Which engine..

[Guest]

Ok, I got the donor engines for Old Red last night.

They need some help cosmetically as there is a bit of oxidation on them. However I'm not too concerned about that at the moment.

Here is the deal.

The 81 engine appears to turn freely, however he doesn't know if it has good compression or not.

The 82 engine He had tested the compression by turning it over with the starter 8O 8O 8O And all the cylindars appear to have good compression.

However the intake boots on the 82 engine are much shorter than those that came off my 81 and the 81 I picked up at the same time. However it is noted on the 82 that it came off of an L model. So did they use different intake boots on the L models to fit into the different frame?

I haven't had time to actually measure the distances between the screws used to mount them, but they do look the same.

So, the really big question.

Should I mount the 82 engine into the 81 frame? I like the fact that the 82 no longer has screws for the side covers etc, plus the fact that he did "test" the compression on it. My concern is the intake boots and possable other differences that I haven't noticed yet.

I'm open to your opinions on this.

Amos

[shaftzuki]

Amos - this is one of those "times" you hear about - you have all of the parts in front of you, you can do it - you can make it better. :?

It is possible to bench test for compression, provided you have a sturdy place to mount the engine, a good starter and a charged battery (you'll also need a compression gauge).

If I were you, I would want to perform all of the tests I could before I made my decision. It's hard for us to have an opinion, when we can't see what you see. 8)

[bwringer]

I guess you could check to see if the boots have different part numbers on bikebandit.com. The airbox could be different from year to year or between the L and regular model, so that explanation makes sense. Changes to the cylinder head are much less likely.

If it were me, I would definitely get a reasonably strong and sober buddy to hold things down and do a compression test on both engines. Make sure you do wet and dry tests, too. If you can, try to get a look down inside the cylinders. I would also check the valve clearances to get an idea of the kind of maintenance the engine had. If one of the engines has a few tight valves, I would definitely consider using the other one. With the valve covers off, you can also get an idea of the engines' condition by looking at the amount of varnish, scuffing, etc. on the cams.

Are you planning to take the engine apart before you install it? Personally, I would at least install all new gaskets from the cylinder base up while you have it sitting there. If you're poor or in a hurry, you can usually get away without new piston rings, assuming the old ones are good. You run the chance of needing to take it all apart again, but it's only time...

Of course, you could just slap the best-looking engine in there for the summer and then take it out again to deal with all the rebuilding this winter! It's time to RIDE, man.

There's no right answer, really -- you have to examine all the parts and use the best. My bike's engine is made up of the best pieces from three different bikes.

[Anonymous]

chain it to the floor and hook up some electrics to it and fire it up *L*

i've always wanted to do that, friends of mine in highschool fires up a small block chev on an engine stand and had fun blipping the throttle to bounce it across the floor *L*

but seriosly, do as the guys above said

[Anonymous]

Hi Cool another Local GS owner
We should get together wouldn't it be cool if we could all met for sportbike west and ride up as a GS group
Mikey

[Dink]

Amos in all seriousness, I think you should put an 1150 in it!!!!
that would wake it up!!!!!
Dink

[TheBigRed]

chain it to the floor and hook up some electrics to it and fire it up *L*

i've always wanted to do that, friends of mine in highschool fires up a small block chev on an engine stand and had fun blipping the throttle to bounce it across the floor *L*

but seriosly, do as the guys above said

He did this with the 82 engine these are the compressions he got from 1-4 in that order
120:90:120:120

Between that (having known compressions) and the fact that the side covers have actual bolts, not screws, I'm thinking go with it.

I do think that I'll try to at least have a look down in the cylindars though.

If it doesn't look pretty, I should be able to bolt my jugs and put the pistons from Old Red on her. I know they worked well, since it was just the transmission I was having problems with.

There's no right answer, really -- you have to examine all the parts and use the best. My bike's engine is made up of the best pieces from three different bikes.

Yup, that is pretty much what this one will be from as near as I can figure. Parts from Old Red, and parts from these two engines (though probably more parts from Old Red than from the 81 donor engine that I picked up)

Amos