Iron Duke to SB swap - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Iron Duke to SB swap

FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectSavvy Aluminum Gas Tank SkidFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye Kit

Reply
Unread 01-22-2009, 09:17 AM   #1
Cheap-o-Jeep
Registered User
1980 CJ7 
 
Join Date: Jan 2009
Location: Mt. Morris, MI
Posts: 16
Iron Duke to SB swap

This appears to be a pretty straightforward project, but I want to get my ducks in a row first...
I have a 1980 CJ-7 with the Chevy Iron Duke and a 4-speed trans.
I just got a 1970 Chevy 307 2bbl to drop in.
I don't hotrod this car, and I'm running stock size tires. I just use it to go fishing, hunting and running the fire trails in the national forest. I don't go looking for challenges. I have a Hemi Dodge for that. The main reason I'm doing the swap is because I would like to be able to maintain 60-70 MPH on the expressway if I happen to have a headwind!
...And there's no way to make the exhaust sound cool with a 4...
And this tired old engine will not last for long doing a lot of e-way driving to my wheeling spots.

Anyway, I digress. I plan to use the stock 4-speed, at least for now. I have a powerglide I would like to use, but for now, it's bucks-down. I know I will need a new SB clutch, pressure plate, throwout bearing, flywheel and pilot bearing, radiator, a set of motor mounts and a HEI distributor. The only other thing I can think of is the new exhaust system.

Am I missing anything?

I know the transmission is a weak link, but I think it will be OK for a while, given the way I use the car.

Cheap-o-Jeep is offline   Reply With Quote
Unread 01-22-2009, 09:49 AM   #2
davemci
Registered User
1978 CJ7 
 
Join Date: Dec 2008
Location: Grand Rapids, MI
Posts: 96
I assume you have a Borg Warner SR4 4-speed. Jeep only used that tranny for 2 years 1980/81 and only with the 151 engine. I don't think anyone made a bell housing for a SB Chevy to SR4. I'm sure you can find a cheap better tranny on your local craigslst. In 1970 I bought a 71 Nova with the 307 engine. It has a small bore and long stroke. In other words it had a lot of torque. I don't think the SR4 will take it.

I really liked your original plan and I'm not sure putting the 307 to a SR4 will be a lot cheaper.
davemci is offline   Reply With Quote
Unread 01-22-2009, 09:59 AM   #3
Jeepfreak81
Registered User
1994 YJ Wrangler 
 
Join Date: Apr 2002
Location: Lennon, Mi
Posts: 2,041
IIRC the Iron Duke uses a SBC bell housing pattern.

That trans is extremely weak. I think you will find it will explode sooner then later. With a CJ it would be much better suited to find a 304/360 and appropriate trans. Everything will bolt into place pretty much. Much less work then fabbing in mounts for the SBC.

*you will have to unbolt your motormounts and bolt in the 304/360 ones

For CJ stuff (that you want to buy), contact Pavementpounder http://jeepspace.jeepforum.com/PavementPounder

He is local to you, and I have dealt with him a lot. He is cleaning out his inventory as he is getting out of used jeep parts I have heard.

His parts generally are reasonable unless your a tool bag to him or lowball him then he just will ignore you
__________________
94 V8 YJ, SOA, H1's, 37's, HP D44, D60, 4.88's, winch and some other goodies
1946 CJ2A, 225 V6, T98 D18, Warn OD, D30/D44. Dual winches mild lift & 34's
1966 M416 1/4 ton Military Trailer Expo Trailer
Full Page Club member #004
Green Jeep Club Member #005
Jeepfreak81 is offline   Reply With Quote
Unread 01-22-2009, 10:34 AM   #4
davemci
Registered User
1978 CJ7 
 
