[GOAT8U2]

Good news IF this turns out to be a worthy piece and can stay close to $1000.

But there are only so many Chinese factories doing cranks and at that price this sounds like an Eagle crank. If so, Eagle's getting their Chinese cranks back in pretty good shape ( bunch of engine builders quotes ).

Now if only someone would take the time to make us a single turbo bolt on kit to test out these cranks around the 1000hp mark

[HWYSTR455]

I too would get one of these for a <650hp street engine, (ok, without spray!), because I don't want to have to shop for a crank every time I do a rebuild. I drive the crap out of my street cars, use them as daily drivers, all with 400-462s in them. I usually do a rebuild on each every 3 years or so, or about 120k miles. On the one daily I plan to go IA2, same principle, block shopping is a pain.(and I refuse to go 'corporate'!)...

[lugnutt]

Originally Posted by lugnutt

How will these cranks compare to the Moldex? As far as stregnth goes. Are they going to be just as good?

[White Warrior]

If a 4" stroke forged crank becomes available it would be easy to have it offset ground to 3.75 with a 2" rod journal. I have stroked a couple of 3.75" cranks to 3.875" with good results but going the other way with an offset journal would be a great way to go as you would loose some friction and have a slew of SBC rod bearing choises
I think a 4.31 x 3.75 " combo could make 900 hp N/A with the right heads,like the new KRE High Ports. Would be a piece of cake with Super Chiefs or Tiger heads.

[PONTIAC DUDE]

My 4.5 crank uses a 2.100 rod journal.

and lots of Nitrous. LOL.

[tom s]

Dave,how can you run a 2in chevy rod with a pontiac journal?When I looked to do it they were too narrow so had to use the BBC.Tom

[White Warrior]

You use a BBC rod with a 2" end,they will make them anyway you want

[bobzdar]

Do they make 2" bearings in bbc/pontiac width?

[tom s]

with a custom rod you could also run the 1.88 HiPo bearing and get more offset.Tom

[BVR421]

heres a 3 1/4 stroke for you
http://cgi.ebay.com/ebaymotors/ws/eB...MakeTrack=true

[Brian Baker]

Moldex = billet.

Opinions vary, but for all intents and purposes, a forged crank will be just as strong as a billet...and in some instances stronger. With a billet, the grain runs in one direction, and when it is cut, it is done so to minimize weaknesses in certain areas of the crank in relation to the grain flow.

With forgings, the grain does not flow in the same direction.

Think of a wooden baseball bat. We were alway taught to swing it with the label either facing up or down, that way the lines of the woodgrain would run in the same plane as the ball when making contact. Try to hit the ball with the label facing the pitcher as you swing, and you run the risk of cracking the bat, because the ball is contacting it in a 90-degree plane (or perpendicular) to the plane of the woodgrain.

Now compare this with a blow on the rod journal from the piston/rod. It's better to have that grain in the rod fillet and throw area perpendicular to the blow. With a forging, the grain will follow the shape of the forging, whereas with a billet, it runs all in one direction when the ingot or "blank" is made (which is then whittled into a crank). I'm not a metalurgist, and the examples I'm using are greatly simplified, but I think you can still get the gist of it. Others like Tom Vaught could explain it in greater detail.

[Tom Vaught]

Billets are more expensive than forgings basically because the forging allows less time to finish the cranks vs hogging the shape out of a large piece of steel, (Billet).

Brian is correct about the grain flow too.

The billet does allow a vast array of different main/stroke/rod journal sizes vs the forging which will have only so much material in any one direction.

A Forging must have two key ingredients to be successful:

1) Clean steel of the correct material type like 4340.

2) Proper machining of the forging in all dimensions at all parts of the crank and the right oiling scheme to survive high rpm loads.

You get both of those things for your $1100.00 and you have a great part.

JMO

Tom V.

[Skip Fix]

I thought I remember reading an article that since on a billet crank/rod you actual cut across the grain you loose some strength whereas a GOOD forging keeps the grain pattern just changes its directions, so no spots for stress riser to start as in a billet. I'm no metallurgist but that arguement made some sense. Same thing Brian was saying.

[GTO]

Has this 'Grain flow theory' ever been proven? The same argument comes up with Aluminum rods, forged or billet. Don't the Top Fuel guys run Billet cranks? If a forging was stronger I'm sure they would be the first guys to run them. Not trying to start a pissing match here! LOL. ... ERic.

[Tom Vaught]

One of the extremely few Carrillo failures I heard about was due to the cap section of the rod grain structure not being 90 degrees to the rod beam when the cap was made. The cap failed due to the grain structure deal.

Tom V.

[Tim Corcoran]

My guess is forgings will be available early to mid 2007. Prior to that you will see promisses of much earlier dates and lots of people holding their breath. Don't hold up any projects waiting for a forging. Let's hope when they do come out that the forging is done well and the machining is good. Does pro stock use forgings or billets? How about top fuel?

Tim C

[Herb Hagan]

No theory...Fact

[Brian Baker]

Top Fuel uses billet cranks. Pro teams with heavily sponsored budgets may only use one for a half-dozen passes or so...and then they throw it away. They turn up on Ebay from time to time for around $150, and after machining to remove cracks, are perfect for lower HP applications.

The argument that if forged were stronger they would use them instead of billet is moot. The teams purchase these cranks in bulk quantities from the manufacturer's and for them (believe it or not) the turn around time on getting them is quicker than for us. Manufacturer's can turn out enmasse the same crank way ahead of time for them because they know they'll get the bulk orders. With us, we have to wait in line for them to "shut down the line" and reconfigure it for a Pontiac crank.

[GTO]

If it's 'fact' and not a theory then there must be some proof like non destructive or 'destructive' tests out there somewhere. I've been trying to find out about this grain thing in Aluminum rods. I've got BME's which are forged and I've been told to go with Billets instead. But there seems to be a 50/50 split in 'theories'.

I can see where a Top Fuel team would like the 'mass produce' billets. But since these guys have such big budgets you'd think that if forgings were better, they would run them. I'm sure they could order up a bunch of forgings. If you throw a stick of billet in the lath or a forging, what's the difference? I know as a driver, if there is something better out there for approx. the same price, and it could keep you off the wall one day, I'd buy it. They probably have not moved up to forged cranks in Top Fuel yet 'cause those Hemi's aint putting out enough power yet! LOL! We'll show them how it's done. ... Eric

[BVR421]

Originally Posted by GTO

you'd think that if forgings were better, they would run them. I'm sure they could order up a bunch of forgings. If you throw a stick of billet in the lath or a forging, what's the difference?Eric

I think the difference is, its easy to find a billet blank, where the hell do you find forged blanks? If you find a plant able and willing to produce quality forged steel blanks you are half way there. Then all you have to do is convince a grinder to shut down and retool for a handful of Pontiac cranks.
Im ready for 2 forged cranks right now but Im not going to hold my breath for new ones.
and for the smartasses out there, yes I did bid heavily on the last 990 that was on ebay.