I need the help of someone intimately familiar with the 5th Gen oil system

I'm running a 5th Gen engine in my mini buggy and am trying to sort out a couple of different oil concerns.

First, this buggy as an isolated forward/neutral/reverse (FNR) transmission. This FNR box has it's own oil but I want to find a way to integrate it into the engine's oil cycle. My concern is that this box is not designed to hold pressure and I believe the seals will not hold. My idea was to tie it into the oil cooler plumbing but I do not know if the oil cooler is on the high pressure or low pressure side of things. If the oil cooler plumbing is all high pressure, do you guys happen to know of another way I could pull this off?

Second, I'm wanting to run a large oil cooler. Not so much out of a need for more cooling, but rather of convenience. The factory oil cooler is a poor shape and fitment for the buggy. I'm wanting to use one that measures roughly 3/4" x 3" x 9". My concern here is over cooling and I would like to know if that may present a problem.

Thanks in advance!

 

Typically separate gearboxes are oil bath so I can't understand why you wish to graft it into the engine's oil system. What type of oil is the 'box designed to have in it? It may not be compatible with bike oil. It may even disrupt the oil circuit by not flowing thereby starving the cams and valve train.
Out of interest could explain how you by-pass the engines own gearbox, if indeed you have? Perhaps a photo or to would help to explain the configuration.

 

The FNR box is difficult to maintain...the plugs to fill and drain are in hard to reach locations and I'm simply trying to find a way to eliminate it as a maintenance concern (if possible). It is oil bath but I've been running the same 15/50 Mobil 1 oil in it as the engine. Roketa (the manufacturer) doesn't really make a clear specification for what's required.

My plan was to plumb the oil in from the drain port on the box and let it just fill and flow "up" to the fill port and drain back into the engine. However, as said, the FNR box isn't meant to be pressurized so this would only work if the oil, after passing through the cooler, specifically did drain back into the oil pan.

The VFR transmission is not bypassed. The engine drives the input shaft of the FNR box, and the FNR box drives the wheels. This video has a biut of the driveline in action.

https://www.youtube.com/watch?v=4ldKSUDr3fo

 

Run the bike motor on 10w-40. And I think what you're calling a gearbox is a transfer box or a differential. Check with the manufacturer but I would suggest a gear oil 80 or 90 fill it, usually until it's up to the filler hole then change it every couple of years.

 

I get better results with the 15/50 Mobil 1.

It's an FNR gearbox. I suppose you could call it a transfer box since it takes the power from the engine and then transfers it to the wheels in either forward or reverse, or not at all if it's in neutral.

To add to that, it's not that there aren't clear answers from Roketa concerning what to use, it's that there are multiple responses ranging from 8wt hydraulic to 100w heavy gear oil. I'm getting very good wear results from the 15/50 Mobil 1 I've been using.

While I appreciate your responses, I do know how to maintain the equipment in it's current state. I'm looking for answers concerning changing it to another state. Which is why I need to know what I need to know about the oil flow system.

 

Wear results? Please explain as unless you're using a micrometre how do you tell.
10w-40 is better for cold starting and for getting through the small oil ways in a bike engine. If that's Mobil 1 car oil it will have friction modifiers which will damage the clutch and break down faster because of the shear forces in meshing gears in the bike engine gearbox.
The oil pump wasn't designed for an enlarged circuit and your diff' was only designed to for splash lubrication , not pressure or forced.
I can only advise you from a purely engineering stand point and the choices are yours to make. Like to hear about the outcome though so good luck with it.
Looks a lot of fun!

 

http://www.blackstone-labs.com/

A slightly heavier weight synthetic will not have any detrimental affect on overall performance.

No it doesn't.

Better wear results than 10/40 dino.

 

I wouldn't think it's a good idea. The aux gearbox is not designed for a pressure lube system, as others have mentioned splash lubrication. It only needs a certain level for proper operation. Using an outside pressurized system would completely fill the aux gearbox case full of oil, and under pressure. Then I wouldn't want any wear particles from the gearbox in the bikes engines oil system. I would be concerned upon shut down that the gearbox using shared oil would self level and create an open air space. Then upon start up part of the oil system would be pumping nothing but air thru the engine, starving components of lube.

 

Sounds like a bad idea. The only way I can think to do it would be to plumb the gearbox into the return line to the sump which wouldn't require any back pressure. But this would allow unfiltered oil from the gearbox to flow into the sump. Not a good idea. A decent gearbox shouldn't require much in the way of frequent oil changes.

 

If none of the exposed system is a strict drain (no backpressure) then it wouldn't work anyway. That's why I was curious about where the oil cooler was in the scheme of things.

Thanks for the input.

 

Just for info...both sides of the oil cooler will have pressure. Just one side is the inlet while the other is the return, but still under pressure.

 

I thought the only time you changed the oil in those gearboxes was when you were rebuilding it

 

That's the general approach, but I'm running 100hp through it...needs a touch better care I think.

 

Just watched the youtube vid----sweet buggy! But noticed one issue. Check the bolt on the rear control(?) arm. In the beginning of the vid it's half way out, then around the 3:05 mark looks like it is either completely out or close. That things gotta rip!!

 

Interesting solution for shifting gears~

 

yeah at 0:23 or so I had a bubble that said I saw the bolt. It has been corrected.

I'm looking for something better. As it is when I shift it throws the shifter against it's limits, which is going to ultimately screw with the splines and the probably the innards. I need to gate the hand lever at the very least. I also need to redo my floor pedals to accommodate a clutch. I hate the hand clutch.