Play in valve guides and where to buy tuned heads - please help!!
21-12-2008, 04:26 PM
#1
teamwoodspeed
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Play in valve guides and where to buy tuned heads - please help!!
Hi all
I was so close to getting the engine in my rally Ka all finished and put back together today, when I found something that I suspect is fatal. As I was grinding the valves in, I noticed that there was some movement in the guides - meaning that although the valve seats fine, when it lifts it can move from side to side. It just so happens that the ones with the most movement coincide with the pistons with the most damage too. Valve not sealing properly = air into combustion chamber = weakened mixture = overheated pistons.
The head was worked to the tune of £2k by Rally Equip in Bury (who have been most unhelpful so far in giving advice so I'd prefer to ask the question on here if I'm honest) around 2 years ago, and has done two events since. There has been a lot of machining of the valve guides anyway - they are significantly shortened, and the whole head has had a hell of a lot of work, which is why I'm gutted it probably can't now go on.
My question, and it's more to confirm what I'm sure is the case to be honest, is whether there could conceivably be any reason for valve guides to be machined so much that there is play with the valve (without the springs in place of course), or if, regardless of cause (bad machining/wear) this is always going to be bad news.
Secondly - does anyone know if valve guides in a cast head can be filled and drilled or fixed by alternative means?
THIRDLY (and finally I promise!) does anyone know of anywhere that does 'off the shelf' tuned 1.3 Endura heads, either straight sale or exchange?
Cheers
Paul
I was so close to getting the engine in my rally Ka all finished and put back together today, when I found something that I suspect is fatal. As I was grinding the valves in, I noticed that there was some movement in the guides - meaning that although the valve seats fine, when it lifts it can move from side to side. It just so happens that the ones with the most movement coincide with the pistons with the most damage too. Valve not sealing properly = air into combustion chamber = weakened mixture = overheated pistons.
The head was worked to the tune of £2k by Rally Equip in Bury (who have been most unhelpful so far in giving advice so I'd prefer to ask the question on here if I'm honest) around 2 years ago, and has done two events since. There has been a lot of machining of the valve guides anyway - they are significantly shortened, and the whole head has had a hell of a lot of work, which is why I'm gutted it probably can't now go on.
My question, and it's more to confirm what I'm sure is the case to be honest, is whether there could conceivably be any reason for valve guides to be machined so much that there is play with the valve (without the springs in place of course), or if, regardless of cause (bad machining/wear) this is always going to be bad news.
Secondly - does anyone know if valve guides in a cast head can be filled and drilled or fixed by alternative means?
THIRDLY (and finally I promise!) does anyone know of anywhere that does 'off the shelf' tuned 1.3 Endura heads, either straight sale or exchange?
Cheers
Paul
22-12-2008, 07:07 AM
#2
20K+ Super Poster.
You should certainly not be able to see any play, yours are shagged.
Most heads can have a different guide put in quite easy though, shortened guides will wear quicker though, by how much a I don't know.
Roosie off here has had some real quality head work done on a cossie head by IMPULSE DEVELOPMENTS, but people like burtons will have heads ready to go on thier shelves I'm sure.
The endura e is still a basic x flow so still plenty around!!
tabetha
Most heads can have a different guide put in quite easy though, shortened guides will wear quicker though, by how much a I don't know.
Roosie off here has had some real quality head work done on a cossie head by IMPULSE DEVELOPMENTS, but people like burtons will have heads ready to go on thier shelves I'm sure.
The endura e is still a basic x flow so still plenty around!!
tabetha
23-12-2008, 05:02 PM
#3
firstly, there is always some play in the valve guides. If there wasn't, they would be stuck solid! In an hcs, i would expect the clearance to be 1.5 - 2.5 thou. This unfortunately isn't easy to measure without the right equiptment! The best thing for you to do would be to fit bronze guide sleeves into your guides. It's an easy enough job and makes sense if you're running stainless valves. Pm me if you need any more help or advice, i do machinework for a living! 
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