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Re: 1957 NH Re-Fresh

Posted: Fri Jul 30, 2021 9:44 pm
by Julian Murphy
I have re-fitted the cylinder head. Hardened valve seats, new valves, guides and springs.
SAM_1093.JPG
SAM_1087.JPG
A 'top hat' insert was made up to overcome the cracking under the head to barrel fixing bolts.

From this:
Head Bolt Down Face.jpg
To this:
SAM_1080.JPG
I also designed and made a collar to locate a Viton O ring instead of the rubber sleeves to seal the push rod tube. The green O ring is just visible in picture 1.

Like this:
SAM_1084.JPG
Push fit into the head (and a smear of Wellseal) as in picture 2.

Re: 1957 NH Re-Fresh

Posted: Fri Jul 30, 2021 9:49 pm
by Julian Murphy
If anybody is interested this is the design drawing:
Pushrod Oil Seal Mod.jpg
.

The engine is assembled but not yet run, nor the modification proven.

Honed the bore:
Bore Honed 1.jpg
I meant to say previously, cylinder head work was by Seager Engineering in Ipswich.

Very pleased with the quality of their work.

Re: 1957 NH Re-Fresh

Posted: Sat Jul 31, 2021 8:57 pm
by Julian Murphy
Petseal......argghhh.

Remains of Petseal applied 40 years ago. Destroyed by un-leaded and E5 petrol.
SAM_2147.JPG
Spent ages shaking it out and blowing it out with the airline and a long nozzle on the air gun.

Re: 1957 NH Re-Fresh

Posted: Sat Aug 07, 2021 9:49 pm
by Julian Murphy
Final stages now - Lubrication

Oil tank filled with SAE 50.

Dropped the gearbox oil out. What a hopeless design. Due to the location of the drain bolt unerneath the Burman box, immediately the drain bolt is out, then its oil eveywhere. Some of it went into the tin that I put underneath, did not manage to get a small funnel underneath quickly enough. Now the hydraulic bench is lubricated :o

Anybody share any tricks to get around this?

Good result. The oil is clear, no evidence of any metal in there

Will refill with SAE 50.

I had planned to fit a magnet to the drain plug before re-fitting. Have done this to the oil tank drain.

However, there does not appear to be enough room to fit anything much longer, or protruding from the drain plug. Just feeling in the drain hole with the end of a small screwdriver.

I previously bought a pack of https://www.first4magnets.com/circular- ... 6|ps_1_518 and there is obviously plenty of room in the oil tank.

Looks like I will have to turn one of these down to just a few mm long, and then inset into the drain plug.

Anybody done this already? By how much did the magnet protrude?

Better check first that the magnet can be turned shorter, or maybe it will 'collapse' when a turning tool is applied in the lathe.

Re: 1957 NH Re-Fresh

Posted: Sun Aug 08, 2021 4:10 am
by garycullen
Julian,
You should be able to find small but powerful button magnets.
Turning down those rod type magnets will probably break them as I think they are very brittle.
Turning Dow may also weaken the magnetism.
They will attach happily to you gearbox and oil tank drain bolts.

I have one on the drain plug of my 1946 VB600 oil tank.
I also have them on my 1933 Austin ten, crankcase drain plug and the gearbox drain.
I am amazed each time I change the A10 engine oil how much “furry” particles are attached to the magnet.
My VB is just starting to be run in so first oil change should be revealing.
Gary
Auckland.

Re: 1957 NH Re-Fresh

Posted: Sun Aug 08, 2021 9:13 am
by Vincent.vanGinneke
Hi Julian, if no debris came out of the box then why fit a magnet?
Only material that gets grinded up in a gearbox comes from the bushes and those are not so very magnetic.
And.... I dont want to start a debate on ‘what oil to use’ but do you put sae 50 in the gearbox ?

Re: 1957 NH Re-Fresh

Posted: Sun Aug 08, 2021 6:03 pm
by Julian Murphy
Hi Vincent.

Always use sae 50 in the engine and gearbox.

I suppose having a magnetic drain plug is 'peace of mind'.

Re: 1957 NH Re-Fresh

Posted: Sun Aug 08, 2021 8:23 pm
by JohnnyBeckett
hi i have got a magnetic in my gearbox that i got off a club member on this forum, :D and don't forget you have got 5 or 6 metal bushes and gears in the box :?: as well as the bronze bushes :roll:

Re: 1957 NH Re-Fresh

Posted: Sun Aug 08, 2021 8:57 pm
by Mike Nash
Julian, I strongly urge you fit a magnet; see below a 4mm neodymium rod about 14mm long I've Araldited into a hole drilled into a plug recently acquired from Draganfly. It has a neat counterbore for debris to collect.
Ariel g'box magnetic drainplug 8aug21.jpg
The magnets that Johnny Beckett mentions above ran in my bike for decades but the g'box collected very little. However, elsewhere I've captured a piece of broken tooth which I was delighted never went into the rotating parts!
I'm a bit magnet mad and fit them into my compressors, mowers, cars etc. The small 3mm dia rods will go into the 6mm bolts that are often used as plugs. And finally, don't forget car back axles. They bounce about so the debris is thrown all over the place. Fit a magnet and you'll collect years of crap!
Regards from MikeN.

Re: 1957 NH Re-Fresh

Posted: Mon Aug 09, 2021 7:51 am
by garycullen
I meant to add to my reply that the type of button magnet to look for are the ones described as “rare earth” magnets.
The ones I use are described as Neodymium.
These are very powerful and once attached to the drain bolt will remain there under all engine or gearbox running conditions.
It is difficult to remove the magnet for cleaning, it has to be forcefully slid off.
It is actually also difficult to clean the iron fur that gathers around them.
I use a linen cloth and rotate the magnet around in it for some minutes, pushing the debris off.
Cheers
Gary
Auckland