Eagle 4340 forged 383 crank
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Eagle 4340 forged 383 crank
Jags catalog got sbc w/ 1 piece rear main seal forged crank 3.75 stroke sell for $ 679. Any one of you have any bad experience about this crank? Will this crank work on my 1993 LT1 motor???? I just want to learn more about this now before I order it for the up coming Spring to build up low compression 383ci going to Force Induction. As for Rods. I will go with Eagle ESP forged 6 inch H beam rods. But why one say smll journal and other is large journal. The question is which one is the right one for my LT1 motor? I appreciate if anyone here can tell me the differences.
Bruce
93LT1 Con w/ZF6
top end mods
Jetted 150hp NX
Bruce
93LT1 Con w/ZF6
top end mods
Jetted 150hp NX
Burning Brakes
Joined: Nov 2001
Posts: 1,189
Likes: 2
From: Austin TX
Re: Eagle 4340 forged 383 crank (Bruce)
Small block Chevy engines up through '67 had 2.0" diameter rod journals. These are known as the "small journals". Beginning in '68 Chevy went to 2.1" diameter journals (large journals) in order to maintain adequate overlap between the main and rod journals (for strength in the crankshaft) when they developed the 350, which at the time was the longest stroke SBC they had built.
You want the large journal rods.
Dan
You want the large journal rods.
Dan
Drifting
Joined: Aug 2001
Posts: 1,606
Likes: 14
From: Vacaville, CA
Re: Eagle 4340 forged 383 crank (Bruce)
Almost all cranks today are forged in China except for a few high dollar names such as Callies, Lunati, and Crower. They are shipped as rough castings and then machined in the U.S. These crankshafts are perfectly fine for street use. Most dirt track / circle track racers use these cranks up to 7,000 RPM without any problems whatsoever. There philosophy is that they can buy three for the price of one of the name brand cranks and since they rebuild there motors annually, why not. As far as a street 383 you can get away fine with even a cast crank, but you might as well spend the extra $300 to go with a 4340 forging. I have seen the strength comparisons between cast, 5140 forgings, and 4340 forgings and there is a huge difference between the cast and either forged type, but negligible difference between the 5140 & 4340 forgings; (4340 is the strongest, not including billet material). I used an Eagle 4340 crank in my 383 but opted for Manley 4340 H-beam long rods. The weakest link in your motor will be the connecting rods. I chose the Manley rods since they are made in the U.S. and only $100 more than the Eagle's. Also, H-beam rods are stronger than I-beams and the Manley's come with ARP blots. By the way, my Eagle crank only cost $595 so be sure to shop around!!! :cheers:
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: Eagle 4340 forged 383 crank (Bruce)
I haven't seen the ad you are refering to. Besides Danno85's correct critique on the rod bearing sizes, there COULD be a main bearing issue as well. The original CHEVROLET 3.75" crankshaft that the 383 has been based on from the beginning was for the 400 cid small block. The 400 used larger MAINS than any other SBC for the same overlap reasons Danno85 expressed for the rod size change above. The first 383's were simply 400 cranks with the mains turned down to the 350 size and slapped in to a 350 block. Of course custom pistons with a reduced compresson height were required. If the ad is refering to the mains size you want the "small" 350 mains. Big, 2.1" rod size. Small(actually medium), 2.45" main size. Any other combination would really be an oddball for a one piece seal crank.
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: Eagle 4340 forged 383 crank (CFI-EFI)
CFI-EFI
I got the last month Jegs catalgo. Its says SB-Chevy wtih one piece rear seal for 350 (383) 3.75 stroke It does not specify Rod size.. They also have list for 400 (3.75) stroke. refer to rod size 400(3.75) stroke, 5.7 or 6.0 rod
Bruce
I got the last month Jegs catalgo. Its says SB-Chevy wtih one piece rear seal for 350 (383) 3.75 stroke It does not specify Rod size.. They also have list for 400 (3.75) stroke. refer to rod size 400(3.75) stroke, 5.7 or 6.0 rod
Bruce
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: Eagle 4340 forged 383 crank (Bruce)
Bruce,
Pardon me, but I don't know what you are saying here.
I just reread your origonal post. Maybe I got confused. Does your journal question apply to the crankshaft? Or the rods, themselves? I thought you were talking about the crank. Then I just picked up off of Danno85's post and went into a "possible" main size diatribe. If you are referring to journal size as it applies to rod selection, ignore everything that I wrote. You can double check with the crank supplier, but you WILL want the 2.1 large journal rods. Sorry, if I caused any confusion. If your last post (as quoted) contains a question, please restate it it and I will try to answer it.
Pardon me, but I don't know what you are saying here.
