Eagle 4140 crankshaft
- Thread starter 434nova
- Start date
- Joined
- May 26, 2001
You are correct Jerryl, the production block will give up long before the Eagle 4140 crank!
The Granny
Active Member
- Joined
- Sep 30, 2015
i think the OP is thinking about this crank for another block, he's been posting threads looking for 4.1 or stage 2 blocks
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- Joined
- May 26, 2001
I have not perfected the art of reading someone's mind, especially with a keyboard?
A production 4.1 block is no stronger than a 109 block.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Instead of goofing around here, call an experienced vendor and tell them your goals. Have them build an engine to meet them. There are 109 blocks running 9s all day and 109 blocks failing running 12s. All depends on combo and tune. A few have figured it out. Pay them for their knowledge. Either way don't expect a high hp engine to last without meticulous attention to the tune and supporting actors. I've watched rears blow, trans fail, fuel pumps fade, and a host of non engine items ruin the day. Oh bring you wallet too. Wouldn't expect the build to be anything short of 20k to make low 9 second power.
434nova
Active Member
- Joined
- Sep 30, 2013
I agree with you pronto that it will cost 20k for a build. Shit my 109 build cost around 10,000 and that was 15 years ago. But im just looking for real world results on actual users to a eagle crank. Isnt this a techincial forum? If we all just picked up the phone and called vendors then there wouldnt be a need for this board. I learned alot from the tech sections.
434nova
Active Member
- Joined
- Sep 30, 2013
What 4340 crankshaft are you using in the 3.625 stroke? Arent all the eagles 4140? Im running 133 now with a stock crank.
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
The Granny
Active Member
- Joined
- Sep 30, 2015
How much power are you planning on making with your next build?
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- Joined
- Feb 18, 2006
Years ago I cracked a 109 block up one of the webs. That motor had a eagle crank. I took the rotating assemble out and put it in another 109. Still running to this day. 
You don't hear a lot about Eagle cranks failing.
You don't hear a lot about Eagle cranks failing.
Is the crank a 4140?Years ago I cracked a 109 block up one of the webs. That motor had a eagle crank. I took the rotating assemble out and put it in another 109. Still running to this day.
You don't hear a lot about Eagle cranks failing.
Do you have a 4140 in your personal stock block 4.1 stroker or your stage 2 4.1 stroker?
- Joined
- Feb 18, 2006
Considering it was a much earlier model, it could have been 4340. I can't say with 100% certainty. Still I haven't heard anything bad about the 4140s. More recently I built a couple engines with 4140's and so far so good. They are in the 700-800hp range.
You gonna bracket race or?
Rick
You gonna bracket race or?
Rick
marleyskater420
still needs to learn
- Joined
- Aug 14, 2004
Rick,
I believe the earlier Eagle cranks were 4340. The more recent ones were 4140.
I don't have any personal experience with either Eagle crank. Only information from builders I have spoke with, and depending on who you talk to, or what their bias may be, I have heard comments from a few people about getting the Eagle 4140 cranks to neutral balance being a difficulty and requiring a fair amount of material in order to work.
However please keep in mind this is not my personal experience, this is from engine builders that I have spoken with about these cranks. Please keep in mind that not every builder said this, and people do have their biases, for whatever reason.
