Well I am building another one. I have an XL that was dropped off that I will be transplanting the Yamaha Nytro motor and an RPM Gearbox in over this winter. Figured I would do another build thread and this time capture the RPM gearbox install and everything associated with that.


I started on the project last Saturday and did radiator repair. 3 of the mounting tabs were wallowed out really bad. So I cut off all 4 tabs and made new ones. Made them out of 1/4" thick bar stock instead of the 1/8" thick ones that failed. Needless to say spent most of the day on that repair and did not get much started as far as the actual swap.


Back at it today, I got the car prepped to drop the motor in and also machined the rear bearing carriers for the brake caliper bracket for the outboard brakes as that seems to be the best solution on the forum when it comes to the RPM gearbox swap.


Here are a couple of pictures of the beginning of this swap.









Marc

The RPM Gearbox arrived and I have been working on mounting brackets for the conversion. I welded the rear bracket up today and it turned out pretty nice. I have the front bracket pieces cut just need to align and weld.

NICE, how well does the exhaust clear on a stock engine with the RPM box ?

I don't mean to step on your thread here Marc,but we have done a couple of these RPM gearbox swaps here in Oregon. They are almost the same size as the stock gearbox. As long as you put outboard brakes on your car, there is no problem clearing the normally aspirated or even the turbo charged exhaust. The problem in the past was the brake rotor was either on the top or intermediate shaft on the RPM gearbox. There is no problem with the Polaris RZR style outboard brakes installed on the Redline cars.

No worries Dave, I was going to suggest that we get input from you or Scott as I know that you guys have already done those conversions with stock motors.

Maybe you or Scott could help me out with some information on the bearing and carrier that you have to run on the input shaft of the RPM gearbox for proper secondary clutch alignment.

Thanks for the good information as always.

Marc

Mark,


Here a couple of pictures of the bearing stay I came up with. It is a self aligning pillow block bearing. Bracket welded to vertical frame member with an adjustable bracket to the bearing. Also modified stock bumpstop.
You can call me for some of the details on the bearing, spacers and such.

Attached Images

File Type: jpg	RPM Final Install 004.JPG (2.57 MB, 59 views)
File Type: jpg	RPM Final Install 006.JPG (1.94 MB, 54 views)
File Type: jpg	RPM Final Install 009.JPG (1.85 MB, 52 views)

Marc, Scott also figured out that there is a collar on the input shaft that fits into the seal in the RPM gearbox. That collar needs to be held in place by the pillow block bearing or with spacers between the collar and the pillow block bearing. If it slides out of the seal you will have a oil mess. The purpose of the pillow block bearing is to support the input shaft in the RPM gearbox so the case doesn't brake or crack. The RPM gearbox doesn't have a snout sticking out to support the long input shaft that we have for our secondary clutch to mount on. That support bearing needs to be mounted solid to the frame like the gearbox is. You will still need a bump stop between the gearbox and the engine like Scott's picture shows to keep the engine and gearbox distance constant. That bump stop can't be mounted solid to both because the engine has to move. Scott's and Jeff's cars both worked perfectly with the RPM gearbox mounted like Scott's pictures show.

Thanks Dave! Thanks Scott!

That definitely helps and I appreciate the knowledge and experience sharing.

Marc

I finished the front gearbox mount tonight.







Marc

Well from Pilot's and Klemdotter's posts and a phone call to Klemdotter I am pretty good to go with info on the bearing and carrier. I ordered a self aligning mounted bearing from McMaster Carr. Almost all the mounted bearings for a 1 inch shaft dia. are 1.5 inches wide and about 5.5 inches long. So that is the dimensions of the one that I am using. I built a billet aluminum adjustable mount for the bearing. I will make some tabs off of the frame that will secure the aluminum mount.








I'll have to make minor adjustments to make sure the FNR lever on the back of the gearbox moves freely. But all in all I am pretty pleased with how it is turning out so far.


Marc