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View Full Version : Custom Billet Crankshafts.....



XR7 Dave
05-26-2005, 08:42 PM
We are in the discussion phase with this. I'm just posting to let people know that there is a company who is interested in possibly providing us with billet cranks. My question is, who would be seriously interested if the option were available in the near future and how much would you be willing to pay for one?

The crank would be significantly lighter than the stock crank, stronger than anything else in the SC motor and would accept standard SBC or 351W rods in various lengths. It would be made with a 3.75" stroke for 4.3L displacement.

Post your feedback. :)

V6Sprout
05-26-2005, 09:11 PM
I bet some of the mustang guys would be interested. Try posting about it on www.v6power.net as well.

super red91
05-26-2005, 09:28 PM
Depends on price

Mike8675309
05-26-2005, 09:39 PM
A forged steel stroker crank for the SC block? priceless? Ideally the whole block could use an upgrade with something like that.

Honestly I would think that if the vendor wants large numbers, they'll need to keep it pretty competitive with similar parts for other motors since finding replacement SC cranks is a pain in the arse.

$450 - $600? Not sure how realistic that is, just comparing to eagle chevy small block models.

Jason Wild
05-26-2005, 10:44 PM
Dave,
Yes this is something I would be willing to buy. I guess I might pay 800$ for one.
Can I be the first. :D

XR7 Dave
05-26-2005, 10:54 PM
This is not a forged crank, rather this is a billet crank and it won't be $600-800. The only current offering is from Moldex at $2300, I'm hoping this would be less but I don't know how much.

This is not something that you would just toss in there because you didn't feel like resurfacing a stock crank. This is for that person who is building a motor with H-beam rods, forged pistons, etc., and would be expecting to either toss a load of nitrous against it or a lot of boost.

This crank would be made to be interchangeable with NA V6's as well as 4.2's or any other Ford V6 based on the same block, so ya I will post the question to the other V6 boys as well. I'm waiting on a few more details first though.

Mike8675309
05-26-2005, 11:09 PM
Oh... well for billet it's probably out of my league when looking at my 5 year goals. For that much machine time on a CNC machine I'm sure you looking at into the custom wheel prices. That puts you at $2500 plus or minus $500..easy.

I have to imagine there are quite a few drag racers though that would see that as a wise investment for the kind of power many of the guys want to put down. A short block package with billet crank would likely be the best way to sell something like that. What's that give you then? $3800 or so for a complete short block with billet crank? not a bad ballpark considering the potential.

Part way down this article it talks about the difference between billet and forged cranks
http://www.automotiverebuilder.com/ar/eb040554.htm

Toms-SC
05-26-2005, 11:12 PM
Um. What would set this apart from Morana's stroker kit? For $2000 US you get the whole kit. :confused: I just can't justify spending $2300 for a crankshaft that still requires piston/bearing/connecting rods. Aswell as the fact there has been no posted dyno's from any stroker kit. Meaning that, for $2300 are you getting 5 HP? :)

XR7 Dave
05-26-2005, 11:48 PM
Tom,

Morana's kit will not hold up to the kind of power this part is intended for. Just ask Pro Street Rich.

Anyway, I'm thinking ahead. With a billet crank you will have the ability to run 700rwhp from this motor. We are starting to see some forced induction that is capable of providing the airflow/boost for those kinds of HP numbers so it only makes sense to start thinking about the parts necessary to support that HP level.

This part is not being considered simply because it allows a longer stroke. The longer stroke was merely an added benefit. The crank offers many advantages, one of which is the reduction of rotating mass by as much as 20lbs. That's not a misprint.

Really I can go on, but if you don't see the value in this already I'm not here to convince you. With the right other parts to go with it, this crank could provide another 50rwhp easily over a comperably built 3.8, but then it also has the ability to go into territory that a stock 3.8L crank simply cannot go. There is a 3.8/4.3 being built right now that will give you that comparison. The motor made 305rwhp before the conversion. I believe it will make 375-400rwhp afterwords utilizing the same M90 blower and cylinder heads.

I'm really looking for people who are already aware of the benefits and have been waiting for an opportunity such as this to come around.

:)

XxSlowpokexX
05-27-2005, 12:58 AM
Wasnt Chris Wise car a stroker?..We all know what his car made...I;d be more interested in a forged steel or cast steel stroker crank at an affordable price personally.

KwikGSeX
05-27-2005, 11:35 AM
Anyone ever thought of knife edging and cryoing the stock crank? On DSM's you remove around 7lbs of weight and the crank can hold 900hp easy..

