nacnac

just wondering my crank neads a regrind but it already has been done to .25 oversize. is it possable to regrind again or wil i need a new one .
thanx.

SteveB

iTrader: (3)

It'll go to .75 using Pinto bearings but not really a good idea, .50 will be ok just not for big BHP..... It maybe worth looking for another crank just incase

GARETH T

what hp you got?

nacnac

stage 1 at the moment but gona be looking at st3 in the near future tbh

GARETH T

tbh i would look for a good crank,, they can be bought for 300 quid for one on standard size bearing jurnals

nacnac

thanx lads info much app
i will be on the look out for one now thn
ta nick

Steve Escos

iTrader: (18)

Theres one for sale at the moment in the parts section Steve

Mr RS500

iTrader: (6)

You can go to .75 and you can get propper bearings , without useing PINTO items
I used a crank at .75 in an old cossie i had on stage 3 and i propper kicked it everywhere i went , and it is still running perfect today and this is over 5 years ago

I am very interested in peoples opinion as to what is wrong with a crank at .75 so please educate me

GARETH T

everytime you grind a crank you are removing strength from the crank!

is it worth the risk after a rebuild bill?

Ian M

i am interested as well as i have used ground cranks and pinto bearings [ duraglide etc ] and never had any probs.

Mr RS500

iTrader: (6)

I understand that you are removing strength , but they are a steel crank and will stand .75 without a problem ,,,,

I raced cars for 8 years and reved them to over 8000rpm using a cossie crank at .75 and never had any problems , ok they where not turbo powered but the engineering company say they will go to .75 without any worries and they have built loads of cossie engines for me and i have never had one let go on me yet

plus ,,have you ever seen a snapped cossie crank ????

GARETH T

no

is it worth the risk though? personally i wouldnt

brad

taking .75 off anything made of solid steel wont effect the strength too much surely

Ian M

any problems with cossie cranks are down to two causes
a/ det
b/ oil issues
i know of quite a few descent bhp cars that are on ground cranks with no probs at all.

Mr RS500

iTrader: (6)

Brad
EXACTLY MY POINT

Gareth ,,
People who build engines , repair them etc cover there arses by saying you need a new crank ( imo ) as said i have run many engines that have a crank at .75 and never had any problems ( as said tho this is my opinion ) and if anyone has proof that .75 is a problem then please tell me as i am always willing to learn

I an not trying to start a argument , just interested to know if my opinion is wrong or not

GARETH T

it would be nice to know if anyone has had problems

Mr RS500

iTrader: (6)

nobody had a problem with .75 then

Ian M

obviously not.

nacnac

well regrind it is then that will save me some cash

ImaRacing 700

Hi...i also use a crank on .50 and would not hesitate to use it at .75 ....never had a problem always had superb oil pressure.

Unfortunatly this is another tuner myth that you must not go over .25 ...i have NEVER heard of a std crank snap in any condition and some drag cars at over 800bhp use std aswell ...plus a new crank is fine for over 600bhp road builds....so a .75 oversize bearing on a stage 3 is hardly getting the stress a 600bhp new crank would be getting!..imo of course

CozzyBrom

case hardning on jornels cosworth dont even sell a .75 shell the max out at .05
ya take the risk its down to you
i heard horror storys of regrinding bent cranks to .05 on mains cranks gone weak at some point so its bent grinding it stright again is bodging imo
genral rule max mains .5 big end .5 i wuud find another crank personally

GARETH T

now that is a great assumption

Ian M

brom, no one is suggesting grinding a bent crank straight again. if a crank has some slight scoring that wont polish out a regrind to the next size is no detriment at all.

Mr RS500

iTrader: (6)

Brom ,
Nobody said anything about trying to bodge a bent crank
Also if its bent i dont care who you are you wont grind out a bend all we are saying is if its scored etc , and in my opinion and the engineering company i have used for over 10 years there aint a problem .

CozzyBrom

paul av seen slightyl bent cranks that have been ground to 0.5 to true them up
crank pins out of line due to bearing lockin up and am surwe u know all about what happenswhen they lock up scraps rod and crank or it will grind at .075 but the heat involed with of fuked the crank imo
everybody will do there own thing am not giving out avise am just sayin thats what i wud do if i was building it get another crank imo

Mr RS500

iTrader: (6)

Thats the key poiny Brom ,, its hard to advise people as we all have our own opinions Its what we are happy with in our own minds .
Its hard to give advice because if it goes wrong you get the blame