11 replies to this topic

[Com_VC]

Hi all,

I plan to put a blue/black motor counter balanced crank into a red 202, was just wondering what prep work I should do to it.

 

I don't want to go knife edged as I have heard this can weaken them.

 

Is it ok to deburr and clean up the casting, as it looks rough in a few places.  Maybe even polish it so it reduces oil drag.

 

Though after I do all this I am wondering if this is going to have an affect on the balance?

[S pack]

Only things Ron Richards did to mine was check it was straight, crack test it, balance it, measure and linish the journals and machine the rear main seal journal down to suit the neo seal.

Other than that he advised $$$$wise to leave it as is for a street engine.

[warrenm]

If you are doing the the deburring, you've got nothing to lose. I personally don't believe there's much to gain out of "knife edging" a Holden 6 crank, but plenty to lose in removing the mass. Just take the sharp edges off. 

[Com_VC]

Hopefully I won't need the rear main seal journal machined.  From what I understand the later Red's ran the same style rope seal as the blue/black motors.

After the deburring will it need to be re balanced or will this not be necessary?

 

Also if it need re balancing, is it balanced as a complete unit with the flywheel/pressure plate and harmonic balancer fitted?  Planning on running an aftermarket balancer and maybe an aluminium flywheel.

[warrenm]

I don't have any problems with using a rope seal. I'd re-balance the rotating assembly(crank,flywheel,pressure plate & balancer) as you are going to use new balancer & flywheel, if it's mainly a road car, don't go too light with the flywheel.

[Com_VC]

I don't plan to go over 6000rpm, this will be a turbo engine.

Can any engine shop do the balancing or is it specialized work? I assume it will be a dynamic balance not static?

I will need to weigh the flywheel and decide whether I want to use it or not.

[claysummers]

May I ask why you don’t use the black block? If you are running a turbo you’re not looking for an original engine bay.
Cheers
Clay


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[S pack]

I don't plan to go over 6000rpm, this will be a turbo engine.

Can any engine shop do the balancing or is it specialized work? I assume it will be a dynamic balance not static?

I will need to weigh the flywheel and decide whether I want to use it or not.

Most engine shops should be able to do the balancing work for you however, as we all know, there are blokes that can do the job and there are blokes that can do the job properly.

Always best to choose from shops that come highly recommended.

The turny parts are dynamic balanced and the up and downy parts should be weighed and matched to their lightest brother.

The std blue/black flywheel is lighter than the red flywheel to compensate for the heavier reciprocating mass of the fully counter weighted crankshaft.

So at least use a blue/black flywheel or a red flywheel lightened to the same weight.

An alternative would be the Yella Terra billet steel flywheels that can be had in various weights.

[Com_VC]

Only real reason for using the Red motor is because it had recently been recoed so has aftermarket dished pistons and the bores look good.  I am just trying to get a motor setup to iron out all the issues of the turbo and fuel injection and i'll build up a blue/black motor down the track, if I can swap a few bits out of the blue/black motor to make it stronger then I may as well.

 

May I ask why you don’t use the black block? If you are running a turbo you’re not looking for an original engine bay.
Cheers
Clay


Sent from my iPhone using Tapatalk

[Com_VC]

Here are some photos of the black crank I took, first photo it looks like a dab of weld was used possibly when they balanced it when new?

Second photo not sure what it is.

 

I have another black crank and it was pretty much the same as this.

 

There are also a lot of really sharp edges, gotta love quality control in the 80's

 

So I assume I can linish these bits off without any issues?

 

 crank1.jpg   78.51K   4 downloads

 crank2.jpg   91.75K   4 downloads

[S pack]

The 1st pic, the lump is the casting time clock.

2nd pic looks like casting numbers and letters?