Topic: Geared Primary Drive

[kmb69]

.....
Bear was running 125+ HP with an auto crank in his sidecar rig..

Bear was for sure running a DOHC crank in his sidecar. Not sure if he ever ran an auto crank.

[scottly]

OK, I stand corrected about the lube and Bear's crank.

[Tracksnblades1]

After initially corresponding with Bear and later with Ramsey chain, this wheel may have already been spoked....

Ramsey has some high speed offerings exceeding 7000fpm. With their engineering department's assistance, perhaps more.

I think Bear had this wheel tried, trued, and blued.

Excepting nitromethane,  the centrifugal force may become a primary concern.

I don't see my plans traveling anywhere as fast as what has already been done.

[bear]

Just to be clear.
I use the 900cc DOHC cranks, so both cam and primary chains are Morse.
The motor's do not exceed 9'000rpm.
I have never had an issue with torque loads on the chains. The limiting factor was harmonics.
I use a manual primary chain adjuster made by Brent aka Captain and a hybrid cam chain adjuster made by me using a foot also supplied by Brent.
Chains where not my problem.
The weak links for my motors where cush drives and then gears if the cush drive fails.
Having said that I stick to a100 hour lifespan for my motors and then their on the bench for a touch up without fail.
My motor's could not survive running at 12'000rpm+ like Brent's, they are two completely different animals.

Cheers,
Brian

[scottly]

I don't believe Morse's claims either. However, the DOHC's come stock from Honda with a pressurized lubrication system for the chain.
And the 750A's have a pressurized lube system for their chain also.

Keith, please educate me about the pressurized lube systems for the auto and dohc primary chains. I haven't found anything in the Honda manuals so far.
Thanks in advance.
Scott

[Tracksnblades1]

I don't believe Morse's claims either. However, the DOHC's come stock from Honda with a pressurized lubrication system for the chain.
And the 750A's have a pressurized lube system for their chain also.

Keith, please educate me about the pressurized lube systems for the auto and dohc primary chains. I haven't found anything in the Honda manuals so far.
Thanks in advance.
Scott

Not sure if eBay has an offering for one for a 750a right now.

[dragracer]

Bear, in a no bar  dragbike street, I think your set up would work fine. I don't think any of us would RIP the cush drive apart as we must using a certain amount of clutch management to launch or bike which does not create heavy shock to the drive line. I'm still very much interested in building a DOHC  crank conversion, Sohc based engine for drag racing. I'll need to look back over some of the old threads whereby you gave some details on how you did the swap.

[Don R]

 I have an A motor with the top end already removed if anyone needs a peek inside. It's evident a PO had it apart judging by the gooped gaskets so I need to look inside anyway. I too, am watching the progress on the dohc crank swap with interest. 

[Medyo Bastos]

DonR just a heads up JimF was selling gasket kits. Give him a shout.


Sent from my iPhone using Tapatalk