EAGLE crank and rod update

[John Wilde]

These cranks ar forged and not billet.
A billet crank is between $1900 and $2500 depending on options.
I was considering waiting on one of these and not picking up a $2200 Crower Billet for a future stage 2 project.

 

[TRBON8R]

Pardon my ignorance but how does a forging differ from billet? I thought they were one in the same?

 

[John Wilde]

Forged is a process were the metal is heated up an then formed into the shape. Billet is a solid metal bar that is machined to the final shape. The billet has less chances for inperfections and all surfaces are machined. I am sure someone with a lot more knowledge can go into the specifcs. I have heard that some cranks start out as a 100lbs metal bar.

 

[86brick]

http://victorylibrary.com/mopar/billet-c.htm

This is a good little article on the differences of Cast, Forged, and Billet........

 

[ijames]

Absolutely. The fact that they're going to come right out with a 3.59" unit tells me they're going right after the <250" folks.

Funny, isn't that the CI limit in TSM?

Looks to me like they are also going after the TA performance block 270 cu in folks, since those blocks can be machined to accept stock cranks . Either way, we win by having a new source of parts.

 

[86brick]

Originally posted by ijames
Looks to me like they are also going after the TA performance block 270 cu in folks, since those blocks can be machined to accept stock cranks . Either way, we win by having a new source of parts.

Very good point Carl!

 

[Nick Micale]

Originally posted by ijames
Looks to me like they are also going after the TA performance block 270 cu in folks, since those blocks can be machined to accept stock cranks . ......

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The TA block accepts a stock crank w/o being machined.

The Eagle crank may not be a direct drop-in for either a stock block or TA block? Will not know for sure until we have one in hand. Their other cranks usually require some work when installing, as do the BMS forged cranks in a stock block.

 

[GNSCOTT]

The Eagle crank may not be a direct drop-in for either a stock block or TA block? Will not know for sure until we have one in hand. Their other cranks usually require some work when installing, as do the BMS forged cranks in a stock block.

Shouldn't it be a direct bolt in if they are using a stock TR crank as their guide??

 

[QuickWrench]

I wonder if this type of crank will be allowed in all of the GSCA classes (TSS, TSM, etc.)?

None of the GSCA classes place limits on the reciprocating assembly pieces; they simply establish a cubic inch limit.

Shouldn't it be a direct bolt in if they are using a stock TR crank as their guide??

I doubt that Eagle would use the stock unit as a guide for much of anything, especially where the counterweights are concerned.

 

[ijames]

Nick, I thought that most billet and bms cranks for stage II blocks used a big block chevy rear main seal, instead of the stock size, and that you could get the ta block machined for either one, and I was assuming that most of the early ta blocks would be set up for the bbc seal to match the available cranks. I didn't mean that any extra machining would be required by ta, just a difference choice when the block was ordered. Am I wrong about the majority of cranks used in stage II motors these days? Of course, you are right that we will have to wait and see what the counterweights look like, to know where they will fit and how much clearancing will be needed.

 

[Scott231]

Originally posted by QuickWrench
<snip>they're going right after the <250" folks.

Funny, isn't that the CI limit in TSM?

We chose that as the limit in TSM for 2 primary reasons:

1. A stock block does not readily (literally?) accept a crank larger than 3.59"and bores larger than .030" over are not wise.
2. We had to allow the 4.1L motors in their STOCK bore & stroke configuration as those were factory stock motors back in '81-'84(?) which fits the general rule of "Factory Stock Appearing". (Note - anyone that shows up with a 4.1L block in TSM will be measured during tech!)
   [/list=1]

 

[Scott231]

Originally posted by John Wilde
I was considering waiting on one of these and not picking up a $2200 Crower Billet for a future stage 2 project.

John - I have never dealt with Stage 2 TR equipment, but why would you want to put a narrow-journal crank into a Stage Motor?

FYI - It is my understanding that what Eagle will produce will be narrow journal crankshafts.

