Author Topic: Converted an inlet valve into an 'ex-valve'  (Read 583 times)

Offline Chipmaster

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Converted an inlet valve into an 'ex-valve'
« on: April 14, 2020, 06:13:25 PM »
I couldn't get my twenty plus year old model Gardner O Type to run yesterday. I hadn't run the engine for almost a year and it seemed to be lacking compression The inlet valve was leaking so I removed and dismantled the combustion chamber / valve block and reground the valve but that failed to do the trick. Close inspection revealed wear to the valve face so I thought I'd re-face the valve in my lathe holding the stem in a chuck and the top slide set at 45 degrees. All was going well, I was on the home straight then the tool dug in and bent the 1/8" diameter stem somewhat.

Here are a couple of pictures of the old bent valve and the replacement made by soldering the head onto the stem -  1/8 diameter silver steel,

IMG_1254 (2) by Andy, on Flickr

IMG_1256 (2) by Andy, on Flickr

There is a happy ending - the engine has been running well this afternoon.

Andy


Online kvom

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Re: Converted an inlet valve into an 'ex-valve'
« Reply #1 on: April 14, 2020, 06:26:48 PM »
Quote
bent the 1/8" diameter stem somewhat.

 :Lol:

Online Roger B

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Re: Converted an inlet valve into an 'ex-valve'
« Reply #2 on: April 14, 2020, 06:29:40 PM »
Glad you've got it working again  :ThumbsUp:  :ThumbsUp:  :wine1:  I guess that the original valve had been hardened a bit by running.

I tried several times to repair cracked tubular exhaust manifolds on my competition cars but they always cracked again  :( I finally realised that they were at red heat in a carbon rich atmosphere from the exhaust and were being hardened  ::)  :toilet_claw:
Best regards

Roger

Offline Chipmaster

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Re: Converted an inlet valve into an 'ex-valve'
« Reply #3 on: May 28, 2020, 10:04:12 PM »
Here's a video of the repaired engine. I used the 'slo-mo' option on my iPhone and was impressed, particularly by the sound track.

t=76s

Andy

Online crueby

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Re: Converted an inlet valve into an 'ex-valve'
« Reply #4 on: May 28, 2020, 11:03:11 PM »
Runs great! The slo-mo is pretty cool too!