[JoePapa]

I need to get a crankshaft now too so this is good reading. I remember when the AllPontiac forging came out, several folks did metal tests on it and reported that it was a good forging - solid product. Has anyone done similar tests with the Ohio cranks and if so what were the results? Will these new forgings seal properly with a rope seal?


Thanks!

[T-Mac]

I called on the 3.25 main 4.250 stroke crank, they are all out.
He said that they were overwhelmed with calls for these cranks.

Sold out in one week!

Some of the Pontiac vendors have grabbed the bulk of them, so you might try them if you are interested.(and pay the mark up)

Todd

[screamingchief]

Maybe you could explain your rationale?

Simple enough,is it not easier to turn down the 3.75" stroke/pontiac rod journal crank to the BBC rod journal size if that's what you wanted?

Kinda hard to add material to the journal after the fact,is it not?

Rather than requiring those who desire a direct replacement sized crank for their existing combos change the rods and/or pistons to make the bbc journal crank work?

You say use the eagle 6.635" rod,that's fine,but either way you'll need to change something,either you'll need to open up the pontiac piston pin bores to use the .990" pins,or re-bush the brand new rods to use the pontiac .980" pins.

Lets see,cost of rods,machine work to pistons or rods,the crank itself,now I'm into the swap for well over a grand!

Maybe chump change to some of you,not for me!

I already have the pistons,I dont wanna mess with the rods,why turn your back on the basic stuff when it would be easier to make these 3.75" cranks the OE dimension first,and lets those looking to improve the package with the bbc journals change the crank themselves,after all is it not likely they'd be "cleaning up" these cranks dimensionally anyways,what is the big deal with those wanting the chevy journal having to turn down the rods to get that???

For somebody looking to just upgrade what they currently have to use the forging your telling them "tough luck cheapskate" and in my opinion that's just plain arrogant and extremely shortsighted.

I have 1 complete and 2 more "in-progress" 400 combos going together for the race car,and these use the off the shelf pieces,I have no desire to re-invent the wheel,just use these parts with as little grief as possible,cheap you say,damn skippy I reply,I have to be if I expect to get this car to track this decade,ask me that choice was extremely short sighted,and just plain boneheaded,no matter who is "spinning" that fact,and how much they argue their point.

I have zero need for the chevy journal 3.75" crank,but I would have been interested in at least two pontiac journal forged 3.75" cranks to begin with,and another one after the other motor(s) are together and I pull apart the first motor to update and refresh it,so already Ohio crank has lost four potential crank sales for those 3.75" stroke forged cranks by using that flawed logic.

I guarantee the forged 3.75" cranks sales will suffer for that logic and choice.

[455-4+1]

Originally Posted by screamingchief

Simple enough,is it not easier to turn down the 3.75" stroke/pontiac rod journal crank to the BBC rod journal size if that's what you wanted?

Kinda hard to add material to the journal after the fact,is it not?

Rather than requiring those who desire a direct replacement sized crank for their existing combos change the rods and/or pistons to make the bbc journal crank work?

You say use the eagle 6.635" rod,that's fine,but either way you'll need to change something,either you'll need to open up the pontiac piston pin bores to use the .990" pins,or re-bush the brand new rods to use the pontiac .980" pins.

Lets see,cost of rods,machine work to pistons or rods,the crank itself,now I'm into the swap for well over a grand!

Maybe chump change to some of you,not for me!

I already have the pistons,I dont wanna mess with the rods,why turn your back on the basic stuff when it would be easier to make these 3.75" cranks the OE dimension first,and lets those looking to improve the package with the bbc journals change the crank themselves,after all is it not likely they'd be "cleaning up" these cranks dimensionally anyways,what is the big deal with those wanting the chevy journal having to turn down the rods to get that???

For somebody looking to just upgrade what they currently have to use the forging your telling them "tough luck cheapskate" and in my opinion that's just plain arrogant and extremely shortsighted.

I have 1 complete and 2 more "in-progress" 400 combos going together for the race car,and these use the off the shelf pieces,I have no desire to re-invent the wheel,just use these parts with as little grief as possible,cheap you say,damn skippy I reply,I have to be if I expect to get this car to track this decade,ask me that choice was extremely short sighted,and just plain boneheaded,no matter who is "spinning" that fact,and how much they argue their point.

