Forged Steel Crank Cast Crank Questions

[Chatt69chgr]

I have two 440's for possible use in my Charger.  One is a 69 and the other is a 77.  For various reasons, I may want to use the 77 block for my buildup.  Could I use the 69 forged crank in the 77 block if I wanted to?  I havn't torn into either of these engines but may end up wanting to use the 77 cast crank.  I don't plan on builidng a real high hp engine.  I don't see the rpm going much above 5500-----6000 at the absolute max.  HP will be stock to 10% over stock.  Stock input and exhaust.  I should say that I tend to baby machinery and don't race.  What would be the downsides of using the cast crank if I need to besides the pilot bushing issue?  And speaking of that:  Can a good machine shop machine the end of the cast crank to accept the pilot bushing/bearing?  And which should I use---bushing or bearing?  I realize that I will have to weight the flywheel properly as the cast configuration is externally balanced.  I bet a bunch of you have been down this road so I thought I would tap into the incredible knowledge base on the forum.  All replies will be greatly appreciated. 

[firefighter3931]

For what you're looking to do with this engine, the cast crank 440 will be fine. The best thing you could do is to have the rotating assembly balanced and have good rodbolts installed when the rods are being reconditioed. The speedpro 6-pack forged pistons work great in this type of build. The 77 engine will also have 452 heads which allready have the hardened exhaust seats for use with unleaded fuel.

Cast cranks are good to approx 550hp...anything more than that and you should be looking at forged. I have a friend with a cast crank in a 383 race car and it holds up under some serious abuse.....5000 stall, 4.56 gears and shifting near 7000rpm on occasion.  The machine shop will be able to drill out the pilot hole for the 4spd trans. You will also need a scalloped flywheel which is for an external balance engine along with the correct dampner. 


Ron

[Chatt69chgr]

Thanks Ron.  I appreciate the reply.  I have never heard of a scalloped flywheel.  Does scalloped describe a dished area on the block side of the flywheel to clear a portion of the crank?  I don't have the 77 engine in my garage to look at yet.

I assume the the dampener should always be replaced as a matter of course-----probably due to the fact that the rubber in them goes bad and they could slip.  Would that the case?

[firefighter3931]

Does scalloped describe a dished area on the block side of the flywheel to clear a portion of the crank?  I don't have the 77 engine in my garage to look at yet.

The cast crank flywheels will have either a cutout area aroung the perimeter (scallop) or could have holes drilled into it. I don't have any pics of what it looks like but you will know it when you see it.....looks like a symmetrical chunk is missing. Macloed also makes a cast crank aftermarket flywheel for the external balance combo.....that is another option. The OEM cast crank flywheels can be difficult to find....you might be better off with an aftermarket unit anyway....those are usually SFI rated. 


The cast crank harmonic balancer can be rebuilt....i can't remember the name of the company that does this but the service is available. I'm not sure if anybody makes a (new) aftermarket cast crank balancer....all the ones i've seen are for internal balance applications.



Ron

[Chatt69chgr]

Thanks for the reply Ron. 

I found the Mcleod flywheel last night.  It's part number 4642002-17C and will accept several different clutch sizes and types.  Someone recently told me that a good source for a flywheel was a 80-85 Dodge Truck/Van with 3-speed manual transmission. Even if this source was accurate, it wouldn't be SFI approved and probably would be only drilled to accept a B&B pp.  I plan on using a diaphram type.

I didn't know that aftermarket external dampeners were not available.  Do these normally need to be rebuiilt as part of an engine rebuild?  Assuming that these need to be rebuilt, maybe someone else reading this post would know who provides this service. 

[firefighter3931]

Chatt, i would just go ahead and get the SFI flywheel and a steel bellhousing or scattershield....no sense in taking any chances with your feet....or anything else that might get in the way of an exploding clutch/flywheel 

Ok, i found the balancer rebuild service.....see below. 

http://members.aol.com/damperdoc/


The way I see it....any 30 year old part is gonna be suspect. The rubber will vulcanize over time and eventually the balancer will fail. Usually it starts with the outer ring shifting. I've tried to index several oem balancers only to find that they've shifted (outer ring) and this is quite evident when you line up the timing marks and the piston is several degrees away from TDC. 

