Farymann Diesel Generator Cylinder Head

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kashurst

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Finally got around to sorting my generator. The non-start was again caused by lack of compression, caused by a very rusty exhaust valve.
The valve itself cleaned up ok in a drill with some emery cloth, but the valve seat is badly pitted. After a lot of lapping the seat became at best "functional". If it needs doing again, it really needs a new exhaust valve seat. Is it possible to put valve seat inserts into Farymann 18W single cyclinder diesel head?
 
I can’t help on the valve seat but….

I‘ve read elsewhere that the problem is saltwater sitting in the exhaust creating a corrosive environment for the valves. The genny must be run at least once each month (under decent load) to burn off any corrosion - unless it is winterised. I’ve re-rigged the raw water intake on mine so that it is now very easy to run the genny off a bucket of fresh water, one could also add some corrosion inhibitors, essentially this is easy winterising after use, so if you know you’re not going to need it for a week or so just run some fresh water in. I reckon it should help the problem.
 
Won’t it carbon up with use ? Naturally fill the pits in the seat .

Replacing the seat or having it reground + oversize valve @ machine shop does not solve the original problem of seawater stagnation nearby + in frequent running .

Could the geny be mounted higher up in relation to the WL so the air gap increases as it drains after a stop ?
Could it be more frequently run in the off season .As you know I am a great ( I know minority on this forum ) believer of regular winter running up of everything.
Just returned from another WE in Loano and ran everything up , main engines , geny , toilets , Aircon , windlass , taps , flaps rudders , black tank pump , extractor fans etc etc . The whole shooting match .
Spent knack all on repairs last season = nowt bust .Or the last few indeed .
 
Bran said:
Yes you can fit an insert into the head. I had it done a few years ago, should be an easy job for any engine refurb company. Cost me £60 and is working well since.
Click to expand...
thank you! good price too. I will see how it goes over the summer etc. I have made a metal blanking plate to put on the exhaust port when it's not going to be used for a while too. Just slacken the two exhaust bolts, slide it in then tighten hand tight, the generator battery isolator switch key is tied to it, so I can't start it by accident.
Hopefully it should then be OK after being left for a few months.
 
kashurst said:
Finally got around to sorting my generator. The non-start was again caused by lack of compression, caused by a very rusty exhaust valve.
The valve itself cleaned up ok in a drill with some emery cloth, but the valve seat is badly pitted. After a lot of lapping the seat became at best "functional". If it needs doing again, it really needs a new exhaust valve seat. Is it possible to put valve seat inserts into Farymann 18W single cyclinder diesel head?
Click to expand...
Yes it is I’ve done this many times , my local guy does it for me .
 
Bran said:
Yes you can fit an insert into the head. I had it done a few years ago, should be an easy job for any engine refurb company. Cost me £60 and is working well since.
Click to expand...
Bran
I need to do exactLy the same. Do you by any chance have the details of the valve and valve seat you used so I can track down the right parts? I’m in Fiji so finding the workshop is the next challenge. I know I can get valves from diesel power Ltd but know nothing about getting valve seats.
Thanks
Dave
 
djs said:
Bran
I need to do exactLy the same. Do you by any chance have the details of the valve and valve seat you used so I can track down the right parts? I’m in Fiji so finding the workshop is the next challenge. I know I can get valves from diesel power Ltd but know nothing about getting valve seats.
Thanks
Dave
Click to expand...
I just took the head and valve to my local engineer, they re used the original valve and fitted an insert from their own stock. See the picture, it’s the only information I have. They would select the insert size accordingly from the amount of metal around the valve seat area. See what your local engineer has, I know you can get insert bar and machine your own insert to suit. I did use a company Serdi for inserts several years ago: You would need to measure the head and see what size insert is the best, see what your local engineer has, let me know if you need any more information.
www.serdi.co.uk/engine-components/valve-seat-inserts



430886FC-5BA4-4DBF-B620-720B7E707C1C.jpeg
 
I had this issue on the genny engine on my Turbo 36, and I tried lapping the valve, but the hardened layer is very thin, and doesn't take much to grind through to soft metal below, and the valve won't work for long.

I took mine to and engine shop near Southampton for new seats and would have been about £50 ten years ago.
 
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