Aftermarket Product Review Provide questions and answers about aftermarket parts for the Third Generation F-Body.

Eagle Forged Crank

Thread Tools
 
Search this Thread
 
Old Jan 6, 2002 | 11:50 AM
  #1  
Metalifann's Avatar
Thread Starter
Member
 
Joined: Mar 2000
Posts: 185
Likes: 0
From: Land O Lakes, FL USA
Eagle Forged Crank

Where is the cheapest place to get an Eagle forged crank for a 350? I know definately not summit or jegs. Also, whats the difference between 4130 and 4340 steel. I know one is stronger, but what other aspects are diferent and how much stronger is 4340?
Reply
Old Jan 8, 2002 | 01:43 PM
  #2  
Pony Killer's Avatar
Senior Member
 
Joined: Jul 1999
Posts: 726
Likes: 1
From: Atco, NJ, USA
Car: 1986 Z28
Engine: 355
Transmission: th400
i'm not sure wht summit or jegs charge, but the machine shop got mine for 400 bucks.

the differnce in 4130/4340 is the type of steel and the how it was forged.
4340 is a tougher steel, but generally not used on street motors because of the tolerances needed.

one of the things that make them stronger are the radia on the crank. wider the radia at the journals, the stronger the crank.

the 4130/4340 both have wide radia, with the 4340 being stronger,with a wider radia.

the problem is... you cannon run standard bearings on them, (p bearings) you must run H bearings.
The P bearings are more or less an oval shape, when torqued down, and keep the oil pressure up.

the H bearings are round, and generally run larger tolerances, but they will fit a crank with the wide radai. they are needed for these cranks.

Forgive me if i've spelled radia wrong every time, i just can't remember the latin suffix plural form of radius.... all that schooling gone to waste
Reply
Old Jan 8, 2002 | 07:06 PM
  #3  
Metalifann's Avatar
Thread Starter
Member
 
Joined: Mar 2000
Posts: 185
Likes: 0
From: Land O Lakes, FL USA
So for a street motor the 4130 is a better crank? I've already got the 2-piece forging connecting rods from eagle. I want the bottom end to be able to take whatever I throw at it.
Reply
Old Jan 8, 2002 | 07:50 PM
  #4  
Pony Killer's Avatar
Senior Member
 
Joined: Jul 1999
Posts: 726
Likes: 1
From: Atco, NJ, USA
Car: 1986 Z28
Engine: 355
Transmission: th400
yeah you can run the H bearings on the 4130 at street tolerances (tighter) and be Ok.

The crank will most likely be the last thing to break.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Falcon50
DFI and ECM
81
Aug 22, 2020 03:26 PM
RS Reaper
Electronics
4
Oct 17, 2018 07:52 PM
LT1Formula
Engine/Drivetrain/Suspension Parts for Sale
7
Oct 8, 2015 08:34 PM
skinny z
Engine/Drivetrain/Suspension Parts for Sale
5
Oct 5, 2015 06:23 PM
Badass355ciz28
Power Adders
4
Sep 28, 2015 08:31 PM




All times are GMT -5. The time now is 09:32 PM.