E: Engine Muff / Liner.

[Bill Thomas]

The heat transfer 'grease' which is referred to in #21 above is available from anywhere that supplies electronic bits and pieces. A lot of electronic devices run hot and have heat sinks attached to them. These have to be linked to the hot component via the heat transfer grease to ensure that the heat can flow to the heat sink.

I am hoping the shop who makes my liner, Will fit it and bore to fit the piston ,
Which I will leave with him, So it will be out of my hands as far as a heat transfer.

 

[Albervin]

The quality of the piston? The rings? The fuel? I did some not so serious damage to one of my cars with a 120mm stroke a couple of years ago. Just one piston!!! But that lead to honing four bores, four pistons etc. Not cheap. The problem?? One piston was 1.5 thou "off" .. For twenty years it was not a problem and then I did a big "outback" trip with long periods of sustained speeds. That is why my Vincents have that extra clearance; no smoke, no seizures but lots of smiles.

 

[Bill Thomas]

What gaps do you use Al,
Greg says it's a sticking Plaster, But if it works !.

 

[Albervin]

As I said depends on pistons. I go for 4.5 thou on the Rapide and 5 on the Shadow. Forged pistons. 276 and 289 carbs. Nothing flash except the Shadow has that high first gear... Over 25,000 miles on the Rapide. Modern BT-H with 34º advance using 95 octane fuel.

 

[Monkeypants]

Hi there Glen, Yes true but only so far.......To get these things breathing, you really need to make new heads that are taller.........need to increase the height from the valve seat to the guide boss about 20 mm or so........this will give better port angles and you can stand the valves up more, thus the combustion chamber can be less deep, no need for a big tall piston crown........just gets better and better......this is exactly what the Horner brothers have done........gone to a bigger bore short stroke........near same specs as a 327 Chev.......this bore/stroke combination is excellent for building big HP. I've been conversing with Steve Hamel a little lately and he is making up some special billet heads from scratch, using some of the things i've just mensioned........Its all just a bit of fun.

Racing is a different world, isn't it?

The large TP engine sure is fun on the street, especially in a light bike.

The graph below is crankshaft tq . The TP 1330 was recently built by Fritz Egli Jr for a customer I chat with.
The test was done on the Egli dyno which Godet told me was " not a joke like some"
I added the line to Triumph's graph.
The 1200 Thruxton R engine makes about twice the torque and horsepower of a standard Vincent twin and goes zero to sixty at least as fast as my 161 bhp Daytona.
I would say that Fritz's customer is in for a fun ride!
They stopped the test at 5700 as the engine is not fully broken in yet. Max hp is supposed to be right around 6500 with the TP mk5 cams used here

 

[Sten Jensen]

I was wondering if it would be better going for a thicker liner,
At the expense of even thinner muff,
I mean lots of bikes run iron barrels.

I believe BSA did that on the Gold Star, went from a thin liner in alu Cylinder to an iron Cylinder with shrunk on alu cooling ribs.

 

[Bill Thomas]

Thanks Sten, I am in a bit of a Rut,
I have had other English Bikes and a Kwaka Mach 3 ,
But I don't remember much about the spec's of them.

With our Pushrods where they are we can't do much,
But they have done me for 57 ish years , So if I am lucky, I might get another few years .

I will stick with 3 mm liner walls, I must be a Standard Man ?.

 

[vibrac]

6 thou for me most of my engines were racers once and I never had any troubles

 

[Sten Jensen]

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

 

[greg brillus]

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.