Cerbera speed six shimming: my two pence
Discussion
Hello,
just finished to set valves clearance on my speed six Cerbera.
A couple of things about my experience which could be useful to someone who have to do the same:
-If you don't want to mess up with spanner to rotate the crankshaft, it's possible to put the fifth gear and rotate the rear wheels if you're able to lift the rear of the car.
-shims are motorcycle's one so you can purchase easily every 10mm diameter shims you find.
Certainly will be some products better than others but consider that even specialized TVR shops sell generic ones and hide the brand (for example I bought a kit form Motaclan which turned out to be AHL cause I found the brand engraved on the plastic case)
-you can't reach easly all shims cause the "lift and slide the finger follower" method isn't good for all valves.
In that case you could slacking cams or trying to compress springs manually as you probably know.
I feel unconfortable with both of them.
So here is my method:
Rotate cams until the lobe fully compress the valve spring.
Put a metal template covered with tape between valve spring cap and finger followers bar (slightly smaller than the gap)
Rotate cams again until the lobe point up.
Now you can easily extract the shim.
Put the new one and rotate again the cam to compress the spring with the lobe.
Put out the metal template.
I found necessary to strip down everything under the windscreen, even the wiper motor, to have enough space to do the last shims.
Hope this could be useful to someone..
Alternative source for V8 top hat shims . . .
https://www.burtonpower.com/shim-180-top-hat-type-...
and valve spring shims . . .
https://www.bighealey.co.uk/index.php?route=produc...
and you can get half the minimum thickness of the TVR ones - so you can really dial in valve height when rebuilding.
https://www.burtonpower.com/shim-180-top-hat-type-...
and valve spring shims . . .
https://www.bighealey.co.uk/index.php?route=produc...
and you can get half the minimum thickness of the TVR ones - so you can really dial in valve height when rebuilding.
Andrea7 said:
Hello,
just finished to set valves clearance on my speed six Cerbera.
A couple of things about my experience which could be useful to someone who have to do the same:
-If you don't want to mess up with spanner to rotate the crankshaft, it's possible to put the fifth gear and rotate the rear wheels if you're able to lift the rear of the car.
-shims are motorcycle's one so you can purchase easily every 10mm diameter shims you find.
Certainly will be some products better than others but consider that even specialized TVR shops sell generic ones and hide the brand (for example I bought a kit form Motaclan which turned out to be AHL cause I found the brand engraved on the plastic case)
-you can't reach easly all shims cause the "lift and slide the finger follower" method isn't good for all valves.
In that case you could slacking cams or trying to compress springs manually as you probably know.
I feel unconfortable with both of them.
So here is my method:
Rotate cams until the lobe fully compress the valve spring.
Put a metal template covered with tape between valve spring cap and finger followers bar (slightly smaller than the gap)
Rotate cams again until the lobe point up.
Now you can easily extract the shim.
Put the new one and rotate again the cam to compress the spring with the lobe.
Put out the metal template.
I found necessary to strip down everything under the windscreen, even the wiper motor, to have enough space to do the last shims.
Hope this could be useful to someone..
ERRATA CORRIGE:just finished to set valves clearance on my speed six Cerbera.
A couple of things about my experience which could be useful to someone who have to do the same:
-If you don't want to mess up with spanner to rotate the crankshaft, it's possible to put the fifth gear and rotate the rear wheels if you're able to lift the rear of the car.
-shims are motorcycle's one so you can purchase easily every 10mm diameter shims you find.
Certainly will be some products better than others but consider that even specialized TVR shops sell generic ones and hide the brand (for example I bought a kit form Motaclan which turned out to be AHL cause I found the brand engraved on the plastic case)
-you can't reach easly all shims cause the "lift and slide the finger follower" method isn't good for all valves.
In that case you could slacking cams or trying to compress springs manually as you probably know.
I feel unconfortable with both of them.
So here is my method:
Rotate cams until the lobe fully compress the valve spring.
Put a metal template covered with tape between valve spring cap and finger followers bar (slightly smaller than the gap)
Rotate cams again until the lobe point up.
Now you can easily extract the shim.
Put the new one and rotate again the cam to compress the spring with the lobe.
Put out the metal template.
I found necessary to strip down everything under the windscreen, even the wiper motor, to have enough space to do the last shims.
Hope this could be useful to someone..
So sorry but, unfortunately, my english isn't so good and I mess up with my thinking sometimes....
Reading again what I wrote and it's heavly misleading......
The metal template obviously goes between the valve spring cap an the cam!!! Just near the lobe and the finger follower, covering one side of the valve spring cap until it's touch the finger follower bar.
Hope now it's clear.....
Regards
Edited by Andrea7 on Thursday 4th July 07:43
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