Kurt K
05-27-2005, 01:04 PM
Anyone ever thought of knife edging and cryoing the stock crank? On DSM's you remove around 7lbs of weight and the crank can hold 900hp easy..
Dennis, I actually looked into knife-edging my crank, but once my running engine broke, I didn't have time to go through with it.

Thomas
05-27-2005, 01:18 PM
If its in the near future I'll have to decline but if it doesnt happen for another 1-1 1/2 years I'll be all for it. Do you know if they'll manufacture these outside of a group purchase if/when it goes through?

David Neibert
05-27-2005, 03:49 PM
Wise had an offset grind to his stock crank to obtain more stroke, Fred H. has a Moldex billet, and I think Jim Demmit had two of them. One in a shortblock and one loose. I'm sure others have them, but don't know who.

Dave,

I have not seriously considered the billet crank, because I thought the limiting factor on our motors were the heads lifting. Do you have something in the works to address that problem first ?

David

Thomas
05-27-2005, 03:54 PM
wouldnt the only effective way to prevent that be more bolt holes in the head? And that would require completely brand new heads and I dont know if the block could be tapped for that or if a new block would be necessary. But there is a v6 mustang guy with ARP studs and MLS gaskets and he pushes 27psi of turbo boost throught it without problems. He also has a cast 4.2 crank and made 587rwhp.

XR7 Dave
05-27-2005, 04:53 PM
The problem with lifting heads has to do with running too much boost at too low of an rpm combined with too much timing due to overly agressive tunes and insufficient fuel octane.

The better crank will create less parasitic drag on the motor, allow higher rpms, handle more stress, create more displacement..... the list goes on.

Lifting the heads is a problem with the current configuration. That is why another approach is needed. By increasing the rpm capabilities of the motor and using a supercharger (or turbo) capable of keeping up, we can create MUCH more HP with the same cylinder pressures that we have now. 700rwhp would not be an unreasonable goal with other currently available parts.

David Neibert
05-27-2005, 06:01 PM
The problem with lifting heads has to do with running too much boost at too low of an rpm combined with too much timing due to overly agressive tunes and insufficient fuel octane.

The better crank will create less parasitic drag on the motor, allow higher rpms, handle more stress, create more displacement..... the list goes on.

Lifting the heads is a problem with the current configuration. That is why another approach is needed. By increasing the rpm capabilities of the motor and using a supercharger (or turbo) capable of keeping up, we can create MUCH more HP with the same cylinder pressures that we have now. 700rwhp would not be an unreasonable goal with other currently available parts.

Dave,

How much higher rpms are you talking about ? At present I think my crank and rods are good to about 7000, but the valvetrain is iffy above 6500 rpms.

David

XR7 Dave
05-27-2005, 08:08 PM
7500rpm isn't unreasonable.

seawalkersee
05-28-2005, 01:53 AM
Wasnt Chris Wise car a stroker?..We all know what his car made...I;d be more interested in a forged steel or cast steel stroker crank at an affordable price personally.
Uhhhh...I think he was around and gone before I got here. Can you enlighten me there Pokey?

I think the idea is excelent Dave. However, these other parts you speak of are probably more of the RACE engine parts like the 2.2 blower and stage three Steig heads correct? For a Joe Shmoe like myself, I would be interested but it is a hard sell. Im more in the street car scene that sees the track now and again. That means price is a HUGE component. By knife edging our factory crank do we give up any strength?

Chris

XR7 Dave
05-28-2005, 10:32 AM
I'm not trying to sell anyone a billet crank. Like I said before, if you don't already see the value in it, then you aren't a potential buyer. ;)

That being said, how much time/money do you want to put into a stock crank only to have it break on you? Sure you can knife edge it, you can lighten it, you can balance it, you can spend $1000, you can do all sorts of stuff to it, but when it cracks between journals 1 & 2, what good were all your efforts when you window the block and destroy a cylinder head?

Let me toss this out there one more time. 6.2" H beam SBC rods come as light as 500 grams. Stock 5.9"ers are over 700grams and bend like pretzels. Think about that.

If you are serious about performance and will be running your SC for years to come, suddenly a couple G's on a crank isn't the end of the world. For me it would mean waiting another year to build the motor I want instead of doing it now. I can deal with that. I've had the car since new and I'll have it for a few more yet - wait I've got two, dang it there's a couple more years.

