Interlocking 'zig-zag' flat metal bar

[SHogan]

This might sound a bit odd but I can't think of the correct way of describing the type of flat metal bar I'm after. Essentially I'm after a mechanism to move a small engine backwards or forwards to tension a belt depending on the size of pulley that's being used on the crankshaft. What I was thinking was using some flat bar with a zig-zag face on the chassis of the machine and the same bar on the base of the engine. That way when the bolts are tightened the zig-zags interlock and the engine won't shift backwards or forwards.
What's the name of the stuff I'm after as I can't seem to find the right words to describe it so that a Google search will reveal where to buy it from!
Thanks

 

[WorkshopChris]

Not to sure what you ar looking for but is it like rack and pinion bar.
http://www.bandhgears.co.uk/rack_pinions.php

 

[rtbcomp]

Search Google Images for "Linear Ratchet", should find something.

 

[sardine]

Usually on a small engine a base with two slots for the holding down bolts is sufficient.

 

[tinman123]

something like this.

 

[Pete.]

Or mount the engine on a pivoting base. Release the pivot and rock the engine towards/away to tension the belt.

OR, use variable-speed pulleys, then you can change the speed on the fly.

 

[tinman123]

ptes idea of a mounting base like an alternator mount is a good one, faster too.

 

[sardine]

Doesn't need to be fancy, just a base frame with two milled slots. Depends the size of this mystery engine ?

 

[MCKDAVID]

from what you're describing, I think what tinman was proposing would be best, we use these all the time on fan units to adjust the drive belts, nothing complex about them, angle iron, and screwed rod, you'd make one up in no time.

not sure I'd go with a pivot point, as depending on how much you need to change the tension it might incline the engine, which could result in oil starvation if it was that much.