Bottom line....rebuilt engine deserves a rebuilt balancer. 




Ron

[Chatt69chgr]

Concerning harmonic balancers for 73-78 440 cast crank applications:  The link didn't work and I played around on the internet for a while and couldn't find any places to rebuild the balancer.  What I did find out was that it appears that Mopar Performance doesn't have a balancer for this application.  The only one they have that is close is the P5249696 which appears to be for a 400.  Don't know if the same piece was used on both 400's and 440's.  It costs about $300 discounted.  It appears that BHJ Dynamics has one that would work as does ATI.  They are expensive, in the 300 to 400 dollar range but are SFI.  The one I will probably get is not SFI but is available from Bouchillon Performance.  They say it's a new product.  Fits 73-78 cast crank 440 applications, is called a stock replacement, and works with stock pulleys.  Part number HBF440CAST for $152.55.  One link I ran across in researching this said that any balancer over 25 years old needs to be replaced or rebuilt as the rubber deteriorates and is not reliable any older than this.

IF someone does happen to find a place that does rebuild these balancers, I would be interested in knowing who they are and what they charge.  If they performed this service for less than what I can buy one from Bouchillon for I would want to consider that option. 

Again, thanks Ron for the knowledgeable assistance.  I am slowly but surely getting my drivetrain nailed down.

[Charger-Bodie]

Concerning harmonic balancers for 73-78 440 cast crank applications:  The link didn't work and I played around on the internet for a while and couldn't find any places to rebuild the balancer.  What I did find out was that it appears that Mopar Performance doesn't have a balancer for this application.  The only one they have that is close is the P5249696 which appears to be for a 400.  Don't know if the same piece was used on both 400's and 440's.  It costs about $300 discounted.  It appears that BHJ Dynamics has one that would work as does ATI.  They are expensive, in the 300 to 400 dollar range but are SFI.  The one I will probably get is not SFI but is available from Bouchillon Performance.  They say it's a new product.  Fits 73-78 cast crank 440 applications, is called a stock replacement, and works with stock pulleys.  Part number HBF440CAST for $152.55.  One link I ran across in researching this said that any balancer over 25 years old needs to be replaced or rebuilt as the rubber deteriorates and is not reliable any older than this.

IF someone does happen to find a place that does rebuild these balancers, I would be interested in knowing who they are and what they charge.  If they performed this service for less than what I can buy one from Bouchillon for I would want to consider that option. 

Again, thanks Ron for the knowledgeable assistance.  I am slowly but surely getting my drivetrain nailed down.

if you are going to need to spend that much on a balencer ect. you may as well buy a steel crank or heck a stroker kit

[firefighter3931]

Chatt, i just tried the link and it still works fo me. Not sure what's up with your 'puter ? 

The cast crank balancer rebuild is $179.00 and they will credit you $40.00 for your old balancer. The way i'm reading this is that the service basicly costs $139.00 if you supply a dampner. Here's the contact info from their website :

Contact Information:

Email: sales@damperdoctor.com   

Phone: (530) 246-2984
Fax: (530) 246-2987

Shipping Address:
Damper Doctor
1055 Parkview Ave.
Redding, CA  96001



The aftermarket SFI is certainly a better option as long as you can live with the price. Pully alignment is often problematic with many aftermarket units. An SFI version with guaranteed stock pully alignment would be something worth considering very seriously. Good work on that piece of research. 



Ron

[Chatt69chgr]

Thanks for the contact info on Damper Doctor.  I'll call them next week and obtain a clarification on their services.  It sounds like the price will be more or less the same as Bouchillon and I would kind of like to stay with the Mopar dampener.  My computer still doesn't like that link.  It goes there but then won't let me look at anything.  Probably some of the anti-viral software.  I am running three or four programs to try to protect the computer.  After I had one computer trashed by virus' I am almost paranoid on this.

[is_it_EVER_done?]