When people look at a car like mine and say "Ya, I want to do that but I'm not loaded like him", well I'm not loaded either. Because I've stuck with one car for 15 years, I can budget a couple thousand dollars a year to make it better. When Stieg heads first came out I put all other things on hold and saved the money to get them. I did this because I knew they were worth it even though my current motor can't begin to use them properly. So now instead of having some $1100 heads on my car that have run out of headroom at 400rwhp, I have some $2000 heads on the car that are loafing along at the .500" lift cam and 6000rpm rev limit I currently have. When I get the new crank and a cam to match, I'll be able to run with the best and I won't have taken food off the table to do it.

How cool is it to have the highest HP today? Not as cool as it would be to have a 500+rwhp SC in a couple years when today's SC are looked at as "babies". Only a few years ago people looked at Neil Frisbee's SC as the pinnacle of performance with a 12.48 ET on a 100hp shot of nitrous. Now we are beating that on pump gas. Look at David and Gary running mid 11's on a 100HP shot. Guess what. Soon pump gas SC's will be beating those times and we will be looking for 10 second street driven SC's with nitrous. You want to come along or you want to give up? It's not unlike the first efforts to get a BHJ balancer made for our cars. $400 for a balancer? Are you out of your mind??? lol Well, fast forward to today and half the SC's out there have them. If we'll pay $400 (now $350) for a balancer, why wouldn't we pay a lot more for a crank that will take us to a whole new level of performance?

It's all about planning ahead and looking at where the problem spots are. Rods and pistons are no big deal. That has already been developed. However, fear of the bottom end has always been a problem with these motors. Just ask some people who've been around what they think of the stock crank. They all cringe because they all know that our cranks are like ticking bombs. Like David Neibert said "mine's doing fine at 480rwhp..." for now. ;)

Randy N Connie
05-28-2005, 11:38 AM
Thanks
Randy

David Neibert
05-28-2005, 12:19 PM
Dave,

What needs to be done to keep the valvetrain together at 7500 rpms?

Not sure I'd be in the market for one until the Turbo car is done, but who knows. Do you think I can use the pistons I've got now and just go with a longer rod ?

David

Randy N Connie
05-28-2005, 12:32 PM
thanks
RANDY

seawalkersee
05-28-2005, 02:37 PM
Dave, You make excelent points. At this time I only have ask you to answer the rest of the questions I asked not just the one about the price. What else are we talking about here for 700 HP?

Dave N. You want to keep a 1.5:1 ratio as a minimum of rod ratio. The longer the piston stays parked (may need some help from the forced induction guys for this) the better VE you get. The closer to 100% the better. There are cars that have better then 100% VE but that does not kick in till higher rpms.

Chris

Mike8675309
05-28-2005, 06:01 PM
here is a link to a post in the member area where Randy laid out thoughts on piston speed as well as the calculations. (Randy, you can cut and paste, save you some typing)

http://www.sccoa.com/forums/showthread.php?t=55471&highlight=piston+speed+randy

XR7 Dave
05-28-2005, 08:03 PM
With same height pistons, you would need a shorter rod
than you have now with a longer stroked crank.


When increasing stroke you need to go with piston speeds.
To know if you would want to lower RPM redline.
I forgot at the moment ,but you dont what to go over 6250fpm
in piston speed.pistons start to melt.

I am in a hurry ,Will post numbers and formula later.
Going to cook-out.

RANDY

3.75" stroke will provide piston speeds of 4700ft/min at 7500rpm. Valve train weight is a reasonable concern with rpm. A hydraulic cam can be spun as high as 7500 with the right parts. Preferred of course would be solid roller.

Keep in mind that 400-500rwhp doesn't require 7500rpm. The 7500rpm idea comes in to play with someone wanting to put out more than that. Can you imagine an SC motor that was "happiest" between 5500-7000rpm? Now there is a concept. :D

Thomas
05-29-2005, 03:34 AM
I can see mine wanting to spin up to at least 6500rpms when Im finished with it. Right now, naturally aspirated, it will shift at the stock 4200rpm's. If I hold it out until 5000rpms in 1st and 2nd it will gain .2 seconds in the quarter mile. Once I get my built tranny in I'll spin it to 5500rpm's and see what it does. I can only imagine what turbo boost will do to it. That's why I'd be very interested in this billet crankshaft. I'm not sure I want to spin a 3.8 SC crank to 6500 rpm's through 700hp.

XxSlowpokexX
05-29-2005, 04:06 AM
Can you imagine an SC motor that was "happiest" between 5500-7000rpm? Now there is a concept.

Yah its a sweet thing especially with 4.10 gears

Randy N Connie
05-29-2005, 09:23 AM
Thanks
RANDY

XR7 Dave
05-29-2005, 09:49 AM
The M90 will not spin past about 6000 and make any power. Coy Miller has proven that. ;)

Randy, Moldex can make the crank for you now, their price is $2300 and it takes about 12 weeks to produce. I'm trying to get another company to do produce a lighter weight crank for somewhat less. I haven't gotten a price out of them yet, hopefully in a few days I will have something to report.

