Lockdown: Time for big service, changes and improvements of my SQ4

[rschurr]

I toke the chance (have now the time!) to make a total strip down of my SQ4 for revivising and improvments (hopefully!):

Regrinding the crankshafts, added some Mallory Metal.
Now all Bob weigths, all rods and all pistons equalized in weigth.
Static balancing of the crankshafts with counterweigths.
Nearly perfect valve timing.

Repositing the oil filter in a hided position.
New clutch sproket with 40 Tooth.

Installing a BMW TLS brake .

But no chance for testing, we have 1 meter of new snow.

Cheerio Rudolf

[Bob.Murphy]

Lovely work, it should go very well. Let's see some pictures when the snow clears.

BUT -

I'd love to see pics of those three Chevvy Corvettes - please .

Bob (more into Toyota Landcruisers . . But if its got an engine . . . . ).

[rschurr]

Ok here is my Corvette family:

The C3 is Stock but goes 13,25 sec on 400 meters:

and has now a new painting:

The C2 has Triple Dual Carbs:

The C1 has Dual Quads:

[fpassmore]

Very, very fine cars, my brother-in-law has five of them and it is quite an obsession.
Frank

[allan.walker]

Hello Rudolf,
Some fine cars there!

Nice work on the Square Four, too. May I ask how you balanced the crankshafts? I know what Mallory metal is, but what procedure did you follow to determine where to add or remove weight, etc?

Allan.

[rschurr]

Hi Allen,
I followed exactly the AOMCC con-rod booklet (by Bruce Longman).

I weighed the con-rods and determined the proportion of the big end.

Then I used strips of lead to simulate the determined weight. I tightened these strips around the crank pins and then turned the crankshaft on the balancing stand. The crankshaft must stop in all positions and no longer turn itself, then it is "static" balanced.
Also with lead strips I determined how much more the bob-weights should be heavier.

Now I brought the bob-weights in each case to the same weight (con-rods and pistons of course as well) and added the tungsten rods using the formula weight of tungsten rod minus weight of the drilled steel, I achieved a net 23 grams per bob-weight.

Finito !

Rudolf

[Bob.Murphy]

Rudolf

Thanks for the Corvette pictures - very nice cars indeed. I guess you spend a lot of time keeping them 'just right'. They are a credit to you.

Bob.

[allan.walker]

Hi Allen,
I followed exactly the AOMCC con-rod booklet (by Bruce Longman).



I weighed the con-rods and determined the proportion of the big end.



Then I used strips of lead to simulate the determined weight. I tightened these strips around the crank pins and then turned the crankshaft on the balancing stand. The crankshaft must stop in all positions and no longer turn itself, then it is "static" balanced.
Also with lead strips I determined how much more the bob-weights should be heavier.

Now I brought the bob-weights in each case to the same weight (con-rods and pistons of course as well) and added the tungsten rods using the formula weight of tungsten rod minus weight of the drilled steel, I achieved a net 23 grams per bob-weight.

Finito !

Rudolf

Thank you Rudolf. I think that I can follow that!
I have an odd pair of crankshafts which I would like to check for balance before use.

Are they the original con rods that you are using? If so, have you carried-out any checks on them (e.g. crack testing?)
Are you going to polish them before re-use?

Allan.

[rschurr]

HI Allen,
The picture with the scales shows a BSA connecting rod as example.
I got a bunch of new AOMCC con rods after one of my old ones got cracked (fatigue fracture ).

And so I got the booklet that I have my knowledge of. In the excerpt from the booklet you can also read that you would need a lot more counterweights with the original con rods.

Rudolf

[allan.walker]

HI Allen,
The picture with the scales shows a BSA connecting rod as example.
I got a bunch of new AOMCC con rods after one of my old ones got cracked (fatigue fracture ).

And so I got the booklet that I have my knowledge of. In the excerpt from the booklet you can also read that you would need a lot more counterweights with the original conn rods.

Rudolf

Thanks for the clarification, Rudolf.