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Author
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Topic: Forged crank for the 3x00 could it be true???
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Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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Is it true ??? Did GM mass produce a forged steel crank for the 3x00 engine ???
I stumbled into this doing some research on the 3900 engine. It seems that some people out there are claiming that the LX9 sports a forged steel crank with a casting number of 7484. Below is one of the web pages I found some of this information on along with the claim of forging.
http://www.v6z24.com/registry/SuperDave
3500 LX9 is listed as having….
Forged steel crank 7484 casting
Stock forged steel rods
9.8:1 SCR stock pistons (Nice ratio for a turbo engine and are probably turbo friendly hypereutectic material)
If this is true these cranks could support the high horsepower that so many of us desire.
I see Joe Upson has a couple of these engines and seems to know something about these cranks.
I have a 3900 thread going where he has posted before, I will ask what he knows.
If any one has info on this let me know.
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Scoobysruvenge IP: Logged |
Coinage
Member Posts: 1458
From: Hershey,PA,USA
Registered: Apr 2003
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http://realfierotech.com/ph...0&hilit=holset+turboIP: Logged |
Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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The 7484 crank is indeed a real factory forged crank with 2.25” journals this means that this crank will bolt directly into a 3x00 engine. Using aftermarket forged small block rods (which by the way can be had ridiculously cheap) in a 3.4 requires only minor machining on the Big end of the rod (100$ or less at your local machine shop) I doubt you will need to remove any other material as the aluminum small Chevy rods I have will fit my 3.1 Mclaren block with very minor material removal.
When I had my aluminum test rod machined I asked about having the small end hole bushed and was told that the bushing would be so thin that it would be easier and cheaper bore out what ever pistons I was going to use.
So here’s the skinny
1. Acquire a LX9 3500 crank – I plan to go to the local kidney foundation junk yard to get mine (129.99) cheaper if I simply remove the crank.
2. Buy some forged rods (400 $) or less for a 600 HP set of Eagle or Scat rods.
3. Machine the rods and pistons (200 $)
4. That’s it.
129.99 + 400 + 200 = 729.99
That’s a seriously potent bottom end good to 600 HP for under a grand, if any of you have read the “Head gaskets for a turbocharged 2,8 v6” thread the guy is making almost 500 HP with a 2.8.
Crazy right, it just goes to show with the right parts and level of boost massive power can be extracted from these little engines.
After reading his thread I was truly inspired other than that Norwegian forged crank he was using, but with the confirmation of the 7484 factory forged crank I look forward to stretching the 3.4 DOHCs legs with this information.
By the way if you haven’t looked at that Head gaskets for a turbocharged 2,8 v6 thread you really should.
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Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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The crank has to be machined to accept the chevy rods, the crank pins are 2.25" and I'm not aware of a chevy rod with that pin diameter. I could be wrong but thought I recall reading that there was a problem somewhere during an attempt to place the steel crank in an earlier block. It may have involved clearance of the connecting rod big end because of the increased crank pin diameter so for earlier block use it may need to be machined for that purpose as well, I'm not sure however.IP: Logged |
Dennis LaGrua
Member Posts: 6114
From: Hillsborough, NJ U.S.A.
Registered: May 2000
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I don't know what all this commotion is about a forged crank, but if you own a 3800 engine those cranks have held up to over 500 Hp and 8 second 1/4 mile times.
There are guys running boosted 3.4L engines to over 400 HP and I've never heard of one crank that has broken yet.
Do any 3X00 engines need this? ------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE " IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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I know that folks throw around that the factory has a forgde crank ,piston or rods when they dont and I am not saying that there is not one. I like to see the parts due to any one looking at the part can tell if they know what to look for . Forged crank will have a wide parting line while a cast have a very thin line same on the conecting rods.[This message has been edited by engine man (edited 10-14-2009).] IP: Logged |
hookdonspeed
Member Posts: 3999
From: baltimore, md
Registered: May 2008
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yep, its true, the 3500 LX9 im putting in my car has that crank 
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Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
I know that folks throw around that the factory has a forgde crank ,piston or rods when they dont and I am not saying that there is not one. I like to see the parts due to any one looking at the part can tell if they know what to look for . Forged crank will have a wide parting line while a cast have a very thin line same on the conecting rods.
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Powder metal rods have no parting lines aside from the cap fracture. GM states they are forged. In addition to the parting line, members of the 60 degree V6 forum are pretty accurate most of the time on the technology because the engines discussed over there are much further along than what is usually delt with on the Fiero forum which has not caught the aluminum head engine bug yet. We have also seen the cast and steel version side by side.
