[vhgmcbuddy]

Parts have arrived, and I am surprised that the clearing between the new valves and the new guides is more than I expected! I do hop all this effort results in a non-Smokey engine!

I will update later,,

[vhgmcbuddy]

No lathe here unfortunately, and I have had a look online with no luck re buying a driver/drift/tool (they call them allsorts…)

The manual says the valve should be : –
Inlet stem; 7.061 – 7.087mm or 0.278 – 0.279″
exhaust stem; 7.036 – 7.061 or 0.277 – 0.278″

and the guide, from my measurements has an OD of about 9.76mm or 0.373″

so if can get a drift with and ‘ID” of 1/4″ and an OD of 11/32″ I should be ok? remember I am from the metric age and imperial measures really frys my noodle!

Re keeping the mrs happy, I will go for a combo of blow torch and freezing I think!

the search for the drift is on-going as I am determined to do all the work myself unless forced!

[vhgmcbuddy]

Its confirmed, I am going quietly mad!

I have just been cleaning up the gasket surfaces on the block in readiness for re-assembly and I find that, despite all my rambling about the valves running directly in the block, the engine does actually have separate valve guides!

I should have had my suspicions aroused when Meetens told me that only the early engines didn’t have them, the Autobarrow is getting on but its not that old!

So, I now have two more questions: –
1, when I get the new guides can I fit them myself? I think with a combination of risking the wife’s wrath with the oven and a blow torch I could get the block hot enough but I am going to need a well fitting drift to budge them – not sure where to get that.
2, having fitted the new valves and guide will I need to re-cut the seats or can I just lap them by hand with paste and old suction cup?

lots of fun…..!

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[vhgmcbuddy]

I would like to get a copy of that, I will look our for it.

Also, I have been on to Meetens who surprise me by telling me that latter F15’s had valve guides fitted (rather than just running straight in the block) – although they are still steel – which is strange. As the block is otherwise unchanged we can assume that there is enough meat there to allow machining etc.

What this tells me is that this must have been a problem for them to bother updating the design? my old Mountfield has the old alloy block that start describes, in which the valves run with no guides and it must be 50 years old and still running strong with very little smoke!

I have a feeling that the similar materials might be susceptible to corrosion/pitting when left standing for a long time, and then sticking followed by accelerated wear – i think an engine that has been used all its life would be in much better condition guide-wise.

So, i have ordered (along with a gasket set and other bits and bobs) new guides and standard valves and i will get my local engineering place to machine the block to suite.

The mystery thrust washer in the reduction box was a figment of my imagination after all – i must be losing it! – i have ordered a replacement for the very slightly worn crankshaft/output shaft thrust washer as a might as well as i am in there.

one last thing, what colour red is the F15, mine is very faded and looks more orange?

I will let you all know how i get on!

[vhgmcbuddy]

That makes sense re the breather

My search for the tools to ream/cut the valves as drawn a complete blank, any ideas? – I wonder if Meetens has something? I will try tomorrow…

and a diagram of the reduction box?

[vhgmcbuddy]

wristpin, good point re the material quantity in the block – don’t want to mess-up the engine for no other reason than over-enthusiasm! Also, I have a theory that this engine is strange in having badly worn guides but well seating valves and the bore/piston/rings that are in good nick = great compression. This makes me think that the below piston pump pressure will be very healthy and forcing oil around more then had the whole engine been as worn as the guides?
I meant to test this theory by running the engine for a while without the crankcase vent ball in place but didn’t get around to it in the end.

It would seam Charlie that the maintenance manual for the mk10 to 15 engines is quite a lot better than for the F15 which is very sparse and not that much more detailed then the operating manual really. I am interested to see that, assuming you had the right tools, you could ream the guides and re-cut the seats in you garage by hand – I was thinking that an engineering shop with a big mill would be the only way to go – i would like to buy the tools to do it myself but it might not be cost-effective for one engine? where should i look for them?

stuart, this is quite a way but i am in Birmingham often enough, it might be an option – i will cost up the tools and see!

