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Topic Review (Newest First)
10-13-2012 02:54 PM
1Gary Not sure why we got hung up comparing Eagle VS Scat when all along it should be resolved with this Howards Track Smart 3.75 stroke 5.7 rod hole lighting crank.





10-13-2012 12:56 PM
Mr. P-Body As said, heard about it, haven't seen it. Perhaps due to it, Eagle fixed the problem? There were a small number of Pontiac castings that "got out" with a rough thrust face. They caught and corrected it. They paid us to repair the ones we found. I KNOW Eagle does try to make things better all the time. As for Scat, well, the balance issue is very real. AND, when one calls a company to talk about a problem, condescention and arrogance are NOT how to win loyalty. One of the highest "ranking" people in Scat told me "SAE AND Sunnen are wrong" about a specific process. The details don't matter. I submit, SAE is THE "final authority" in certain areas, including the one in question. Sunnen supplies the best machine equipment on the planet and has the best trainers for that equipment. No. Scat was wrong.

The "steel" in the Eagle castings is quite different to grind than the factory nodular cranks. I'm NOT a metalurgist, but I can tell the difference in "sound" and finish. Based on the process, I prefer the factory nodulars for anything serious. The bigger-mained (3"-up) cast steel cranks seem to be okay up to 750 HP and about 7,500 RPM. We've used them in Fords and Pontiacs without incident. BBCs do NOT like them at higher revs.

FWIW

Jim
10-12-2012 06:16 PM
1Gary
Quote:
Originally Posted by Mr. P-Body View Post
Funny, but this isn't the first time I've heard this about Eagle/Scat. I suppose it depends on what you build, and "how many". The majority of our experience has been with "un-Chevys" (we build about 30 engines per year, more than 1/2 are Pontiacs). We have, however, tried pretty much all the available stuff in the small block circle track applications. (If you wanna know what holds up and what doesn't, circle track is a GREAT "proving grounds"). The Chinese castings consistently "beat out" # 2 and 4 mains.

We have one case where an Eagle 461 "kit" was used in a 400 Pontiac. He put 751 1/4 mile passes and over 3K street miles on it. Consistently "finished" in the top 5 in points at two tracks over a 4 year period, turning 10.30s and .40s, 3.400 lb. '70 Firebird. The one time we tried a Scat 4.25" stroke, we couldn't balance it without adding weight to the leading edge of the counterweight (not good). Others have reported the same issues with the 383/400SB castings (9000 series).

We heard about quality issues with the Eagles, but have not seen them. In more than one case, where it was said the crank was "out", the crank was fine and the BLOCK was bad. This falls under the "chicken or the egg" question. Often, crankshafts get "blamed" for problems in an engine when the issues ly elsewhere, the crank being "caught up" in the wreck (so to speak).

IMO, if you have something that "works" for you, go ahead and use it. For those that aren't "in the business", sort this out best you can! Neither are "wrong", just different POVs.

Jim
2000 pc Eagle order.About 1/3 was checked and QC issues ranged from taper on the journals if used would need 10/10,to out and out cracks. Puts customer relations and rep at risk. Not worth it. Than those same issues was confirmed on this site in a thread afterwards. Kind of ironic.
10-12-2012 02:25 PM
oldbogie
Quote:
Originally Posted by atcoscrazyest69 View Post
I have and it would be much easier but i was under the impression that cast steel was stronger. And my famous question if i got the crank from napa do you think it would need to be balanced?
I'm less than convinced that these so called cast steel cranks are actually steel rather than nodular iron. Certainly when you see numbers like 80-60-06 you know this is a designation for nodular iron. What 9000 series cast steel crankshaft is, I don't know. Are they actually casting an AISI 9000 series silicon/manganese steel or is this a nodular iron casting, which SCATs own data sheet titles this as "9000 Series Nodular Crankshaft".

The difference between iron and steel is the amount of carbon. Cast iron sees carbon as 2% by weight and higher. Steel sees carbon as 2% by weight or lower. Either can have alloying elements such as nickel, chrome, and other common and rare metals, but the presence of alloy elements doesn't change the base material from high carbon cast iron into lower carbon steel. So I don't really know what this 9000 stuff is. That's not to slam SCAT's 9000 series casting, we've built and run them and they prove to be pretty sturdy shafts for performance street and light/claimer competition.

But are they technially steel?