 

[John Wilde]

Scott,

I was thinking that they would have 2 versions.
Would it be that difficult to make the wide version after
all the work on the narrow?

 

[ijames]

Nick, am I right or wrong about the bbc rear main seal requiring different machining of the block? What are the guys buying the early TA blocks specifying? Inquiring minds want to know .

 

[Two Lane]

Originally posted by John Wilde


I was thinking that they would have 2 versions.

Would it be that difficult to make the wide version after
all the work on the narrow?

Probably not so difficult to do, but unfortunately from an economic point of view, how many would they ever sell?

 

[Nick Micale]

Originally posted by ijames
Nick, am I right or wrong about the bbc rear main seal requiring different machining of the block? What are the guys buying the early TA blocks specifying? Inquiring minds want to know .

All TA blocks have been designed and machined for the BBC rear main seal.

 

[TRBON8R]

Originally posted by Nick Micale
All TA blocks have been designed and machined for the BBC rear main seal.

Since the subject of the TA blocks has already come up............ Sorry to take this slightly off topic, but when talking about the new cranks it is only natural to segue into talking about the TA blocks. Nick, do any of the AZ cars have a TA block installed and running yet? If so can you elaborate on the buildup and combination used? Like I said, sorry to go a bit off topic but I think we are all hoping this new crank will be a perfect match for the TA block. Nick, if you feel the need feel free to make my post a new thread.

 

[Mease Performance]

forging vs billet

a forging is indeed stronger by nature as compared to a billet piece, in a billet piece, the grain/aka stress structure is a straight pattern along the length of the crank, they are machined from forged "billets" but the grain structure does not follow the throws of the crank once they are machined into place....

In a forging, tooling used to forge the crank actually creates its own grain structure for the material...and also the amount of force applied can bring the grain density closer which results in s stronger piece....forged cranks 4340's are stronger than billets, if you look at how a billet crank breaks (if you've ever seen any broken Top Fuel parts) you would notice that it is a clean break with an (for the most part) even grain structure....when a forging breaks, you will notice that the grain structure is much different.....when a CAST crank breaks, it can have a very erratic grain structure since the molten material was simply "poured" into place.... Also in a "no-twist" forging tooling companies will usually opt to create a grain structure that spirals in the reverse rotation of useage, which also results in a stronger "no twist" finished part!

I believe the single most important key in a well built buick engine is NOT the engine itself, but the tuning, ignition, and fuel system used to run it....it doesnt matter what kind of block, crank, and rods you have, if it isnt tuned properly, you are going to break your $6000 shortblock! a stock crank will handle 650hp, some push them, and some dont, either way they can break if not tuned properly...so can your block..... The block is about as weak as the stock crankshaft, maybe with the crank being favored slightly since the mains on a stock block were originally designed to withstand a whopping 110HP N/A regal.......main threads and caps are very weak as well as the skirts......if you decide to go with one of these cranks, opt for full balancing of the rotating assembly, and either billet center caps or an RJC girdle, we have had very good luck with both!

Good luck to all and glad to hear the good news, Eagle manufactures excellent parts for the price range, but remember, you SHOULD NOT install ANY ENGINE parts without being checked by a renowned machinist, we would also reccomend magnafluxing on all components new OR used....

 

[Nick Micale]

Originally posted by TRBON8R
Since the subject of the TA blocks has already come up............ Sorry to take this slightly off topic, but when talking about the new cranks it is only natural to segue into talking about the TA blocks. Nick, do any of the AZ cars have a TA block installed and running yet? ......

TA is now assembling an alum motor for a local racer. When I have this installed, will certainly post the results.

 

[panic]

Billet vs. forged

That link (http://victorylibrary.com/mopar/billet-c.htm)
is on my site, but I only editted it - the credit goes to Bob Powers, a great Oldsmobile enthusiast. Here's his own site:
http://www.robertpowersmotorsports.com/Technical_Info.html