Help needed with finding a set of rocker arms!!

topcatcustom · Post by **topcatcustom** » Wed Mar 12, 2014 9:29 am

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

crayefish · Post by **crayefish** » Wed Mar 12, 2014 10:29 am

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?

topcatcustom · Post by **topcatcustom** » Wed Mar 12, 2014 11:26 am

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!

crayefish · Post by **crayefish** » Wed Mar 12, 2014 11:35 am

I did notice you were being elusive about the engine type in the ignition thread

Guessing it's a big beast!

ChrisJC · Post by **ChrisJC** » Wed Mar 12, 2014 6:17 pm

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

Chris.

crayefish · Post by **crayefish** » Wed Mar 12, 2014 6:33 pm

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.

ppyvabw · Post by **ppyvabw** » Thu Mar 13, 2014 1:45 am

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?

topcatcustom · Post by **topcatcustom** » Thu Mar 13, 2014 10:20 am

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?!

crayefish · Post by **crayefish** » Thu Mar 13, 2014 10:33 am

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

topcatcustom · Post by **topcatcustom** » Thu Mar 13, 2014 12:32 pm

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

crayefish · Post by **crayefish** » Thu Mar 13, 2014 12:43 pm

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.

topcatcustom · Post by **topcatcustom** » Thu Mar 13, 2014 1:37 pm

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

crayefish · Post by **crayefish** » Thu Mar 13, 2014 1:49 pm

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

kiwicar · Post by **kiwicar** » Sat Mar 15, 2014 7:32 pm

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

unstable load · Post by **unstable load** » Sun Mar 16, 2014 1:03 pm

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.