I see they are offering this option for there 4.250 stroke cranks now. Anyone use one yet, or opinion on there strength/quality
http://store.440source.com/Ultralight-Crankshaft/productinfo/44042506800-6-LW/

I hadn't seen that before but I like the idea. I used a SCAT superlight crankshaft in my last 470 build. I really like the idea of taking unnecessary weight off the crankshaft if you can afford it.

From the pics it looks nice, Pendulum counter weights, Drilled thru the Mains, Scalloped bolt flange. Just missing knife edged counter weights.

Thanks for posting that.....I have a 400 block I was thinking of doing a low deck 512 for next year with....Not sure how much faster I really want to go though....My pump gas RB 512 has already been 6.13 in the 1/8th....And I am not sure what the safety requirements are for going faster.

i just got my std 400/512 Source crank back from being balanced. the machinist said he only had to take 40grams off the crank to match my rods n pistons. how do you go with a crank thats 3000 grams less to start with?

Was that a special order? They only show the RB mains and no 3.91" strokes on the website. Thanks, Steve

Just depends on WHERE the weight is and where it isnt..
I normally turn down the counter weight a considerable
amount so they spin quicker.. along with a sharper edge
on the leading edge.. I've want to do the same edge on
the trailing side to reduce windage

Andy... that Scat crank looks pretty nice..what did
it take to balance in on your set up

Well the crank came balanced for the stroker kit but the pistons ended up being lighter than advertised so we had to re-balance the crank. It took a little work to do the re-balance. Had the crank come un-balanced the job would've been easier.

Final bobweight on this crank was 2222 grams so it is fairly light for a big block.

Kind of a semi-custom order. SCAT has raw forgings on hand and they can machine up most anything. They make a lot of NHRA Super Stock cranks with Honda journals and stuff like that that isn't in the catalog. You just have to tell them what you want and wait a few weeks for it to show up.

SCAT has the CAD files on hand to produce fully machined lightweight Mopar cranks but they don't really advertise it. You just have to call them and talk it over with the engineer.

The nice thing about working with SCAT is they have the ability to do all of the machine work and heat treating and finish work in the USA. Some of the other crank vendors are just box movers. So if it isn't in the catalog they can't make it. SCAT imports raw forgings and then does the rest on shore so they can move things around if you want.

Nice! Thanks for the info. So....How much $$$?

440 source offered the lightened cranks about 10 or so years ago. Remember they blew them out at a really low price to get rid of them. Not sure if it was an issue with the cranks or just no demand. I wanted one at that time but they were sold out when I finally placed my order. But we ran their regular crank for many years with zero issues in a drag only motor.
Good luck with it.

Is pendulum cuting really worth anything or just good for advertising? Seems that as close to the centerline as that weight is they could remove smaller weight farther out and be just the same inertia to accelerate it? Seems like it would make the crank a tiny bit more flexible as well where turning down the outer diameter of the counter weight would remove unwanted stress.

Taking the weight off the crank is primarily to remove weight from the front of the car, not to reduce rotating inertia. My SCAT crank is 54 lbs which is 13 lbs lighter than a factory 383 crank. So that is 13 lbs off the nose of the car. My pistons and rods are also lighter than stock by roughly 1 lb each so that is another 8 lbs off the nose of the car.

It probably doesn't matter on a bracket car but on a competitive class car there is a huge advantage to taking 20 lbs off the nose of the car and putting it in the trunk.

You should see some of the circle track cranks, especially the sprint car stuff. They take a ton of weight off of those cranks, mostly to get the car as light as possible.

That is correct. We offered these lightweight crankshafts from 2006-2008, but discontinued them due to low demand. We never had any problems with them. Over the last year or two, we noticed that we had an increase in people asking for them again, so we decided to bring them back.

Also, on the question about 3000 grams being taken off the crank, bobweight is being confused with total weight of the crankshaft. The 3000 grams is being removed from the total weight of the crankshaft (as if it was being weighed on a standard scale.) The bobweight, which is related to how the crankshaft is balanced, (essentially the "difference" between the crankpin side of the crank and the counterweight side, if you were to split the crank in "half") remains unchanged.

I have one of the lightened 440 Source stroker cranks in my 493". It's swinging a set of max-lightened & coated Ross forged flat tops in a zero-decked block and fed by a set of ported Indy EZ's and an aluminum Eddy sixpack intake. It's a high quench motor with those little heart shaped chambers on the Indys. The crank was beautiful.

The motor spins up almost instantly, and even with a McLeod steel flywheel and street twin clutch hanging on the back of it, it takes a little extra attention to pull away from a stop from an idle without all the normal inertia. I can feel the difference in reciprocating weight when I drive my buddies 440 manual trans car. I forget what the bob weight came out to.

It's got around 6000 something miles on it, and is still going strong. Hopefully it will live a long healthy life. The car it's in puts people right in shock on a regular basis.

so are the SCAT cranks similar to 440 source cranks? I guess that means I could order a stock stroke super light by the sounds of it

I'd like to be able to get a forged hardened super light stock stroke crank for the rb 440

Call Scat they can make one.

Crower can do it as well. Don't have a picture of my Crower crank handy though