Randy N Connie
05-29-2005, 10:06 AM
The steel billet cost as much or more than the price
that some said they would pay in above post. :rolleyes:

Twenty pound off a crank could add up to more performance gain
than the increased stroke.If you can make it this much lighter.

XR7 Dave
05-29-2005, 11:42 AM
The steel billet cost as much or more than the price
that some said they would pay in above post. :rolleyes:

Twenty pound off a crank could add up to more performance gain
than the increased stroke.If you can make it this much lighter.

Randy, I'm told that the Moldex billet weighs 20lb less that stock. This company I'm talking to says they can do it lighter than that. You are right on both counts. People do not understand what this part costs in materials alone nevermind CNC time. And also, the stoker part is just an added benefit. The big benefit is that it is much lighter and stronger and it allows the use of lighter rotating parts. (smaller journals, etc).

Jake
05-29-2005, 11:54 AM
Glad I decited to wait until next year to build my 94 block this is the first thing that will be giong in it! This crank is going to make all the difference in a motor. About time we started gertting some kick @zz parts! Sign me up for one Dave in Jan 06.

BT Motorsports
05-29-2005, 12:45 PM
The big benefit is that it is much lighter and stronger and it allows the use of lighter rotating parts.
David, please expand on how this crank will be stronger than our forged crank.

Paul

Randy N Connie
05-29-2005, 04:14 PM
A stock 3.8 SC cranks weight is around 45lbs.

Randy

seawalkersee
05-30-2005, 02:29 AM
Uhhhh....I dont think that thing will support a 2.2. Thats 1.1 L per cyl. :D Seriously though, Thinking about this, If we were to step up to a taller deck height and keep the same or only slightly higher displacement and then add a longer rod, our VE would be outlandish. Im not sure of the total gains of the piston being parked at TDC with a supercharged engine on the intake side, but with larger valves and then adding the extra time for evacuation, with proper porting, it would evacuate itsself right?

Chris

XxSlowpokexX
05-30-2005, 03:34 AM
Dave,

I'm not up to date or really know what was involved in Chris W car or whats involved with this crank?

WHat rods and pistons are used with this crank?

For everyone else.

Weather it be cast, forged or billet steel crank or even nodular iron there are pros and cons to all designs. Some bend, some crack, some twist..Some do all when they fail. Some are less forgiving then others. We can start a whole new post on that subject.

cougarsc
05-30-2005, 05:10 AM
From memory, Wise's was an offset grinded SC crank with 6.0 chevy rods. 2.0 inch journals. I think it was a 4.1L. I don't remember what the weight was on his crank.

seawalkersee
05-30-2005, 12:01 PM
From memory, Wise's was an offset grinded SC crank with 6.0 chevy rods. 2.0 inch journals. I think it was a 4.1L. I don't remember what the weight was on his crank.
Where is he now? Was it like the SC to beat all other SCs?

Chris

XR7 Dave
05-30-2005, 12:35 PM
The billet crank would be available in 2.3, 2.1 or 2.0" journals. For comparison, the stock SC rod is around 720g. An Eagle lightweight H-beam 6.2" rod is 560g. That amounts to over 2lbs off the rotating assembly where it matters most - on the reciprocating parts. Then there is the corresponding 2+lbs off the crank, that all in addition to the already lighter design of the crank.

Standard SBC rods would be used with the crank and the pistons would be ordered with the light weight SBC pins and the correct compression height for the 6.2" rod. There is an even larger weight savings in the pistons than the rods. :)

Chris Wise offset ground his crank from a 2.311 journal to a 2.100 journal which resulted in a .2" increase in stroke (3.59"). He also bored his block .040" over for a total of 4.1L. You can check the fastest SC's lists for more data on that car.

seawalkersee
05-30-2005, 01:30 PM
I know that you have listed the possible price of 2300 for the crank. Are you trying to get a KIT price that will take it to the next level? What kind of issues now will come with the current heads? By this I mean with every power level, any engine will run into problems. It will start with the lower quality stuff first. Once that is fixed something else will go. Are you confident that the SC top end will withstand 700hp?

BTW, what is Wise driving now? And who got his old car?

Chris

XxSlowpokexX
05-30-2005, 01:54 PM
There has already been an SC based motor turbocharged in the 1,300hp range....So ya know..Its been done

seawalkersee
05-30-2005, 02:59 PM
There has already been an SC based motor turbocharged in the 1,300hp range....So ya know..Its been done
? :eek: ?

