Triumphrat

Fixed_Ops · 04-13-2009, 05:36 PM

Hey all - back again after pulling the engine with the failed motor mount on a 99 Speed3 engine I was swapping into my 2000 Daytona 955. There is another thread (Need 955 Motor) that has pics of the rear engine mount failure....it looks pretty 'terminal' to me as though it will not be able to be welded so I'm on to thinking about rebuilding the 'original' engine that came in my steed

If you look at the attached pics, you'll see that all three of the piston domes have a heavy carbon layer and the #3(?) piston (left side of engine) has a fair degree of oxidization on the piston dome from leaking coolant - this engine 'allegedly' had a blown headgasket on this cylinder which is why I decided to replace it after purchasing the bike. The other photos show the piston domes 'a little' cleaner after using lots of pentrating fluid in an effort to get some of the junk off. Also, note that in all three pics you can clearly see no failure of the head gasket....the head bolts were all seemingly torqued to spec when I unbuttoned the head and I didn't see any obvious cracks/failures in the head itself upon inspection although the valves for this same cylinder also had some 'schmutz' built up on them with a little more telltale coolant oxidation on their stems. But otherwise, the head looks very clean and solid with no damage that I can see. I'll post more pics tomorrow of the head and valve stems for commentary and analysis.

The question is, based upon these images, would you recommend I even [I]try[I] to rebuild this motor? Or would you steer clear of it simply based upon the obvious damage? My concern is that the head could be warped or could have an interior failure/crack that I cannot see and will run up against once I reassemble. I have a good cyl head on the 99 Speed3 motor that I could swap over I suppose but then I'll have to deck the head (I would think) and I start down the path of a lot of labor and $ into getting this 'suspect' engine back together (suspect since, although it turns freely and has no obvious cylinder scoring, it has a LOT of carbon build up and an as-yet unknown cause of coolant leak). Anybody out there give me thoughts/opinions....worth it or not?

Also, I'm still looking for another complete engine (99-01) if anyone has one for a reasonable price....a couple people thought they could help but no one's been able to come through yet. Thanks in advance.

drakewn · 04-14-2009, 10:24 AM

I would replace the head gasket, check for any obvious cracks that could be the cause of the leakage, and throw a straight-edge on the head to see if there is any warp. Are there any telltale signs that the gasket could be the culprit?

The general rule of thumb for warp is a maximum of .002" for any 6" length, and .004" for the whole length of the head, and .002" across the width. Some people even believe that .006" along the whole length is ok.

It might be a good time to take the opportunity to strip the whole engine down and rebuild it properly. Like magnafluxing the head and block, new bearings, etc. If you buy a used engine, who is to say that it isn't a lemon in need of a rebuild?

Fixed_Ops · 04-14-2009, 12:13 PM

Drake - thanks for your insight on this. Basically, the engine with the 'broken' case is a known good engine from a 99 Speed3 and this one is a somewhat unknown engine that came with the bike.

I was really hoping to use one of the engines to get through the summer of riding and then rebuild the other one in the autumn/winter next year....don't have time right now to do a full rebuild and, for the $ I'll spend on gaskets alone I can probably just buy another known good engine as a surrogate heart for the time being. Nonetheless, as I was pulling the head on this motor, I noticed that aside from being grimy (and filthy piston domes - the prev owner was running a TOR high pipe and I suspect he had the wrong tune and was running rich as hell) I don't see any internal 'damage' on the cylinder walls or other mechanicals. I'm probably going to pull the oil pan later today and see what the bottom end looks like....if I don't see any obvious scoring or metal flakes, I reckon that I'll redo the head gasket (after checking head for true) and throw it back together for the summer...then I can do a 'proper' rebuild next winter....

Just out of curiousity, do you have any idea where I could get the best deal on all the various bits needed to rebuild a complete motor (i.e. gasket kits as well as crush sleeves, etc)? One of the things dissuading me from rebuilding right now is the astronomical price of the bits needed to do it! Re-friggin-diculous IMHO....

Also - the Triumph manual notes to reuse the head bolts???? This seems counterintuitive to me but since they are relatively low torque, is this really okay to do? Thanks again.

drakewn · 04-15-2009, 09:58 AM

I like to play it on the safe side and replace the head bolts everytime. Especially if there is any warp, the bolts are the first to give and will stretch a bit. But if you just want to get riding this summer, and the head is ok, then your old bolts are probably fine. You could try these guys for more info on rebuild kits:

www.triumph-ant.co.uk

They rebuild triumphs, but I'm not sure whether they sell bits and pieces.