CFI-EFI
Its says SB-Chevy wtih one piece rear seal for 350 (383) 3.75 stroke It does not specify Rod size.. They also have list for 400 (3.75) stroke. refer to rod size 400(3.75) stroke, 5.7 or 6.0 rod
Its says SB-Chevy wtih one piece rear seal for 350 (383) 3.75 stroke It does not specify Rod size.. They also have list for 400 (3.75) stroke. refer to rod size 400(3.75) stroke, 5.7 or 6.0 rod
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Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: Eagle 4340 forged 383 crank (CFI-EFI)
CFI-EFI
sorry for the confusion.The crank is 1 piece rear 350 main and 3.75 stroke. My question is will this work on my 93 LT1 motor?. As for rod I asked , I did not know about small/large journals. And which one do I need to to buy. Hope this clear up. They also have 400 main with 3.75 stroke but that is not what I need. Thanks Buddy.
Bruce
[Modified by Bruce, 2:11 PM 12/24/2001]
sorry for the confusion.The crank is 1 piece rear 350 main and 3.75 stroke. My question is will this work on my 93 LT1 motor?. As for rod I asked , I did not know about small/large journals. And which one do I need to to buy. Hope this clear up. They also have 400 main with 3.75 stroke but that is not what I need. Thanks Buddy.
Bruce
[Modified by Bruce, 2:11 PM 12/24/2001]
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: Eagle 4340 forged 383 crank (Bruce)
Bruce,
I'm not really "up" on the later LT engines. I think that the 1 piece seal crank will work for you, but I defer to the experts. Somewhere along the line a 5.7L ceased being a 350. The bore went from 4" to something like 3.91" and there was a corisponding stroke change. I know just enough about the later engines to be dangerous. BTW, a 3.75" crank with 400 mains is a 400 crank.
I'm not really "up" on the later LT engines. I think that the 1 piece seal crank will work for you, but I defer to the experts. Somewhere along the line a 5.7L ceased being a 350. The bore went from 4" to something like 3.91" and there was a corisponding stroke change. I know just enough about the later engines to be dangerous. BTW, a 3.75" crank with 400 mains is a 400 crank.
Drifting
Joined: Aug 2001
Posts: 1,606
Likes: 14
From: Vacaville, CA
Re: Eagle 4340 forged 383 crank (Bruce)
The $595 price I quoted for the Eagle crank was a "jobber" price that I paid when I had my 383 built. I didn't mean to mislead you, but there are some other great discount shops around that can come close. Check out http://www.allchevyengines.com and http://www.flatlanderracing.com. Also, I'd get a copy of Scoggin Dickey's parts catalog. Most importantly, do not buy anything until you have completly decided which route you want to go and have found a good builder. The UPS fee's to return an item and the -20% re-stocking fee's add up fast! You may also consider building your LT-1 into a 396. Close to the same config. as a 383, but uses a 3.875 crank which provides a bit more torque. Due to the longer stroke, usually requires a 5.85" rod depending on the pistons used; (everything has to match-up together). More performance are the 396 experts. (You need experience to clearance the block properly for the 3.875" crank and not hit the water jacket). Best of luck with your build!!! :cheers:
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: Eagle 4340 forged 383 crank (BlackRocket)
Blackrocket.
Again thanks for helpeful hints and also thanks to everyone who replied as well. I am firmly decided 383ci instead 396ci. I will have a speed shop here in my town build me low compression 383ci. They have build a few 383LT1 short block that supercharged and made 613rwhp with custom ground cam. Which is I have already ordered. This cam cc Xtreme Energy 214/224 @.05 .569/.606 LSA 114 with my 1.6 roller rocker. This cam made 613rwhp and also idle very good with 16-18 of vaccum idle. I am after 700rwhp with 75hp shot of my N2O. Its will be running 12psi with ATI P1SC. I am confident this combo can produce 700rwhp.
ps. Blackrocket, your're using Manley 6 inch H beam rod, part# 14054? sbc-Lg- Journals is this correct?
Bruce
93LT1 Conv w/ZF6
top end mods
Jetted 150hp NX
Blown 383ci is coming very very soon Spring 2002
[Modified by Bruce, 12:49 PM 12/25/2001]
[Modified by Bruce, 1:22 PM 12/25/2001]
[Modified by Bruce, 2:37 PM 12/25/2001]
Again thanks for helpeful hints and also thanks to everyone who replied as well. I am firmly decided 383ci instead 396ci. I will have a speed shop here in my town build me low compression 383ci. They have build a few 383LT1 short block that supercharged and made 613rwhp with custom ground cam. Which is I have already ordered. This cam cc Xtreme Energy 214/224 @.05 .569/.606 LSA 114 with my 1.6 roller rocker. This cam made 613rwhp and also idle very good with 16-18 of vaccum idle. I am after 700rwhp with 75hp shot of my N2O. Its will be running 12psi with ATI P1SC. I am confident this combo can produce 700rwhp.
ps. Blackrocket, your're using Manley 6 inch H beam rod, part# 14054? sbc-Lg- Journals is this correct?
