138 grey Crankshaft breakage

[Matthew4655]

Im going to end up putting a grey in my 61 EK sedan im building hopefully with twin stormberg carbs. I was wondering if theres any way round the posability of crankshaft breakage. Any other cheap tips to make it go better would b appreciated

[Harv]

Couple of options, in order of increasing complexity:
a) Don't flog the hell out of it . Most survive quite fine unless they are raced/loaded.
b) Fit main bearing bridges. Search this forum, as there have been a few posts here. Can't remember if anyone is still making these for "over the counter" sales.
c) Fit a main bearing girdle. Take a look at eBay, as Sonic are making them new:
http://www.ebay.com.au/itm/Holden-138-G ... 3cca0ecbf8
d) Find a Vauxhall forged crank and have it machined to fit. Again, search the forum as there are a few posts here on this mod. Vauxhall cranks are like rocking horse poo though, and machinists who know what to do with them are getting rarer (though still exist).
e) Have a custom crank made up. From memory, you are looking at the $4,000 mark for one though.

Cheers,
Harv.

[choppedfan]

Have to agree with Tim and Harv, I run a warm grey and breaking a crank isn't even on my radar and I do "drive" my car occasionally to stretch its legs and its fine

Unless you are going to run High comp pistons and shave a ridiculous amount off the head then you won't have any problems, remember these old greys have done everything from being used in stock car racing, drag cars and self taught backyard mechanics (like me) hotting them up. Read the forum and see what others have done to their greys and you'll end up with a good streetable engine, BUT be aware it won't be cheap grey motor bits and pieces are getting more expensive



Mick

[Matthew4655]

wow awesome thanks guys

[bootlegger]

Probably wouldnt hurt to get the crank crack tested .

[Stygian]

The part of the crank that will cop a hiding in a hot grey is the cam gear keyway, apparently from the extra load imposed by a hot cam and stiffer valve springs. An old trick to combat this is to secure the harmonic balancer by means of a bolt in the end of the crank. This ostensibly helps share the load. This was done to my hot grey and another that I know of.

A Vauxhall L model crank is used primarily for racing. They aren't rare if you know how to get them. Fitting them requires machining. My engine builder knows what is involved. I assume that it is not cheap.

[bootlegger]

I got told once that you can fit a vl commodore
Crank into a grey. Has anyone seen this done.

[Harv]

Dave,

From a quick look at VL Commodore and grey motor crank specs, the stroke is a crapload bigger on the Nissan motors. Grey motor is 3.125”, whilst the RB30 is 85.0mm (~3.346”), with strokers available (Nitto, RIPS, Spool Imports) up to around 3.7”. Even at standard 3.346”, my guess is you would be looking for pistons with significantly lower crown thickness or higher pin height to avoid mooshing them on the valves.

The bigger worry though is the mains - greys are 4 journal cranks, and some Googling shows the RB30's are 5 journals (unless I miss-Googled). Can't find anything on journal diameter or journal spacing other than the 5-journal pictures.

Wouldn't work anyway, the grey motor doesn't make that pssshhht! noise .

Cheers,
Harv (anti-Zim Pirate).