8 port pushrod length

[App K]

I wonder if one of you kind chaps could measure the length of one of the eight port pushrods supplied by mini spares.
Im in the middle of a 999cc S engine build with a mowog eight port head/windsor rockers and have set up the rocker geometry which gives me a pushrod length of "around" 8.930. I believe a standard 1275 pushrod is 8.0735?...the minispares ones are advertised as being 0.220 longer than standard, so they should be in the ballpark but would like to check if possible..

Cheers

[mk1]

If you are building a 970 then I mwould have thought that you should be using shorter push rods. Longer than stangard 970 rods, but not much longer than standard 1275 ones.

Best bet is to contact Rich @ Mini Spares North about this as he is the resident 8 port expert their. You could also PM him through the forum. rich@minispares.com

Mark F

[App K]

Mark, you are quite correct in theory, and I was wondering who would comment on that one.

They should be around the length that you are suggesting. However, even though the build is a new block, head , cam, cam followers, etc, the Windsor roller rockers require to be shimmed to the correct level to enable the rocker roller to “roll” over the correct part of the valve tip as the valve compresses (which although they are new valves, were slightly longer by a few thou than specification). The combination of all this dictates the pushrod length.

I have carefully measured numerously valve lift/spring crush, pushrod in out shake it all about and mocked up (welded) a makeshift pushrod eventually to the correct length..hopefully…and all seems to operate correctly at the dimension that I have arrived at?

Hopefully.

[Astro]

Hi,

what is about longer MG pushrods? I would not trust these welded rods.

[mk1]

I would suggest the best bet is to contact Rich & see what he suggests.

I seem to remember talk of a tubular one that may be able to be cut to the correct length.

M

[rich@minispares.com]

if you wish to make pushrods to a 'non-standard' length, you can buy the three piece ones and cut and glue them yourself (or work the length you need, and our supplier can provide an assembled set)


really, until the engine is dry built and the rocker ratios worked out, its a guessing game - same as a decent built five port

[App K]

Cheers for the info Guys

Will chase up that number Rich,thanks.