4.750 4340 crank

At PRI, I thought Scat was coming out with a new 4.750 4340 crank for the 460.  I called them and they know nothing about it.

Was it Scat or someone else?

Lem knows

I heard that they were too.

Scat 4.750" = Billet.

4-460-4750-6700-220 4340 Pro Comp Light Weight and in Super light

Found it on their online catalog.

Callies also do a 4.750" crank.

http://www.callies.com/crankshafts/magnum/magnum-ford-460/

hienergy557 wrote:Callies also do a 4.750" crank.

http://www.callies.com/crankshafts/magnum/magnum-ford-460/

Correct....I've sold a few.

Is there a point where increasing the stroke will diminish gains due to bad rod ratio?

We have had some forged cranks available from non us suppliers for some time now. Is there any feedback on serviceability on these units? Good luck not so good?

Thx

Tom

747JetMech wrote:Is there a point where increasing the stroke will diminish gains due to bad rod ratio?

We have had some forged cranks available from non us suppliers for some time now. Is there any feedback on serviceability on these units? Good luck not so good?

Thx

Tom

Just what do you call Bad Rod Ratio? and whom said it is good or bad?

I remember reading something in Smokey Yunick book quit some time ago... Over 10 years ago..

Tom

747JetMech wrote:I remember reading something in Smokey Yunick book quit some time ago... Over 10 years ago..

Tom

ok now forget what you read, Rod Ratio, it is what it is just a ratio, .the Rod serves a purpose it connects the Piston to the crank, it takes a lot of stress. but there is no proof good or bad, it is just a word a lot of people throw around, and the Chebby guys like the word evidently. I have ask this question to 100s of chevy and ford guys and no one can explain what a good or bad Ratio is and how they came to the conclusion it was either....

I asked and was told not to concern myself with that stuff.

747JetMech wrote:I remember reading something in Smokey Yunick book quit some time ago... Over 10 years ago..

Tom

That was back in the day when cylinder heads needed as much help as they could get because a higher rod/stroke ratio makes cylinder demand less near the top half of the stroke.
With the air flow capability of heads today, it is almost easy to get enough air flow for the combination.

I agree, the modern cyl. heads make something like a 632" engine more viable than it would have been decades ago.

The small negitives of a 4.750" stroke and a 6.700" rod are greatly offset by the advantage of the extra displacement.

Thanks guys for answering my question.

Tom

Lem Evans wrote:I agree, the modern cyl. heads make something like a 632" engine more viable than it would have been decades ago.

The small negitives of a 4.750" stroke and a 6.700" rod are greatly offset by the advantage of the extra displacement.

Hey Lem, how about in nitrous applications? I've been reading where guys are moving away from the 4.750 to the 4.500 cranks, is this because of the pin placement in relation to the rings?

68formalGT wrote:

Lem Evans wrote:I agree, the modern cyl. heads make something like a 632" engine more viable than it would have been decades ago.

The small negitives of a 4.750" stroke and a 6.700" rod are greatly offset by the advantage of the extra displacement.

Hey Lem, how about in nitrous applications? I've been reading where guys are moving away from the 4.750 to the 4.500 cranks, is this because of the pin placement in relation to the rings?

That's not the case locally.....then again the tall bbc block is .100" shorter....so maybe they have an issue.

Lem Evans wrote:

68formalGT wrote:

Lem Evans wrote:I agree, the modern cyl. heads make something like a 632" engine more viable than it would have been decades ago.

The small negitives of a 4.750" stroke and a 6.700" rod are greatly offset by the advantage of the extra displacement.

Hey Lem, how about in nitrous applications? I've been reading where guys are moving away from the 4.750 to the 4.500 cranks, is this because of the pin placement in relation to the rings?

That's not the case locally.....then again the tall bbc block is .100" shorter....so maybe they have an issue.

That makes sense, thanks Lem.