Triumphrat

Old Cafe Racer · 12-02-2012, 03:36 AM

You wasting your time with a head torque plate unless you can hone it at running temperature.

.

tommytiger · 12-02-2012, 03:10 PM

Getting back to honing!

When I re ringed my Tiger I took my barrels to a friend of a friend to get them honed, he has worked on Triumphs for the best part of 50yrs, his garage is the dream garage of all dream garages. He has rebuilt from scratch god knows how many bikes and he built race engines in the seventies, his knowledge is time proven and I trust his word. He honed my bores using one of the spring loaded stone tools using a hand held cordless drill. The barrel was thoughly washed beforehand, whilst honing it his hands moved in and out the bore at a very precise speed, it was like watching a robot arm working, he also kept the speed of the drill constant (not too fast or slow). It was a very quick process and I had to squirt a cutting fluid into the bore as he did it, he then throughly cleaned the bores again. When finished the bore had a neat, even spaced but not too rough cross hatch pattern. I rebuilt the engine with LF Harris rings and all has been good since ( well apart from a little misfire I have at the moment, see my new thread!!)

Looking at the Triumph manual they also rec a 300grit hone when re ringing, this is enough for me to think there is definatly somthing in it.

Nobody has mentioned the idea that oil is held in the grooves, what this achieves I don't know, I presume it makes the break in period less aggressive by providing a little more lubrication.

Triton Thrasher · 12-02-2012, 03:30 PM

Quote:

Originally Posted by tommytiger

Looking at the Triumph manual they also rec a 300grit hone when re ringing, this is enough for me to think there is definatly somthing in it.
.

If you go back to the first page of this thread, you'll see Pete's recommendation for coarser stone than 300.

The way I heard it explained was that Triumph went to a finer hone because it seemed more modern or something, but the rings actually bed in better with a coarse hone, soap and hot water wash, "dry" assembly, cheapo running-in oil and a big handful of throttle as you take off up the road from your shed.

JohnA · 12-02-2012, 06:08 PM

Well this thread has pretty well convinced me that rings can and probably do rotate in use. I'm far from convinced that honing is a waste of time, and I remain deeply sceptical that a big handful of throttle and a thrash down the road immediately after firing the bike up for the first time after a complete rebuild is a good idea! Does anyone really do this?

Morris the Cat · 12-02-2012, 07:12 PM

Theoretical from actual 'hands-on doing' has always been a perceived problem. . here. . .

Sometimes you need moral support to 'go-in'.

Once all-in, who knows what mystery might break in!

Mr.Pete · 12-02-2012, 08:15 PM

Quote:

Originally Posted by Old Cafe Racer

You wasting your time with a head torque plate unless you can hone it at running temperature.

I don't agree.Temperature differences around the barrel can cause distortion,but it won't be as localised as stresses at the threads.Eliminating one cause of distortion is surely better than being stuck with 2 causes.

Quote:

Originally Posted by JohnA

I remain deeply sceptical that a big handful of throttle and a thrash down the road immediately after firing the bike up for the first time after a complete rebuild is a good idea! Does anyone really do this?

I really do this.Within 2 seconds of start up,I'm in gear with the throttle open.3 seconds later it's fully closed.2 or 3 seconds later it's open again.
On hard/fully closed and nothing in between until I've done enough miles.Run at about 4000 rpm.You don't have to worry about heat;the throttle is closed 1/2 the time.Average power output is low.Heat is the only enemy;engine load is your friend.

RII · 12-02-2012, 09:07 PM

Forgive if we strayed off topic!

For the record, no problem at all on my end with honing, and have done so on multiple machines. I just suggest there are "criteria" that can be used to establish the need.

Just be sure to consider the difference between a hone, where the goal is to remove a minimum of material, compared to a re-bore, where you are changing dimensions to match a new set of pistons. The principle is the same, but they really are two processes that require two totally different plans of action.

triumpt120rv · 12-02-2012, 09:11 PM

Quote:

Originally Posted by Mr.Pete

I really do this.Within 2 seconds of start up,I'm in gear with the throttle open.3 seconds later it's fully closed.2 or 3 seconds later it's open again.
On hard/fully closed and nothing in between until I've done enough miles.Run at about 4000 rpm.You don't have to worry about heat;the throttle is closed 1/2 the time.Average power output is low.Heat is the only enemy;engine load is your friend.

I followed Mr.Pete's post initial startup tips after my top-end rebuild last fall. I am very happy with the results. I timed the start-up in fall on a cool day so I could avoid the heat issues with timing and bedding the rings. Was able to ride all winter fortunately which helped as well. Thanks again Mr.Pete.

Triton Thrasher · 12-02-2012, 11:35 PM

Quote:

Originally Posted by JohnA

a big handful of throttle and a thrash down the road immediately after firing the bike up for the first time after a complete rebuild is a good idea! Does anyone really do this?

I've only been in a position to do it once, but it certainly worked. Very firm compression and no smoke.

lovecuba · 12-03-2012, 03:52 AM

Quote:

Originally Posted by Mr.Pete

I don't agree.Temperature differences around the barrel can cause distortion,but it won't be as localised as stresses at the threads.Eliminating one cause of distortion is surely better than being stuck with 2 causes.

I really do this.Within 2 seconds of start up,I'm in gear with the throttle open.3 seconds later it's fully closed.2 or 3 seconds later it's open again.
On hard/fully closed and nothing in between until I've done enough miles.Run at about 4000 rpm.You don't have to worry about heat;the throttle is closed 1/2 the time.Average power output is low.Heat is the only enemy;engine load is your friend.

Does this apply when cams and followers have been re-ground and covered with cam lube?
I have been advised to run the engine for 20 minutes (2 x 10 minute intervals) at 3-4000rpm on the stand. Then get it out and place under load on the road as described above.