"Heading" Out..

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RoadScholar

RoadScholar

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I have a customer that is sending me a 750 engine for rebuilding. During a conversation he expressed some concern about removing the engine as a lump; I suggested that he take the head off which would give him more room to maneuver the engine out; he sent me this picture:

"Heading" Out..


Was "rebuilt" once by a PO, possibly the hack that can fix anything as long as he has enough beer?

And it ran many miles; I suggested that he stop buying lottery tickets as his luck was clearly spent.

Amazing!

Best.
 
swooshdave said:
Are you going to recommend new valves? :D
Click to expand...

Not if they can be straightened...Probably can save the pistons too, after all look what they have been through; true survivors...

I'm sure that a complete forensics analysis will have a broader tale to tell, I'll keep this thread updated.

Best
 
Does the engine really need to be rebuilt or was the owner complaining about it being a bit down on power (perhaps, ahem, due to some valves not opening all the way)?

If it's to be rebuilt then wouldn't new valves and pistons be replaced? Neither are horribly expensive.
 
Modified in situ. How did it survive when so many disintegrate for less cause?
 
Someone certainly had their head up their arse when they "handed" those pistons.
 
Having never looked at a engine with it's head off like this, forgive me but what are you seeing here? Is it the coking or are those witness marks there?
 
Fast Eddie said:
I wonder how many times that’s been done ?!

It’s a reminder that dear PO’s can often be a large contributory cause of old bikes reputation for poor reliability !
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Very salient point. Seems to me that as a motorcycle starts moving down the food chain so does its care; there is always a friend or uncle that has enough tools to be dangerous.

Best.
 
Tornado said:
Having never looked at a engine with it's head off like this, forgive me but what are you seeing here? Is it the coking or are those witness marks there?
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The pistons are are around the wrong way :eek: Hence the "Dings" inboard of each valve pocket.
 
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Fast Eddie said:
I wonder how many times that’s been done ?!

It’s a reminder that dear PO’s can often be a large contributory cause of old bikes reputation for poor reliability !
Click to expand...

I've seen it twice so far on engines I took apart, and once on a friend's bike after he pulled the head, but that's over a 49 year time span owning and working on Nortons.

Ken
 
We have seen other motors on here with the same witness marks. I would think that the pistons are now tempered so probably better than new! Imagine hiring an elf to tap the top of the piston with a hammer a few thousand times a minute for an extended time. It would be expensive as hell!
 
I was once playing silly bugger's with a big bore BSA b25
And I hadn't cut the exhaust valve pocket deep enough in the piston and the exhaust valve "just" caught the piston , the noise was horrendous
No where near as bad as the norton pictured above!
I just wonder how loud it was??
 
Well, part of the problem is that Emgo pistons (if these are them), were mis-marked L and R for years. Many shops that didn’t know any better, simply installed them like this. Seen a few of these for sure. It gets really ugly on a 72 Combat with the shaved head and high lift cam since those valves go a whole lot further down into the piston
Maybe roadscholar can see if this is the case by cleaning up the carbon a bit in the center
 
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It took me a while to see the problem. My emgo pistons (purchased about 8 months ago) were marked l and r
"Heading" Out..
 
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