Tuesday, 17 June 2014

Honing and ringing the changes

After buying a 3 legged  glaze busting tool it was time with the help of my son Callum and some WD40 to 'hone' the bores ready to accept the new piston rings. This allows them to bed in correctly.
I had already been advised that it was difficult to over hone the bores, so a nice matt finish was what I was looking for. I think the slight recess near the top is normal on a higher mileage engine.....don't forget this isn't a full rebuild, just a way of reducing oil consumption, a refresh.

Half an hor later and a large can of WD40 and all 6 bores were done. I had covered the crank journals with blue paper roll before starting to catch the swarf . I was pleased with the results we achieved and put clean roll back in the bores once they had been liberally cleansed with more WD40.

So to my £10 purchase from Stafford last year. A set of standard size Cords rings, specifically designed for sprucing up an older engine.

Following the instructions soon had the cleaned pistons looking much better. Just a matter of  re-installing them back in the bores with the aid of the piston ring clamp and lots of fresh SAE30 engine oil, my chosen lubricant for the initial 500 mile breaking in period.  

Thursday, 12 June 2014

Two heads are better than one?

After some rotary wire brush action the valve heads and combustion chambers looked much better.
The plan was just to stem the oil consumption so I wasn't going to dismantle the valves at all.

Pi heads have double valve springs with two piece valve spring caps, the idea I am reliably informed is that the two parts can rotate separate to each other. I spotted something strange on one of the exhaust valve caps. You can just about make out a hairline crack in the picture below.

So now I had a valve out and curiosity got the better of me. I found that there was a fair bit of wear in the guide............. The solution was sitting on my spare mk1 pi engine at the side of the garage. After stripping all the valves out of the spare head, I found 3 cracked exhaust valve caps but minimal guide wear. Round 2 of rotary wire brushing of a head was completed and I got ready to lap the valves in.
To my disbelief I then noticed something on the exhaust valve seat of number 1.

At this point, reverting to the original but more worn head was the only solution so I consoled myself with removing the front subframe, steering rack and sump. All six pistons followed and at least the news was better this time. The crank had been ground to +10 thou. I had some NOS glacier bearings in just that size.

The big end shell bearings weren't in bad condition and the crank journals although a little marked would polish up fine.

More to follow.......

Saturday, 7 June 2014

Curing FRanK's smoking habit.

With only 4 weeks until the 2000 Register National in Northumberland and the Club Triumph RBRR looming ever closer I decided that what was needed was an engine refresh for FRanK.
After conducting a dry compression test with 120-135psi readings across the cylinders and performing a wet test on the lowest which increased the reading to 180psi, I was fairly certain the rings were at fault.
So one evening I dropped the coolant out on the drive and pulled FranK back into the garage and over the pit.

A little spannering saw the battery out of the way and the injectors out, along with throttle bodies and exhaust manifold unbolted.

The complete water pump housing and under manifold pipe removed. Rocker gear and pushrods were safely stored in a numbered piece of card and the head securing nuts removed.
A little persuassion soon had the head lifted and on the bench.

The colour of the valve heads looked Ok but pretty dirty.

The good news continued when scraping off the top of a piston showed standard (original) size markings. The bores looked good to go with a little bit of work with a glaze buster and the Cords rings bought last year at Stafford could add the lease of life FRanK needed.

To be continued........