3500, 7484 crank
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engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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well from what i can see it looks like the parting line on that first rod throw is wide but it is not the best angle to look at it but i would say you got a winner and I am glad to see GM do it rightIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
well from what i can see it looks like the parting line on that first rod throw is wide but it is not the best angle to look at it but i would say you got a winner and I am glad to see GM do it right |
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It's about ten times the width of the line on the cast crank. Even at an angle it's still about the width of an index finger. The purpose was for rigidity and noise reduction according to GM, that's why the crank pins are larger.[This message has been edited by Joseph Upson (edited 10-14-2009).] IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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you say the rods are 2.250 that is the same as 4.3 V6 and Eagle makes a set of H beam rods they might be the ticket oh and ther 5.7 lengthIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
you say the rods are 2.250 that is the same as 4.3 V6 and Eagle makes a set of H beam rods they might be the ticket oh and ther 5.7 length |
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4.3L rods will not work for two reasons, first they are too short, stock 3900 rods have been measured in two lengths; 5.827" and 5.9". GM advertised 5.9". Since the journal diameter is the same the 4.3L rod can't be used in an offset grind the way the V8 rods with the smaller journal can however, you may be able to find an LS1 piston with the right pin height to use with them but that defeats the purpose since the intent was to come up with a stronger rod and more displacement. Since the 3900 has the same bore as the LS1 there are several piston pin options in forged pistons available off the shelf that's how I came up with my combination that is within .009 of the stock piston height.[This message has been edited by Joseph Upson (edited 10-15-2009).] IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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Ok i dint know they changed the rod length what is the stroke of that crank compard to the one it is replacing and how much more inches will it turn it into a 3.9 and is there a way to make the block 4 bolt are the mains 2.65 the same as a 400 SBC IP: Logged |
Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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It seems that the 60D guys get a bad rap when it comes to trying to one up the competition, whether it be from the 3800 crowd, the V8 boys or anyone else who enjoys a good beat down.
It seems that we 60Ders are on trial again as to whether or not these forged part claims are true and whether it is relevant when building one of these little engines ???
As my first witness I call Mr. Borretti and his Dyno sheet found here on PFF at
http://www.fiero.nl/forum/Forum2/HTML/103956.html
Surely with this kind of power (440 lbft of torque) this speed conscious jury can see the need for high quality forged internals at these loads if only to protect ones investment of capital.
Mr. Borretti has a custom made crank and rods which is way out of the financial means of most of us, if such parts available without the extreme cost the reliable HP of the average 60D could skyrocket.
That is what this case is about.
Good people of the jury the mere claim of the existence of such high quality components readily available to the general 60D public scares the hell out of the competition.
In an attempt to discredit these claims the plaintiffs have questioned whether 2.25 SBC rods even exist….
I would like to enter exhibit number two your Honor and would like to call Mr. Summit Magazine as an expert witness.
As you can plainly see my good people that these rods do exist, even with this hard evidence some of you may still have a reasonable doubt that these rods will even fit with out massive modification of the crank and block due to the slanderous comments made by the plaintiffs.
I would now like to enter exhibit number two your Honor and would call myself as a witness that machining the crank to accept the rods is in fact not true (See my thread for the rod swap details.)
http://www.fiero.nl/forum/Forum2/HTML/102001.html
My closing argument is as follows…
You the jury must find the little 60D innocent of all charges, the defense has proved without a shadow of doubt that the need for such hardened parts is obvious for those 60Ders who choose to push the envelope and that forged cranks and SBC rods will indeed bolt right up with 100 or less of machine work to the rods not the block and crank.
The defense rests your honor.
Now I hope no one takes the embellishments here to seriously, they meant to spice up the reading experience for you here at PFF
I would like to thank Joe for clarifying the forged crank is indeed real, with out his input us 60Ders might just be wishing on a star.
Thanks for all the help Joe
The LX9 crank fits only 3100 3400 as the 3500 LX9 was based on the 3400 engine.
The bore spacing has 1.5 more spacing for the bore on the 3900 engine and the other 2 types of 3500 engines that are based on the 3900 and would not work anyway.
