Rockers

Hi Phil
I see we both have the same problem. This may be a standard problem with the INGLIS Rocker housing. Please , other members ,look at your Inglis Rockers and parts and report if these housing cracks are common. If you look at my damaged housing you can see it had been repaired by welding before.
If you look at the underside of your Rockers , Phil , you can see they have been cut away near the mounting possibly to make clearance for the valve spring. I do not think this would affect things too much.
Other Members , Please report your experiences with the Inglis Rockers. If there is enough interest it may be worth our while to make a few new housings?
Regards
Peter

Hello,

when I got my ABC's, these rockers were mounted.
You can see that they were broken, I didn't even try welding, I built new ones.

Greetings

Wolfgang

Hi Peter

Can you please let me know how long are the spacers that sit between your Inglis rockers and the cylinder heads? Mine are currently of various lengths which I need to do something about.

Thanks

Phil

Hi Phil
I have two groups , the older ones are 21.4mm 27/32" and the newer ones that came with the ABC NOS parts that have never been used are 22.7mm. This 22.7 does not appear to be an Imperial size that is standard and they are all very close to each other ( a few hundreths of a mm). I do not think it is that important as long as they are all the same size. The unequal length may have contributed to the cracking?
Regards Peter

Thanks Peter, much appreciated.

I did wonder if the unequal lengths of the supports had something to do with the cracking of the rocker blocks and I would imagine that the alloy casting is quite brittle.

I am going to try supports of about 19.5mm to allow me to put a steel support plate beneath rockers to prevent any further warping. Well it's a plan.

Phil

Hallo Phil,
The distance between the spot-faces on my cylinder heads to the cast aluminium of my Inglis rocker-blocks is 23.2 mm. This space is filled by four-off aluminium spacer-tubes and four-off steel washers. But, as Peter writes, the important aspect of all this is, that the spaces are exactly identical for each rocker block: the actual distance is not critical.
Your idea of fitting a steel plate is entirely pointless! Its rigidity could never approach that of the cast iron cylinder head, upon which each rocker block depends. As a precaution, you could check the coplanarity of the head's spot-faces, using a surface-plate (a largish glass mirror would serve) and height gauge (alternatively, a marking-block and set of feeler gauges) Any deviation would then need to be treated with compensatory shim-washers.
You may regard all this as a Rolls-Royce treatment of a mundane situation, but - don't we all own the Rolls Royce of motorcycles?