Triumphrat

loxx101 · 07-19-2012, 07:00 AM

Okay, fair!

My oil tank has been cut out and replaced with a thicker walled tube due to the monoshock so shotblasting may be the easier option...

I think my castings have been fully plugged up. I'll double check!

DAVE M · 07-19-2012, 07:34 AM

you said that you were considering filling the unused part of the under tank frame with oil?

I'd assume that any work you do to create the tank will be before paint removal and replacement. Shot gets everywhere and removal will drive you nuts

If you're going with an external oil tank. fine.

loxx101 · 07-19-2012, 08:37 AM

Yeah I am planning to do the tank after it's shotblasted I think. Either that or cut a hole right on the bend of the top tube and have them blast inside too. If I have a big hole to work through then getting shot out shouldn't be too bad. I can always weld that back on.

I'm going to have to remove any rubbish that is in the tank anyway. Rust etc.

If I shotblast it first though, there will no openings into the tank so no chance of any shot getting in. That may be the best idea.

loxx101 · 07-19-2012, 03:12 PM

I spoke to the local machine shop today (who I have been referred to from a couple of local triumph people).

After an hour and a half on the phone I have a rough price list together and work I will most probably have done.

I'm having the bores done, new pistons, rings, gudgeon pins, circlips.
Crank will be cleaned, shotblasted, sludge trap done, journals checked and renewed if need be. Conrod weights matched etc.
Crank is then being dynamically balanced by Dave Nourish.
New main bearings both sides.
All castings for engine & box aquablasted and painted.
New needle rollers in the gearbox.
Head ported.
New valve seats cut, new valves, new guides & new springs.

Probably going to fit some new NH 1/2 race cams or something while I'm at it.

I think then I'm going to go with a brand new Amal carb purely because the rest of it is costing me a fortune so need to save money somewhere. Brand new 32mm Amal will do perfectly well for now anyway.

DAVE M · 07-20-2012, 06:38 AM

how much is that lot costing?

loxx101 · 07-20-2012, 09:35 PM

With the NH cams and a new amal it'll be just shy of a grand if it needs all the work doing. If the engine is in good nick measurement wise it'll cost a lot less!

DAVE M · 07-29-2012, 08:53 AM

I wouldn't get them to blast the inside of the tank.

The stuff that gets in will be far harder to get out than anything that they manage to remove. There shouldn't be too much gunge in there and a pressure wash with mechanical scrubbing would get it out easier.

When I did my bike I had the bottom of the tank off and just kept going until the cleaning fluid came out clear. Not an option in your case, but you can use the oil filler hole

loxx101 · 11-26-2012, 12:48 PM

Just a little update as things are starting to come together now. This isn't a comprehensive update by any stretch of the imagination but a small snippet into what I've been doing.

Basically, I've had a lot of stuff shotblasted, engine bits powdercoated, rebore etc. I have all brand new cams, new bearings, crank has been balanced etc. Bought a Tri Spark system for it including the heavy would dual fire coil. 3 phase alternator, regulator, rectifier etc. Head is having the valve seats re-cut and new valves fitted, probably new guides as well. Tonnes more going on but I can't remember what now, wallet feeling lighter than ever before though.

I have gone for the standard T140 inlet cam but new and a late 650 exhaust.

I've gone for a firetec coating on the head and rocker boxes. Bores are painted and baked, all other casings are done with a rough textured finish. Factory finish for Triumphs would have been a fine texture (probably not on bikes this old but still). Nothing like standard and I am loving it!

Shotblasted, ready for some minor mods (making a dual fire coil recess in the top tube etc)

Got hold of some new (old) tappets and cleaned them up a bit and had them reground for the new cams:

GrandPaulZ · 11-27-2012, 09:37 AM

Gotta love those 4-month gaps...

Mr.Pete · 11-28-2012, 12:04 AM

Quote:

Originally Posted by loxx101

The bores cleaned up fairly well but not perfect. Gapped anyway and they read 15.5 thou. The book states between 10 and 14 thou so unfortunately (or fortunately, whichever way you look at it) it's going to need a rebore.

Since I now have to get that done (and of course, new pistons) then it'll be 0.040 oversized but perfect bores and perfect gap. Gonna cost a bit but there you go, at least it'll be right.

This is complete rubbish,and I'm surprised no-one picked up on it.I don't read every build thread,and expect technical issues/queries will end up in the technical section,or more often the general forum.

For any practical purposes,it wouldn't matter if the ring gap was 0.060" as long as the rings otherwise fitted well.You would be hard-pressed to notice any difference in performance or oil consumption.

The most worn T140 cylinder I've re-ringed had 0.007" taper/wear.That's enough to increase the ring gap at the top of the cylinder by 0.022",compared to the lower part of the cylinder.So if I had 0.012" gap at the unworn part of the cylinder,it would be 0.034" gap at the top of the cylinder.

Did it run fine with a hone and re-ring?Yes,of course.It still ran fine 20 years later (never been apart since).

I would always recommend you use about 30% bigger gap on the second compression ring,compared to the gap on the top ring.It helps the top ring to seal,increases power,and reduces oil consumption.
If you had 0.010" on the top ring,0.013" on the second ring.