Rod Length EVO Gold Head

[Marty Davis]

Does anyone know the rod length on the older CMB 67 EVO Gold Head with the Dual Plug Head?

Thanks in advance....

 

[mtruex]

Take it apart and measure ?

 

[Dan Kramer]

Marty, is that the short block with the steel rod and stacked crankshaft? i have several of those and maybe andy brown might also have the measurements.

Dan

 

[dwilfong]

1.605 same as the Picco / OPS is what I used.

Don't remember where / how I got it bin a wile.

That is what I have loaded in your program.

Makes a really nice rod angle with the .67 crank.

Push one of those cranks apart that I gave ya that is not welded and check.

Thy press apart real easy in the vice with a socket and a bolt.

 

[Marty Davis]

Take it apart and measure ?

It is a crank with both ends pressed together so it is not possible to measure without a problem pressing apart and then trying to press together after measuring.

By the way, your friends are really pleased to see this year's successes at your real job.

Life is obviously MUCH better this year for you in all aspects.

 

[Marty Davis]

1.605 same as the Picco / OPS is what I used.

Don't remember where / how I got it bin a wile.

That is what I have loaded in your program.

Makes a really nice rod angle with the .67 crank.

Push one of those cranks apart that I gave ya that is not welded and check.

Thy press apart real easy in the vice with a socket and a bolt.

I will do that if nobody has the measurement. Just didn't want to sacrifice one of the crank assy's if I didn't have to.

 

[dwilfong]

Thy have bin pressed apart and back together already once.

A small vice will work with ease.

That is why you need to weld the pins in place.

Thy move real easy.

Steve Wood explained to me how to true them with a V block and a indicator mounted in a vice.

Then get Tom to weld the pins.

 

[jeff baham]

the cmb evo-1 67 gold head black case engines have a rod length of 1.605

 

[Marty Davis]

Thy have bin pressed apart and back together already once.

A small vice will work with ease.

That is why you need to weld the pins in place.

Thy move real easy.

Steve Wood explained to me how to true them with a V block and a indicator mounted in a vice.

Then get Tom to weld the pins.

Looks like the two holes through each of the halves would be a good way to align the parts. A perfect fit pin of the exact length to allow for .005" clearance for the rod might allow for a perfect press for the halves. I will order some pins and then grind them to the perfect length and see if that works.

 

[Marty Davis]

the cmb evo-1 67 gold head black case engines have a rod length of 1.605

I tried that measurement and the results didn't look reasonable so I parted one of the crank assys to measure the rod. I guess that I must have had a stretched rod as the measurement was 1.625" rather than the 1.605".

 

[jeff baham]

I had ernie lefleur mod my twin 67s and that's the rod length he used , plus I have a picco 80 rod with the length of 1.637 , wonder if it could be an 80 crank you have, just a though.

 

[steve wood]

I don't know what size the rod is in a evo 67/80. the cranks are the same,and the rod length is the same. I do know that you will never ever be able to put one back together without indicating it to get it to run tru. I have repaired several dozen of the evo/rs style cranks in the 67 to 1.01 sizes, and every one is indicated in after reassembly,and no amount or type of ground pins will get them close enough.

all that's needed is an indicator and a vise, in a mill (a drill press may work,may not), I use the 90° corner where the vise jaw meets the flat of the jaw carrier. a vee block works, but is overkill. hold the crank in the 90° vee and put the indicator against the short bearing end and rotate 180°. check it at 90° from the crank pin rotate an recheck. I put the crank in the lathe to move it around to get it lined up, recheck with the indicator set up. sometimes this takes 2 minutes sometimes 10. most times you can't get them perfect,stacked tolerences from parts ground separately at the factory. if you can't get it under a .001 runout don't fret about it, cause new ones out of the box don't always run this good,as I check all new ones I work on. if you don't understand this call me

o and I would never weld one, unless I could afford to buy a new crank assembly,as you can't repair a welded one anymore