E: Engine Muff / Liner.

[Bill Thomas]

3 mm will be good But I would try to get it supported in the crankcase mouth.
I am surprised that the previous owner of your crankcase was able to open it up to 100 mm. I thought you risked breaking into the cyl. studs threads... Unless the studs were moved.
Cheers... Sten

I do worry about that Sten, But I worry about everything .
But as I said to Greg, There is a gap all the way round on a "D",
Not like the older Bikes, "B" and "C",
So how does the engine know how big a gap ?,
I am thinking the liner could crack with vibration ?,
But with the standard liner in my hand , It feels heavy / strong ish ?, At 3 mm
I need a man with a van to follow me !, When I give it some stick .

The only stud that is ground away a bit is a small one that goes across at the front,
About 2 or 3 inches below the top.

 

[Monkeypants]

Glen, I just hope for them that the TP Mk 5 cams survive.........if they were made later than yours then they and the followers will fail........anyway, as far as pistons go........manufacturers look at engines running at ideal conditions, with correct ignition, fuel delivery and so on.........CP and other piston makers give clearance figures around 0.0025"....... I tend to give a little more on account of our hot climate here in Aussie....so 0.0035" on twins and around 0.005" on singles.........After a rebuild/restoration I do go to a lot of trouble to ensure the ignition and carb settings are good......It is very risky and poor practice to carry out a full rebuild, then take the bike on a 2500 km rally the next day. Good to give the bike some short 5 to 10 km runs to check for any issues/leaks, as tempting as it is to keep going, this gives you the chance to sneak up on things and fix them before any real harm is done.

Apparently they reshaped the MK5s a little. They are limiting rpm to 6000, I'm not sure why.
Perhaps they reshaped the cams for this rpm change as the MK5 s normally hit max bhp at 6500.
After the grind they sent the cams and followers out for DLC coating.
I'm not sure if that stuff really works, but it sounds amazing.
The last time I heard about a miracle coating it was being used on pistons for a hotrodded Norton motor. The coating came off after a few hundred miles and wrecked the engine.

Glen

 

[Bill Thomas]

Just had a hard job getting the Drive side main bearings out,
Someone had hammered all the way round the edge,
I had to trim it back with a wood chisel !, Before I even started.

Did they ever use a steel ET19 outer oil thrower ?, I thought they were alloy ?, With the inner steel ?,
I have never seen one, It had a thin one with another steel ring up to the inner outer ring of the bearing.

This was the engine when I took it apart the drive side inner main stayed in the engine, I had to knock it out !,
Looks like it had Loctite round the outside and when cooled trapped the inner bearing = Too tight ,
This poor motor has had a hard life.

 

[Black Flash]

And I thought mine was bad. What really annoys me is that despite 27 punchmarks the bearing Ring simply fell out when I turned the case over. So obviously it was a total crap repair in the first place

 

[Bill Thomas]

I got a bit worried with mine, Just by eye the holes were not in line, I started to think the case had been messed up,
So I had to get them out quick, Nearly gave up and built a standard engine !,

The centre of the oil thrower, Was out of line, When I took it apart it had 2 outer rings, A small bit under size,
And made of steel instead of alloy !.

I used a narrow chisel to get the alloy out of the way,
But mine was so tight, It held on to the inner !, Some kind of loctite around the outside ?.

The big end was the same, It was so tight he had left some of the old type rollers OUT !,
I will use lipped main bearings , So it would not matter if it was a bit loose.

We will never know why the jobs were done that way , Strange.

 

[Vincent Brake]

And I thought mine was bad. What really annoys me is that despite 27 punchmarks the bearing Ring simply fell out when I turned the case over. So obviously it was a total crap repair in the first place

We will machine a ring to suit Berndie!!