Join Date: Dec 2008
Location: Grand Rapids, MI
Posts: 96
I think it still would take a bell housing adapter. Novak made one for a short while but it was short lived since it didn't make much sense to adapt a V8 to such a light duty drive train.
davemci is offline   Reply With Quote
Unread 01-22-2009, 11:54 AM   #5
amcjeepman
Registered User
1986 CJ7 
 
Join Date: Dec 2005
Location: Reidsville, NC
Posts: 180
The belhousing will work, you must use the 153 tooth flywheel. A mini starter fits better.
The transmission willl not last.
__________________
James Belcher, Jr
Carolina Trailblazers PR
86 CJ7 401 TF999
81 CJ7 360 T177
05 Rubicon Unlimited
and others ;)
amcjeepman is offline   Reply With Quote
Unread 01-22-2009, 12:13 PM   #6
davemci
Registered User
1978 CJ7 
 
Join Date: Dec 2008
Location: Grand Rapids, MI
Posts: 96
Yep, my bad. What was I thinking? Use the 151 bell housing.
davemci is offline   Reply With Quote
Unread 01-22-2009, 12:29 PM   #7
Full Tank
Registered User
1980 CJ5 
 
Join Date: Jun 2007
Location: SK, Canada
Posts: 593
Some of the I-4 Iron Duke CJ's came with the T-176 transmission which will stand up to V8 power.

If the shifter is straight it's a T-176.

If the shifter has a curve in it it's a SR4.

FT
__________________
1980 CJ5 39k
Dana 30--AMC20--D300--T176--258

1986 CJ7
Dana 30--AMC20--D300--T5--2.5L
Full Tank is offline   Reply With Quote
Unread 01-22-2009, 12:34 PM   #8
Jeepfreak81
Registered User
1994 YJ Wrangler 
 
Join Date: Apr 2002
Location: Lennon, Mi
Posts: 2,041
Quote:
Originally Posted by davemci View Post
I think it still would take a bell housing adapter. Novak made one for a short while but it was short lived since it didn't make much sense to adapt a V8 to such a light duty drive train.
The AMC 151 would need a bell adapter but not the Iron Duke 4 cyl. 2 different motors. The 151 has a 60* V6 bell pattern from GM.
__________________
94 V8 YJ, SOA, H1's, 37's, HP D44, D60, 4.88's, winch and some other goodies
1946 CJ2A, 225 V6, T98 D18, Warn OD, D30/D44. Dual winches mild lift & 34's
1966 M416 1/4 ton Military Trailer Expo Trailer
Full Page Club member #004
Green Jeep Club Member #005
Jeepfreak81 is offline   Reply With Quote
Unread 01-22-2009, 06:57 PM   #9
rodjr
Registered User
1980 CJ7 
 
Join Date: Sep 2008
Location: seattle
Posts: 373
im in the same boat, iron duke, sr4. ive got a fresh mild 350 ready to go and am considering putting it in front of a good t5 trans ive got which is the same size as sr4 and a direct swap so it would go in pretty easy but i dont know if the t5 will live w/300 lb/ft torque but a 307 2bl i would feel better about. i picked up my t5 in very good shape for $75.00 so you could probably get one for reasonable price. ford put them behind 302s and 307s are similar power.
rodjr is offline   Reply With Quote
Unread 01-23-2009, 09:20 AM   #10
Redmanchew
Web Wheeler
 
Redmanchew's Avatar
1982 CJ7 
 
Join Date: Oct 2006
Location: Central Virginia
Posts: 1,534
Just an FYI, check with the sect. of state up there. You may not be able to put an older motor then what your taking out and still have it be legal....
__________________
1982 CJ-7 2003 4.3 chevy vortec, 4L60E, Clocked Dana 300 35 x 12.5 x 15 KM2 on Cragar 399's. Vanco Brake Booster. Power steering conversion. Warn front and rear bumpers with swing away. Moser 1 piece rears. Rear OX.