Bruce
93LT1 Conv w/ZF6
top end mods
Jetted 150hp NX
Blown 383ci is coming very very soon Spring 2002
[Modified by Bruce, 12:49 PM 12/25/2001]
[Modified by Bruce, 1:22 PM 12/25/2001]
[Modified by Bruce, 2:37 PM 12/25/2001]
Drifting
Joined: Aug 2001
Posts: 1,606
Likes: 14
From: Vacaville, CA
Re: Eagle 4340 forged 383 crank (Bruce)
The Manley rods I'm running are 14054's. As far as supercharging is concerned, be sure to discuss this with JE / SRP to be sure to get the correct pistons with the ring-land down the piston as far as possible. Also, be sure the ring end-gap is not too tight. And, many supercharged app's blow head gaskets for obvious reasons. There is a procedure where special head milling takes place to cut a relief into the head surface. Then special head gaskets are used that have a steel ring that fills in this relief. Much stronger and prevents blown gaskets. Are you going to change the engine managment system? If so, which one were you planning on using???
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: Eagle 4340 forged 383 crank (BlackRocket)
Blackrocket
For the pistons. I was just finished browsing on the Ross Racing piston website. I think I might have to end up ordering custom made piston because I got such a high lift cam .569/.606 with my 1.6rr. For that reasons I don't want to buy the off shelf piston that may not clear piston to valves. My buddy made 613rwhp with this cam he use 1.5rr .530/.567 and 14cc J.E piston. He is going to experiement with 1.6rr in the summer which would bring the lift up to .569/.606. But I am getting my motor done in the Spring and I can't wait that long til summer. I will stay with the stock ecm unless tunning is a problem
Bruce
For the pistons. I was just finished browsing on the Ross Racing piston website. I think I might have to end up ordering custom made piston because I got such a high lift cam .569/.606 with my 1.6rr. For that reasons I don't want to buy the off shelf piston that may not clear piston to valves. My buddy made 613rwhp with this cam he use 1.5rr .530/.567 and 14cc J.E piston. He is going to experiement with 1.6rr in the summer which would bring the lift up to .569/.606. But I am getting my motor done in the Spring and I can't wait that long til summer. I will stay with the stock ecm unless tunning is a problem
Bruce
Safety Car
Joined: Nov 1999
Posts: 3,891
Likes: 2
From: Houston, TX
Re: Eagle 4340 forged 383 crank (Bruce)
Bruce,
Give me a ring today or tomorrow. We sell Eagle parts and can get you a great deal on them. We can also build the engine for you if you are interested.
We will be in and out of the shop today. We are supposed to be closed, but I just could not stay away! :)
Give me a ring today or tomorrow. We sell Eagle parts and can get you a great deal on them. We can also build the engine for you if you are interested.
We will be in and out of the shop today. We are supposed to be closed, but I just could not stay away! :)
Melting Slicks
Joined: Mar 1999
Posts: 3,029
Likes: 137
From: Nashville TN area
Re: Eagle 4340 forged 383 crank (Bruce)
bruce,
i'm using the eagle forged crank along with eagle h-beam rods forged and je/srp pistons in my '94 lt1 ... 383.
combo is working well, have 4000 miles on the new motor already :)
i'm using the eagle forged crank along with eagle h-beam rods forged and je/srp pistons in my '94 lt1 ... 383.
combo is working well, have 4000 miles on the new motor already :)
Thread Starter
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: Eagle 4340 forged 383 crank (mikey)
hi Chris and Mikey.
I got home late, did not have a chance to read the forum until now :). Mikey yes I am going to use Eagle forge crank.
Chris, I will call you tomorrow or Friday about the 4340 forge eagle crank. Also I think I like Manley 4340 H beam 6 inch rod.
Bruce
[Modified by Bruce, 11:13 PM 12/26/2001]
I got home late, did not have a chance to read the forum until now :). Mikey yes I am going to use Eagle forge crank.
Chris, I will call you tomorrow or Friday about the 4340 forge eagle crank. Also I think I like Manley 4340 H beam 6 inch rod.
Bruce
[Modified by Bruce, 11:13 PM 12/26/2001]
Safety Car
Joined: Nov 1999
Posts: 3,891
Likes: 2
From: Houston, TX
Re: Eagle 4340 forged 383 crank (Bruce)
The be honest, I would use one of Eagles rotating assemblies including pistons and such. I have used the Manleys and I really do not feel they are much better than the Eagles! Unless you are planning an all out 600 RWHP+ engine, I would stick with the Eagles....
JMHO,
JMHO,
