The V8 Owners Forum -

Hi all, I've been searching in vain with no luck, I need a set of shaft mounted rocker arms. I have done a basic sketch below, the ratio I think is 1.6, but the dimensions are most important, i.e. length of the rockers.

So far I have looked at big block Chrysler and Mopar ones as they are shaft mounted, but they are too small, the long arm is approx 40mm long so quite a bit too short.

Can anyone think of an engine which would have close dimensions? I don't need shafts as will have to custom make them to suit hole centres etc.



Thanks

I don't know enough engines to help, but those dimensions look huge! I would be surprised if you found any that match that... I guess most engines would have them shorter to reduce the loading on them.

If cost isn't such an issue, you could always get some machined from 7075... I don't think it would be too difficult. You'd have to do a quick FEA on them, bush them (a replaceable bronze bush perhaps?) and fit steel inserts for the tips. Oilways would be easy for the machinist. Would be a fun project I reckon!

What engine is this?

Top secret! They are pretty big, the ones fitted don't actually look too bad in fairness, maybe they will survive until I can get some made up. Could actually be fairly easy to make some billet aluminium ones on the mill with a roller bearing at the tip, if I got some good ally!

I did notice you were being elusive about the engine type in the ignition thread Guessing it's a big beast!

I think he's doing something with a Meteor V8.

Chris.

ChrisJC wrote:I think he's doing something with a Meteor V8.

Chris.

You'll get in trouble for spilling the beans

Is that a V8 version of the Merlin derived Meteor engine used in tanks or something? I have a friend with a V12 Meteor. LOVELY thing to hear. As with the Merlin, apparently you need to skim the heads EVERY time you remove them as they have no head gasket and warp a little when removed.

ChrisJC wrote:I think he's doing something with a Meteor V8.

Chris.

Do they not have overhead cams, obviously with a completely different rocker arrangement to the usual push-rod and rocker depicted in the diagram?

Nope!

A guy in the US got back to me after measuring a BB Chrysler rocker and the long arm is 1.5" so considerably too short.

I think I'll use the originals and machine some from ally or steel, can't see it being too hard? A stout little bearing for the tip, bronze bush or needle roller on the shaft, and a standard ball ended adjuster screw on the back would be easy to make I think?!

topcatcustom wrote:Nope!

A guy in the US got back to me after measuring a BB Chrysler rocker and the long arm is 1.5" so considerably too short.

I think I'll use the originals and machine some from ally or steel, can't see it being too hard? A stout little bearing for the tip, bronze bush or needle roller on the shaft, and a standard ball ended adjuster screw on the back would be easy to make I think?!

I think making your own would be pretty sweet! If you ask nicely I might even FEA them for you

Great offer thanks! How do you do it, Solidworks or something more serious?!

I use Solidworks for designing parts, but for FEA it's not even worth wiping your bum with!

I use either Abaqus or Ansys depending on whether I want speed or accuracy.

All my critical parts such as wheel centres, uprights, rocker arms, hubs and diff mounts etc were with Abaqus and hypermesh but I use Ansys for anything where I don't need a 1.1 safety factor.

You may find a PM coming your way soon then!!!

Though you might have to wait a month or so... rushing to get this bloody thesis done before I start work!

Hi Tom
have you looked at push rod hemi engines such as the chrysler or the two Daimler hemi engines. There are a few other push rod hemi engines but you will need to google them, the other place to look might be at the dolomite sprint exhaust side rockers or I think the lancia Fulvia had long rockers to operate every other set of exhaust/inlet valves. . . even a VW VR6 might have long rockers.
best regards
Mike

You may need to look at the Diesel market for those sizes. Cummins, Detroit Diesel, Mercedes, Nissan Diesel etc.
Maybe Continental or Lycoming at a push in the Aero world.