4age Crank Info for 4agte usage

[Sam_Q]

interesting, so which brand of Cro-mo crank did you buy?

[Dongaz]

http://cgi.ebay.com.au/4340-EN24-Bil...ht_1317wt_1137

It was this crank but I was able to get it for $1016 delivered I think it was. All the 4340 cranks you see on ebay are the same anyways. As you can see from the picture there is basically no counterweights. It also weights 2kg less than the standard crank. This is what is missing.

Looking at the early model 40mm and 42mm rod journal cranks you will notice that the 40mm ones have the counterweights lightened on only some. This was because it was a N/A motor and it was to make the motor easier to rev. They also used the lighter rods which are thinner than the later bigport and use the 18mm small end aswell instead of the 20mm.
TRD used these same cranks but just remember that they would pull the motor down a lot and change the bearings often aswell. It is all preventative maintenance in racing. I highly doubt anyone on here with a road going car would do such a thing.

Another thing with the TRD F/A p/n:13401-FT001-A was heavy than standard but they where allowed to remove some material in certain areas and needed a minimum weight of 28lbs* (12.7kgs) This is a bit heavier than stock. The 20V p/n: 13401-16020 had a slightly lighter crank at 12.695kg (27.99Lbs.) This shows that you still need weight in the crank for it to work properly and it makes sense considering the are able to rev better than the earlier 16v by having lighter rods again. The small journal crank p/n 13401-16010 has a weight of 11.660kg* (25.70Lbs.)
*Weight was measured on a single sample.

The main reason you see custom cranks that don't have a knife edge or more of a shaped counterweight end, is that the people that use them use a dry sump setup. As the oil is under pressure the whole time the crank doesn't need to cut through the aerodynamic drag of the crankcase atmosphere like in a wet setup.



If you want a decent crank either stick with the stock one or get one made up properly.
I worked at Tighe Cams and they will make you a crank. He has one of his own in his 16v clubman and it revs to 11,000 I think it was.

Probably have missed out on something but I think that's enough ramble for now.

[Sam_Q]

what a lump of crap!!

I will post up soon what I have been offered

[dangdang]

Look forward to a view of what you have been offered sam.

Looks like a stock crank is the go for my budget.

Lots of phone calls later and I still cant find one locally though.

[toddw]

I have purchased one of the 4340 cranks on Ebay. After much research and contact with the seller I purchased one. The quality is superb. I am not building a shitter. It is quite a serious motor with Pauter rods, Arais pistons 288 deg cams, extensive head work,quads, Haltech etc. My application is a race car with very limited street. I was going to use a GZE crank but I was afraid of losing that peaky high reving motor that I currently have with my current set up - blue top rods and crank.
I have had my bottom end balanced including the new crank and the guy said it came up really well. I am yet to assemble the motor but from what I have leart from building engines over the last 20 years in my opinion the counter weight issue that has been mentioned is not a problem for a 4AGE. I will let you know when i get it all assembled and in the car. Any other opinions regarding the counter weight or lack of.

ToddW

[trdee]

end of the day, unless you're going to serious business revs or a full race application etc, a stock crank is more than suitable. they are forged, well balanced, and well designed for pretty much any application.

[Squeak]

why is it that the stock crank is not good enough , I have been using them for years and they have been abused , constantly 8500 + revs ,computer on car is autronic and has 8800 cut out, motor has been in our rally car for 4 years with no drama , Quads , 304 cams with 9.00 mm lift, group A headwork. and produce's 103kw at rear wheels,all on a standard 42 mm crank!!!!!! and the same crank all along.

When talking to TTA years ago they said not to even worry about the surface cracks that appear under xray.

[toddw]

I still dispute the opinion that they are forged. I know there is a lot of information around saying that the are and arn't. By looking at them from my experience from my chevy building days they look cast. They do not have the teltale seam on the longitudinal section. They have sand castings that tell me that they arnt forged. Can anyone say definitivlty that they are forged. I have seen a lot of forged cranks and they don't look like these.

[trdee]

talk to oldcorollas, thats where i got my info from. i know chemicals, not metallurgy

edit seems like this info was from shinybluesteel and terryo in this instance. still reliable references nevertheless (well, as reliable as an internet reference can be )
http://www.toymods.org.au/forums/sho...ghlight=forged

[Casey-G]

As above, they definitely are forged.

[dangdang]

Forged or not doesn't sound like anyone's ever broken one, even in heavily boosted setups.

It seems to me that an aftermarket crank is only needed for big revs. 8,500 fine for me.

[toddw]

Forged or not doesn't sound like anyone's ever broken one, even in heavily boosted setups.

It seems to me that an aftermarket crank is only needed for big revs. 8,500 fine for me.

That is a fair call and you are probably right. I have done some more research and from what I have found it seems to be that they are a "forged cast crank" whatever that is. I assume most forged cranks that arn't billet are the same. Can someone confirm? I am looking at the high 8k rpm range so the steel billet will be a better option for me.

I am still keen to see what SamQ has been offered to him.

[mookschank]

Forged cast means cast then forged, or forged whilst casting as the name infers. I think confusion lies where people may think casting and forging are exclusive. It seems logical in automotive high volume production that cranks are cast, either wasted with sand, or permanent mould, then final process forged or whatever if the maker wants to do this.

Aftermarket cranks are billet and milled/turned as I assume makers can't afford the expensive casting mouldings and m/c's. And 'billet' doesn't always mean it's forged.

[dangdang]

Makes sense, cast then hot forged. During my apprenticeship we were taught a similar process as to how turbine blades in aircraft are manufactured.

[Sam_Q]

ok guys sorry for taking so long:



the company is called furious racing parts, their other bits look really good too.