Where?

Chris

XxSlowpokexX
05-30-2005, 04:24 PM
Nelson Hoyas Ford Focus...3.8 punched to 4.7 Twin Turbo..Based of a Thunderbird motor..Look it up:O)

XR7 Dave
05-30-2005, 04:33 PM
It ran in the NHRA Sport Compact series. It wasn't really an SC motor anymore though.

The valvetrain in these motors is pretty much the same as any other SBF so as long as you have upgraded parts appropriately there should be no valvetrain issues. As for cylinder head flow...well, that may be come an issue but I'm not ready to put artificial limits on it.

To make 500rwhp at 400ftlbs torque requires 6500rpm which is 1000rpm more than what I had with my stock block motor. I think this is a reasonable goal, most likely it is achievable with a stock crank, but it would be much easier with some better parts...

Randy N Connie
05-30-2005, 06:05 PM
Nelson Hoyas Ford Focus...3.8 punched to 4.7 Twin Turbo..Based of a Thunderbird motor..Look it up:O)

The only thing I can find in a search is Nelson Hoyos.He runs a
chevy,with a 4 cylinder chevy motor.

I could not find a Nelson Hoyas in NHRA compact racin.

XR7 Dave
05-30-2005, 06:49 PM
Here's a picture of the motor....



http://members.tccoa.com/xr7dave/1300hp.jpg

racecougar
05-31-2005, 12:56 AM
BTW, what is Wise driving now? And who got his old car?

Chris

When his 35th Anny was rear ended just after being painted, he swapped the drivetrain over to a 93 SC. I bought the 35th from him, and I still have it. I'm not sure who owns the 93 now. The 35th ran 11.9's, and he was able to get the 93 all the way down to 11.16, IIRC.

-Rod

XxSlowpokexX
05-31-2005, 01:12 AM
Kenny Duttweiler had a part in building that motor..Hoyas motor that is...Maybe if you give him a call you can get soem infoo

seawalkersee
05-31-2005, 02:58 AM
Dave, you listed an rpm for hp level. What does this depend on? Is there a valve/number of cyl.x rpm or some formula that you have? Is it possible to make that much power lower in the rs?

Chris

Randy N Connie
05-31-2005, 03:17 PM
Kenny Duttweiler had a part in building that motor..Hoyas motor that is...Maybe if you give him a call you can get soem infoo

he is not in my phone book.Would he have a buisness name?
or a web address? I really would like some more info about
this motor.

My e-mail address is rbpertek@csuol.com
Thanks RANDY


Chris… David uses two slid-rulers taped together.To get the RPM to horse power ratio.:)

XR7 Dave
05-31-2005, 04:23 PM
Dave, you listed an rpm for hp level. What does this depend on? Is there a valve/number of cyl.x rpm or some formula that you have? Is it possible to make that much power lower in the rs?

Chris

HP = tq x rpm / 5250

Yes, you can make the power at lower rpms but cylinder pressure must go up to do so.

seawalkersee
05-31-2005, 06:55 PM
I was looking for something along the lines of valve size and number of valves or something to that effect. Thanks though, I will remember that.

Chris

XR7 Dave
05-31-2005, 07:05 PM
No, I'm not saying that the motor won't or can't make more power. I'm saying that if we could rev a little higher we could achieve our HP goals without lifting the heads.

David Neibert
06-03-2005, 06:09 PM
Bob Simms (St. Louis area guy who doesn't post much) bought Chris Wise's 93 with the offset grind stroker crank. He installed a Gear Vendors overdrive and drove it off and on for about a year, then sometime last year I heard he blew the motor and it's just sitting now.

David

XxSlowpokexX
06-04-2005, 02:11 AM
Duttweiler Performance
1563 Los Angeles Ave.

Saticoy, CA 93004

805 - 659 - 3648


My v8 turbo cam is from him..He used to be the guru of all that is Grand nationals..And even got into the stangs turbo wise..I forgot the machine shop he used but give him a call mayeb he can help..I'd love to know

Thats what franks motor shoulda looked like;IO)

Jim Demmitt Jr
06-04-2005, 12:19 PM
"My two stroker cranks"

Had mine made by Crankshaft Specialist Co. at a cost of $2100.00 ea one I sold to Valintino of Southern Calif with Eagle Rods. he can tell you how nice that crankshaft is contact Crankshaft Specialist Co. have one built. look for Val to thunder hard into the record books soon. We put 427 cranks made by Crankshaft Specialist Co. into Cobra engines there the best.

