Datsun Roadster Forum-311s.org

I joined because of this thread.

Any news?

I recently saw your YouTube video! I have to say it’s messing with my head ! Haha but luckily I have nowhere near the space , skills or time to do something like this . What’s next?

News?
What's next?
Sorry I've been on a bit of a Walkabout on this project.... I still haven't found a good solution to the vibration problems. So with that I've been taking a step back and hopefully will get some perspective on how to move forward. I've been in contact with the drive line shop in North Carolina and just about everywhere in between - there is just no good solution that I like. Basically I'm down to:

Twisting the Reverser towards the Engine output shaft (passengers side) and run Double Cardan U-joints at the engine output shaft and the output shaft of the reverser. Pretty sure this will all but eliminate the vibration but this still doesn't get me a Guibo (rubber cushion) to dampen the shifts.

Other options is to move the Reverser forward and into the passengers area just before the seat. That will lessen the angle of the front drive line and virtually make the rear drive line straight in line, but the gains will be minimal as I cant move it very far as the rear drive line must still go down the trans tunnel. Thinking to sending the rear drive line to North Carolina to be made into a ball and cage CV so it is truly a Constant Velocity joint. This will eliminate any clocking variance between the two drive lines because of the Reverser. I believe the front drive line is too much of an angle for a Ball & Cage CV and will not survive the RPM. Half Shaft on front wheel drive cars are on the Torque side of the differential and don't see the RPM of the Drive line side of the differential.

I've even looked into Drop Transfer cases to move the front drive line over to the middle of the chassis. Big, bulky, heavy and not much room between the engine and firewall, not to mention the power loss through another gear box.

What to do? hence my heart still wants to make this Motorcycle engine work but my head and pocket book is saying it's SR20 time.........It's the safe bet.

Ak

Such an intriguing project, would hate to see you abandon it. Motorcycle engines have been used extensively in SCCA racing, most notably in the Sports Racer class. Perhaps you could seek some knowledge from this arena. Also I believe the Legends class use a motorcycle engine as well. Good luck moving forward. Yes

Ok, now I need to read the whole thread again to see what you are fighting. It would kill me to see this project die..

There will be a solution.

RCMike wrote: Fri Jun 29, 2018 1:48 am Ok, now I need to read the whole thread again to see what you are fighting. It would kill me to see this project die..

There will be a solution.

Haha This Pictures says it all........ That front drive line angle.
My first order of business is to make a moveable mount between the reverser and the frame. This mount needs to be able to angle the reverser towards the passengers side (output of engine) Also be able to raise the front of the reverser, compound angle, left to right and top to bottom. By moving it a little and testing the school of thought is we might get the vibration to cancel out in the front drive line. If the rear is ball and cage CV's both ends and true constant velocity drive line, then it wont matter about clocking and we just need to address the front.

Ak

Why not make your own simple chain drive system to get power back on centerline. The mud bog guys do it all the time. Sealed bearings, double or triple chain, simple keyed shafts. How many miles a year are you figuring on putting on this thing?


Just my 2 cents

Regards,
Steve

Steve,

Yes on the chain, looked into it quite a bit. The biggest problem with Motorcycle Sand Cars is the short chain. Unlike a Motorcycle the chain needs to be very short, coupled with the fact I would need a 1 to 1 ratio the sprockets would need to be small - so lots of bending around sprockets and short chain lengths, and no air flow = high heat and it will not survive Dune speeds much less Highway speeds. My brother fights this even with a 14 front sprocket and a 63 tooth rear sprocket. Next is Silent chain, probably the most viable with it's oil bath, but space is at a premium, need to space it back towards firewall to pass engine, then how to hold secure? Engine is solid mounted, but case would need to be mounted to frame - could be some flex between the too under torque load - need a Guibo but that's pushing it more towards firewall. This is basically the same scenario as a drop transfer case with out the chain stretching problem of a silent chain, gear case would probably more reliable.

Thanks for the interest.

Ak

Full disclosure - I had to Google Guibo - Never heard that term before. How about if you go for broke, remove the X member, run your power shaft straight back, then a silent chain offset, to reverser, and on to diff. I'm guessing that's a reverser in the X frame?? Then build an new X frame structure around everything as needed. Given your research, I'm guessing you've been there already. Probably need to put a channel in the pass floor pan to clear things??? Just thinking.

Regards,
Steve

SABLT194 wrote: Sat Jul 14, 2018 6:46 pm Full disclosure - I had to Google Guibo - Never heard that term before.
Regards,
Steve

Glad I spurred some intrest..... lots of new cars have them in nowadays, as well as getting rid of u- joints and going true ball and cage CV's drive lines, mostly 4 wheel and All wheel drive vehicles. If I made the car a race car and took out the passengers seat all my troubles would be over, and so would my marriage....
The drive line shop in North Carolina makes the drive lines for Ken Block. If I send them the frame with motor they think they could build something that would work, I just need to win the lotto is all. Here is a pic I sent them mapping out my problems. The X-brace isn't the problem and is great for the reverser platform. The output shaft is just bebow the 45 degree brake in the firewall that the problem. If I could build the trans tunnel over about 6" I would be golden.
From the picture first thing to do is raise the nose of the reverser as it dips down 3/16" front to back. Seems easy except the bolts go through the X- brace so I need to build the moveable mount the let's me lift the nose and twist the nose to the right, maybe get lucky and the vibrations cancel each other out. Still thinking a true CV shaft for the rear is needed as the two drive lines fight depending on how their clocked coming out of reverse.

Ak

To be honest I have only scanned through this thread.
What I see as a possible solution.....much too much work....LOL

Why not rotate the engine to lower the output?
Notch the X member on the passenger side just off center to mount the reverser "in the frame"


The frames are very strong, my 69 has not X cross member at all and never had a problem with chipping the paint at the doors.
It does have a strong bolt-in transmission mount.