I have zero need for the chevy journal 3.75" crank,but I would have been interested in at least two pontiac journal forged 3.75" cranks to begin with,and another one after the other motor(s) are together and I pull apart the first motor to update and refresh it,so already Ohio crank has lost four potential crank sales for those 3.75" stroke forged cranks by using that flawed logic.

I guarantee the forged 3.75" cranks sales will suffer for that logic and choice.

Agree 100%. I was dissapointed when the first AP forgings didnt include a 3.75" crank
Then delighted when told Ohio had a 3.75" deal

Looks now like I am back in the dissapointed camp once again

I am releived at the end of every 60 second 6200 rpm full throttle run that my N crank has lived .

I would throw a 3.75" forging in that engine tomorrow, If I didnt have to replace my pistons and rods which have 6 meetings on them

Some people are restricted to cibe limits or CID/lb classes and there is a need for a stock replacement 400 crank.

Will the super Stock guys be able to run these cranks with the Chevy rod or do they have to be dimensionally "stock" ?????

[Jack Gifford]

Originally Posted by taff2

PontiacJack, the BOP forged cranks are made by Scat.

So... are they the inexpensive Chinese-made cranks?

[PONTIAC DUDE]

I don't understand?

The forged 3.75 crank is over $600 and people want to run a larger diameter rod and what piston?

[Mr. P-Body]

Ken,

I too, don't understand. Any engine that would use stock rods, or press-fit aftermarket rods, would be fine with the stock 400 crank. No 700-plus HP engine would use stock rods or pistons... No engine under 700 HP really NEEDS a forged crank. The stock crankshaft is the strongest piece inside a Pontiac V8. The forgings make high revvers do better... And yes, they're ALL "imported" forgings.

Jim

[JKrull66]

Originally Posted by T-Mac

I called on the 3.25 main 4.250 stroke crank, they are all out.
He said that they were overwhelmed with calls for these cranks.

Sold out in one week!

Some of the Pontiac vendors have grabbed the bulk of them, so you might try them if you are interested.(and pay the mark up)

Todd

They are also out of the 4.21 3.25 cranks
John

[Mo]

A few questions. What are the actual rod dimentions of the 3.75 crank? Their website states "pontiac journal".

I know there are 6.625 BBC rods with 2.20 rod ends. Will they work with the new crank? Is the problem with the small end? I think Spotty had a few crower sets for sale a while back. Any ideas? Thanks

[Mr. P-Body]

Mo,

The "Pontiac journal" would indicate 2.250" on the rod. BBC is 2.200". Pontiac pins are .9804" and BBC pins are .990".

Eagle has a rod they stock in volume, BBC journals, 6.635" C-C. That's .010" longer than stock, but that just means less to be decked...

Jim

[screamingchief]

No engine under 700 HP really NEEDS a forged crank.

That does'nt matter,what matters is what the owner WANTS...

What if a fella has a stock dimensioned 450-550 HP/NA 400 and sprays it with 175-200 HP (or more) of nitrous?

Would he not find some piece of mind with a forging???

And again why turn your back on that customer?

Especially for the sake of even fewer customers that are likely to build that "all out" sorta 3.75" stroke crank combo to begin with,when those guys could simply turn down a stock journal crank to get what they want for very little trouble.

Why not make the BBC journal an option on the stock pontiac rod journal and charge a small fee for that?

Just how many folks do you guys think are out there building 700HP with their 3.75" stroke combos compared to the "cheapskates" who build closer to 450-550 HP with their 3.75" combos?

If a fella were a suspicious type they may feel your stand on the subject is based on the theory you "machinist guys" might be affraid that cuts into your business?

That or ya'll have just lost touch entirely with that segment of the hobby...

Count them fellas,there have already been at least 5 cranks that could possibly have been sold if they used a stock journal here in this thread,and I'm sure there are alot more that would feel exactly the same way we do.

Eagle has a rod they stock in volume, BBC journals, 6.635" C-C. That's .010" longer than stock, but that just means less to be decked...

And what if I already have the rods?

What if I dont want to modify my pistons I already have for the .990" pins??

What if the combo has already been zero decked???

It's easy to "armchair quaterback" this debate when it's not your budgets bottom line that's at stake...

I know there are 6.625 BBC rods with 2.20 rod ends.

Do tell,,,where,,,who makes them???