Bogie
10-12-2012 07:25 AM
Mr. P-Body Funny, but this isn't the first time I've heard this about Eagle/Scat. I suppose it depends on what you build, and "how many". The majority of our experience has been with "un-Chevys" (we build about 30 engines per year, more than 1/2 are Pontiacs). We have, however, tried pretty much all the available stuff in the small block circle track applications. (If you wanna know what holds up and what doesn't, circle track is a GREAT "proving grounds"). The Chinese castings consistently "beat out" # 2 and 4 mains.

We have one case where an Eagle 461 "kit" was used in a 400 Pontiac. He put 751 1/4 mile passes and over 3K street miles on it. Consistently "finished" in the top 5 in points at two tracks over a 4 year period, turning 10.30s and .40s, 3.400 lb. '70 Firebird. The one time we tried a Scat 4.25" stroke, we couldn't balance it without adding weight to the leading edge of the counterweight (not good). Others have reported the same issues with the 383/400SB castings (9000 series).

We heard about quality issues with the Eagles, but have not seen them. In more than one case, where it was said the crank was "out", the crank was fine and the BLOCK was bad. This falls under the "chicken or the egg" question. Often, crankshafts get "blamed" for problems in an engine when the issues ly elsewhere, the crank being "caught up" in the wreck (so to speak).

IMO, if you have something that "works" for you, go ahead and use it. For those that aren't "in the business", sort this out best you can! Neither are "wrong", just different POVs.

Jim
10-11-2012 11:24 PM
1Gary We found too many QC issues to suggest the use of Eagle products. And we only suggest selected Scat parts.
10-11-2012 03:00 PM
Mr. P-Body I stated quite clearly, the factory nodular cranks are superior to the cast steel. Like Bogie, I do this stuff for a living. The Chinese FORGINGS are better than the factory nodular, IF you choose a good one. We've seen LOTS of balance issues with Scat cranks. Not so many with Eagle. We too, buy them in "pieces". Seldom to kits have all the correct combination for optimum performance. We generally use different pistons and bearings than Eagle supplies. Their rods and cranks are as good or better than any.

RED FLAG! Crank kits may or may not be a good idea. For a pickup truck "to get down the road", they're usually okay. For any performance application, they can be a real roll of the dice. Companies like CRI (Crankshaft Rebuilders, Inc.) and "Standard" (East Coast remanufacturers) are perfectly willing to weld up a torn up journal on a cast crank. This is bad. A casting isn't receptive to welding like a forging. It changes the surface tension, a known "sore spot" in castings. If you find one that's 10/10 or 20/20 (.010" or .020" undersize on both mains and rods), you have a good chance it's not been welded. It shold be magnafluxed before being used in a performance engine. They also usually come with the cheapest bearings known to man. Not ALL Clevite bearings are the same. They have various "levels".

Bogie's description of "internal/external" is right on the money. For those that are still confused about just exactly WHAT IS BALANCING?, here:

All pistons are weighed. The lightest one is "matched" by removing material from the others. The rods are weighed, both "ends" and "static". Again, the "light" ones are found and the rest matched. A set of rings (1 piston's worth) is weighed. The rod bearing is weighed. The piston pin and locks (if so equipped). There are two specs: Rotating weight (rod bearing, "big end" of rod, 4 gr. oil) and reciprocating (piston, pin, locks, rings and "little end" of the rod) weight. For most V8s, 1/2 of the reciprocating weight and 100% of the rotating weight are used to calculate the "bob weight". A weight made up to match a PAIR of rod/piston assemblies is attached to each rod journal. If "external", the flywheel/flexplate and balancer are attached. The crankshaft is "spun" by a motor. There are sensors in the stand that detect the "heavy spot" at given RPM intervals. Material is removed or added until the triggers are not activated. If you've ever seen a tire balanced with a strobe light, exactly the same principle. This is a simplification, but accurate. Most modern machines are computer controlled.

FWIW

Jim
10-11-2012 02:43 PM
1Gary
Quote:
Originally Posted by cdminter59 View Post
Read this article from Eagles website. It has all the infomation you want to know. Eagle Specialty Products, Inc.
I don't like the Eagle imported parts.Sorry.
10-11-2012 07:19 AM
cdminter59
broken crank

Read this article from Eagles website. It has all the infomation you want to know. Eagle Specialty Products, Inc.
10-11-2012 04:09 AM
1Gary I worked as a engine tester at the Tonn Chevy Plant when the 400's when being built. We would balance those engines in the test stand. We almost never rejected a engine because of the flexplate being out of balance. All the balancing was done with oz pins driven into the balancer. We didn't have a welder to add wt or change the wt to those flexplates. Where they balanced to race tolerances??. Certainly not.