Contact info (901) 452-6663

280 Tillman/Po Box 12535
Memphis,Tenn. 38112 (Ask for Doug Rowe)

Randy N Connie
06-16-2005, 10:24 AM
Any updates on this stroker crank.
And some pistons and rods to go with it.

Thanks Randy

XR7 Dave
06-16-2005, 03:32 PM
Well, the contact I was working with has gotten back to me with some numbers and I'm a little discouraged. Seems either Crankshaft Specialties or Moldex are the two best choices at the moment and costs with them are around $2500.

The new company will sell them for $2500 also but they require an initial production run of 5 units and of course someone has to pay $5000 the prototype.

Ouch.

Jason Wild
06-16-2005, 09:40 PM
Dave,
thats a lot to be putting out for a crank.
I know CNC time costs as does 4340 I think thats what they use but still it's a lot.
I'm woundering how hard it would be to do up a CNC program something I can do my self and then get some one to run it for me. This Might be the way to go about making an billet crank.

Now i'm starting yo think :)

Thomas
06-16-2005, 11:06 PM
if someone had the ability to make the file for the crank in whatever program they have, that would cut down on the design time the shop would charge, which would be a lot of money.
-Thomas

Randy N Connie
06-20-2005, 07:00 PM
Here's a picture of the motor....



http://members.tccoa.com/xr7dave/1300hp.jpg

This is a V-6 SVO BLOCK AND HEADS.It is not a SC 3.8 BASED BLOCK
& HEADS.

This infor comes from Kenny Duttweiler.

Thanks Randy

Thomas
06-20-2005, 09:23 PM
since when was there a V6 SVO block? Any info on it?

XR7 Dave
06-20-2005, 10:09 PM
Well that is certainly interesting to know Randy. It makes it all the more fun to see what we can get out of this motor. :D

If everyone thinks I'm overstressing my rods/pistons, do you think then that it would be unwise to drive the car to Miwaukee and race Pro Street Rich? :p I really hate the thought of trailering the car out there. :(

Jason Wild
06-20-2005, 10:49 PM
Svo block has been around for sometime most have become junk or go for a high price.

Dave you know what i'm going to say is go for it lets see the 11sec pass. :)

seawalkersee
06-20-2005, 11:13 PM
Svo block has been around for sometime most have become junk or go for a high price.

Dave you know what i'm going to say is go for it lets see the 11sec pass. :)
Yeah...that would be cool with a 2 ton car...

Chris

BT Motorsports
06-20-2005, 11:35 PM
I still would like to know why it has been stated that a billet crank will be stronger than a forged one for our application.

Paul

XR7 Dave
06-20-2005, 11:48 PM
Well, I guess it starts with the steel used in the first place. Do you know what steel is used in our stock cranks?

BT Motorsports
06-20-2005, 11:59 PM
Do you know what steel is used in our stock cranks?
I certainly do not which is one of the primary reasons why I asked the question. I will also say the wording of your statement gave me the impression you feel a billet crank would be stronger than a forged crank made from the same material, is this so?

Paul

Randy N Connie
06-21-2005, 12:02 AM
I still would like to know why it has been stated that a billet crank will be stronger than a forged one for our application.

Paul

Many reasons.Just a couple.
Larger radius,makes the crank stronger,and better fit for after market rods.

The crank can be made lighter in the right areas..This can make it stronger.

Metal can be left in the right areas for strength.

An after market crank should have better care takin during heat treatments.

ETC.

The main reason that factorys use forgings ,is to get a ruff crank shape
to save machine time,This is my thought.

Thanks Randy,

BT Motorsports
06-21-2005, 12:06 AM
Many reasons.Just a couple.
Larger radius,makes the crank stronger,and better fit for after market rods.

The crank can be made lighter in the right areas..This can make it stronger.

Metal can be left in the right areas for strength.

An after market crank should have better care takin during heat treatments.

ETC.

Thanks Randy,
Randy, are you stating that two aftermarket cranks in comparison will exhibit the results you mentioned or an aftermarket billet vs. aftermarket forged? If you are comparing to our stocker, what is your opinion of a billet vs forged aftermarket piece.

Paul

Randy N Connie
06-21-2005, 12:24 AM
I was compairing billet to stock factory SC crank forging.

Being stronger has a hole lot to do with design,as much as the alloy
being used in some if not most cases when building a crank.

Your question are very indepth to answer.There are a lot of depends.
With the exact same design,machine process.exact same heat treatment,
exact same alloys,one being billet rounds and one being forged.I would go with a forged crank for the same reason Ford uses forgeings or casting,
to cut machine cost.

