T/A Rocker Arms

[Rbob]

I know they are offset but I thought they were a 1.6 ratio, I cannot find any info saying what the ratio is.

Does anyone have knowledge of this?

[MOPAR MITCH]

Both T/A rocker arms are 1.5: 1 ratio.  In fact, for the exhaust, some people will substitute the 273 v8 rockers (less robust as the T/A, but same ratio).

[Rbob]

Thank you, Mopar Mitch,  good to know. 


I just mailed them to Rockerarms Unlimited, somehow they have been abused.

http://rockerarms.com/

[MoparLeo]

The rockers on the roller Magnum series engines from 88-03 had 1:6 rockers.

[MOPAR MITCH]

Rbob -- I recently used RockerArmsUnlimited (Spring of 2020) to recondition my T/A rockers... and improve them for racing usage.  They did an excellent job... high quality!  Excellent service!

[68bee]

What did they do to the rockers and how much did it cost

[MOPAR MITCH]

They added bronze bushings, new adjusters, polished/cleaned, slightly narrowed the side faces for allowance of serrated shim washers (for better on-center alignment over the valve tip)... and less drag between the rockers.    I forget the exact cost... ~$450 if I recall.   I also sent them the shafts (new from Hughes with slots) so they could properly fit them with the bushings.

Make certain you talk with Gary at RAU... he's got a wealth of knowledge to do things right.

Pending your valve spring retainer-to-rocker arm clearance, you may have to slightly grind some extra clearance... you'll have to assemble and visually inspect that on your own for each rocker arm.

[Rbob]

Surfing internet today and found some info on offset rockers that may be of help to someone.  Indy Heads used 440 rockers as the offset rockers on the 340 t/a head.

I do not know if it would work but it may.

[68bee]

They added bronze bushings, new adjusters, polished/cleaned, slightly narrowed the side faces for allowance of serrated shim washers (for better on-center alignment over the valve tip)... and less drag between the rockers.    I forget the exact cost... ~$450 if I recall.   I also sent them the shafts (new from Hughes with slots) so they could properly fit them with the bushings.

Make certain you talk with Gary at RAU... he's got a wealth of knowledge to do things right.

Pending your valve spring retainer-to-rocker arm clearance, you may have to slightly grind some extra clearance... you'll have to assemble and visually inspect that on your own for each rocker arm.

Thanks for the information

[MoparLeo]

The Indy head is using a 440 rocker because they moved the rocker shaft over to align with the larger port. The rocker is aluminum and because of the much wider face, they can off set the adjuster in the rocker arm. Not a bolt on for a T/A.