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MG Midget and Sprite Technical - Push rods
|The push rods on my engine that may just been rebuilt are worn (they have that pip on the bottom). I bought some new push rods from a local MG parts supplier but they are remanufactured, not original parts. The Minispares website says these should be used on standard engines only. They sell a 'performance' push rod that is thicker but, it is claimed, does not require any mods to the holes in the head. Can anyone advise on:|
1) whether my remanufactured push rods will be OK with a perfomance engine - are they likely to be up to the job (my head has Cooper S valve springs and Peter has fitted a hot cam);
2) can I just grind the pips off my old rods and reuse them. I would have thought not, as this might change the profile and aren't these hardened at the end;
3) has anyobe experience of using the heavy duty push rods from Minispares? Are they really able to be used without head modification. These rods are part No.C-AEG583 and are 6.35mm along their entire length and not to be confused with the carbon fibre or ally ones that increase in diametre in the middle. They are, however, hideously expensive.
Any advice gratefully accepted.
|Chris H (1970 Midget 1275)|
|You can take the pips off. I've never had a problem anyway.|
|I think I still ahve one set of NOS genuine Rover pushrods left|
midgetbitz at gmail dot com
|Dave O'Neill 2|
|Standard push rods can bend and stay bent after which they rub, sometimes in more than one place. Probably it's high rpm that does (7K+) or hi-lift rockers or a bit of both.|
I think hi-lift rockers are a cause of a straight but perhaps thicker than standard push rod rubbing on a standard head.
|I bought new standard push rods from Minispares when I built my engine. They are with 1.5 rockers and a 286 cam. They seem fine after 3 or 4 seasons of high revs. The head has standard size holes and the pushrods are slightly 'polished' where they must slightly touch but that hasn't caused any problems so I have just left as is. I would think the thicker ones would need the holes oversizing.|
|John, have you buzzed it to 8200rpm by mistake yet?|
|Maybe! Occasionally on purpose as well. I'm just waiting for it to go bang one day.|
This thread was discussed between 09/12/2010 and 10/12/2010
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.