But here comes a Depends.We are trying to get a small number of stroker cranks made,So most if not all crank machine buisness would not want to
make the form to forge are cranks.So IT will be billet cranks made,unless
someone can talk Ford or there after maket company that forges there cranks to loan there forging machine to stamp out about 5 to 10 cranks for use to
have machine.So I would only use billet rounds for DAVID D. project.

I am not a metalurgest (sp) but I have freinds that are.And I ask
them for there opinion before making any moves on my projects..

Randy

XR7 Dave
06-21-2005, 09:36 AM
I have read an in depth technical engineering article on the processes and steel that went into the stock crank. However, I will have to find the person who showed it to me because I can't remember the details. I do recall the closing comment (and this was not written by someone at Ford) was that they felt that Ford had really done their homework on it and if there was one thing that would never break on an SC it would be the crankshaft. :cool:

I don't necessarily think that the stock crank is so bad, but I highly suspect the quality control process at Ford. I think that many cranks have latent defects that result in random failures.

There are lots of things that could be done to the stock crank to make it better also, but I hate to invest a lot of time and money into it if if has a latent defect that is going to cause it to snap anyhow.

Randy hit it right on the head with his comments. All of the reasons he mentioned are why I am personally looking for a billet. I'd be happy with a 4340 forging but I don't see that happening.

David Neibert
06-21-2005, 02:34 PM
Here is a portion of an article written by some expert on crankshafts.

Forged Vs. Billet
Is a forged steel crank better than a machined billet crank? Some say yes, some say no - and it depends on what you mean by "better."

Forgings generally produce a flowed grain structure that provides great strength parallel to the lines of flow. The metallurgy of a forging also depends on the alloy used and the heat treatment that is applied to it after it has been shaped. The one drawback of a forging is that it requires a die to shape the metal. Dies and forging presses cost a lot of money, so the availability of forgings for various applications depends on their popularity and how much people are willing to pay for a forged crank. According to Boes, "The vast majority of performance-related cranks in use today are made from forgings, even some that are claiming to be billets."

Brian Adix, of Howards Cams in Oshkosh, WI, says his company sells two basic forged crankshafts, a "Track Smart" forged crank, for SB/BB Chevy (their least expensive cranks), and "Pro Series" cranks that are also 4340 forged steel, have drilled rod throws for lightness and are "Permatuff" heat treated for SB/BB Chevy racing engines.

He says these forgings are done by Trenton Forging, one of the few remaining U.S. forging operations.

Billet crankshafts, by comparison, are CNC machined from a solid chunk of metal. The machining process cuts through the grain structure so there are fewer residual stresses in the metal as there are in a forging.

Proponents of billet cranks say billet steel alloys also tend to be "cleaner" in terms of impurities and inclusions, which improves strength and durability of the finished product.

The main advantage of billet cranks, however, is that CNC machining allows the supplier to custom fabricate a crankshaft for virtually any engine. No mold or forging die is necessary, so there's no limit on the shape or dimensions of the crankshaft.

A one-of-a-kind crankshaft can be created to any specifications. This gives high performance engine builders a great deal of flexibility in choosing stroke lengths, journal diameters, the positioning of the journals and counterweights, and the configuration of the crank itself.

If somebody needs a performance stroker crank for a sport compact engine or an oddball application, a billet crank can be tooled up from scratch. Of course, billet cranks require a LOT more machining than forged or cast cranks. As a result, they cost more. Billet cranks typically fetch anywhere from $1,800 to $3,000 (or more) depending on the amount of work required to make it. A typical street price for a small block Chevy stroker billet crank is around $1,900 to $2,000. A comparable big block Chevy crank would be a couple hundred dollars higher.

Joe Squires of Bryant Racing, Anaheim, CA, explains that 90 percent of the crankshafts his company produces and sells are billet cranks. "Billet gives us the flexibility to control every aspect of production, from the placement of the crank pins and size of the journals to the location and profiles of the counterweights. We use two different alloys depending on the application, either 4340M or EM30B. We also do our own heat treating in-house and cryogenically treat every crankshaft to improve durability."


David

Mike8675309
06-21-2005, 10:43 PM
That was my understanding as well. That there isn't anything inherently "stronger" in billet than forged. It's simply a different process that allows for more variation in the end result that isn't cost effective to do forged.

Properly engineered and heat treated, a billet and forged can be equally strong.

Just as improperly engineered or improperly heat treated cranks can create a weak part.

