RS Motorsport :: Classic Speed Restored

When a standard Pinto crank is modified for competition use (say ~200Hp, 8000rpm) what is usually done to it? Obviously balancing but is much metal taken off of it? Other mods?

Is a race ready standard crank available off the shelf? Don't want nor need a steel item.

The Vizard or Hammil book indicates that the Pinto crank journals should not be ground below a specific diameter (cannot recall the figure). Is their recommendation reliable or should the largest possible be used?

I have the engine in the hands of the builder who is undecided whether to grind and reuse my current crank so am just looking at options again.

I really can't help you with your technical question but if your engine builder is unsure weather to use your old one or not, perhaps that should suggest either it's really not the best idea if you want piece of mind at those revs and power levels, or he doesn't know enough to be offering good advice?

Llewellyn

I'm not much up on high end crankshaft prep either but if I remember my Hammil, he states that a well prepped, crack tested standard crankshafts rarely fail at that level. I dont recall him saying much about knife edging pinto cranks but I guess its doable by an expert.

If your journals are that bad then maybe look around for another block and crank. Its the availability of non standard bearing sets that limits how much you can grind really.

Glenn it's easy to decide whether a crank is usable
Holding out in front of you over a clean stretch of concrete and drop it!
if it breaks in half it's clearly fucked and if it doesn't and has a dull ring to it, then hand it to the engine builder and tell him to go for it, but just tell him to make sure it's got some decent clearances

Plenty of guys I know are using the standard crank with over 200hp no probs and one will go in my race engine build too.

Contact Warren Heath as he has built plenty of healthy pintos using the standard crank.

Cheers,

Matt

are new std cranks available or would it be a case of buying second hand until I find a useable one?

I got mine from Warren but yes a 2nd hand one in good condition is what you want.

Here's a quote from David Baker @ PUMA Race Engines - "The standard crank is very strong and there is no need to change it for even race use. It does supposedly have a tendency to snap flywheel bolts though on very high output engines and the Cosworth crank has 9 instead of 6 bolts to prevent this. Adding extra dowels is a good security measure or just use the Cossy crank as they are more readily available these days".

Cheers

Matt

http://www.ebay.com.au/itm/Ford-Escort- ... 257b9f3ba9

There around. Buying sight unseen is a bit iffy I guess.

Hopefully, as a fallback, the crank in the $200 Farcebook motor that was installed to get us through Targa Adelaide might be OK

Thanks for the replies. Should find out after Easter whether I need to find one or not.

Hopefully it'll be OK.

Cheers

Matt

You will need to get the block and crank line bored to suit each other. They may not have to machine much but it has to be checked. You'll be back to Milton's again with the credit card before you know it.

Steve you never line bore a block unless you've replaced main caps or it's got a major issue like a twisted cap from new because every time you line bore the journals the centre line of the crank is moved upwards cocking up your gearbox to clutch alignment

Never thought of that before. I assumed when they line bored that the top of the new bore was made as close to possible to the existing bore top. How many times could you get away with a line bore before the alignment issue becomes to great?

Just had a quick chat with Chris Milton. Big difference between line boring and line honing. A line bore will remove up to 10 thou and as Danny said will change the alignment of the crank to the gearbox. A line hone may only remove 1-2 thou. Replacement caps should come oversize to allow for this. Feel free to call Chris or Sam and they will explain the process or call into the workshop and they will show you how it's all done

Yes I know about line honing and again I would only do it if I was replacing a cap and too be honest if a block needed anything more than a very light hone to sort out a cap I'd dump the block in a wheely bin