Bets are on: Is 3.6L/221 crank forged steel?

xctasy

xctasy

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Just want to get some feed back. I was told by my machinist that the 3.6 litre, 221 cubic inch displacement I6 had a drop forged or twist forged steel crank. Bill Mann Performance (does he, or his company still exist?) from Brisbane gave a write up to Noel Tuckey from Street Machine in page 99 of September 1991, and they both stated the 3.6 crank was steel, not cast nodular iron. Others on this forum doubt it very much. At the moment, I'm not prepared to drill the flange and check the cuttings of my worked 221 crank, which is sitting under my house. From that, you can see if its steel or cast because of the differences in swarf.

My crank has the same code numbers on it as the 1991 Street Machine artical crank, namely:-

1.221 embosed on the crank between cylinder 2 and 3,

2.ARC80E/6303A on the forth cylinders crank pin throw

3. and 5C punched on the flange adjacent the throw of the 5 th cylinder.

Any one with experience in these cranks know for sure?
 
Bill Mann now owns or has something to do with Performance Wholesale in Slacks Creek Brisbane.

The 221 crank is suposedly much stronger than the 250 crank. I don't know if it because it is steel. John Patrick of Turbo supplies has a 221 twin turbo engine that he built for a drag car some 15 or more years ago. He was explaining to me that the crank is much stronger and perfect for turbo engines.

The extra strength is largely to do with the fact that the stroke is shorter hence the big end journal overlaps the main journal when the crank is viewed from its end in section. This means the web between the main journal and the big end is much stiffer. 250 engines have a serious harmonic problem when you try to rev them past 5500rpm, especially on a turbo engine.

The only problem with the 221 crank is you need to use the old rope seal type blocks. The late XF or OHC blocks are stronger and have the updated rubber lip seals which make them much nicer. I have always wanted to investigate getting the 221 crank into the lip seal blocks.

I think a 221 crank fitted in a 250 block with long rods and good pistons would be good for huge power!
 
would there be a notable difference in crank density vis a vis nodular iron versus forged steel?

ie EUREKA??
 
NO
if the 221 crank was forged it wouldnt have any raised numbers such as the forging #.
Yes they may be marginaly stronger than a 2560ci crank because of the overlap, but what of the later 200 large journal, which would have considerably more.
A7M
 
Crank looks like a drop forging which has been twisted by some industrial machines to me. You're thinking what I'm thinking Aussie 7mains. But they are huge letters over 25 mm tall. Ever seen a drop forged vanadim tool set with raised words on it...I have!

Oh, and when I was into Holdens, even a 149 steel crank was heavier than a cast 186 crank by 6 kgs.
 
Take a picture, it'll last longer (I'll host it for you if you dont know how / dont have the space, etc) :D
 
aussie7mains":1rmm2g1p said:
Yes they may be marginaly stronger than a 2560ci crank because of the overlap, but what of the later 200 large journal, which would have considerably more.
A7M
Click to expand...
But the 200 has 21 less ci.
Is it possible to fit a pre x-flow crank into a x-flow block? If so, you might be able to fit a 221 crank into a 4.1 block (you would at least have to enlarge the rear main bearing), and have the rod ratio, have the breathing, have EFI, alloy head (higher comp), have a decent rocker system, and better tranny options (I think - not sure), as well as TURBO!!

There was a person who posted a few years back saying he fitted a 221 crank to a 250 - can't remember if it was x-flow or not - but he had to enlarge the rear bearing to the 250 size.
 
yes Ive thought of this, even tried it, the OD of 221 mains bearing shells, just happens to be the OD of the 250 crank so you should be able to use two sets of bearing to use the 221 crank in the 200/250 block (yes pre crossflows and crossflow 250s have same crank and rods).
But WHY, you get get a favourable rod ratio by useing 200 rods in the 250 with special ACL pistons, then the thing will rev better anyway, stop worrying about the stoke, the OHC has the same stroke and its revs up just fine.
If your REALLY seroius about ultimate revs and BHP then use the crossflow 200 with the rod ratio of 2;1, stick a couple of turbos on the thing , 850bhp, just prior to blow up.
A7M
 
1.Sounds yummy to me. Theres little doubt that a crank with a 79.4 stroke and 159 mm rods is the best option for hauling some revs. Clearly, the shorter the sroke, the better the overlap. Just the reason little trashed 144 cube sixes never broke cranks with only 4 main bearings..because it had a 63.5mm stroke.

2. Only problem is, I've already sunk a pit load into my 221 crank. After doing all the procurement of forged 305 pistons (decked 56 thou,), rods (bead blasted 3.3 Falcon rods, reamed 15 thou to fit the Chevy wrist pin), and cranks(welded mains to suit the 250 bearing size, rebalanced to suit the heavier rods and 250 harmonic balancer and stock flexplate), I have to agree that a 200 cross flow is a better, more cost effective setup. I'd rather spend $1000 odd bucks on a turbo, than more on forged pistons. But whats done is done.

3. Just look at the January2003 Street Machine magazine, with an EFI turbo'd 3.3 XU1 ACL pistons, and 400 rear wheel ponies. GTS 300 drivers would get upset if my XE got away like that 9.92 second ET T'rana!

