cossie891

iTrader: (1)

Hi guys just had the crank done on my 3 door but after 30 miles it started knocking again so pulled it out again
The mains are .50 and my big ends are .75.
On inspection no1 has spun both shells not on top just spun around it has too much end float and the middle main has kinda bent out of shape the ends are closer together if u know wot I mean.
So my question is, can the crank be ground again or is it at it's limits?
I wanna keep it really as it's been lightened and balanced when it was ground

Danny @ Enhanced Performance

iTrader: (3)

That crank is scrap now im afraid...sounds like the rods needed changing or atleast no 1 last time or just that it might of needed oversized thrusts????
Did you check/change the oil pump last time???


cheers danny

cossie891

iTrader: (1)

No never changed pump mate I thought it need oversized thrusts
it had the rods done when the crank was done I've got 2 sets of rods I'm taking them
to the shop with a spare crank now to get checked out
I've got a good pump here aswell its just hassle
CheeRS Danny for the help

tabetha

If it's done that after 30 miles, then almost definitely clearances have not been correct, spun shells are normally due to wear/picking up or oil break down.
If someone else has done the work it's 100% down to them, shells should have been sized/supplied correctly when crank was ground.
What thrust did they set it to, should be around 5 thou ideally, the newer all steel thrusts from Glyco(federal mogul) etc are ok but the older original ones are better, I've re-used my 200,000 mile old thrusts, and still well within limits.
tabetha

cossie891

iTrader: (1)

They gave me STD thrusts mate can't go back to him as it was a cash in the back pocket job on the side sort of thing
My spare crank is at another respectable place who I trust just got to pay slot more money there

tabetha

The thrusts are the issue really, it's the shells, ie need to be correct for the crank size, best always having the whole job done at one place then it's down to them.
What bearing clearance did you measure/get if you put it together ?
What sort of power you pushing anyway ?
tabetha

cossie891

iTrader: (1)

I never checked em mate oops lol
The guy promised me they were fine just fit in and run in
Oh and it's stage 3 btw

cossie891

iTrader: (1)

The spare crank and rods are being checked 2moro for me he said the same the other 1 is scrap now
How's the best way to refit it mate
I would normally use grophogen on the shells and that's it just torque it up and away I go so to speak

tabetha

As to refitting the crank, you need to establish the turning torque firstly after fitting, to ensure it is not tight.
Refit as normal, I use std engine oil to lube the shells, after thoroughly cleaning everthing in sight, then refit with shells and thrusts, check thrust is correct I run around 4 thou on a used set of the older sort.
You should be able to turn the crank by hand no problem(no rods etc attached), that's assuming the clearance etc has been done for new bearings correctly, I would in your case check with some plastigauge just to be 100% safe.
My mates just had a crank screwed by a certain engine centre in norwich, they ground it 1 size undersize then supplied him bearings for 2 sizes under, but still not accepting it's thier fault.
tabetha

cossie891

iTrader: (1)

Cheers tabetha I will get the guy grinding the crank to install it for me this time

cossie891

iTrader: (1)

Just had the call about my virgin crank and alls not good.
He said it's bent 20thou so is scrap now spoke to pete RS specialist who said farndon can sort it for but I've heard if the straighten it it won't last for long
I'm all confused now wot do I do?
Has any 1 got a spare crank for sale?

tabetha

I'll ask brian in the morning, they may even have a spare yb crank, you could always have your old one built up size wise, easy to do with the right kit.
Brians been doing machining/engine building for 54 years so is bound to know, does mostly just competition stuff, it's who I use and trust 100%, pm me if I forget to ask, or phone him on 01359 251888, ask for brian or barry.
I put my crank in today, after cleaning everything etc etc, used the OLD 200,000 mile thrusts and have 5 1/2 thou thrust clearance, which is pretty astounding as up to 8 is ok on a NEW set, crank turning torque is under 2lb ft!!
tabetha

cossie891

iTrader: (1)

Please do mate thanks for your help

cossie891

iTrader: (1)

Please don't forget to ask ure mate boss

tabetha

Hi
Spoke to brian today, and he says forget it, if wanting high power, he's had metal sprayed in past and radius is never right, and had fusion weld built up ones which ended up in the bin.
So need to find a decent one again I'm afraid.
tabetha

cossie891

iTrader: (1)

Cheers again mate for my bad news lol