Lastly, i cannot get hold of an exploded diagram for the reduction gearbox, i could be going mad here but i seem to remember a steal shim being used on the splined cog that comes off the camshaft but for the life of me i cant find it – i don’t mean the large phos-bronze job that goes between the crankshaft and the output shaft – i have that. Does anyone have an assembly pic of the box?
It could all be a figment of my imagination as i have just finished re-assembling an old Ossa trial bike engine that is riddled with shims!!

[vhgmcbuddy]

Brogdale and Hassocks events articles and photos emailed to Alan this week.

[vhgmcbuddy]

Oh, thanks all. I will talk to Meatons.

Its odd that the manual – which I just bought as I am the kind of person who likes to flick through such things of an evening – doesn’t really talk about the guides much but as you say it does mention oversize jobs being available – I have never come across oversized valves and assumed that they meant the head not the shaft! not sure why.

So that’s good news, although might like to fit phoz-bornze jobs just because I like to tinker and improve things and I might be a bit of a weak point if it has gone bad so quickly?

stuart, where are you – maybe you could do this for me? I am in Epsom….

[vhgmcbuddy]

Yep, all ring gaps under 0.3mm – so fine according to the manual….

So, I will be looking into getting some suitable phos-bronve guides and having the block machined to fit – what does everybody think? any ideas what/where I could get them?

Also I have been in touch with Meetens (very knowledgeable and great service), I will get all my gaskets and what not from them and I think they might have an idea about what guides I can retro-fit?

[vhgmcbuddy]

I am about to check the ring gap, but initial eyeballing would suggest its tiny!

also, and I am equally confused as to why it would be so, the exhaust valve moves approx. 1mm side to side in the guide – there is about 0.01 to 0.02 mm variation along the valve shaft, the inlet less so but a significant build up of carbon in the inlet port would suggest that too much oil is arriving under the valve?

Lastly I see that the valves run directly in the block – so its not as if I can just get more pressed in!

I am going to go and check the ring gaps now (watch this space) but I really think its the guides – I wonder if fitting new valves would be enough? or maybe I could get proper, phosphor bronze guides from something else and have the block machine to fit?

Fascinating stuff! and like you I am a real fan of this engine too, lovely quality and clever engineering – I love the fact that, to allow the gearing in the reduction box they just take the drive off the cam shaft….

[vhgmcbuddy]

Hi There, I am so glad that I am not the only one to have one of these great machines, as I said in the first post I am a real admirer of the engineering and general quality of them.

Do you have any photos and have you had to do any work on it? also, when you made the replacement box did you use the original fittings? I am finding getting equivalents very difficult/expensive – to the point that I am thinking of just getting the box off a small trailer and attaching it – not my preferred solution but what are you going to do…

I actually bought it as a trailer – tug to drag around a relatively small but surprisingly heavy trailer I use..

either way, I would love to see pictures of yours!

[vhgmcbuddy]

Ah, I had a feeling the engine would have to come apart! well, I will have to order that Gasket set!
Who’s the best person to get a full gasket set and, assuming I need it, and oversize piston and rings from?

Any chance at all re getting an original box from somewhere do you think?

[vhgmcbuddy]

Thanks for the link, that will help a lot.

It could be the oil ring but is this lightly to be more worn than the compression rings which I can assume are ok as the bore is immaculate and the compression is very good indeed?

I ran it again at he weekend and it is still very smokey!

[vhgmcbuddy]

That’s right, an F15, and its definitely oil smoke. The odd thing is that the bore and valves are perfect – loads of compression..

The crankcase vent valve looks fine – the ball is clean and free, I might try running it without the ball for a while – see if that makes any difference.

Re over-filling with oil, the operating manual says to use 1.2 pints in a F15 with has a reduction box (as this one does) but that seems like a lot more than it should be considering the statement later the in the booklet which says that the oil should come to the bottom of the filler hole threads – which only took a pint – and may yet be too much? I suspect that there are a lot of nooks a cranny’s in the engine which hold oil even when the engine has been drained.

I will keep on researching…!
any ideas where a box might be available?

[vhgmcbuddy]

I’ll get it written up for you next week with photos Alan

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