Does a forged 4340 or 4130 4.25 crank (or any forged long stoke crank for that matter) require heavy metal to internal balance or do they just use heavy metal in cast cranks? I'm looking at cost options.
Mitch

Yes, they use mallory, spell? to internally balance long stroke cranks. Then you can use a non external weighted balancer and flywheel or flexplate like one for a 427. That's what was done to my 572.

Thanks Redmanf1. smile.gif

Mitch,
If you get the 6.385 rod crank & use the longer rod with a reasonable piston weight you should not need to add Tungsten & it will internally balance.
Also, Scat is coming out with a cast 6.385 crank in a month or two.
None of the cranks come with Tungsten in them, it is added to balance the crank.
Be very wary of mail order balance jobs, I have had to redo almost every one that people have brought in.
Get the balancing done by a reputable shop or buy the balanced assembly from one.

Mike,
This whole engine build has got me flustered. Each machine shop I go to has there OWN ideas , one dont like scat , one dont like eagle , one dont like anything about strokers , or "if you dont buy my rediculously high priced parts youll be sorry", and none of them like the idea of me using my own parts. I understand they have make some on parts but to try and sell them to me at such an inflated price really pi$$es a guy off. There are some excellent machinists in Omaha but, no one seems to care what I want.
Now with all that crying said , I think I'll give you some buisness Mike as soon as my life slows down here and I can get on track.
Can you tell me more about this crank from scat , or is it just the 9000 series?
I would love to have a forged crank but the $600 + price tag scares me off. Why dont anyone make a less exspensive forged 4.25 crank , like maybe a 5140 or 1053 (hope I got the numbers rite)?

First, yes it is the 9000 series but it isn't available yet.
My preference is a forged crank but don't sell a good cast crank short.
A long as you aren't going to be spinning the snot out of it a cast crank is pretty strong.

The 9000 series is basically just a premium casting that has been profiled sort of like the hi dollar cranks.

I have used them in applications that were bordering on stupid & they have held up better than I would have expected.
I had one in a 383 alcohol modified that ran three seasons before breaking. Not my choice but the customer had the crank already so I balanced it & did the machine work & he slammed it together & it dynoed at 550HP at about 7200 as I recall.

I have my own opinions on Scat vs Eagle but suffice it to say in over 10 years I have not had a problem that you could blame on the crank or had to send a Scat crank back or resize the damn rods.
I have gotten cranks that were slightly below low limit & rods that were bigger than I would prefer but nothing I couldn't fix with the right bearing.
I am sure some get through as they are human also but I haven't gotten them.
In the last 4 or so months I have had 3 sets of eagle rods, two I had to resize & one that the pins would not go through.

Now on every other set of Eagle rods I have had brought in they were about as perfect as you could ask for & up until lately I have had no quarrel with the Eagle rods but three out of three sets recently makes me a bit leery :D

Scat has a 4130 forging of which they had about 20-25 left as of last week.
They will not have any more when they are gone as the steel pricing is now such that they cannot sell them for hardly any less than the 4340 ones so other than some questionable "deals" out there you probably aren't going to find a decent forged crank for $600 any more.

Scat just had a price increase on most of their forged stuff so the jobber price on the 4.250 has increased from $675 to $703 & the "racer" price no one in their right mind pays went from $844 to $879

BTW, I have them at a bit less than Jobber ;)
I also have a couple of 4130 4.250x6.385 cranks left for a pretty good deal but again when they are gone there is a good chance I will not be getting any more.

For info, both the 4130 & the 9000 series will take the standard "P" type bearings which are a bunch less than what the chamfered "H" bearings are that you need to use with the 4340 crank cost