I've yet to find anybody making a 6.625" long,2.20" rod journal,.980" pin rod yet,not from any vendor,and I've looked pretty damn hard.

The only rods I've found available like that would be custom built,and the cost is obviously more than "off the shelf" rods that are currently available.

If Spotts had them,he had them make a batch custom for him likely,I doubt they were "standard production" pieces,and they are'nt listed on his website,,,soooo...

If indeed rods like this were available at competitive prices,that alone might quiet the debate a bit.

But that still would'nt make a bit of difference with the motor that has the eagle rods in it now...

The logic is simple,you can take material off very easily,you cant put it back on...

Would you guys buy a bunch of 2' long 2x4's to build something that needs 8' or 10' long 2x4's???

I seriously doubt it.

[bobzdar]

Originally Posted by Mr. P-Body

Bobzdar,

What's wrong with improving geometry and durability? Eagle and others offer a BBC rod in a 6.635" length (plenty "close enough"). That .050" in rod journal diameter is the difference between an engine notorious for rod bearing issues (Pontiac) and one that is not (BBC).

I suppose I don't fully understand the "leave it alone" mentality when dealing with mid-level and high-end race engines. These cranks aren't exactly intended for "replacement" use, as there is no need for such a strong crankshaft under 700 HP.

Maybe you could explain your rationale?

Jim

Rules dictate I use stock geometries, cheap (thanks Baker, I knew I could count on you to shove your nose in where you can) when it comes to the cost of rods/pistons has nothing to do with it. It's also why I've been pushing for the raIV repro heads and would pony up the 50% up front if I could get 20 other people interested in ordering them - hardly cheap (unported originals hardly every show up for sale). I could probably get away with 6.635" rods...But I don't like 'cheating' however minor it might be. I suppose I could get rules clarification on if I could just run a smaller rod journal and be fine with the slightly longer rods, though I doubt they'd allow it if the car is faster than everyone else. Besided that, 6.625" gives about an ideal r/s ratio even if the rod journal is a little larger, though I don't anticipate an issue. If there were no geometry rules I'd be running a 4" stroke 6.8" rod combination; a 4.21" stroke (which would be legal as it was available in 2nd gen birds) is just way too much in friction and stress as you can't fit a rod long enough in it to relieve it, and it wouldn't be legal even if you could. I'm going road-racing, so I need the engine to live and not overheat or push the pistons out the side of the block or send shrapnel through the oil pan - hence also the desire for a forged crank. I hope that answers your question - I'd like the durability of the forged but can't modify the geometries.

[455-4+1]

Originally Posted by bobzdar

Rules dictate I use stock geometries, cheap (thanks Baker, I knew I could count on you to shove your nose in where you can) when it comes to the cost of rods/pistons has nothing to do with it. It's also why I've been pushing for the raIV repro heads and would pony up the 50% up front if I could get 20 other people interested in ordering them - hardly cheap (unported originals hardly every show up for sale). I could probably get away with 6.635" rods...But I don't like 'cheating' however minor it might be. I suppose I could get rules clarification on if I could just run a smaller rod journal and be fine with the slightly longer rods, though I doubt they'd allow it if the car is faster than everyone else. Besided that, 6.625" gives about an ideal r/s ratio even if the rod journal is a little larger, though I don't anticipate an issue. If there were no geometry rules I'd be running a 4" stroke 6.8" rod combination; a 4.21" stroke (which would be legal as it was available in 2nd gen birds) is just way too much in friction and stress as you can't fit a rod long enough in it to relieve it, and it wouldn't be legal even if you could. I'm going road-racing, so I need the engine to live and not overheat or push the pistons out the side of the block or send shrapnel through the oil pan - hence also the desire for a forged crank. I hope that answers your question - I'd like the durability of the forged but can't modify the geometries.

Seems fair enough to me. Not everyone out there wants more cubes for racing. In a street car or certain bracket deals etc go for it.

I would not build a 350 or a 400 (3.75" crank) for a street or bracket car if a 46X or bigger would cost the same. cubes per lb is a different story though

So is a dimensionally correct race engine

Dotto on the repro RAIV head. Where do I send my 50% deposit cheque (a cast iron head thats not 35 years old, cool??) Only problem I can see id people bleating about the devaluation of their hoarded iron head stocks.

Wonder if we will see a fire sale of "ready to run" iron heads being sold off if a better alternative come out on the market ???

