bent valve removal

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louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

bent valve removal

Post by louislou »

hi all

all my parts have arrived, removing valves from the second hand head was easy however trying to get the bent ones out is proving more difficult has anyone got any tips on how to remove them
cheers lou
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VTRDark
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Re: bent valve removal

Post by VTRDark »

Have you removed the collets and valve springs. You may need a valve spring compressor. What part of the valve is damaged. If so bad that they wont come out, then I suspect the valve guides will be damaged as well. That would have to be a hell of an impact.

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benny hedges
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Re: bent valve removal

Post by benny hedges »

yeh push it down, take off the collets and spring and top then cut the valve with a dremel.
dont try to bash it through or youll damage the guide
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louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

Re: bent valve removal

Post by louislou »

hi

ive got a valve spring compressor but it wont quite push it down enough, i can see most of the seats and all look fine :confused
i think its because the valve are bent about 3 to 5 mm out from the seats and need to be up tight, i suppose just got to keep trying and if all else fails go up the pub lol

cheers
lou
louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

Re: bent valve removal

Post by louislou »

sorry

im not being very clear, i cant push the cap down far enough to get the collets out

cheers
lou
louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

Re: bent valve removal

Post by louislou »

hi all

just removed one, i tilted the head over and the colets popped out

result 3 more to go
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VTRDark
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Re: bent valve removal

Post by VTRDark »

If you can't push the cap down past the collets then I guess you will have to compress the spring the other way to get a dremmel in. You would have to make sure the spring stays compressed. Are you sure the collets are not just really stuck together. They can get quite stuck with the years of pressure and oil which sort of sticks them together like a vacuum. Give the cap a tap with a hammer before using the spring compressor to break any suction seal betweean the cao and collets.

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tony.mon
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Re: bent valve removal

Post by tony.mon »

Use a magnet on a stick to pull the collets out, while pushing the shim end of the valve spring compressor side to side towards and away from the collet- what you're trying to do is to leave the collet free enough to pop out onto the magnet.

To get them back in again you can stick the collet to the end of a flat blade screwdriver with a blob of grease, ease it into place ans slide the driver upwards- it'll stay stuck top the valve and in it's groove.

Once you've removed the compressor, give the head of the valve a tap with a wooden stick- it'll move the valve off its seat and let the collets settle, and the valve sit squarely on its seat. CAUTION- support the head on a couple of blocks, otherwise you'll bend the valves again, because when they are pushed off their seats they extend further down than the head's gasket surface

If you don't do this, you'll set the shims and then find that they immediately go out of setting when the engine's first run.

BTW, the clearances will close up .02-.03 mm when run for a few mins, as the seats and valve faces learn each other's shapes.
So set gaps slightly larger than mid point in the adjustment range, to allow for this, and you'll end up with the clearances in the middle of the range next time you check them.
Last edited by tony.mon on Sun May 05, 2013 12:31 pm, edited 1 time in total.
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louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

Re: bent valve removal

Post by louislou »

all 4 removed, i think i was trying to compress it to much and there was really no need, i rocked the cap back and fourth like tony said and it worked a dream
ive ground two in going well "THANKS FOR ALL THE HELP"

CHEERS
LOU
louislou
Posts: 16
Joined: Thu Mar 14, 2013 8:16 pm

Re: bent valve removal

Post by louislou »

unreal ive struggled to grind in a valve and noticed the guide is cracked gutted are these changed easily ?
can anything else go wrong lol

cheers lou
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