Support your local MS foundation. You don't know how much this disease sucks until it affects someone you love.

http://main.nationalmssociety.org/si...al&fr_id=18331

Quote:
Originally Posted by twoleos617 View Post
To reiterate for the 1,067th time, when towing...
remove rear axle, xfer in N, trans in 5th, remove neg batt cable, key to Run and go??
Redmanchew is offline   Reply With Quote
Unread 01-23-2009, 09:24 AM   #11
Jeepfreak81
Registered User
1994 YJ Wrangler 
 
Join Date: Apr 2002
Location: Lennon, Mi
Posts: 2,041
Quote:
Originally Posted by Redmanchew View Post
Just an FYI, check with the sect. of state up there. You may not be able to put an older motor then what your taking out and still have it be legal....
Not technically legal anywhere. In MI there is no smog testing though and no one bothers you. Too many hot rods around, they would take out half the vehicles on the road in the summer

I have been pulled over a few times in my V8 YJ, 98% of the time the cop just had questions about the jeep
__________________
94 V8 YJ, SOA, H1's, 37's, HP D44, D60, 4.88's, winch and some other goodies
1946 CJ2A, 225 V6, T98 D18, Warn OD, D30/D44. Dual winches mild lift & 34's
1966 M416 1/4 ton Military Trailer Expo Trailer
Full Page Club member #004
Green Jeep Club Member #005
Jeepfreak81 is offline   Reply With Quote
Unread 01-23-2009, 09:26 AM   #12
DT5150
Registered User
1983 CJ7 
 
Join Date: Jun 2007
Location: Lakes Region, NH
Posts: 1,494
Quote:
Originally Posted by rodjr View Post
im in the same boat, iron duke, sr4. ive got a fresh mild 350 ready to go and am considering putting it in front of a good t5 trans ive got which is the same size as sr4 and a direct swap so it would go in pretty easy but i dont know if the t5 will live w/300 lb/ft torque but a 307 2bl i would feel better about. i picked up my t5 in very good shape for $75.00 so you could probably get one for reasonable price. ford put them behind 302s and 307s are similar power.
that t-5 is equally as weak as the t-4/sr-4. if i recall correctly, ford used the "world class t-5" in those applications. different tranny than the jeep/borg warner t-5.
__________________
SOLD! 83 CJ-7. TBI Small Block Chevy 350/TH350/D300, Scout II Dana 44 front, CJ Dana 44 rear. 4" BDS Lift with 35's. Currently Jeepless.
DT5150 is offline   Reply With Quote
Unread 01-23-2009, 10:33 AM   #13
davemci
Registered User
1978 CJ7 
 
Join Date: Dec 2008
Location: Grand Rapids, MI
Posts: 96
Quote:
Originally Posted by Jeepfreak81 View Post
The AMC 151 would need a bell adapter but not the Iron Duke 4 cyl. 2 different motors. The 151 has a 60* V6 bell pattern from GM.
Aren't the Iron Duke, 2.5 liter and 151 synonymous? Isn't the AMC a 150?

Anyway, I think Cheap-o-Jeep has a good handle on the conversion. I was really hoping he'd go with the Glide but the adapter is almost $500. Add all the other things needed to convert to an automatic and it gets pretty expensive.
davemci is offline   Reply With Quote
Unread 01-23-2009, 11:02 AM   #14
Jeepfreak81
Registered User
1994 YJ Wrangler 
 
Join Date: Apr 2002
Location: Lennon, Mi
Posts: 2,041
Quote:
Originally Posted by davemci View Post
Aren't the Iron Duke, 2.5 liter and 151 synonymous? Isn't the AMC a 150?