Dude, if they arnt stock dimension 3.75" cranks your factory 400 ones should still be easy to move and very desireable.

As stated here they are good up to at least 700 horsepower right ?

And when speaking of "stock dimension" parts, I think we were meaning just that. "Stock parts " is a different story.

Why couldnt the crank be offered in "stock dimension" rods and turned for aftermarket Cheby if needed. 2 products out of the same bit of steel ?.

Not sure on the surface treatment but assume its done after initial machining ?

[Pontirag]

If you have two cranks sitting side by side and dont know which is which How do you know the difference between one crank and another. That is an American made one and an Asian one. Do you get material analysis documentation like melt and heat numbers. Are there specifications or what. No coin drop test please as some of these cranks are $2100 bucks and thats enough coin dropped already. how do you "take a sample" What size chunkage and from where.

[Tom Vaught]

The chunk I had analysed was about the size of a quarter and twice as thick. It was removed from the edge of one of the crank counter-weights. Bring some grease with you when you ask what it will cost to have the metal properly analysed.

Tom V.

[AG]

Tom V.,
Can you post the results of the analysis?

[Mr. P-Body]

Bob,

Okay. I'll buy the "class racing" thing. NHRA has some pretty strict rules, as well. So does NASCAR.

But there's still the bearing speed issue, and undersize bearings. As Ken said, you can always run your Pontiac rod on it, using a .050" under bearing, effectively killing the "rule" issue and gaining the benefits of the smaller journal and the forging.

We "machinist types" aren't worried a bit, about cutting into our profit. If you had any idea how little profit there is, in selling aftermarket performance parts from a machine shop, you would appreciate the irony in such a statement.

When it comes to crankshafts, if forged, you can ALWAYS add material. It's done every day. We shy away from cast cranks with welds, as the surface tension and grain are adversely affected by the process. But a good steel one? If done right, has zero ill effects.

Jim

[Brian Baker]

Originally Posted by bobzdar

Rules dictate I use stock geometries, cheap (thanks Baker, I knew I could count on you to shove your nose in where you can) when it comes to the cost of rods/pistons has nothing to do with it.

You're welcome! You do realize your situation is the exception to "the rule". What class/sanctioning body do you run in with these rules?

[Cliff R]

"When it comes to crankshafts, if forged, you can ALWAYS add material. It's done every day. We shy away from cast cranks with welds, as the surface tension and grain are adversely affected by the process. But a good steel one? If done right, has zero ill effects."

Jim, do you see any problems with adding some material to the counterweights of the cast cranks with nickle rod for balancer purposes?

We have also had quite a few "tightened" up at the thrust without any noticable ill effects (never broke one at the thrust journal, even on high HP applications) by welding them up and turning them down........Cliff

[screamingchief]

When it comes to crankshafts, if forged, you can ALWAYS add material. It's done every day. We shy away from cast cranks with welds, as the surface tension and grain are adversely affected by the process. But a good steel one? If done right, has zero ill effects.

It's still twice as much work as having those wanting the smaller journals would be required to go thru to get that journal size they want if these were offered in the standard journal size to begin with.

Is that such a hard concept to grasp here?

So let me get this totally straight,,,your telling me it makes more sense for a guy wanting a standard rod journal 3.75" stroke crank to have to take his brand friggin new forged crank in to get it welded up and reground,possibly straightened and re-indexed to get what he wants vs. asking the folks wanting the smaller rod journal to do a simple re-grind/turn down of the journals on the crank to get what they want???

By the time you spend the $$$$ to do that you might have just as well ordered a custom billet crank the way you want it to begin with...

Ask me that's just a$$-backwards,plain & simple.

There are plenty of standard rod journal engines out there that run hard with zero issues for doing so,,,are you guys trying to now tell me that every standard rod journal pontiac engine you guys ever built is a ticking time bomb for doing such???

Yeah,,,I did'nt think so...

I mean what would your customers think about that scenario?

And I dont really care that much for the idea to use Dude's "double top secret/extra special" rod bearings he says he has for this sorta application,flawed logic is still flawed logic no matter what spin is put on it,JMO/FWIW.

I'd bet $$$$ these 3.75" cranks wont sell that well at all with the bbc journals,and likely will be the first crank offering they either dump entirely,or end up having to offer them with the standard journals to get more sales.