Please help! 72 650 tiger engine. What frame is it in? Can't find a VIN

The frame looks like the remains of a BSA.

 

I would not trust an anonymous frame like that any further than I could throw it.
Who made it?
Are they competent at tube bending and welding?
What grade of steel was used in its manufacture?
Is it fit for purpose?
Do you have a boat in need of an anchor?
Is the world round?
Is space infinite?
Is my tea ready yet?

Anyway, welcome in.

As you may be able to tell, I have no idea what your frame is, but it has obviously been hacked about more than a little bit, so I would be very wary of it.

Or am I just being over cautious?

 

If I was you I would look for a standard frame or a donor bike, it looks a bit pants

 

Any one that owns up will be admitting bike theft!!! Hmm! I think your search will end there! What is the position with reging a bike with a nicked frame?

 

Hi and welcome - and good luck with this.
Someone has tried to file off the number to make it untraceable - normally a sign that it's been stolen.

 

Looking at your second pix i am sure that your frame is a BSA a75 Rocket Three front loop and the rest made up, the original number would have been on the left frame lug and that has been ground off :-(.

 

Sorry didn't mean to offend, it looked like the number had been ground off which was a popular practice way back in 70-80's with nicked bikes and jokingly thought someone in here might recognise their handywork!

 

I took a pix of my Su's frame for you to compare with yours, as you can see on her frame there is a raised part with a flat surface that the numbers go on that is clearly missing on your frame :-(.

 

The above would only apply if it is a A75 frame, it could also be an early A65 frame and the numbers would be on the headstock reinforcement plate on the left.

 

Hi Durantson. Alberta eh, (I'm jealous as f**k), a very nice bit of planet Earth.
When you get it all the crap of the frame I would SERIOUSLY SUGGEST that you get the whole damned thing checked by someone whos up to speed with non-destructive testing such as magnetic particle or dye penetration are pretty good techniques or if you have loads of cash ultra-sonic testing. Speaking as someone who used to inspect steel work and pipe work for a living, some of the welding looks a bit suspect as does some of the corrosion. A competent repair shop should be able to sort out most of the problems with the frame.
Just my opinion based on your photos but better safe than under a truck, and you have some bloody big trucks out in Alberta