Rolled fillet crank. Anyone found one yet?

[myclone]

ok ive got a guy that runs a boat shop , and he said he
can get the crank all day long for 1500.00 . Thats his price
so if anyone wants one tell me and I will order it . Maybe if
we order more at once maybe we can get a better price.But 1500.00
for forged crank is not that bad.

the hitman gene

Not to sound negative but thats basically the same response I got from the boat shops/marinas that are local to me. I didnt give em my business because:

1.) They though I was stupid enough to believe any 4.3 crank they sold me was "forged".
2.) One place thought I was stupid enough to believe "all 4.3 cranks are forged". I didnt bother argueing.
3.) They had no clue what a "rolled fillet" crank was since all but one pointed out a reg 4.3 crank and then tried to sell it to me for an astronimical amount (Ive prolly got 3 or 4 reg cast 4.3 cranks for next to nothing out of bone yard engines. Ive got enough stockers :wink: ).
4.) One "head mechanic" at the last boat shop never could grasp the concept of a rolled fillet crank after I explained it half a dozen times.
5.) Boat shops/marinas are just freakin creepy. They dont like car ppl at all and they like you even less if you know more than they do or they just think you know more than they do.

That being said Id be VERY skeptical of the availability of a $1500 forged crank for a 4.3 from GM/Mercury marine.

 

[canadian]

3.) They had no clue what a "rolled fillet" crank was

looking at the picture *i* still can't figure out what a rolled fillet crank is. anybody have a more accurate description?

 

[lavaman]

in the above pic the arrow points to corner. It's the transition point between the con. rod's bearing surface and the crank's counterweight. It's more of a C shaped, rounder corner which has more metal versus the cast crank's sharper almost L shaped corner which has less metal. Sharper corner's lead to stress cracking whereas the C shaped corner has more strength...something like that... :lol:

Terry

 

[canadian]

Re: got it

Re: got it

ok ive got a guy that runs a boat shop , and he said he
can get the crank all day long for 1500.00 . Thats his price
so if anyone wants one tell me and I will order it . Maybe if
we order more at once maybe we can get a better price.But 1500.00
for forged crank is not that bad.

http://www.mercurypartsexpress.com/

old crank p/n is listed for $779.95
new crank p/n is listed for $872.40

his price must be double retail then. if these are the part numbers you gave him, he's :drinking: :drinking: :drinking:

 

[93 TY 2185]

Hey guys,
Finally got information back from my uncle on the marine crank.
The Marine crankshaft is the same as production.
Meaning any of the 2003 4.3 V6 now use a rolled fillet crank.
This information is straight from GM Powertrain.

 

[myclone]

Hey guys,
Finally got information back from my uncle on the marine crank.
The Marine crankshaft is the same as production.
Meaning any of the 2003 4.3 V6 now use a rolled fillet crank.
This information is straight from GM Powertrain.

COOL!!!! Thanks for the info/update..

 

[nightdiver]

I bought my crankshaft two years ago and i noticed the different ratio at the corners . It was not like the old "L" shaft i had, it is the rolled fillet i see in the picture.
The guys at the machine shop are friends & customers and they said this is stronger
I asked the guy that sold this to me where did it came from and he told me "its from an Astro " :roll:

 

[JSM]

I noticed my spare 4.3 crank, also has the radius's. Didn't pay any attention before, but with this thread I was going :wink:

 

[canadian]

anybody have any up close pictures of the two to illustrate the differences? just wondering how noticable the roll is in the crank. i have an extra crank sitting in the garage i'll have to take pictures of.

 

[smeagol]

I have one I'll have to take some pictures of as well.

Plus I have a buddy at a junk yard that is gonna get hassled by me pretty soon :wink:

 

[canadian]

would casting numbers help as well to try and figure out when/what they were used in?

 

[JSM]

My spare crank is out of ty #1414 (1992).

I will get some pics tonight.

 

[10secTy]

My understanding is all 4.3 cranks are rolled fillet cranks.

I have one from a 1987 Astro van and it is.

I will have to pull out my syclone engineering papers.

Nolan

 

[myclone]

My understanding is all 4.3 cranks are rolled fillet cranks.

I have one from a 1987 Astro van and it is.

I will have to pull out my syclone engineering papers.

Nolan

FYI. Ive got one out of an 85 astro van (two piece rear main seal). A 88 S-10 truck. A 89 full sized 1500 W/T. None of em are rolled fillet and they all look like a shortened SBC crank (well, sorta.. no common pin as they are all stock type even fire cranks).

 

[4C FED]

I was looking at the 2 cranks that I have and they both look like that picture, hmmm.

 

[canadian]

FYI. Ive got one out of an 85 astro van (two piece rear main seal). A 88 S-10 truck. A 89 full sized 1500 W/T. None of em are rolled fillet and they all look like a shortened SBC crank (well, sorta.. no common pin as they are all stock type even fire cranks).

can you take pics?

 

[canadian]

here's some shots of the crank i have sitting in the garage, not sure if they show enough detail to determine if it's got a rolled fillet or not:

 

[myclone]

Heres the $64k question though... Are the stock cranks cast with those fillets or are they "rolled" into them using dies/pressure? Big diff in the strength of those two operations.

Im looking into finding an answer..

FWIW.. I went out and dug out all the cranks I have. The 85 doesnt have those fillets. The 88,89, and 91 I have do (dunno what I was thinking before :-? :roll: ). All of them are used and I have no clue as to their history. Hell, I havent even mic'd em to see if they are any good. Anyway, the early crank (the 85) was ran until it seized as I had to beat/torch the bottom end to get it apart. Im guessing it was driven with no oil in it or something similar. Could this have ground the journals down far enough that the fillets are no longer visible? I guess so but I dunno how the engine would have ran long enough to do it. Makes for a very effective paper weight.

 

[MattGE]

Doing my homework for my engines class and ran across this paragraph:

STRESS RELIEVING THE CRANKSHAFT

The greatest area of stress on a crankshaft is the fillet area. Stress relief is achieved by blasting the fillet area of the journals with #320 steel shot. This strengthens the fillet area and helps to prevent the development of cracks in this area. Gray duct tape :wink: is commonly used to cover the journal to prevent damage to the rest of it. Stress relief procedures are usually performed after the grinding and polishing of the crankshaft.
(Automotive Engines, Halderman, James)

 

[kbbeckius]

marine crank

marine crank

Most marine engines are GM in origin, not only Mercury marine's but also the Volvo pentas. GM owns Volvo's heavy duty truck and marine divisions, kind of weird since the automotive division was bought by Ford a few years ago. Anyway, was looking on the 'net for 4.3 cranks and came across the part number for Volvo's marine 4.3 crank its 3858693-9. Check out http://www.stemtostern.com/ It costs over $1000 bucks!!! Doubt it's forged though.. They also show the Mercrusier crank at $750. Probably no different than the automotive part other than you can bend over boat owners more :-?

Thx Brad