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engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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I think it is good and hope you dint think i was picking on you or any one i just have seen the 3800 guys claim all sorts of things. i should realy be building a 3.4 DOHC engine due to the dam heads flow so good the intake flow like 270 cfm in stock form the Brodix V6 10 for the 4.3 I am building only flow 260 out of the box. I say a well though out 3.4 DOHC engine realy could kick the sh!t out of a 3800 . the 3800 heads dont flow that great but if they coud stick a set of those old stage 2 aluminum racing heads on there engine then you would have somthing . IP: Logged |
Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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Thanks for the vote of confidence Engine Man, I was curious is there even a forged crank available for the 3800 engines???
I have been waiting on a guy with a 3.4 Dohc car to respond to my emails and have heard nothing from him lately and was looking into a 3900 swap, but after reading Borretti’s thread I was drooling.
Then out of the blue I read this email this morning…
I'm sorry for the delay. As I mentioned I am currently studying abroad in Italy. I wont be able to make it home till late december however if you are still interested in the car then I will be sure to contact you.
Subject: RE: 1996 Pontiac Grand Prix GTP Needs Trans - $250
To: dmellinger@XXXX.com
From: louis.a.barnette@XXXX.com
Date: Wed, 14 Oct 2009 09:25:12 -0400
The 96 has the preferred heads and intake and I will gladly wait for December to acquire it, it has less than 100,000 miles with maintenance records.
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Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
Ok i dint know they changed the rod length what is the stroke of that crank compard to the one it is replacing and how much more inches will it turn it into a 3.9 and is there a way to make the block 4 bolt are the mains 2.65 the same as a 400 SBC |
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It's still the basic 60 degree crank design just stouter, I don't recall hearing any mention of the main journal diameter being changed. Depending on which chevy rod you use; 2.1 pin or 2.0 pin you should be able to increase stroke by .075 and .125 respectively. Technically it is already a four bolt main due to the cross bolts going through the side of the oil pan. Specs for all of the 60 deg motors can be found on the 60 degree forum, I just didn't find exactly what I was looking for to determine the main diameter.
A company has been machining this crank for use in the earlier engines but the cost seems uncompetitive by far with what it would probably cost you to take one and have it prepped yourself.[This message has been edited by Joseph Upson (edited 10-15-2009).] IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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I was thinking of the 3.4 dohc that dosnt have the cross bolting corect or are you using a different block with DOHC heads or are you talking a different engine all togetherIP: Logged |
Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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This is a good question, does the 91-97 dohc engine use the cross bolted pan and main caps ???
If Will is poking around he may be able to answer this question, I know he has one or two of these blocks.
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Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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Joe,
Do you have a spare 3500 crank ??? If so is it for sale ???IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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can the 3500 caps and pan be put on a early 3.4 dohc engine with line boring the mainsIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
can the 3500 caps and pan be put on a early 3.4 dohc engine with line boring the mains |
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I believe you have to use the pan and cap combo from the 3400 down, if I recall correctly there is a slight difference in at least two of the pan rail bolt locations on the 3500 compared to the earlier pans, otherwise it shouldn't be a problem aside from the align bore requirement but I'm pretty sure you are aware of that.
| | | quote | Originally posted by Scoobysruvenge:
Joe,
Do you have a spare 3500 crank ??? If so is it for sale ??? |
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I don't, I plan to take the crank from the burnt 3900 I have and have it offset ground, aside from being burned the engine was still like new internally. I may do some other experimenting with the block in the future. If having the crank welded and stroked didn't cost so much I would go that route for even more displacement. The individual throws cost more to deal with.IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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Ok so let me get this right the 3400 have cross bolting and it could be adapted to the 3.4dohc if so then that plus the crank it would be a stout engine and with a custom intake and them grate flowing heads it would kick @ss . I think i almost got my self talked out of my 4.3 lolIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
Ok so let me get this right the 3400 have cross bolting and it could be adapted to the 3.4dohc if so then that plus the crank it would be a stout engine and with a custom intake and them grate flowing heads it would kick @ss . I think i almost got my self talked out of my 4.3 lol |
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Here are some flow numbers for the 3900, not sure how accurate they are due to the testing method, mid page.
http://60degreev6.com/forum...ormance-t41450/page7IP: Logged |
Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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Ok here is are some thoughts on the subject.
The LX9 3500 has a 94mm bore and the 3.4 DOHC has a 92mm bore this is only 2mm difference.
2.01mm = 79 thousandths that’s a little over the maximum suggested over bore of 93.52 (60 over) is so close it’s not funny.
Provided the heads will cover bore you could simply swap the heads and oil pump jack shaft from the DOHC engine to the LX9 3500 block.
The DOHC head swap to a non DOHC block is doable and documented at the 60Degreev6.com site.
