Jasu

How reliable is it?
And when to switch Arrow one?

v man

the standard crank is an amazing piece
very strong

i would only change to an arrow if i was looking to change the cc in the engine tbh

Jasu

Can original crank handle over 9000rpm without problems with vibration?

Paul_RS

iTrader: (4)

I think so, the standard one is forged steel, arrow ones aren't forged. Karl Norris uses standard cranks for up to 8500rpm, not sure if they can got to 9000 rpm.

750hp escos

A load of rubbish!!

Any one risking a std crank for upto and over 9k are mad!! its not the strength its the harmonics caused when using these at that rev and power level..

Iv had a custom narrow journal arrows one made for my conversion under mike jennings advice and drawings..

The crank is stronger lighter and twin counter balanced to help with harmonics as well as having cross drilled big end journals...

A std crank is an awesome bit of kit to say 600-650 hp imo but after that you need something like the arrows


cheers danny

Fullflush

Speak to Karl Norris about this, he knows more than the forum trolls

750hp escos

Karl norris is a clever bloke for sure but he has his own ideas ..

Im not a pf troll ,i have had literally 100s of cossies and just about done every conversion for my self and others under the sun..

Been working along side joe stevens building these engines for nearly 15 years now and he was doing them for years before that..

I know tommy field well also piero (ex mountunes top engine builder)and speak to more or less everyone thats built with or played with a yb and 99% of them all agree with the long studding of a block where as karl doesnt so imo thats one big mistake so id rather not take that advice..

Everyone has their own ways for sure and unless you try different things you cant be sure it will work just like when martin did his long block conversion,everyone said it wouldnt work or last but as far as i know its one of the longest standing 700+hp engines i know of..

I agree dont listen to a troll or to many different people,go your own route and listen to someone who knows his stuff,buy the right parts once and you will have an awesome engine when mapped well..


cheers danny

Fullflush

Sorry the troll comment was not directed at you, it just so happened I posted after you.

At the end of the day the kind of information the guy wants will only be known by a few people who have many years experience and knowledge, Karl being one. He is not one to shout from the rooftops about what he achieves, so as per my first post, speak to Karl Norris for the informaion you require.

750hp escos

Ok cool..

I still think i can be very usefull to the guy myself though but its down to him as is everyone that chooses who to go to for advice and at the end of the day unless he is building this up him self he has to go to a tuner anyway so should always talk to them about what he wants etc..


cheers danny

TommyB

It's not just the crank you have to think about with those rpms, piston weights will be another major thing to think about.

Fullflush

Danny, you seem to know your stuff and are willing to be very helpful. Top guy

Jasu

And rods, i know.

750hp escos

Thanks mate..i love to try and help and always would for anyone but as said people all have their own choices and of course need to trust their engine builder to get the best from their set ups..


cheers danny

750hp escos

Exactly!!! the moving parts have to work in unisun with eachother..harmonics is a massive issue when running massive power out of these old 4 pots..

You need to start thinking out the box imo..

The block conversion were working on wont need to rev to 9k at 2.5 bar plus of boost to achieve 700+hp on pump fuel because of the extra capacity etc and thats a big factor..

Like martin hadlands achieved engine that was making 700 hp by just over 7k!!!

cheers danny

Jasu

Who does billet cranks?

750hp escos

Arrows are the best imo.


cheers danny

JonnyBravo

Who made the cranks you were selling ages ago Danny ? They were only a grand or something weren't they ?

750hp escos

Hello mate..

Yea i still have one now actually,its an ikengineering american made billet crank..

Nice bit of kit and like you say advertised at Ł1095 by ike himself..

You can find them on ebay etc..

I have an unused 80mm stroke one for sale


cheers danny

sierrafun

i found that in ebay ..its a billet cosworth i dont know specs http://www.ebay.co.uk/itm/Cosworth-Y...item3cc6b3b2e7

Jasu

Wow, what a stroke.
But way too much for me.

sierrafun

the stroke is standar ..the price is expencive ..with 100 pounds more you get forged crank which is the best for 10000 rpm 700 + hp ..any stroke you want 80 mm 84mm etc

Jasu

It says 96.95mm stroke? It simply can not be so much.
Well it think that was cheap. Arrow one costs about 2000€.
Who does that forged one?

sierrafun

ik engineering

steveboyslim

You are not going to get very far with your 700+ bhp engine if you thing the price of that ebay crank is expensive, an Arrow crank is about Ł1800 + vat, the rods nearly Ł850 + vat per set, pistons Ł650-Ł750, block Ł2300-Ł4500 depending if you supply a block and who/what liners are used and that is only about 30% of what you will spend.
Standard crank and rods are good, but most are nearly twenty years old, would you want to trust them in a 9k rpm big horse power engine ?

Steve

Most of the ebay parts are China's finest either sold via America or Australia or directly imported, good luck.

Jasu

Hah...
I did mean that stroke was too much for me.

Jasu

I belive that those are not forged ones.

steveboyslim

Thank god for that , lost in translation.
Arrow do standard stroke, 82mm and 84mm, rods standard and 136mm.
They can supply other stroke cranks and length rods at extra money often with a three month lead time.

Steve

sierrafun

we dont want to go so far .we just say the specs of the crank is 700+ you right for the prises ..there many parts expensive

Hoogi

Yep, I've an Arrows Crank in my YB, PEC H-Section Rods and Cosworth Pistons.

Cost me a bit but should be very reliable........

My problem was I wanted to by a Std Std standard YB Crank at the time but couldn't find one that hadn't been ground or in need of a grind.

So bit the built and went the Arrows route...........I'm totally over engineered for what I want but that's what I wanted.

Best of Luck

sierrafun

burtons also are good cranks fardon and 1250 pounds

sierrafun

they are made in usa .is true ?

Jasu

I do not trust those, have seen few broken ones and heard from more.

At least what i did look at those pictures, did not seem forged ones.

sierrafun

how you can see if is forged or not

sierrafun

as i know 1 reason is the weight ..forged are biggggg weight

Jasu

Surface is different.

sierrafun

maybe that helps

4340 High tensile steel
C Si Typical Analysis Mn Ni Cr Mo S P
(Ave. values %)
0.40 0.25 0.70 1.80 0.80 0.25 0.025 0.025

standards

DIN: 1.6565
34CrNiMo6
BS: ~En24
~ 817 M 40
AISI: 4340

APPLICATIONS
Components for the aircraft, automotive and general engineering industries eg.
Propeller shafts, connecting rods, gear shafts, and other automobile parts. Heavy
forgings, eg. Rotors, shafts, discs.
Forge 850-1050oC, slow furnace cool.
Normalize 850-880, air cool.
Anneal 650-700, Cool slowly in controlled furnace
Stress relieve
In the quenched and tempered condition, about 30-50oC
below the tempering temperature. Air cool.
In the annealed condition, 600-650oC. Air cool.
Harden 830-860oC, oil quench
Temper
540-680oC hold for 1 hour min. at temperature, air cool.

HEAT
TREATMENT
Nitride Suitable for both liquid and gas nitriding.