Maney tappet clearances

Status
Not open for further replies.
Fast Eddie

Fast Eddie

VIP MEMBER
Joined
Oct 4, 2013
Messages
20,641
Country flag
Folks,

Steve is away currently and I don’t recall getting the info from him prior...

Can anyone please confirm the tappet clearances with a Maney cam, when using Maney alloy barrels?

I’m I right in thinking it’s nil clearance all round when cold?
 
Concur that zero clearance applies to steel pushrods only.

Steve has a Facebook presence, incidentally.
 
Using his barrels & std pushrods, Steve says use half the usual valve clearances when cold - so that's what I've done - Alan
 
regental said:
Using his barrels & std pushrods, Steve says use half the usual valve clearances when cold - so that's what I've done - Alan
Click to expand...

By ‘standard’ pushrods, do you mean standard Norton?

When you say half the usual clearance, what do you mean? What would that equate to with a Maney cam?
 
Sorry missed that you had a Maney cam (I have std cam) - std pushrods are usual Norton alloy - half clearances are 3 & 4 thou instead of 6 & 8 thou - drop him an email as I did last year - he was away on holiday but still replied - stevemaney@aol.com
 
Context is as mentioned earlier in the thread gents!

Maney cam, Maney alloy barrels, but alloy pushrods (whereas Maney’s are steel).

With Maney steel pushrods it would be zero cold clearance.

With alloy pushrods it’s 0.008”.
 
sorry , am i missing a trick here? are you saying that the tappet clearance with alloy cylinders and steel pushrods is zero clearance and not what ever the cam manufacturer states or is this just applicable with the maney cam ? if so then have is this another thing ive been doing wrong all these years. awaiting enlightenment!
 
The zero clearance mentioned in this thread is for a Maney cam as that’s all I asked about!

Steve said, as regental said earlier, that for other cams he generally advises people using his alloy barrels with alloy pushrods to use half the running clearance suggested by the cam manufacturer for a standard application (ie iron barrels).

I do not know what he would suggest for the above but with steel pushrods. Anyone doing this should contact Steve and not take advice from this thread.

Remember the cam manufacturer will assume use of stock alloy pushrods and iron barrels. Alloy expands more than iron with heat, so the tappet clearance will reduce.

Clearly, changing the barrels to alloy and pushrods to steel changes the dynamics.
 
Last edited:
Clarification

The problem with steel pushrods in aluminum cylinders is that the cylinders expand but the steel pushrods don't. So with zero clearance cold pushrods & cylinder you end up with about .020" or so tappet clearance when they're hot and you lose lift. Alum pushrods expand along with the cylinders so its not a problem.



Jim
 
Status
Not open for further replies.
Back
Top