VH 500 1949 Head gasket

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kurt.jensen
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VH 500 1949 Head gasket

Postby kurt.jensen » Fri Mar 04, 2011 9:58 pm

Has anyone tryed to use a Copper gasket between head and cylinder on a iron single VH 500 1949

Where can I find float camber fuel heigth, on 289 carburator, has anybody a clou how messure it.

Best regards Kurt Jensen

richard.feltham
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Re: VH 500 1949 Head gasket

Postby richard.feltham » Tue Mar 08, 2011 8:43 am

I had a 1949 VH 500 that had a thin copper head gasket - way back in the 60s - Kurt. The then Ariel dealer was adament that I should change it at every decoke. I believe the 350s did not have them though.
Cheers
Richard.

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Re: VH 500 1949 Head gasket

Postby pete.collings » Thu Mar 10, 2011 10:00 am

I believe thin copper head gaskets were only specified for iron singles engines, including the 350, but are not vital if there is a good fit between the barrel spigot and head recess (achieved by lapping in with some form of grinding paste, dependent on the state of both!). I have sold a few copper gaskets via my website (see for sale section).

The alloy head models just relied on the spigot/head joint for a gas tight seal. If this has been overdone (especially on all alloy models) the head flange will sit on the barrel face leaving a gap between spigot and head. I had this problem with a VHA head on a newly lined alloy barrel, it would whistle when giving it some throttle. A cure was found by using a velo copper head gasket which sits neatly on the spigot. I delaminated the gasket to get a 10 thou thick section which did the job of sealing the joint.

The Ariel copper head gasket can be usefully used if there is too large a gap between the head and barrel flange on alloy head models, which could lead to the head distorting where the five (VH) head bolts pull down. Use a gasket slightly thinner than the gap to be filled, after measuring this with a feeler gauge with the head in place. You will need to cut out a nick in the gasket for the fifth barrel stud.

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Vincent.vanGinneke
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Postby Vincent.vanGinneke » Sun Apr 10, 2011 11:04 am

Hello Kurt, My '51 VH has a copper ring in the recess of the head, I made it myself from a 1mm plate.
If your handy with a jewellers handsaw you can do it.
Every time (?) you have the head off anneal it, with a flame to dull red and cool it in water, this will make it soft again
I never had to make a new one in 34 years.
However you can also lap the head and barrel with some fine carborundum paste + oil.
If the barrel is still fitted put a clean cloth in the bore (piston at bottom) to catch any carborundum falling in.
Use a white or so cloth because that way you can see if you dropped anything in.
Turn engine to push cloth up when it's finished.
Is a 289 a carb with separate bowl? For a concentric and monobloc I made up a dummy bottom connection with a small copper tube silver soldered on it bending upward and terminating in a piece of clear pipe near the rim of the float bowl.
Maybe that's a way for you to find out?
Good luck, Vincent

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Postby Jonathan Anderson » Wed Oct 03, 2012 10:59 pm

I had til 29th a '39 "bitsa" with an iron twin port head. I first rebuilt it for my first rally in 2007.It was club machine examiner inspected 3 weeks beforehand for club registration here in NSW and his comment was "you have a blown head gasket". when I got to the rally site the man who had ridden his bike from Cairns to the rally,some 3,000 miles said to me "you have a blown head gasket". With the diagnosis confirmed it was off with the tank and head and I was advised to throw away the gasket and using valve grinding paste to lap the head onto the barrel spigot and then assemble with no gasket. The comment being that as the gasket set being universal had a gasket in it the gasket that would have been for an alloy head . I have had no problems in 6 years and 4,500 miles.
Regards,Jonathan (Jon) Anderson
PS I now have a '59 leader to get back on the road.

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Postby nevhunter » Thu Oct 04, 2012 12:38 am

I have NEVER run a copper gasket on a ohv single and have never had any problems. The technique used is to lap the two surfaces and then only the outer one for a short while. (Clean and put a little on the inner surface so it won't scratch). This gives more pressure on the inner seal area, while preserving contact with the total area. This distributes heat more evenly from the head to the barrell. Sometimes oil will leak down the bolts inside the rocker covers and give the impression of an oil leak at the cyl to head face. A small leak at the joint (which is rare) won't stop you getting home whereas a blown gasket may. The head/barrell face on the iron OHV engines is very stable. Nev

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Postby Simon.Gardiner » Thu Oct 04, 2012 10:10 pm

I think the 51-53 models used a copper head gasket and if I remember rightly the VH spigots are the same size and it fits the earlier ones as well.

(I seem to have acquired one of those copper ring gaskets somewhere along the way, Mr Collings might just have pointed me to its origins!)
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)

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Postby brenton.roy » Thu Oct 04, 2012 10:20 pm

Hi Kurt, the float needle is notched. There's only one setting. You can just take the cap off and see what it is doing.
Brenton
'51,'56 Squares, '48 VH, '27 Model C, R67/2, Mk IV Le Mans, '06 Super Duke and Ariel projects.

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Re: VH 500 1949 Head gasket

Postby david.anderson » Thu Oct 04, 2012 10:53 pm

Kurt
while the float is non adjustable as advised by Brenton you can achieve minor variations in fuel level at the spray tube by using different thickness washers under the float bowl. With age related wear and what was a practice of grinding in the float needle and seat with valve grinding paste very often the fuel level becomes too high. I have seen a 289 carb where the owner thought it was a good idea to regularly lap the needle and seat and he had increased the fuel level to a point where it would flood if the bike was parked at the wrong angle. A thicker fibre washer or even 2 fibre washers to hold the float bowl lower will help return the fuel level at the spray tube to the correct height.
David


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