Matchless
I started with nothing, still have most of it left
- Messages
- 2,547
- Location
- Essex UK
One for engine builders,
I am looking to assemble my Matchless Silver Hawk engine now I have unearthed it from under various benches, problem is valve springs! a while ago I asked other owners for details of their valve springs with a view to getting some made, many differing answers and so the head went back into storage!
The bike is a 1930--35 600cc OHC V4 Matchless super bike, one of 504 made, I have owned one before, a cracking bike to ride, sounds fantastic, goes quite well for the age,
I cannot find the valve spring spec, anyone got any Terry's spring parts books that cover the early 30's?
it has small valves around an inch dia. so not that much inertia, I don't want to stress or wear out the valve gear (bevel gears and Oldham couplings) and camshaft (re-profiled) so don't want to go too mad on the spring tension, it revs well but in the context of a 1930's machine!
The compressed length for the springs is 1.320" or 33.6mm
The springs are 29/32" or 23mm OD with a wire dia of 2.6mm
I have assembled one old spring with a free length of just around 2 1/16" or 54mm and to be honest that feels about right to me, I can push the valve open by hand but it is not easy,
The suggested length is between 2 1/4" and 2 3/8" from talking to other owners, seems to me to be too much tension although I do not have one to test fit,
what does the forum think? would another 3/16" make much difference?
does anyone have any springs that fit the spec? maybe inner springs from a car?
I only have four springs in decent condition.
I am looking to assemble my Matchless Silver Hawk engine now I have unearthed it from under various benches, problem is valve springs! a while ago I asked other owners for details of their valve springs with a view to getting some made, many differing answers and so the head went back into storage!
The bike is a 1930--35 600cc OHC V4 Matchless super bike, one of 504 made, I have owned one before, a cracking bike to ride, sounds fantastic, goes quite well for the age,
I cannot find the valve spring spec, anyone got any Terry's spring parts books that cover the early 30's?
it has small valves around an inch dia. so not that much inertia, I don't want to stress or wear out the valve gear (bevel gears and Oldham couplings) and camshaft (re-profiled) so don't want to go too mad on the spring tension, it revs well but in the context of a 1930's machine!
The compressed length for the springs is 1.320" or 33.6mm
The springs are 29/32" or 23mm OD with a wire dia of 2.6mm
I have assembled one old spring with a free length of just around 2 1/16" or 54mm and to be honest that feels about right to me, I can push the valve open by hand but it is not easy,
The suggested length is between 2 1/4" and 2 3/8" from talking to other owners, seems to me to be too much tension although I do not have one to test fit,
what does the forum think? would another 3/16" make much difference?
does anyone have any springs that fit the spec? maybe inner springs from a car?
I only have four springs in decent condition.