5 main blocks

[johnneilson]

I have looked at a few cast 5 bearing cranks around.
This makes complete sense for 98% of the applications.

I will ask around, I seem to remember coming across the patterns and core boxes.

That is about the going price for billet cranks, I think Moldex was little less.
I have not tried Marine Crankshaft in SoCal, I have seen a couple repairs, nice work.

John

[FRANK PKNY]

Hay Todd I just looked at the videos! Great work, I can't wait to see production start. I wonder how much a OHV set up would be all done? Less assembly. If I could swing it I'd love to have one.

[Tod]

Originally Posted by johnneilson

I have looked at a few cast 5 bearing cranks around.
This makes complete sense for 98% of the applications.

I will ask around, I seem to remember coming across the patterns and core boxes.

That is about the going price for billet cranks, I think Moldex was little less.
I have not tried Marine Crankshaft in SoCal, I have seen a couple repairs, nice work.

John

I won't need a pattern and core boxes. What I need are specs, though. What exact steel to make them.

Tod

[Dodge]

Crower makes the 5 main cranks that a lot of the Bonneville guys are running in their 4 bangers.

[Tod]

Originally Posted by Dodge

Crower makes the 5 main cranks that a lot of the Bonneville guys are running in their 4 bangers.

Price?

Tod

[johnneilson]

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Something to also consider are the rods.
Afterall, going to 5 mains and extending the usable rpm of the motor will require better rods. These will have to be much narrower than stock (bearing).
The bores at each end of the motor are spaced 4.250 CL, placing a bearing between them of 1.0 width means that you are taking away quite a bit of dimension. Especially since the crank will require two separate cheeks (offsets) for the throws. This is not impossible, but consider the rods will need to be less than 1" wide at the crank.
The obvious answer is to go larger in diameter on the rod journal on the crank for more area. (surface speed is not issue if adequate oil press/feed)
Doing this will possibly cause cam clearance issues. Nothing here is impossible, it just takes some work.

Yes, Crower does make cranks and rods. I know of a couple running SCTA.
FWIW, they are all about the same price range, if one is very much less, I would not trust it. The physical dimensions are relative and the amount of material removed is the same.

There was a cast crank made some years ago, iron, meehanite. (3 bearing) Very soft and flexible, it worked fine in flathead configurations, not so much in overheads.

J

[Dan McEachern]

I believe that Donovan put quite a bit of effort into producing a cast 5 main crankshaft and finally abandoned the effort due to problems getting flaw free castings. This was back when they started offering the D block, so technology may have changed in 20 or so years.

[hardtimes]

Originally Posted by Tod

Price?

Tod

Hey Tod,
Email sent details on crankshaft (Crower) pricing question.
NOTE:
Crower of San Diego (619) 6616477 spoke with me today , answering questions regarding making a 5 main crank to work with new 5 main 4 cyl blk.

Specialty order #95204;
Price: $2850 ea, whether single or multiple order;
Material: 4340 machined billet steel;
Info needed: main bearing journal spacing, cylinder bore spacing and main bearing useage (size/type of main bearing to be used, i.e.- chev, etc).

He (Peter) stated that he has made 5 main cranks for ford 4 cyl blocks, for those (racers/others) who have installed 5 main bearings in the ford 3 bearing blocks.
He also stated that it would make sense to use whatever modern commonly available parts , when planning to use the crank that he makes.

Please feel free to comment and/or add info that you have which may help in this matter.

[waxhead]

Good work Rick.

[hardtimes]

Originally Posted by waxhead

Good work Rick.

Thanks.
I tried to 'whittle' him down for a batch price. I suppose that he knows that 4340 Billet is a high grade crank, therefor no give pricewise. This quality of crank is racer ready, IMO. But, maybe our quality / needs are not so high ? Don't know.

This is a good starting point , at least, for a crank search. No doubt prices will vary depending on a number of factors.

As was said earlier in this thread, maybe cast iron with 'right' mixture would be more than sufficient for our job. That's why I asked for those who know metallurgy/crank making to step up with their knowledge/opinions , to use as guide also.

