|
Post by JohnV on Jul 11, 2020 12:52:12 GMT
good that you found something Andrew
|
|
|
Post by Isambard Kingdom Brunel on Jul 11, 2020 16:30:51 GMT
One short pushrod? Probably out of a wrong engine, 1.5 or 1.8 petrol? Rather than a longer tappet screw [ they are a bit special being ball ended and hardened,] get a correct pushrod.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 11, 2020 18:54:18 GMT
I checked the pushrod with another as that was my first thought. Same length as the other one. The adjustment screw is considerably shorter it's obvious when you look at it and the rocker arm is very slightly different but definitely correct. so I reckon that rocker was bent before I got the boat and the replacement rocker had the wrong length screw. All others are ok.
I would suggest,while not knowing for sure, that the engines with the longer pushrods probably have shorter adjustment screws. So the rocker with short adjustment screw is probably from one of the engines with the long rods.
It just seems likely. Mass production of parts would seem to indicate that a shorter push rod would need a longer screw and vice versa. And verce visa.
|
|
|
Post by Isambard Kingdom Brunel on Jul 11, 2020 20:09:16 GMT
I checked the pushrod with another as that was my first thought. Same length as the other one. The adjustment screw is considerably shorter it's obvious when you look at it and the rocker arm is very slightly different but definitely correct. so I reckon that rocker was bent before I got the boat and the replacement rocker had the wrong length screw. All others are ok. I would suggest,while not knowing for sure, that the engines with the longer pushrods probably have shorter adjustment screws. So the rocker with short adjustment screw is probably from one of the engines with the long rods. It just seems likely. Mass production of parts would seem to indicate that a shorter push rod would need a longer screw and vice versa. And verce visa. The rocker would seem to be the part that is foreign then. Can you get a correct rocker? Am I correct in thinking that there are 2 different "hands" of rockers, they are not all the same If I remember. Its been a while!
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 11, 2020 23:56:29 GMT
I checked the pushrod with another as that was my first thought. Same length as the other one. The adjustment screw is considerably shorter it's obvious when you look at it and the rocker arm is very slightly different but definitely correct. so I reckon that rocker was bent before I got the boat and the replacement rocker had the wrong length screw. All others are ok. I would suggest,while not knowing for sure, that the engines with the longer pushrods probably have shorter adjustment screws. So the rocker with short adjustment screw is probably from one of the engines with the long rods. It just seems likely. Mass production of parts would seem to indicate that a shorter push rod would need a longer screw and vice versa. And verce visa. The rocker would seem to be the part that is foreign then. Can you get a correct rocker? Am I correct in thinking that there are 2 different "hands" of rockers, they are not all the same If I remember. Its been a while! The adjustment screw is shorter than the other ones. It's an adjustment screw issue. The rocker arm itself is more or less identical while being very slightly different in some external manufacturing related details. It's the screw. It's shorter and runs out of thread for the lock nut before you get to the correct clearance. A screw with longer thread on it will sort the problem. Hopefully the one I have ordered will do this. If not then I will be tearing my hair out. Again.
|
|
|
Post by lollygagger on Jul 12, 2020 6:19:19 GMT
Rocker geometry, one of my fav subjects. Does the odd one out adjuster need to be wound further through the rocker? I'm with them what think your best shot is to get the correct adjuster AND the correct rocker, there must be plenty rockers to be had on ebay.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 12, 2020 8:16:17 GMT
The rocker definitely seems to be the same geometry as the others it's just that the screw is shorter. I suppose what I ought to do is get the screw out and count the threads then count the threads on the one I have ordered. This is the one I have ordered. About 29 threads. I'll pull the short one and count the threads. Should have done this before... I can see that the thickness of the internally threaded part of the rocker itself could be different and that this would have the same effect but I still think it is the screw.
|
|
|
Post by Andyberg on Jul 12, 2020 9:14:20 GMT
Sounds like a Jerry-built old knacker to me! 🙄 Scrap it!
|
|
|
Post by JohnV on Jul 12, 2020 9:19:23 GMT
Sounds like a Jerry-built old knacker to me! 🙄 Scrap it! Nah !!! they were built in Oxford 'n not Germany
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 12, 2020 9:54:44 GMT
Sounds like a Jerry-built old knacker to me! 🙄 Scrap it! The whole boat is scrap I'm just going to use it until it sinks preferably somewhere really deep then bugger off in my dinghy
|
|
|
Post by JohnV on Jul 12, 2020 10:49:31 GMT
I'll give you a fiver for it
(boat not rocker )
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 12, 2020 11:26:22 GMT
I got the screw out. 21 threads so it is indeed shorter. After much Google searching, head scratching and reading the manual I have come to the conclusion that it is rather a technical fault. The thing is "fucked". Not harm done to the push rod so hopefully a new adjuster screw will do the trick. I wonder if this is a Chinese pattern part problem. Perhaps if the rocker and screw were replaced it happened to have an inadequately hardened ball head. The others are ok but I think they are all original. The temptation to buy cheap stuff, perhaps. or just a gummed up valve and a lot of clearance leading to hammering. I have also checked cam follower that's fine.
|
|
|
Post by Isambard Kingdom Brunel on Jul 12, 2020 12:56:15 GMT
I doubt that the Chinese would be making pattern parts for a 76 year old design engine! If you can't find a screw, an allen cap head machine screw, 5/16" UNF with the end ground to a ball will do, they are hardened throughout. Sam.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 12, 2020 13:02:29 GMT
I've ordered one for a mini which I believe is the same item. 5/16 unf so the thread is right at least. Obviously if it's too long then it might collide with the rocker cover.
As for the Chinese I wouldn't be surprised if they did do parts for such a common engine. It would make sense, to me at least.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jul 12, 2020 17:45:00 GMT
Are we still allowed to write "Jerry" on here ? I thought it was deemed racist. Or is that "Gerry"?
|
|