Neil, if you aren't taking a lot of metal off, then you can ignore the
effects
of pushrod length. As I understand it, you are only skimming enough
material to ensure trueness. If so, then save your money for that full race
motor!
Mike
-----Original Message-----
From: Neil Cotty <neilc@tradesrv.com.au>
To: vscjohn@iamerica.net <vscjohn@iamerica.net>
Cc: mgs@autox.team.net <mgs@autox.team.net>
Date: Monday, 18 January 1999 9:58
Subject: Re: Cam lift, pushrods and other neat stuff. <G>
>John,
>
>>Neil, whatever the cam lift, you should not change the pushrod length.
>John
>
>
>Can you explain in more detail as to why not? The two _blueprinting_ books
>(not motor rebuild books) I have both mention this as being an essential
>adjustment, when a motor has been modified in certain ways - to ensure the
>correct operating geometry of the rockers. They recommend various methods
of
>adjusting the pushrods (not talking about LBC's) which I have actually
>already discussed on this BBS before - I think someone came back with using
>tubular pushrods (Bill?) which can be adjusted by machining & heat - (I
>think) - and that the stock pushrods are non adjustable. I'm not replacing
>with stock pushrods, I just need the length data.
>
>Can someone confirm this for me or am I dreaming again? <G> The net result
>of the decking/skimming etc alters the clearance between rocker arm and
>pushrod. My assumption is that increasing the clearance at the arm will
>resolve the clearance issure, but ultimately the angle of the rocker arm is
>affected by this adjustment and will affect the load placed on the rocker
>arms, and increase load on the rocker mechanism. If I am to spend the $ to
>flowbench the head, I would like to get all this spot on, but more
>importantly, as I'm considering roller rockers, I don't want these to take
>any more load than they already do. Apparently due to the increased weight,
>and different distribution of that weight, r/r's requires the use of
>slightly firmer springs to maintain the same valve bounce rpm.This is what
I
>have read, and am requoting from a few sources. It's an interesting topic.
>:)
>
>Cheers,
>Neil.
>
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