1963 Francis Barnett Restoration

[Mellow Matt]

I recently found out that a mate's dad had an old bike rusting away in bits in his garage and have been enquiring about it ever since, until finally this weekend my dad and I got to go and have a look It's a 1963 Francis Barnett Cruiser 80, single cylinder 250cc stroker. It's not really going to have mind blowing performance, and it's not much of a looker at the moment, but I wanted something I could learn some mechanics on, so this is pretty good for that!

Anyway some pics:

https://i188.photobucket.com/albums/z124/MellowMatt/DSC00389.jpg
https://i188.photobucket.com/albums/z124/MellowMatt/DSC00393.jpg

We came across something that puzzled us though:

https://i188.photobucket.com/albums/z124/MellowMatt/DSC00388-1.jpg

This is a photo of the timing side crankcase, there're two holes of approx 3/32" diametrically opposite each other in the main bearing housing. Does anyone know what purpose they serve? Should they be there?

Anyway, thought it might be interesting to a few people, what do you think? I'll try and update as it goes along

[Barry_M2]

The two holes are probably for some kind of locating pins to fit into.

My dad had a frances barnett when he was a teenager, I've been after one for ages to do up and give to him, if you find the project it too much, I'd be VERY interested in buying it off you, whatever the condition.
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[Jockey]

They may be tooling holes, the size you mention is one we use in my job , the size we use is 3.172 mm which seems to be about right. Have fun with it, it will open your eyes in a gentle sort of way, then the uphill climb begins, have fun with it and don`t give up on it, they are so simple. -Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

Thanks for the reply, I've just spoken to my dad (he's the mechanic!) and suggested what you said, but he doesn't think they're for locating pins. The case needs to be air tight and the holes go all the way through, apparently retaining pins wouldn't need to go all the way though. He's puzzled as to why there would be holes that leave the chamber open to the atmosphere...? Thanks anyway though.

I'll certainly get back to you if it turns out we want to get rid of it, but I think we're gonna keep at it for the time being

[Jockey]

I`ve looked at that pic again and it looks as though the inner chamber relies on the shaft running through it to do the sealing, i note that old fashioned red hermetite has been used, but only on the outer case area, which shaft runs through the opening(crank?). I use to be an hgv technician for many years. The only thing i don`t like about this is that i cannot always look at the picture while i type and think, my memory isn`t the best at quick glances while i`m working it out.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Jockey]

I wish i could see thes casings in the flesh and it would be much easier to work out, was the engine a runner?-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Jockey]

I`ve looked at that pic again and it looks as though the inner chamber relies on the shaft running through it to do the sealing, i note that old fashioned red hermetite has been used, but only on the outer case area, which shaft runs through the opening(crank?). I use to be an hgv technician for many years. The only thing i don`t like about this is that i cannot always look at the picture while i type and think, my memory isn`t the best at quick glances while i`m working it out.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

Thanks Jockey, sorry I missed your first reply as I typed mine too slowly! Yes it had quite a lot of hermetite around the outer edge (cleaned it off now), and the crank does go through the opening, with a seal around it (there was an old seal in the hole, but we got it out as it had perished). I'll suggest what you said to my dad, he seems to think that the holes look like they were made after the manufacturing of the case though, but he can't figure out why! We don't want to fill them only to find there's a reason for them!

I could get some more photos if they'd be helpful? The previous owner blew up the engine then bought the bits to do it up again but never got around to it, so it looks like most of the parts needed are there, and in quite good condition

Ta for your help!

[Jockey]

Those holes look too accurate for random drillings, as though they were meant to be there.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Jockey]

I think i`ve seen what they are for now, they are to use crankcase pressure to keep they seal closed, i`ve just orientated the picture, pressure comes through the openings and helps close the seal, hope that you can see what i mean.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

Hmmm ok, thanks, we thought it might've been something someone had done afterwards as the holes had slightly deformed the hole and raised the surface a bit, you can't really tell from the picture though. I don't know if that's something to be expected when doing such a thing though!

[Jockey]

Just one more question, the view i see of the casing is from the outside of the engine, isn`t it?,(judging by the threads on the studs) if so that is the reason for those holes.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

Yes, this is the view from the outside, the studs attach to the alternator. I've just relayed what you said over the phone to my dad, he doesn't seem to think it's to do with keeping pressure on the seal, as the holes bypass straight by where the seal would go :s

[Jockey]

You`re missing my point, the pressure comes in from the crankcase(via the holes) and fills the inner chamber which closes the seal, (the seal will face with it`s sealing ring out towards the chamber)the inner chamber must be sealed, the inner to the crankcase, the outer doesn`t matter really as it`s not a pressure seal for the crank. Do you understand what i`ve just said? This is a principle of two stroke engines otherwise they don`t work.. You said earlier that you removed a perished seal, did the sealing ring face you,(outside of casing) if so then my point is proved, build the engine, it will work, forget the holes, they are meant to be there, have a great time and let me know how it goes. -Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

I really appreciate your effort mate, but I'm afraid I didn't understand that! The seal doesn't cover up the holes, so surely all the fuel/air is just going to blow out of them? Sorry if I'm being a bit slow!

[Jockey]

Matt,ring me and i`l explain just how this works,01915860935.-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Jockey]

Matt, if you cannot ring me tonight, try tomorrow after 18.00 hrs, i`ll explain things in a very simple manner and i`m sure you will understand what i`m talking about, that bike will run again, i`ll make sure of that!!-Jockey.
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Current bike VFR 400 R NC30, others now gone.

[Mellow Matt]

That's very kind of you, I'm about to go to bed now (got to get up at 5 ) but I'll pass the number on to my dad, as I doubt I'd understand anyway! Cheers

edit: just seen you'd explain in a very simple manner, maybe I might understand then!

[stinkwheel]

I reckon your holes are to allow someone to put a punch through and drive out the main bearing outer race. Possibly after having had them seize onto the crank and the middles come away with it when the engine was split...

Not that I'd ever do anything like that.

They did a very neat job of it anyway.

EDIT: In any case, it's not been breathing through them (no oil staining on the alloy) so either it doesn't breathe through them or it's never been started since they were drilled.

If you aren't happy with them there, you'd easily fill them with lumiweld.
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[stubg60]

hi,
if you send me the pics i may be able to help,
i have the same model in my garage

stuart.baxter@eon-uk.com

[Jack_Cheese]

Sweet, just remember to let the clutch out very slowly when setting off, these bikes have a very nasty reputation of knocking the engine into reverse when they're dropped into first!

Should be an interesting project, there's not too many of these knocking about anymore.
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[Mellow Matt]

Hi stub, we've now assembled the engine after deciding to fill in those holes, it's now in the frame, so gotta do all the electrics, start connecting things up and get the brakes, forks, chains etc in shape.

I've taken a few more pics so I'll have to upload them when I get a chance.

@ Jack - I'll keep that in mind, thanks!
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