Jsut now found a crack (split) in one of my inlet valve guides.
Can anyone tell me before i reduce the head to butter what is the correct temperature for removal and replacement of same?
Nearest gas mark would be helpful.
AL
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Valve guide removal
Moderators: KeithZ1R, chrisu, paul doran, Taffus
Valve guide removal
1981 J1
Would take care old ally is very brittle,better option is to ream out existing guide and i believe you can get inserts now to replace,i bet Debbens know about these, Cheers Paul J.
PAULJAC47,,,,,"She may not look like much, but she's got it where it counts, kid."
-Han Solo
You can't polish a turd, but you can roll it in glitter
Salad is what real food eats.
Anon
PUM 673
-Han Solo
You can't polish a turd, but you can roll it in glitter
Salad is what real food eats.
Anon
PUM 673
Zorded, firstly ensure that the guide(s) you are removing is not phosphor bronze, as they tend to expand at the same rate as the alloy heads and you may have to press it out. This action tends to enlarge the hole and an oversize guide may be required (They guides are available in Std, 0.002" & 0.004"oversize).
Now, after ensuring it's the steel guide and with all valve gear removed (and wife out for the day) I would put in the oven and heat to 125 degrees C for about 15 min.
Have at the ready oven gloves and a suitable bench to lay the head, as well as, a punch about 150 mm long and the outside diameter the clearance dimension of the guide, suitably shouldered such that the shank will be the dimenstion of the valve. the valve should come out easily striking with a hammer from the combustion chamber side.
If you also have, at the ready, a std size guide in the fridge wrapped in paper and you are fast enough, you can insert it in without the need for reheating.
RegardZ
Now, after ensuring it's the steel guide and with all valve gear removed (and wife out for the day) I would put in the oven and heat to 125 degrees C for about 15 min.
Have at the ready oven gloves and a suitable bench to lay the head, as well as, a punch about 150 mm long and the outside diameter the clearance dimension of the guide, suitably shouldered such that the shank will be the dimenstion of the valve. the valve should come out easily striking with a hammer from the combustion chamber side.
If you also have, at the ready, a std size guide in the fridge wrapped in paper and you are fast enough, you can insert it in without the need for reheating.
RegardZ
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4
Thanks fella's i'll go with that.
Garn 1 i was looking in the search forum for @valve guides@ earlier, and guess who's name came out in almost every thread. Yes yours. Fantastic help there, and from back as far as 2006 your MO for valve guide removal has only had one upgrade; 150 degrees c now down to 125 degrees c.
Brilliant contribution to bike help as always, many thanks.
If i clown it up now it will be because i didn't listen.
I have done many over the years on my old brit iron.
Had a B25 Starfire that had new guides with every oil change and my Triumphs used to get through a few as well.
They are Iron at present and i know that the fozzy bronze have better heat transfer properties but i will keep with Iron if i can get one singly. I dont want one valve running cool whilst the other are overheating!!!
Think Z power do them in ones.
This valve guide is the one that had a bent valve in it when i got the head.
There was no visible crack / split earlier in the year but it has developed since. Glad i saw it because i was just about to fit the head after much other faffing about.
Again many thanks and i'll let you know if it spirals out of control.
AL
Garn 1 i was looking in the search forum for @valve guides@ earlier, and guess who's name came out in almost every thread. Yes yours. Fantastic help there, and from back as far as 2006 your MO for valve guide removal has only had one upgrade; 150 degrees c now down to 125 degrees c.
Brilliant contribution to bike help as always, many thanks.
If i clown it up now it will be because i didn't listen.
I have done many over the years on my old brit iron.
Had a B25 Starfire that had new guides with every oil change and my Triumphs used to get through a few as well.
They are Iron at present and i know that the fozzy bronze have better heat transfer properties but i will keep with Iron if i can get one singly. I dont want one valve running cool whilst the other are overheating!!!
Think Z power do them in ones.
This valve guide is the one that had a bent valve in it when i got the head.
There was no visible crack / split earlier in the year but it has developed since. Glad i saw it because i was just about to fit the head after much other faffing about.
Again many thanks and i'll let you know if it spirals out of control.
AL
1981 J1
PAULJAC47 wrote:Would take care old ally is very brittle,better option is to ream out existing guide and i believe you can get inserts now to replace,i bet Debbens know about these, Cheers Paul J.
good advice - I was looking to have this done on a pair of Rover V8 heads and was told that the guides would want to pull the alloy out with them so there is risk of damage.
RV8 heads are in plentiful supply, unlike Z heads so best not knacker it eh?
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