As title I took a working crank out of my engine and was going to use on the new build .. my engineer messaged me to say it was a tad bent but he's sorted it ..so alarm bells rang and I asked a few more questions and it was 2thou out which as far as.i understand hes ground it out ..is it still fit to use ???? in my new build ..the new build is forged and will be running some big boost ...

Thanks Mat.

 

Surely if the machinist has corrected it...then he should be able to deem whether it is fit to use or not rather than some person on the internet who has never even seen it.

 

I guess the question is more "is a reground crank still safe for a high boost engine build?"

Can you get a replacement and sell that on?

 

I had a reground crank in my S2 and ran 24psi no problems.

 

I actually panicked and sourced a brand new rare CVH crank at the cost of 420 quid ..but just wanted to know other people's thoughts as technically its straight now and was told Ford's manufacturers tolerances for the cranks was 5thou .

 

He told me it would be fine ..but the word bent made me panic ..i over reacted and sourced a new crank ..but now I'm sat wondering if it would have been ok since later finding out Ford's tolerance on the crank is within 5thou and mine was only 2thou out

 

A crank should be straight, simple as.....I guess a lot depends where he's measuring and exactly which bit is deemed bent.

 

So why do Ford state on the cvh crank that they have to be within 5thou straight ?

 

5thou measured where and how exactly ?

A number on it's own is meaningless.

 

their will be lots of tolerance on a cvh crank matt

 

If you bought a new one and its a fresh build engine use that and cash the old one in

 

Just use the new one and sell the other one if useable

 

Im Not sure I think there spun from either side and measured in the middle ..not 100% ..only what I reaď up on Google search other day .

I will now I have a new crank ..the threads more towards did i panic and didn't need too or not .?..if it's safe to use ill pass it on that's all as well.

 

You have had a bargain to find a brand new crank for just Ł420! Its a no brainer, use it in your new engine and sell the crank which has been repaired up to Fords tolerances.
Spending Ł420 on the new crank makes more sense than buying a turbo blanket!

 

That's the option ive gone for apart from I may keep the old crank as a door stop .

 

Ive a good used crank in the garage if you need one mat

 

Thanks mate ive managed to find a genuine brand new crank but ill be needing one now for the original engine I'm building back up along side my forged one ..pm me what ya want for it and I'll come collect it at some point.

 

measure the new one, its probably 2thou out too

 

Yea it could well be according to ford . ..

 

If it's now been machined straight mate it'll be fine.

It's all nonsense about reground cranks being weaker blah blah.

The ammount removed is so minimal it'd make virtually no difference to strength

Cheers Paul

 

There can be some cranks that dont like being reground etc...

But in this case, we dont know exactly how/where this was measured, nor has it been stated exactly what was done to correct whatever problem they're saying there is.

 

Be reyt ..im.goimg to build a sister engine up and see how much we can push it ..ive enough spare parts to build another

 

cranks are measured for straightness on the mains, you usually set the ends up perfectly on the grinder and then run along all of the mains to measure for any bends. 2 thou is fine to grind out really though, it may have a minute effect on piston heights depending on what type of grinder was used, but nothing to worry about. 2 thou is about half the thickness of a bit of normal printer paper if you need an idea of how bent it was.

 

Thanks mate i did think it wasn't much to worry about .

 

Im guessing its prob just a few thou off the journals

If thats the case and it now runs true it wont make any diffence to its overall strength

Cheers Paul

 

Bang on mate

Cheers Paul