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Which rocker assembly?

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Rut

Rut

Obi Wan
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I'm in the process of rebuilding my 1275 and I have 3 or 4 rocker assemblies, possibly one from a 948. All look identical except for 1: pressed rocker arms vs forged rocker arms and 2: pedestals on one assembly have oil holes in each one vs oil hole in one pedestal. I have a new shaft and will be using the best components to make one good assembly, should I use all forged or pressed arms and should I just use the pedestal that matches the head?
Thanks, Rut


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Use all of one type arm or the other (stamped steel or forged). Some 1275 stamped arms (like those used on the Austin America) had oval pads instead of round ones. The forged arms are preferred in general with the oval pad stamped arms after those.

Pay attention to the pads on the arms. Minor witness marks on the pads are OK while deep wear pockets dictate replacement.

For the pedestals, pay attention to where the oil feed hole is in the head relative to the feed hole in the rocker shaft. This changed at least once during A-series production. I remember the work around requires drilling a feed hole in one of the pedestals and giving that hole a large chamfer to line up with the supply hole in the head. Sorry... I don't remember the specifics.
 
Thanks for the input! The forged rocker arms are in good shape with no wear on the valve side and fit the new rocker shaft exceptionally well. I'll make sure the oil hole lines up and double check alignment with the valve stems. I do have a couple of buggered up adjusting nuts to replace, but all looks good. I was also very happy to see that the engine actually had a rebuilt head and new pistons!
Thanks, Rut
 

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Rut said:
... and double check alignment with the valve stems.
Click to expand...

It is OK if the rocker tip is not directly over the valve stem. If you do decide to shim the arms to position them better, make sure you look at how this affects where the pushrods pass through the head. It's not uncommon to shim the arm position only to find that centering the rocker over the valve results in the pushrod rubbing the head at some point through its travel.
 
Doug,
Thanks great and much needed advice! My game plan is to trial fit the rocker to make sure it's where it's susposed to be prior to torquing the head.
Thanks, Rut
 
Here's a interesting rocker arm choice, while not roller type, they do have the increased ratio of 1.5 and in the past were referred to as the Kieth Dodds 1.5 rockers. The come as a new complete assembly and the price is right, they sell for 111 UK pounds, so about 165.00 USD, that's alot of rocker arms for the money. I never worked with a set of these, but would love to, my friend, David Anton told me this was the most geometry correct A series rocker set out the box made. Atthe end of teh day gained ratio is way more important than a roller tip, but if that is what you after, you find a deal on the at Mini Spares as well, while I sue to order a good bit from Mini Spares in the past, after homeland security kicked in, and fouled up international shipping, the shipping got too high for me to deal with Mini Spares, but now they have very affordable shipping options, so once again advantageous for us Yanks to buy there. Here'sthe link to the 1.5 forged rocker arm assembly.

https://www.minispares.com/product/...search/classic/rocker 1.5.aspx|Back to search
 
Hap,
that looks like a good option, but I don't really understand the full benefit of these. They give 20% more lift so I would assume that coupled with a 276 cam would stay open longer as well. This contributes to efficiency so increases HP? If so, that would be cheap HP! Could you expand on this?
Thanks, Rut
 
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