Triumph Rat Motorcycle Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
140 Posts
Discussion Starter #1
Hi All

I am restoring a 1969 T100C which hasnt been running for 25 years
The bore is in good order showing approx 1.5 thou wear.
I am unsure as too how to hone for a set of new rings, I dont want to take a lot of metal off the bore, I just want the rings to bed in properly.
Ill have this work done by an engine rebuilder, but which grit, and what type of hone should they be using.
Any opinions would be appreciated

Cheers
 

·
Registered
Joined
·
625 Posts
First off, you should know that 500s are notorious for not wanting to seat rings.

That being said, I am well over 2000 miles into a top end job with successfully and completely seated rings. (and oil tight pushrod tubes to boot!)

If I was to make a recommendation, I would say to use a ball hone. However, when we did mine, we didn't have one the right size, so we used one of those spring-loaded 3 stone cylinder hones, oiled the bores, and made several passes in each until we had a semi-reflective surface with visible cross-hatching.

I did a 1000 mile (REALLY!) break-in period where I avoided sitting in traffic, never let the bike sit and idle waiting for me, and ALWAYS varied the engine speed while riding. (roll on throttle ... roll off throttle) Seriously, I did this for 1000 miles ... pretty annoying ...

At a few different points during the break-in, I actually felt the compression come up (upon rebuild, I could start it with my hand ... easily ... it had VERY little compression) ... the biggest of these jumps was between 700 and 800 miles ... it really woke up then.

Paint your jugs BEFORE honing, btw ...
 

·
Registered
Joined
·
1,034 Posts
according to the factory :






also clipped from an article by John Healy :

"If you provided a 100 grit you would remove too much from the ring during break-in. The ring would loose most of its useful life. As you approach 220 you won't , unless you are extremely careful, wear anything from the face of the ring, or cylinder, and risk oil blow-by and the oil burning onto the cylinder bore called "glazing." There must be a balance. I find 150 to 200 grit to offer a reasonable compromise and I am sure the rings have a chance of breaking in even if the customer doesn't follow through with his part of the job. "


also all this assumes you are using original equipment type grey cast iron rings .

cheers , Woody
 

·
Registered
Joined
·
140 Posts
Discussion Starter #5
Thanks Guys
Great information. RC when you washed the bores did you use hot soapy water and then WD40?
I note that the Triumph service bulletin is for the 650cc engine but presume it would also apply to the 500 cc

Thanks and regards

John
 

·
Registered
Joined
·
625 Posts
As I recall, I used a light soap and water to wash the barrels and (I think) I wiped them down with lacquer thinner to remove any soap residue. I then IMMEDIATELY wiped with oil and stuffed with rags until we were ready to fit them ...
 
1 - 6 of 6 Posts
Top