
Tim 435 wrote:
BALL BEARINGS ! Up to this point we have been using the conventional rollers on the WL crank shafts in our builds, I never cared for the shim to case race friction affect and intend to research the use of ball bearings, there has been some posted in the past of applying ball bearings and there are knowledgeable builders on this forum who have experience on the subject, So I would like to re new the subject of applying ball bearings to WL bottoms and if anybody is willing to contribute your knowledge is greatly appreciated.... Tim



BALL BEARINGS used on drive side of case.
Hi Tim...the following series of pix are not from a race engine but on a project I finished quite a number of years ago. The info and pix may be of use to you.

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Post Fri Nov 09, 2018 5:02 pm
GuS

Posts: 419
Location: Bergen, Norway
Tim.
Million thanks for sharing your experience in the original «race notes» and in this post.
This is mine:
Had it 27 yrs, gradually modifed and finally took it to the roadrace track and lately to the gravel track. And you’re right. racing is addictive.
Present setup is:
4-7/16 stroker
Pop up pistons from Venolia. Total seal gapless rings. At one point I gave up the far east pistons....
Piston reshaped by me to reduce weight.
UL intake nipples.
Cylinders are ported and relieved.
Heads are welded and milled for pop-up and given the no 7ish K-shelve.
Standard exhaust valve size, backcut for improved flow. Chevy intake valves from KNS. Backcut for better flow.
Cams reground by Leineweber. In/ex lift and duration: 0.352/266. 0.352/262.

Hopefully at one point I will be accepted in the Nordic classic road racing Championship. I might have to swap the Mik for a Linkert. If anyone got a M74b or similar sized carb for sale, please give me a call. Also might have to install a std stroke engine.

Dave, nice bike you got there..and cool color :)

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GuS

Post Fri Nov 09, 2018 9:53 pm

Posts: 824
Location: Pa. , USA
WoW ! that's what I'm talking about, great info from both of you, so far I've been researching ball bearings for the WR shaft which calls for a larger bearing and the need to remove too much from the case insert I feel, they may work but for the pounding these weaker WL cases take the smaller shaft and bearing may be more acceptable, however what I'm seeing is a one way thrust with this set up (or am I missing something ?) and still using the stk shimming on the right side for right direction thrust, wondering if a sized spacer would work between the sprocket and bearing, just a thought but then there's the tapered shaft, will be researching all of these directions in order to find a good common process for WL's..
Gus is that a road bike you are racing ? is there a class for that there ? that side stand hanging out there looks scary as well as the stock exhaust and foot control hangers, you will find a much happier road racer with all that removed, also stock stroke wheels will spin faster and higher rpm's needed for road racing, great looking weld job on the heads and thanks for sharing your race notes..
Vintage roadracing, Class C, AHRMA # 335

Post Sun Nov 11, 2018 3:49 pm
GuS

Posts: 419
Location: Bergen, Norway
Tim.
There is a class for vintage roadrace bikes here. 30yr and older. Majority jap from the 1980ies. But there is a pre48 class. Very few attending. Ive tried to attend but was turned down. Talked to them again, and am going to apply once more.
Picture is from a roadracing weekend aranged for street bikes. Side stand is tied up with steel wire. Was expecting primary cover to drag, but only the foot pin was dragging. Flexible, so no problem. Problem was actually on other side, the brake pedal pivot bolt kept dragging. By the end of the weekend 1/2 the bolt was gone. That need to come higher.
There is no class for flat track here, but one Speedway club arrange some open class events and allow other bikes to attend in open classes or for show.
Riding the dirt us great fun, bu I need to get some better ground clearance. The standard wide W clutch and the primary cover keep dragging through the corner.

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What is the best route to get better ground clearance? Install the earlier R clutch and a narrow prmary cover?
Or larger tyres?
I built me some 18’’ wheels. But that didnt seem to help.
Maybe 19’’ and a higher tyre profile?
What tyres are you using for the dirt track?
What was the tyre sizes used for class C racingback then?
Found this picture on the net

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Looks larger than 18’’. And larger front than rear

GuS

Post Sun Nov 11, 2018 10:41 pm

Posts: 824
Location: Pa. , USA
Gus you must get that brake pivot higher ! I had the same experience once at Mid Ohio on an off camber corner and wasn't so lucky, best way like I said eliminate the hangers and pivot the brake and clutch right off the rear hanger support rod, takes a little fabrication but not bad. Several ways to fix the wide primary cover, least expensive is to just do an angle cut where its making contact as high as you can and leaving clearance inside then weld a plate to close the opening or heard of some racers raising the transmission via spacers, then most expensive but the best way is to do a narrow clutch and primary cover, no more dragging. 19" tires front and rear will give you more lift which is what the flat trackers here run, about half way into my road racing I tried flat tracking for a season, was a blast ! but decided to stick with R/R, sometimes I wonder if that was a mistake but still enjoy R/R. Back in the early days they ran 18" then by the late '40's and into the '50's believe most of the pro's were on 19", also on my bike builds I like the +2" XA forks for added road clearance, cool photo of Campanale ! love those flanders !
Vintage roadracing, Class C, AHRMA # 335

Post Mon Nov 12, 2018 8:10 pm

Posts: 66
On my race bike I run 18" wheels but I do have a spacer at the bottom of the head stem to raise the front a little. I run my controls and pegs off the rear support post rod and I've taken an angle grinder to the bottom of my primary chain case to get some more room.

Post Sat Dec 22, 2018 8:09 am
GuS

Posts: 419
Location: Bergen, Norway
Dave and Tim. Great info.

Thanks.

GuS

Post Wed Jul 10, 2019 12:02 pm

Posts: 824
Location: Pa. , USA
Hey y'all, its been awhile since I posted, been busy and also started posting on instagram, the last post I was discussing running the crank on ball bearings , we did a conversion on a test motor using single row on both sides, the crank spins very nice, only had one weekend testing back in May at NJMP and so far holding up well but not proven yet until I get more time on it. Had planned on making the Wauseon meet then racing the following weekends in Wis., and Mich. but 4 weeks ago an unexpected open heart surgery put everything on hold, coming along ok and looking at the Handshift Shootout at Barber in October, we'll see how it goes until then, if anybody's interested I go under tims45s on instagram...
Vintage roadracing, Class C, AHRMA # 335

Post Thu Jul 11, 2019 10:08 am

Posts: 1768
FWIW my WL flat track bike has 19” rims and an R type clutch, with a BSA pressed-steel chaincase. Standard footboard hangers with Servicar clutch pedal.

I must get it out on track! Most U.K. flat track is on speedway tracks, what American call “cushion tracks” so the ground clearance isn’t such an issue.
Shoot, a man could have a good weekend in Dallas with all that stuff...

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