FWIW file:
I have run a cast iron drilled full size B crank (Dan Eubanks) for 15 or so years. The B still runs strong. Running Crower rods also.
However, I can not say that I have run this B crank over 4K rpm for any length of time. Maybe someone who has more experience and has run such cast iron crank harder can say what they know of its durability ?

[Tod]

Originally Posted by hardtimes

Thanks.
I tried to 'whittle' him down for a batch price. I suppose that he knows that 4340 Billet is a high grade crank, therefor no give pricewise. This quality of crank is racer ready, IMO. But, maybe our quality / needs are not so high ? Don't know.

This is a good starting point , at least, for a crank search. No doubt prices will vary depending on a number of factors.

As was said earlier in this thread, maybe cast iron with 'right' mixture would be more than sufficient for our job. That's why I asked for those who know metallurgy/crank making to step up with their knowledge/opinions , to use as guide also.

FWIW file:
I have run a cast iron drilled full size B crank (Dan Eubanks) for 15 or so years. The B still runs strong. Running Crower rods also.
However, I can not say that I have run this B crank over 4K rpm for any length of time. Maybe someone who has more experience and has run such cast iron crank harder can say what they know of its durability ?

I doubt there will be a batch discount since 1) the parts are individually made, 2) there will not be very many 5 main blocks made (I see the market as mainly the 3 main stock A type iron blocks), 3) there is no way to take time out of the manufacturing process, as there is in casting several at a time.

Back in the late 90s/early 2000s, I made a cast crank for the new Genesis 427 side-oiler project I was doing for Genesis. If a cast crank was good enough for that I find it hard to believe that a cast crank would not suffice for the low HP Model A application.

Terry Burtz cast a 5 main crank and nobody seems to consider asking him to buy a casting and see if Crower or Scat can machine it. I haven't leaned that direction since I can make a casting without a pattern and am in the process of beginning to set up my own foundry. I can make my own casting.

Tod

[Dodge]

Why not ask Tom Lieb at Scat why they made their A & B crankshafts a forging instead of a casting. They make so many cast cranks you would think they would have made a cast one instead of a forging if were feasible as cost is definitely a factor in selling to this market.

[Tod]

Originally Posted by Dodge

Why not ask Tom Lieb at Scat why they made their A & B crankshafts a forging instead of a casting. They make so many cast cranks you would think they would have made a cast one instead of a forging if were feasible as cost is definitely a factor in selling to this market.

My opinion (OPINION) - 1) forging will make a better part. 2) enough quantities will pay for the forging die. 3) the 3 main will hold up better in the long run as a forging. 4) a cast crank with 5 mains has better support than with three mains. 5) they will never recover their investment making a forged 5 main A crank. 6) I doubt they would invest in tooling to cast a 5 main A crank (too low of volume). 7) MAYBE they would machine a cast 5 main if I supply the casting. I have not discussed this with either Crower or SCAT since I don't even have the blocks cast yet (aside from one in aluminum).

Tod

[hardtimes]

Originally Posted by Dodge

Why not ask Tom Lieb at Scat why they made their A & B crankshafts a forging instead of a casting. They make so many cast cranks you would think they would have made a cast one instead of a forging if were feasible as cost is definitely a factor in selling to this market.

Hey Dodge,
Not wanting to get into raining on anyone's ideas, but I will say that personally, I would never pay a couple grand for and/or put ANY crank into a warmed up engine (A or B) where the crank has been made with A size rod journals.

Your outcome may vary with such usage in a stock/touring A. But, we are talking of putting MORE hp into the new B 5x5 block and a full sized B drilled crank (cast or forged) is called for. Cast iron crank can be made very strong using a more expensive process (chrome/Nichol mix). This , of course, will be more expensive and that is where these makers draw the line....if large quantity orders are not expected.

No doubt , Tod can make the necessary B cranks for use in his 5x5 blocks. When you run any business, I think that the same economic rules (supply/demand) apply ? He is not in business to lose money. I would buy a crank from Tod, if he were to find a way to provide/make such.