4.I have no web site space at the moment, but I'll post a picture tomorrow of the "supposedly" steel crank I use. I may even phone Performance Wholesale in Slacks Creek Brisbane, and see if Bill Mann, the old stroker 235 Holden man who did 60 stroker 221 cranks, is about. Excuse me if I'm like a dog with a bone, but I gotta know the good oil!
 
I await the picture eagerly. Sounds interesting, a forged crank would be better than cast, thats for sure.

Good to see you're so dogmatic about this :D
 
ruff, ruff. They used to call me Alsation at the gold mine I worked at in the early 1990's. I can get cranky too.
 
Ok, here is the photos of a crank just like mine. When I get my work digital camera fixed, I'll get a picture of my crank.


Falcon_221_Forged_Steel_Crank.jpg



Ford_221_Forged_Steel_Crank_%23101.jpg
 
When changing the cam in the 221 ages ago, I remember noticing that the threads in the front of the crank (for the harmonic balancer keeper bolt) were not clean cut at all. They looked very daggy and torn .. sort of. Could this indicate that it is actually steel or would it be the same deal for cast iron?

Also would it be feasible to perform a density test of the crank? surely a cast iron one would be a different weight to steel?

XECUTE, are those pics from a really old Street Machine?
 
Hey XT 500, the following right back at ya!

I've done no samples or density tests, and my materials manual is under the house with my engine block. I think the difference between spheroidical grain cast iron and steel is about 2% on its bulk density. Most of the extra weight of a steel crank comes from the blanking process which wastes a lot of metal compared to a fairly lean sand casting process

1.Street Machine is pivitol in me being a petrol head!

2. The pics are from a mid 1990 Street Machine write up. It stated categorically that 221 cranks were steel. It, and another article around the same time included crucial information from ex Ford Special Vehicles man BillSantuccione on the evils of long stroke, short rod 250's. This all got me into making up a new hybrid cross flow 250 with post '70 200/3.3 Oz rods and this 221 Oz/Argie crank. I strongly adavocate long rod engines, but only if its cost effective. So far, its not proven to be so...

3. A while back Adam talked about the cuttings from a drilled hole in a steel crank showing different swarf to those of a cast crank. Test I did on the flywheel flange show it to be a drop forged crank. The normal SGI cast iron is very forgiving in comparison to a steel crank. Steel tends to dagg up on the threads and cast iron is much better to machine. I can't remember what happens to the carbon level, but steel cranks are more likely to snap when bent, but don't fatigue like cast ones do.

4. My machinist said the 221 crank was steel when he long run welded the mains up to 250 size and reworked the fillet radius; but I'm not sure Ford Australia would have invested in a drop forge for stamping steel cranks in the Geelong plant and then gone to iron castings afterwards. So I'm picking that the South Americans must have done the raw forging and this is what Ford Oz used?
 
hmm steel crank ... 8)
well i run a 221 3.6 in my supercharged / turboed hotrod and dam ive given it a flogen but really carnt tell u guys if it is steel or not?
ive got a mate with a fj ute and a stroked 186 turbo(with the 221 crank) and plenty of mods to go with it ...it runs a good 450Hp at the wheels and is constantly reving to 7000/7500rpm alot and never given any trouble..except for blown head gaskets!!!(well u get that when u run 22+psi boost....lol

cheers Rod
 
Thats a cast crank, no way is it forged, if it was it would have the typical forging lines, where the dies part in the process, they arent there.
The crank is nicely finished as are all the falcon cranks, and Ive seen loads of 200 and 250 cranks with raised letters like that, so that nothing, in fact to get square corners like that you would need casting techniques.
The cranks were always castnodular, which can be welded and in fact is a better material for cranks than steel, it gives a better serface finish due to the extra carbon.
The definiitive answer will be by doing a micro analysis, an then youll be able to see the carbon nodules in the microstructure.
As to strength, they would always be stronger than the old RED as they have a much larger main an pin journal.
A7M
 
Yay!

I think you are right Aussie7Mains! You've been patient while i've been on my crank crusade!

I think I've thrashed the horse and ended up cast and cranky!

You want me do take a payout in someway, brother? Adam wants me to eat my shoe laces with sauce for claiming an OHC 3.9/4.0 will fit in an early 1960-1965 without spring tower braces getting hit. I'm getting used to not always bein' right now!

What I'm amazed about is how a welded up, cut-down cast 221 crank with pin journals turned down to 1.9 inches from 2.126 inches, and crank journals down to 2.2 from 2.3 inches could handle a 1.425:1 rod ratio Red Holden engine block without crapping itself!
 
If I'd seen those pictures, I would have said "cast", straight away. You have dismembered another urban myth. :eek:

I respect perseverance/dedication no end. Treat yourself to an extra serve of chps and another whitebait frttr. ;)

Cheers, Adam.
 
Xecute.
The Mere fact that youve admitted error is sufficient, no shoelace eating will be needed! LOL
As ive said as far as I know NO Aussie ford ever had a steel crank, and why would a 221 need one? Anyway as to welding cast iron, its obvoius that it can be done, but remember that cast NODULAR is a far cry from grey cast iron.
Anyway that settled we move on to something else.
Seeya
A7M
 
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