Forumites
As some of you will know, back in September (I think), I bought a nice 1968 B25 Starfire, via a post or two on this forum.
I was looking for a project to see me through the coming, dark, lonely months of winter and this old girl fitted the bill nicely . . . . A runner, which would benefit from some fettling.
The valve stems and guides are quite worn and need replacement.
To my questions;
Is there a forumite out there, who can point me at a trusted workshop in Essex, capable of replacing the valve guides of a B25?
Whilst I'm not averse to doing the whole restoration, but, I plan to use steel guides and fitting these to an aluminium head is a job I am not set up to do.
2nd question;
Phosphor bronze or steel guides?
I lean towards steel, but, am I right to use them?
My final question; are valve stem seals fitted to the B25 or not?
Quote from: Janner on 02 Nov, 2022, 22:19
To my questions;
Is there a forumite out there, who can point me at a trusted workshop in Essex, capable of replacing the valve guides of a B25?
Whilst I'm not averse to doing the whole restoration, but, I plan to use steel guides and fitting these to an aluminium head is a job I am not set up to do.
2nd question;
Phosphor bronze or steel guides?
I lean towards steel, but, am I right to use them?
My final question; are valve stem seals fitted to the B25 or not?
The best material for guides is Colisbro.. Not in Essex, but PES in Yorkshire specialise in this sort of job. When my B44 head was overhauled, these type of guides were fitted along with a stem seal on the inlet only.. HTH
Mark Cook of PES recommends only sending the head to an engineer who specialises in replacing valve guides in this type of engine because it is easy to mess it up. Rupert Ratio recommends not replacing the valve guides if at all possible but to get them re-lined instead which is presumably safer to do.
OK gents, thank you.
I have been warned of the potential for damage to the aluminium head when trying to do this job and multiple warnings suggest that there is merit here.
I've also seen suggestions that heating the head and driving the guides out is the way to go, but, an unfettered, heated head and distortion spring to mind.
I will talk to PES, see what they have too say.
Leave the guides in place and have k liner sleeves fitted. Can be fitted to tighter tolerances on the valves and you don't disturb the valve guide in the head.
Talk to T&L in Bedford.
I've contacted both PES & T&L
Hopefully I will see a positive result from one of them, I'd rather use a contact recommended here, than take a chance elswhere
Thanks all
Quote from: Janner on 03 Nov, 2022, 16:39
I've contacted both PES & T&L
Hopefully I will see a positive result from one of them, I'd rather use a contact recommended here, than take a chance elswhere
Thanks all
Please let us know what choice you make and let us know the outcome by posting here. It's always a good thing to see results and learn by that.
I have had 6 heads done by T&L
Will do gents
I've spoken to both and T&L have it, based purely on location, being 60 miles from me, rather than 110.
I'll let you know what is done and the results.
I'm following this with interest. What have you decided to do? Replace them or re-line them?
I didn't even know re-lining was a thing.
I hadn't heard of relining valve guides either. Interesting article about the pros and cons of various methods of guide repair.
https://www.enginebuildermag.com/1996/07/valve-guide-repair-options/
Quote from: AltcarBob on 08 Nov, 2022, 18:44
I hadn't heard of relining valve guides either. Interesting article about the pros and cons of various methods of guide repair.
https://www.enginebuildermag.com/1996/07/valve-guide-repair-options/
TBH I hadn't heard of relining either, but, having decided to use T&L (Barry . . . . . nice chatty bloke), I also decided to take the head to Bedford, rather than use Royal Mail, It's a day out and I have 6 Saturdays and a Sunday in my weeks now.
Anyway, Barry took one look and said . . .reline them, quicker, easier and cheaper.
He showed me a liner, it's spring tempered phosphor bronze, with grooves cut into the bore.
These retain oil, improving lubrication, but are dead ended to stop oil loss into the cylinder.
Drill and ream the guide, press in the liner and ream to size
Barry suggested that I could expect to see the head, completed, within 7 days, IF, the valves I want, arrive on time. He was confident.
I'll keep you all in the loop on this one.
On other subjects;
The piston is marked 67.5, so, I'm working on the basis that there has been a rebore, to 0.020" done and it looks recent, based on the condition of the liner bore, with honing marks across the surface.
The piston is a nice fit and bears no evidence of slap or rubbing, so, I've ordered some NOS (with original packaging) +0.020" rings on ebay.
+0.020" rings seem to be in short supply and very expensive (some are more than a new piston and rings), but, I'm banking on the seller being honest about the rings I purchased . . . . . .again, I'll let you know
I've got a NOS wiring harness and it looks the part, with the original label attached and the black and red wrap
The electrics are going to be an issue.
Over the years the wiring has been extended, altered, and generally mucked about, with an additional (kill) switch and electronic ignition fitted.
I'm going to have to get a new side light and new headlight carrier/connector
It'll sure as hell keep me out of trouble for a few days anyway.
Otherwise, all I'm doing is slowly stripping down the engine, bagging and labelling parts and identifying where new parts are needed.
Once this is done, it's clean everything, repack into clean bags, then polish the hell out of everything that needs it.
The variety of threads incorporated is surprising and TBH I don't understand it;
BA, UNC, UNF, BSW, BSF and CEI, so far . . . . what was wrong with BSF & BSW, or UNC & UNF, why such a ridiculously broad mix?
if nothing else, it means 2 sets of spanners on the bench, when 1 would do.
Well . . . . .the rings arrived, but, I'm not sure they are right.
I'll find out tomorrow, when I get back into the workshop.
On the positive side, my order for a pack of imperial sized, flat and spring washers turned up, so at least I can replace old with new during reassembly.
Not heard from T&L yet, I'm guessing the valves are slow to arrive, but again, tomorrow will tell.
Next job is to split the crankcase, to cure the oil leak and then, clean all the stud, bolts and screws threads, so some CEI taps and dies are on the purchase list.
Then I want to get new nuts for as much of the bike as I can
I've been struggling to replace damaged / broken woodruff keys, so took time out to look them up
The spreadsheet is mine, I've left it open so that forumites who know better than me can make the appropriate alterations
The PDF I pulled off the web . . . .it's going to be useful
What I may do is buy a variety of metric keys and dig out my files . . . .
:) :) :) :)
I have had several heads done by T&L including a Sloper head. All done to a very satisfactory std.
Mike 8) 8) 8) 8)
Collected the head from T&L yesterday . . . . . . . God in heaven what a journey.
It rained so hard at one point the wipers couldn't cope, if I'd had somewhere to pull over, I would have done . . . . .anyway, the head
Looks good
The sleeve in the inlet side seems to have had the oil rings almost reamed out, but, everything fits well, so it's another part just needing a final rinse over to be ready to fit.