Maney Pushrods foul cylinder barrel

Anybody else had this with Maney pushrods....

I don't have any standard push rods to compare with, but putting Maney rods ino my original Norton cast iron barrels I found one in particular fouled the barrel at TDC on compression stroke (valve closed follower on base circle....I am not sure if that is worst case but it must be close).

The culprit was clear when you looked at the oval hole in the gasket....inlet pushrod rod hole in the left cylinder barrel is offset forward by at least 1/8" maybe more....out with the dremel.....and a couple more trial assemblies.....should be easy enough to fix if a littler harder to check....looking for scratches on blue applied to pushrods....

But I wondered if I was the only one.....Chris has told me he has had one foul the gasket...but not the barrel...

I didn't have that problem with my 750 iron barrels, but the machining on some of the original parts leaves a lot to be desired. Even though CNC machining did exist in the 60s & 70s I don't think Norton were using it. I believe BSA did acquire some tape controlled machines but to late to do them much good. Please ignore this if you already know, but the valve clearances need to be halved when using these steel pushrods with iron barrels. When I later fitted ally barrels to the 750, Steve told me to set the clearances to 0 with the pushrods just free to turn. (Maney cam)
Martyn.

Matchless said:

I didn't have that problem with my 750 iron barrels, but the machining on some of the original parts leaves a lot to be desired. Even though CNC machining did exist in the 60s & 70s I don't think Norton were using it. I believe BSA did acquire some tape controlled machines but to late to do them much good. Please ignore this if you already know, but the valve clearances need to be halved when using these steel pushrods with iron barrels. When I later fitted ally barrels to the 750, Steve told me to set the clearances to 0 with the pushrods just free to turn. (Maney cam)
Martyn.

Click to expand...

No, I didn't know that....but I didn't ask anyone either...the PW3 igure is 11 thou...extra 5.5 thou can't do any harm as such, but maybe noisey and lose a few thou lift....SOOOO I called Steve Maney and he confirms...halve it..... 0.0055" it is then

He also points out that lowering the rocker pivot 0.040" (skimmed for compression) will have moved the rod closer to the tunnel a fraction as well...it all adds up.

There is more work in assembling a combination of standard parts than you think.....that all adds up too....

Not sure how you get in there to see if pushrods just turn, unless you have very long skinny fingers :?

Steve

How was the length of the pushrods determined?

J
Cheers steve that was easy.

auldblue said:

Steve

How was the length of the pushrods determined?

J

Click to expand...

Advice from Steve Maney, he does a 'standard' -0.090" set that he recommends for a high lift cam with skimmed head or barrels.

SteveA wrote;

Advice from Steve Maney, he does a 'standard' -0.090" set that he recommends for a high lift cam with skimmed head or barrels.

Click to expand...

I wondered why my standard inlet push rods were longer than Steve M's but didn't get round to asking him.

Reggie said:

SteveA wrote;

Advice from Steve Maney, he does a 'standard' -0.090" set that he recommends for a high lift cam with skimmed head or barrels.

Click to expand...

I wondered why my standard inlet push rods were longer than Steve M's but didn't get round to asking him.

Click to expand...

He will supply them any length you want, but stocks standard length and -0.090"

I suspect he sells more of the -0.090"

Just to clarify something else from my checking this weekend.

I found a set of the service notes that show the OD of the centre (fat) section of a standard pushrod as 0.375".

I measured my Maney rods, at 0.3745"

So Maney pushrods are no fatter than standard pushrods, but they are parallel end to end, unlike the standard rod with its tapered ends.

As far as I can tell we now have sufficient clearance.