This would yield extra cubes along with the cross bolted pan block and mains.
Scary….
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engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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yes those are good numbers but how much to get a 3900 what are the prices you are finding on them then how hard to make them work in a fiero it is just a wiring thing corectIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
yes those are good numbers but how much to get a 3900 what are the prices you are finding on them then how hard to make them work in a fiero it is just a wiring thing corect |
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ALLPro autoparts near Lakeland has had some great prices, a few weeks ago they had two for under $400. You have to check availability. Car-part.com has a good listing so you should be able to find something very reasonable there. LKQ autoparts has a location near you I believe and they ship showing one available in SC for $350IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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you know this isnt nice now I am starting to think maybe no to the 4.3 due to i could spend the money it is costing me for the upper end and the adapter kit i could just be dumping that into making this engine fasterIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
you know this isnt nice now I am starting to think maybe no to the 4.3 due to i could spend the money it is costing me for the upper end and the adapter kit i could just be dumping that into making this engine faster |
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It wouldn't take much, practically everything you need is in the store on the 60 degree V6 forum. The 4.3L is nice, the problem is the weight plus the adaptor combined against an engine that already sports a power output considerably higher than it does with no power adders or upgrades.IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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Joseph Upson what did your 3900 make for power before dieing or did it die IP: Logged |
Erik
Member Posts: 5045
From: Des Moines, Iowa
Registered: Jul 2002
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| | | quote | Originally posted by Scoobysruvenge:
This is a good question, does the 91-97 dohc engine use the cross bolted pan and main caps ???
If Will is poking around he may be able to answer this question, I know he has one or two of these blocks. |
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NO it does not . i has 2 bolt mains but you could make straps for the mains and use studs IP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
Joseph Upson what did your 3900 make for power before dieing or did it die |
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Haven't dynoed it yet and have a lot more tuning to do. It ran great if the videos are any indication however I know it is nowhere near potential with the camshaft fully advanced. I just received the 60-1 ballbearing turbo that's going to replace the twin T3s a few minutes ago. Once that's installed with the built motor I should be impressed enough to no longer bother with anymore performance build ups.
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Scoobysruvenge
Member Posts: 502
From: Richmond Virginia
Registered: Apr 2009
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Joe,
The forged 3500 cranks you have came from A LX9 engine based on the 3400 or are they from one of the 2 3500 engines based on the 3900 ???
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Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by Scoobysruvenge:
Joe,
The forged 3500 cranks you have came from A LX9 engine based on the 3400 or are they from one of the 2 3500 engines based on the 3900 ???
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My 3500 cranks were both in the engine, one was removed temporarily to have a 7X trigger ring added. The other engine I sold. I have two 3900s, one in the car and one (burnt) disassembled. The 3500 VVT engine is a 3900 with a 3" stroke so it has its own crank. The VVT 3500 is the only engine based on the 3900 and as indicated is a 3900 with a shortened stroke. It also has an oil squirter on each piston which is a great benefit for blown motors because the oil takes a good bit of heat out of the pistons which contributes to better strength and less likelyhood of detonation.IP: Logged |
engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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Ok i havent seen the videos but im gona go looking for them and read latter what you went through to put the engine in . I have looked on car parts .com and cant find them for cheap there 1000 and upIP: Logged |
Joseph Upson
Member Posts: 2652
From: Tampa Florida
Registered: Jan 2002
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| | | quote | Originally posted by engine man:
Ok i havent seen the videos but im gona go looking for them and read latter what you went through to put the engine in . I have looked on car parts .com and cant find them for cheap there 1000 and up |
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Look for a 2006 Pont G6, if Tampa is not to far for you these guys have two, one for $450 and another for $500; Gagels Auto Parts USA-FL(Riverview) E-mail 1-800-537-5948 bet they'd bargain with you a little. Keep checking AllPro near Lakeland as they had a couple a while back for under $400. It's a common motor since it was used in so many of GMs vehicles upon the demise of the 3800.
You'll have to pardon the commercials, these guys have sold out so far to advertising that in the future I'll post videos somewhere else. This is the latest video http://videos.streetfire.ne...h-without_680592.htm
Here is the thread http://www.fiero.nl/forum/Forum2/HTML/084972.html
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engine man
Member Posts: 1913
From: West Palm Beach FL
Registered: Mar 2006
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thanks but I have decided I would stick with my 4.3 With the set of Brodix V6 10 heads fully ported but if i where starting from scratch that would be the engine to get IP: Logged |