I would expect that a billet stroker crank can be made stronger than taking a stock SC crank and offset grinding it to make it support a longer stroke, or even using a cast crank from a larger motor in the SC block to gain the stroke.

super red91
06-29-2005, 10:13 AM
I have read an in depth technical engineering article on the processes and steel that went into the stock crank. However, I will have to find the person who showed it to me because I can't remember the details. I do recall the closing comment (and this was not written by someone at Ford) was that they felt that Ford had really done their homework on it and if there was one thing that would never break on an SC it would be the crankshaft. :cool:

I don't necessarily think that the stock crank is so bad, but I highly suspect the quality control process at Ford. I think that many cranks have latent defects that result in random failures.

There are lots of things that could be done to the stock crank to make it better also, but I hate to invest a lot of time and money into it if if has a latent defect that is going to cause it to snap anyhow.

Randy hit it right on the head with his comments. All of the reasons he mentioned are why I am personally looking for a billet. I'd be happy with a 4340 forging but I don't see that happening.

Dave Im the one that showed you the article, Its back at home but Ill see if I can have someone scan it for me so I can post it on here.

V8Supercoupe
07-02-2005, 09:31 AM
Just out of curiosity, was there something wrong with JD's source for cranks at a 2100 price tag? Not saying I am ready to jump in cause I have gone into a stall with a couple projects I wanted to pursue, but I'm just wondering.

Dave, I emailed you about the AR's, think when you get a chance you can drop me a line at:

leforrest@yahoo.com

Thanks man,
Skip

XR7 Dave
07-02-2005, 11:21 AM
Just out of curiosity, was there something wrong with JD's source for cranks at a 2100 price tag? Not saying I am ready to jump in cause I have gone into a stall with a couple projects I wanted to pursue, but I'm just wondering.

Dave, I emailed you about the AR's, think when you get a chance you can drop me a line at:

leforrest@yahoo.com

Thanks man,
Skip

I have no first hand knowledge of any of the available cranks. I am sure they are all very comperable. I was hoping to be able to do better than $2100 but apparently I cannot.

David

fastsc92
11-03-2016, 07:21 PM
Hate to sound like a dinosaur since this thread is 11yrs old, however is there now a decent source for a billet crank? I'm looking for something capable of getting 4.4l of displacement and able to handle some big power, either from a turbo or a blower, and a moderate amount of nitrous on top of it. Aiming for 900+hp.:cool:

CMac89
11-04-2016, 08:54 AM
Dave, is there an update on the status of this? :)

Jay, just about any billet crank company will make you one. Companies treat all one-off crank development processes the same; it just takes sending them a stock crank and knowing what the boundaries of the crank case are so you can get as much stroke as you want. Then other intricacies that they deal with.

Bryant
Moldex
Crower
Winberg

....And so on. It'll still be about $2500 plus typically added cost of initial setup, tooling, and programming. I'd call some up and get a better idea on accurate pricing and resources.

fastsc92
11-04-2016, 11:18 AM
If the process was more dialed-in with a specific supplier, I'd love to take the benefits of not having to pay NRE in addition to the part cost. The crank wont be cheap, but if it helps me get into the 900-1000hp range with some longevity...it may be worth it.

XR7 Dave
11-04-2016, 11:46 AM
Crankshafts are available now as we speak. Crower has made them for a few people in the Mustang V6 world. No one is using one in the SC world yet. They are significantly more expensive than this 2005 thread indicated they might be though. I forget the #'s but a phone call to Crower will get you up to speed if you are seriously interested.

fastsc92
11-04-2016, 11:59 AM
..... I forget the #'s but a phone call to Crower will get you up to speed if you are seriously interested.

Just trying to get up to speed with what's available and to get my ducks in a row for a build in the future. I'll make an inquiry to Crower and see what they say. Thanks for the replies.

20psiofevil
11-05-2016, 08:01 PM
From what I have gathered all the 3.74" cranks that have failed have been oem cranks from ford. Have not heard of any of the china cranks failing yet? Possibly the metallurgy of the china units are different...? Wonder if anyone has weighed a china piece against an oe unit.

On another note my chine 3.74" crank has held up to turbo'd 20psi with a 35hp shot of nitrous. My 4r70w not so much:eek:

XR7 Dave
11-05-2016, 10:53 PM
From what I have gathered all the 3.74" cranks that have failed have been oem cranks from ford. Have not heard of any of the china cranks failing yet? Possibly the metallurgy of the china units are different...? Wonder if anyone has weighed a china piece against an oe unit.

On another note my chine 3.74" crank has held up to turbo'd 20psi with a 35hp shot of nitrous. My 4r70w not so much:eek:

This thread is about billet steel cranks, not cast steel. Topic for a different conversation.