I have read through this thread. My suggestion would for this O/P to take the block to a machine shop to have it checked to see if it needs to be line bored/honed. And as stated have the rods checked as well. Then have the block hot tanked,rifle brush cleaned,new soft plugs and cam bearings.

My Howards 383 crank states clearly on the side of the box any alterations to the crank,you then own it.
10-11-2012 12:23 AM
atcoscrazyest69 I have and it would be much easier but i was under the impression that cast steel was stronger. And my famous question if i got the crank from napa do you think it would need to be balanced?
10-10-2012 11:46 PM
cdminter59
broken crankshaft

Have you considered going to your local Napa store and order a remfd crank kit? It will be a Chevy nodular iron crank with bearings not some chinese cast steel.
10-10-2012 09:34 PM
atcoscrazyest69 Thank you bogie. I think that is exactly what iv been waiting to read. Im gonna get that crank theres no need to get the whole assembly and im gonna drop off the crank flywheel and balancer at the local shop. Thanks for all your help
10-10-2012 06:06 PM
oldbogie
Quote:
Originally Posted by atcoscrazyest69 View Post
I understand the external balance points with 400s and 383 as it is on a 4 speed trans and i had to buy that plate that bolts between the flywheel and crank. I understand that the balancers are different for the externally balanced 400 and all the other internally ballanced motors. The whole reason for trying to make it internally balanced is i do not like having to run that balance plate. I just dont understand why the add says its balanced and a couple fellas on here are saying send all the brand new stuff out to get balanced. If i have to send it ourmt to get balanced either way then theres no need for me to get a whole rotating assembly the only reason i said id get the assembly is because it states its balanced. I just donot know what to do. But i do not want to do it again
That's reasonable; I'm not enamored of externally balanced engines, therefore, work hard to keep 400's and 383's internally balanced.

The kit you sight is internally balanced and will, therefore, require that you purchase a netural balanced flywheel and damper.

The raging argument about how well balanced is one revolving around how good is good enough. Some of these pre-balanced kits have been miles off. Sometimes this is the result of the manufacturer other times it's been the fault of the builder taking to much material from the rods or piston skirts in the pursuit of clearance. Frankly, I prefer SCAT to Eagle when it comes to budget bottom end parts and assemblies. But since you're dealing with Summit, they have a very good customer service reputation so I'd mentally lean on them with this provisio; if you have interference between the rods and cam or piston skirts DO NOT FIX IT. Call Summit and make arraingements to return it in the original packaging in a clean and unmolested state. That eliminates any argument over who did what and has blame. Grinding on the rods and or pistons will alter their weight destroying what ever level of balance they came with. Mayby not by much, but you don't want to get caught in "if you touched it, its yours".

One thing we see a lot of when sending parts to our balancer is that many things that are sold as balanced (including flywheels, flexplates, and dampers) are often well off any reasonable standard for a performance to competition level engine. So we do not even bother with pre-balanced kits. We procure things in pieces, make up assemblies, proceed to a mock-up build that trims parts if necessary, mark them as to where they go and who goes with whom, then have them balanced. This is tedious and adds some cost but the end result is a correctly balanced engine, whether that's spot on or over/under balanced by end use or customer desired requirement. For a mild performance street engine that doesn't go over about 6 grand of RPMs, spot on is the place to be no over/under balance games needed.

Bogie
10-10-2012 05:33 PM
atcoscrazyest69 I understand the external balance points with 400s and 383 as it is on a 4 speed trans and i had to buy that plate that bolts between the flywheel and crank. I understand that the balancers are different for the externally balanced 400 and all the other internally ballanced motors. The whole reason for trying to make it internally balanced is i do not like having to run that balance plate. I just dont understand why the add says its balanced and a couple fellas on here are saying send all the brand new stuff out to get balanced. If i have to send it ourmt to get balanced either way then theres no need for me to get a whole rotating assembly the only reason i said id get the assembly is because it states its balanced. I just donot know what to do. But i do not want to do it again
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