Desireable Things to do During Engine Overhaul

Sorry, there wasn't enough room to add 'While the Engine is Apart for an Overhaul'.

I've got a friend who's at that stage with a Commando when then engine's going to be apart. There have been a lot of off hand remarks about tasks that would never be reason in themselves to tear down an engine but that would be good to take care of if the engine is apart, and most importantly, if you remember to think of it at the time. I've been meaning to make a list but never got around to it. Before somebody thinks about drawing the line between what's absolutely necessary and what's frivolous, I'm thinking about things you might want to do assuming you are going to be keeping the bike for a long time.

So the kind of thing would be like Ludwig's recommendation to remove casting flash and closed up ventilation holes in the head and cylinder. He said it was equivalent to adding an oil cooler as far as keeping the temps down. I just can't recall the details. How about it Ludwig.

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Ludwig is just being dramatic on cooling claims but its not bad idea and very satisfying to clean up the over casting webs in the cast iron barrel and there is an air pocket trapper at front of head fins just one hole drilled will let escape. We have been shown thermogram of engine and the hottest spots is not deep in center of head fins as I expected but at the lower-outer exhaust port area already in most wind with noting blocking it. That is the place some hot racers add another fin too. Intake cold mix strikes the center-medial area of combustion chambers so helps that other wise expected hot spot.

Timeset weaker-smaller threads in head and cases.
Mill cylinder top level as most are .003" off level to base, then mil top of head flat to match.
Grind off ends of rockers pretty close to the ball and cap, mostly to completely solve the push rod fitting puzzle and also relieve valve train loads some.
Fit 850 stud kit to 750 crank.
Fit 7/16" cradle bolts for longer lasting less oval beating in those holes.
Can drill through rocker spindles to feed oil in one side and tap other for oil guage w/o having to stack dual bango rings.
Seal and redrill lower oil level hole in TS cover for less oil windage/heating in that area. A Jim Comstock mod told us.
Leave base plate gasket out and diddle push rods center on stems.
Fit scrolled bushes on cam or dual kind on DS for oil pocket. Groove case walls a bit and funnel open the cam oil holes some for extra peace of mind and something easy and fun to do.
Consider the modes for extra effective reed valve to get away with more blow by sealing before an issue.
Cryo temper everything ya can as long as its taken apart to point there is only one alloy present in each item or thermal differences may damage something like popping valve seats out of head.
Could polish up parts and inside of cases for faster oil drain to carry more heat off with it faster.

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Another ludwig idea, the cam oil trough.

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Lose any cam bushing retaining bend-over tab rings (if applicable).

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Hehe clearing castings is what I came to call my Commando lap dance stimulation. The head fin vent hole is nice touch I did in '03 but how could we know its even detectable for oil temps, so my remark about the dramatic statement. Harley did some very deep study on oil in heads and cooling and essentially found No amount of cold oil flow made a difference in head temps but sure did over cook the oil so ridiculous size cooler would be needed, thus no oil cooled Harley heads. Just lube and some valve spring heat flushing is all we can expect. There is a science to drilling w/o compromise of metal heat flow mass though its pretty much the same as intuitive drilling would produce.

If you have a method to recreate the cam oil bath I'm all ears and will follow your lead. That deserves its own thread. In meantime I an habitual wet sump starter.

Turns out I was not the most abusive to my 1st Combat a shop demo bike in red neck hod rod heaven, which had its case halves clutch drop power torqued to bind on dowels till relieved .003". 10 mm is good but I liked what old racers told me and made sense so interference fitted 7/16" = 0.4375" = 11.1125mm. Not as light as your 10 mm though which is plenty for most sane users if they can overlook the metric part. Peels got meat enough to be 1/3 drilled out, like many other items in my head I'm told.

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Ludwig, how is it fastened on?

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This looks like a "get out the popcorn" kinda thread.

How about repairing or beefing up the exhaust port threads? I think Ludwig has already addressed anything I could list otherwise. They would have been notes I had made from his previous posts anyway.

Russ

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ludwig said:

Maybe I will add some pics later ..

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Your pictures of the roads in Europe have been fantastic, but nothing beats tech pic's with narrative.

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rvich said:

This looks like a "get out the popcorn" kinda thread.

How about repairing or beefing up the exhaust port threads? I think Ludwig has already addressed anything I could list otherwise. They would have been notes I had made from his previous posts anyway.

Russ

Click to expand...

I don't know if it holds up to expert scrutiny, but I heard there might be a reason to go with a sleeve that's threaded in with a key to lock it. The heat from welding in a sleeve can mess with the metal around the exhaust valve seats?

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I suppoose if you wernt short of a few quid , Gold Plateing would look pretty cool . :mrgreen:



A good Kiwi bike , of course . 8)

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Softer cams, smaller carbs, lower compression to 7-1. lighter valve springs, rev limiter set to 6000 ..and a GSX1000RR :lol: Best of both worlds. nice mild classic and a balls out rocket ship...what more can a man want?....its like a good old quite girl back home and a ravin Hooker down the village.....heaven :?: now what man could want better?

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Two girls back home and 3 hookers???

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Greedy!
Next you will want three commados :lol:


Quote="OzT"]Two girls back home and 3 hookers??? [/quote]

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rpatton said:

rvich said:

This looks like a "get out the popcorn" kinda thread.

How about repairing or beefing up the exhaust port threads? I think Ludwig has already addressed anything I could list otherwise. They would have been notes I had made from his previous posts anyway.

Russ

Click to expand...

I don't know if it holds up to expert scrutiny, but I heard there might be a reason to go with a sleeve that's threaded in with a key to lock it. The heat from welding in a sleeve can mess with the metal around the exhaust valve seats?

Click to expand...

The Comnoz alu-bronze sleeve gets my vote. It isn't exactly a home repair but you don't have to weld on the head. I saw somebody who had stainless steel sleeves put in. I dunno, stainless steal is over rated in my opinion. But then I have a 60-year old boat and it is loaded with bronze stuff that still comes apart when I ask it to.

Russ