Page 4 of 5
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 9:50 am
by SPRIDDLER
As
bjorn mentioned, the pushrods will have a 1 to 2mm gap at the base where they meet the crankcase top.
I happen to have a couple of pics, so just for info........
Pushrod tube to crankcase gap (640x480).jpg
You should be able to move the bottom of the p/rods a tad....
Pushrod tube should move a tad (640x480).jpg
Best to insert the p/rod tubes into the head complete with 'O' rings and steel washers already fitted. The 'O' rings are shown in place in the head just for photo below. A smear of grease on the 'O' rings helps...
100_1411 (640x480).jpg
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 11:04 am
by Pharisee
The piston in my '55 G80 is flat topped and at TDC is just about level with top surface of the cylinder.
18S_2305-small.jpg
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 11:17 am
by Pharisee
SPRIDDLER wrote:adz25 wrote:So i may get myself a decompression plate and trim a little off the top rubber rings to get it to work.
I and several others use nitrile 'O' rings which you can stack to the required height. These nitrile rings don't go hard and brittle (and then leak) from the heat like the pattern 'rubber' ones. The nitrile ref number is BS210 Nitrile. Dims are: 3.53mm section, 18.64 bore and 25.7 O.D. readily available but I bought mine from 'Simply Bearings'. I bought a pack of 50 at £6.24 (just 2 off cost £3.69!) and have given the rest away.
https://simplybearings.co.uk/shop?gclid ... gJg-fD_BwE
I prefer them to the NOS rubbers shown in the photo (at 5p each!) which I had in stock so changed to the nitrile rings which have been perfect for ten thousand miles..........
You still use the steel washers although I hadn't fitted them for the photo.
Pushrod 'O' rings seal (640x480).jpg
Just checked current price from 'Simply Bearings'.... a pack of 50 is now £20.13 +VAT and postage.
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 12:00 pm
by Mick D
Hi
They're £6:24 here:
https://simplybearings.co.uk/shop/Seals ... tml?page=1
Just pick the sizes from the drop downs at the top
Regards Mick
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 1:27 pm
by SPRIDDLER
Yep, I haven't lost the plot and as Mick said, £6.24 @ 1.30 p.m. today ......
BS210 Nitrile.JPG
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 1:58 pm
by ajscomboman
SPRIDDLER wrote:Yep, I haven't lost the plot
You let us be the judge of that!!!
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 2:21 pm
by Pharisee
My apologies... I was looking at the price of 'Viton' o-rings not the nitrile ones.
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 2:26 pm
by SPRIDDLER
ajscomboman wrote:SPRIDDLER wrote:Yep, I haven't lost the plot
You let us be the judge of that!!!
That's a bit rich, coming from someone who's just spent a fortune on foot surgery after multiple demonstrations of putting his bike on the centre stand in his socks.
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 3:43 pm
by JimFitz
Top tip Sprid - just ordered 50 with free postage.
Jim
Re: Pushrod tubes
Posted: Thu Mar 29, 2018 5:53 pm
by MikeM.
Adam, re shortened top rubber gaskets, the gaskets were still under compression plus I did put a little gasket compound on them, and no they didn't leak. I have had leaking from the top of the tubes but on that occasion the gaskets had become hard and brittle and literally fell to pieces as I removed the pushrod tubes from the head. That happened only the once.