I have two 440's for possible use in my Charger. One is a 69 and the other is a 77. For various reasons, I may want to use the 77 block for my buildup. Could I use the 69 forged crank in the 77 block if I wanted to? I haven't torn into either of these engines but may end up wanting to use the 77 cast crank. I don't plan on building a real high hp engine. I don't see the rpm going much above 5500-----6000 at the absolute max. HP will be stock to 10% over stock. Stock input and exhaust. I should say that I tend to baby machinery and don't race. What would be the downsides of using the cast crank if I need to besides the pilot bushing issue? And speaking of that: Can a good machine shop machine the end of the cast crank to accept the pilot bushing/bearing? And which should I use---bushing or bearing? I realize that I will have to weight the flywheel properly as the cast configuration is externally balanced. I bet a bunch of you have been down this road so I thought I would tap into the incredible knowledge base on the forum. All replies will be greatly appreciated.

Chatt: Let me take your questions in the order you presented them above. First, you have two engines to pick and chose from, a 69 and 77. The 77 block is going to be stronger assuming that sonic tests of each are similar. IF the strongest block is your goal, why do you want to use the cast crank if you have a forged one to use?

Don't get me wrong. The cast crank is plenty strong. Much more so than anyone gives it credit for, and in my opinion will hold up to anything the forged one will, but the cast unit would require neutral balancing (just like the forged unit) in order to achieve similar durability. The flaw with external balancing is that the further the balance weight" gets away from a true centerline (neutral balance), the more centrifugal forces create an unbalanced/vibration harmonics effect as the RPM increases. In any engine configuration, there is no such thing as balanced (except for an absolute RPM) no matter how carefully the parts are selected, but when you start adding/subtracting weight that isn't based on the centerline, the window of perfection is dramatically reduced, and the much larger (and more important) window of "close/good enough" fades into harmonics.

I don't know if the following has ever hapend to you, but think about a tire that needed a big patch on the inside (one that adds strength, not just seals the tire). The tire/wheel can be balanced perfectly (on a balance machine) but the whole assembly goes through several orders of harmonics as the RPM increases, It may be stable at 50 MPH, but vibrate at 65, and go back to stable a 80.

As long as you don't plan on pushing the engine on a regular basis, this will never create a problem, but what would you be saving the better parts for? Offset balanced components, rebuilt damper (who knows how close the durrometer rating of the replacement rubber is to what was originally engineered, and how well the rubber is bonded to the hub and ring), and other "cost savings" are pretty much guaranteed to be false economy.

As far as getting a crank drilled for a four speed, fortunately there are "no drill" bushings available now days that can address that without the cost of machining. -- I prefer bushings as I find that anything with roller bearings is a source of "shrapnel".

In any event, I would suggest that you carefully consider the costs of everything before you commit to your stock cast crank, as you may very well find it cheaper (and infinitely stronger) to go with a 440Source stroker kit - neutral balanced flywheel - cheap neutral balanced damper - no cost of drilling the crank or special bushing, and ability to achieve huge power increases at much lower RPM's.

otherwise, use your forged crank with everything neutral balanced. I don't know if it will save you money over a stroker kit, but it will last you forever as opposed to an offset balanced assembly, and will be cheaper than maximizing the cast crank for durability/longevity.

This is my 2-cents anyway. I have seen far too many "low buck" builds that end up costing more than a far more powerfull/durable build. Just be cautious (aware) of false economy.

[Chatt69chgr]

Well Is it Ever Done,  you have certainly given me plenty of food for thought.  Right now, I just don't know exactly what I want to do on the engine except that I do want to use the 77 block.  The 69 has one broken mounting ear on the passenger side.  I think it could be fixed but the 77 looks good-------and it has the larger mounting ears.  Secondly, the 69 block had a "A" code on it that means that it was bored 20 over straight from the factory.  As far as the cranks go, I guess I really don't know if either of the two I have are usable.  I am going to ponder the crank issue for a while before I decide what to do about it.  Thanks for taking the time to give me your thoughts on all of this.  I do appreciate it.
 

[firefighter3931]

Isiteverdone makes some good points about the forged crank...an internal balance is more desirable. I don't believe that it will make more power or be more durable below 500hp, though. If you have it on hand you might as well use it. I was assuming that you wanted to keep the 69 engine intact for another project or possibly to sell. The 68-71 engines bring the most $$ on the open market. Bummer about the broken ear. 



Ron