Engine mountings

[Crazymanneil]

Ok, I guess this topic is a perenial favourite though I may have been dozing at the back of the class til now...

Basically the time has come to mount everything up in the tiger frame I now have. Now I have the engine running and a gearbox sitting ready to go into the thing. I think best way will be metal brackets made to fit however the engine and gearbox want to sit in the bike. Rubber will not be possible because it would misalign the primary drive I think. Hopefully this won't be too much of an issue for vibration.

I'm open to suggestions on how to go about this. I.e. how do I hold a gearbox and engine perfectly straight while fabricating brackets at the same time? Do I grow another pair of arms or something? I know the belt drive I intend to use will need to be perfectly aligned so the belt does not run off the pulleys and I can do this with a straight edge. Just not sure how to hold the engine and box in the right position before brackets are made up. Would you build a jig or something? Use ropes?

I was also thinking of using turnbuckles for mounting eg -

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0052120426

Though I realised that the engine would swing left to right in the frame and possibly other ways I'd not thought of. May be possible to use them for a few bars but I think I'll still need to weld the main mountings. Shame because I could use the existing mounts to bolt right though rose joints and make up spacers to take up any slack. Then the thing could be adjusted until perfect.

Anyhoo. Will post some pics once things start moving...

N

[coachgeo]

Can you do me a favor and take pics of your engineless tiger? If it is not pulled out yet can you take pics of the OEM engine mounting system?

Look forward to watching your project.

IMHO uneducated opinioun.. I would build a jig. Sit it on something adjustable like an automotive floor jack in a way so you can make minute adjustments etc.

[Crazymanneil]

Hey coach. I'll take you a photo of the engineless bike. The engine is out, sold and posted away now. Some fun swinging that sucker out let me tell ya!

Wonder if my welding skills are any good....

n

[coachgeo]

fast responce. Im in a rush.

borrowing from Heiko if I understand how he did it right.

A steel plate mounted between bell housing* and block- either with welded on bar or custom plate made larger to also hold tranny. This plate would also have mounts attached that attach to where OEM engine attached to Tiger frame.

Then some extra bracing here and there on between frame and plate, engine, or tranny to make it more solid.

Maybe look close at how custom harley folk attach their ultimas to the harley engine for ideas too?

Would also think an extended custom plate between bell housing and engine that is long enough to include tranny mount would be a good way to make sure the tranny is true to the engine so the belt drive is trued to everything.

*SAE or OEM bellhousing modifed (chuck cut out to pass belt thru) to become cover for belt drive gear at engine side or to build a complete belt drive cover off of.

[coachgeo]

Plate shown in pic.

If no bellhousing used then plate would need to be significantly thicker to hold weight of engine. With bell housing it would be stronger thus you might could go thinner.

[Crazymanneil]

Thanks for the replies coach. I've not forgotten about the photo of the tiger frame, just having some issues getting time at the minute.

I actually have another tiger frame sitting in the garage (bare frame). I think I'll line up the gearbox and make mountings for it first on the bike, using rear sprocket for alignment. Then I'll take that assembly off and bolt it to the bare frame and setup on the bench. I should be able to move things around easier that way to make the rest of the mounts. Oh how I'd love a plasma cutter....

The plate from bellhousing to other side of engine is a great idea. Not sure if it will work on my application though because the bellhousing is basically a cast part of the block (almost in reverse to whats in the photo you showed). I will figure out somewhere else to bolt to though because there is engine mountings on the rear of my engine.

N

[coachgeo]

you may be able to run brackets also from the OEM engine mounts on the block to reinforce or be "the" structural cage your engine mounts with.

[Crazymanneil]

Guess we'll find out what happens this weekend. I just got some spacers made up today although I think the bottom ones are about 2 mm too long. Would appreciate if you have any measurements on the length of the rear lugs on the standard engine. Either they are a bit too long or I need to bash them into place Ho hum.

Heres a pic of the bike with engine out. Mounts are highlighted and same on the other side.

N