Anyway, I think Cheap-o-Jeep has a good handle on the conversion. I was really hoping he'd go with the Glide but the adapter is almost $500. Add all the other things needed to convert to an automatic and it gets pretty expensive.
GM 151 AKA Iron Duke (90* V8 bell pattern)

http://www.jeeptech.com/engine/gm151.html

Quote:
The 151 (2.5L) inline 4 engine was used in '80-'83 CJs including the CJ-8, CJ-7, and CJ-5. The 151 is often called the "Iron Duke", but is actually a Pontiac engine designed to replace the Chevy "Iron Duke" I4 engine. The engine does have the Chevy bell housing bolt pattern though. The engine is manufactured by GM and uses a cast iron block and cylinder head with hydraulic lifters and 5 main bearings. The 151 cetainly is not a screamer, the AMC I4 has much better HP and torque ratings.

The neat part about the engine is it has the same bell housing bolt pattern as a Chevy small block. The bell housing makes a great low buck Ford/Jeep to Chevy adapter since it is basically Ford on the transmission side and Chevy on the engine side. A regular Chevy bell housing will bolt to the 151, so if you plan a transmission swap, a Chevy transmission would be the way to go. Also, a Chevy 305 or 350 will bolt right to the Iron duke bell housing. The down side of dropping in a V8 is most transmissions used with the Iron Duke are light weight units.

The GM 151 has the intake and exhaust manifolds on opposite sides of the cylinder head, but the AMC 150 has the intake and exhaust manifolds on the same side of the cylinder head. The picture at the top of the page is the passenger side with the intake manifold and carb. The drivers side is pictured below with the exhaust manifold removed.
AMC 150 (60* V6 bell pattern)
http://www.jeeptech.com/engine/amc150.html

Quote:
The 2.5L inline 4 (I4) engine used in Jeeps today was first introduced in '84 when Jeep was owned by AMC. Originally, the engine used a carburetor, later versions used throttle body fuel injection, and the current version uses multi-port fuel injection. The fuel induction has been the major change with this engine over the years. The 2.5L uses over head valves with hydraulic lifters and a cast iron block and cylinder head.

The current version of the 2.5L I4 engine uses multi-port fuel injection. This engine is the standard engine used in the Wrangler (TJ) and Cherokee (XJ). It was the standard engine in the Wrangler (YJ) since 1991. The XJ version of the 2.5L has a slightly higher output.
I was going to quote Wiki... but I am pretty sure wikipedia is wrong (did not look at the JF version) especially because it listed an Iron Duke as being called the 'Hurricane' when used in jeep applications. The Hurricane was actually the F head used in CJ3B and early CJ5 applications.
__________________
94 V8 YJ, SOA, H1's, 37's, HP D44, D60, 4.88's, winch and some other goodies
1946 CJ2A, 225 V6, T98 D18, Warn OD, D30/D44. Dual winches mild lift & 34's
1966 M416 1/4 ton Military Trailer Expo Trailer
Full Page Club member #004
Green Jeep Club Member #005
Jeepfreak81 is offline   Reply With Quote
Unread 01-24-2009, 06:54 AM   #15
Cheap-o-Jeep
Registered User
1980 CJ7 
 
Join Date: Jan 2009
Location: Mt. Morris, MI
Posts: 16
I'm gonna use the duke I'm pulling to build a buggy. I talked to Norm King the other day about hooking it up to a corvair automatic transaxle (again, in deference to the wife's arthritis). He's one of, if not the leading Corvair expert, and he happens to live here. While the project is straightforward, it will definately not be routine. But the desire to build it comes from living in opposite world, as my shooting buddy says...

BTW guys...I retired after 30 years at GM Flint Powertrain North. Believe me, the '80-'83 Jeep 4 is the GM 151 Iron Duke 4 cylinder, and the bell housing pattern is standard GM as indicated by Jeepfreak81.

As far as smog stuff, it won't be an issue up here. As said, No state smog checks, as half the cars in the state get hotrodded. Pulling the converter is one of the first and most universal mods anyone does up here. At least the only smog garbage on this jeep is the gas evap return.

You know though, I can't help but wonder what would be involved in replacing the SR-4 with a NP top-loader...
Cheap-o-Jeep is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.