Triumphrat

kurben · 01-07-2008

Hello!

I am new here at this forum and this will be my first post. I am also new to classic bikes and also Triumph so please be gentle

I recently got hold of Triumph Trophy pre-unit from 1957 that needs to be restored in the engine. I will not go into detail in this thread of what my plans are so just this first question.

One of the valve guides has broken and as you can see on this picture it has been trapped between the springs for some time, all the rough edges has been smoothened and also made some damages to the valve stem.

Broken valve guide:

Where the valve guide used to be..

Valve:

What I am going to need is to replace all of the guides and probably all of the valves and springs, I see heavy wear on all valve stems.

I read in "Triumph Tuning" by Stan Shenton, that you should always use bronze valve guides if you are going to change them.
So what type of valves and what type of valve guides should I use? I need the numbers for ordering. Also if there are any performance options regarding valves I am all ears, i.e lighter versions or in any other way better.
The engine will be slightly tuned.

/Regards Martin

Mecchanica · 01-07-2008

High nickel alloy Ampco 45 guides are the best. As are Kibblewhite Black Diamond valves. Try MAP cycle enterprises for the parts.

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=009

You may need to contact Kibblewhite Precision Machining directly for valves for the 500, they would be semi-custom made, I think.

http://www.blackdiamondvalves.com/products.htm

kurben · 01-09-2008

Thank you, I have already seen those Black diamond valves and as I have heard they are also the recomended ones if one would like to convert for unleaded fuel.

If I would go for oversize and also change the seats what is the recomended size? I will also change cams but not shure wich ones, and also new pistons, probably 9:1.

Any recomendations on the complete package? I mean cams, size on valves and pistons. Just to get a midly tuned engine that likes to rev and is supposed to see a track once in a while.

Mecchanica · 01-09-2008

With the iron head, you really need to keep the compression ratio under 9 to 1 for road use, unless you modify the oil system to flood the top end with oil and fit an oil cooler. These long rod/long stroke five hundreds make good torque at mid-rpm, so, to capitalize on the engine's inherent strong suit, a moderate cam with both more lift and more duration works well, and, of course, there is no replacement for displacement, a bigger bore always gives more grunt. A higher lift and longer duration camshaft makes sense, and use STD tappets to extend cam life. Lighten the valve train....lighten the tappets, fit lighter and stiffer tubular pushrods, allen broached adjusters and alloy locknuts. Get the 2 50 tooth cam pinions from a later unit 500...say 69 or later, as they are the same size, have three keyways for cam tuning, and are have flame hardened teeth. If you have room, fit the T140 pinions, which are heavier and wider by an eighth inch. They serve as flywheels to damp valve train surge and pulse. It would be worth it to take the T140 heavy pinions and thin them to fit, as the addl. mass would be helpful.
Have oversized seats installed, since iron doesn't deal with low lead as well as the hardened seats in the alloy heads, and as stated, the Kibblewhite valves. I suspect with oversized seats, you will be able to use the late preunit valves and not have to have them made for your use.
Use the 66-on bottom spring retainers and short springs, alloy top retainers. The short springs have harmonics at higher revs, minimizing the chance of valve float.
Fit a new high output oil pump, a Morgo piston pump is fine, but if you are using the Oil Cooling idea, use the gear pump and an external oil pressure relief valve. If you are interested in this system, I can go into it in detail in a subsequent post.
Use new headbolts and make sure all the threads are clean to get accurate torquing.
The bottom end needs to be perfect, so pull it all the way down and upgrade everything you can. New cam bushes align reamed and honed in place. One piece crank, if available. Stronger con rods, or at least carefully refurbish your stock ones. Smooth, polish, then shot peen. Hardened cams, aftermarket.
Up the carb size to 30mm if single carb, 28mm if dual. Dual carb adaptors are available on occasion on ebay or have a machinist make one.
Dynamically balance the whole rig.
Get a five speed gearset, complete, and install it in the gearbox.
That should get you started.

kurben · 01-09-2008

Wow thanks that will keep me busy for a while!

kurben · 01-10-2008

You wrote steel head? But this head is all aluminium so are the cylinders except for the steel liner. Does that make any diffrence in usable compression?

This is the number of the head E2679 AM2 if that makes any sence?:

Mecchanica · 01-10-2008

Right. Don't see many of those early alloy top ends, I just assumed it was iron. Yes, you can raise the compression ratio to 9.5 or even a little higher, depending on what quality and octane rating fuel you have available and what you are willing to spend for it.

wordman5 · 08-28-2008

Hello, am new here and apologize for commandeering this thread.
However, I have a question regarding the Triumph cylinder head marked E2679 AM2.
I'm trying to put together a 1951 T100 motor, and have a head marked E2679 AM2. I'm not sure if that's the correct head, or if it will even work, on that motor. I have Roy Bacon's Triumph Twin Restoration book, and that head number isn't listed anywhere.
Any advice would be greatly appreciated.
Thanks again.