Off Roading Forums banner
1 - 20 of 28 Posts

·
Registered
Joined
·
422 Posts
Discussion Starter · #1 ·
Swapping a 360 for a 258

My moonguy crew /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/laugh.gif/wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/wink.gif has been out combing the web for swap information and they've not found any single definative source for the 360 swap. My crew has been in "learning mode" on this swap for well over a year, and they're ready to get their hands dirty and get on with the job at hand. They begged and pleaded for me /wwwthreads_images/icons/wink.gif to see to start a thread on this subject for two reasons: First, they wanted to see if any other moon guy crews had scrounged up any valuable information on this subject /wwwthreads_images/icons/shocked.gif. Second, if there isn't a definative guide on the 360 swap out there, then this is the place to put one together /wwwthreads_images/icons/cool.gif.

What the Moonguy crew /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/laugh.gif/wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/wink.gif has learned so far:

1) Bell Housing:
/wwwthreads_images/icons/cool.gif All AMC/Jeep V8s and all '72 and later 258 I-6s have the same bell housing pattern and share the same mounting bases.

2) V8 Crankshafts:
/wwwthreads_images/icons/cool.gif 1966-1971 cranks can be used with torqueflites using a slip-in adapter.
/wwwthreads_images/icons/frown.gif Most cranks are drilled for a pilot bushing, but check to be sure.

3) Transmissions:
/wwwthreads_images/icons/cool.gif TH400s handle just about anything you throw at it, but then the moonguys have heard that a built 727 will handle hard downshifts better (like for mud bogging).
/wwwthreads_images/icons/crazy.gif After 1974 (all CJ7s) the TH400 bolts to the AMC block, but a 0.040-inch spacer is needed, or the front pump will grenade.
/wwwthreads_images/icons/cool.gif 904/999 OK for 304 or a mild 360... be sure to get the kick down linkage with the 360.
/wwwthreads_images/icons/crazy.gif 727s from wagoneers can be swapped in for bigger engines, but the clocking is slightly different and the pan is bigger. To clear the front drive shaft from hitting the tranny pan you will need to either; 1) have a lift of 4" or more, 2) install a two piece front drive shaft, or 3) modify the tranny pan. Again, be sure you get the kick down kinkage with the 360.
/wwwthreads_images/icons/cool.gif '72-'75 T-15 3-spd will easily handle V8 power.
/wwwthreads_images/icons/cool.gif '72-'79 T-18 4-spd will easily handle V8 power.
/wwwthreads_images/icons/tongue.gif '80-'86 T-176 is barely strong enough to handle 304/360 power.
/wwwthreads_images/icons/frown.gif T-4, T-5, and SR5 boxes are not suitable to V8 power.
/wwwthreads_images/icons/crazy.gif AMC V8s are externally balanced, so use matching components for vibration dampers, flywheels, and flex plates. If your having trouble finding a 360 flywheel, a 258 flywheel can be rebalanced and used.

4) Engine Mounts:
/wwwthreads_images/icons/cool.gif The right chassis engine mount must be changed for a CJ piece with a 304 V8 (left mount can be retained)
/wwwthreads_images/icons/cool.gif The mounting brackets on the engine must be changed to '72-'81 CJ pieces for a 304 V8.
/wwwthreads_images/icons/cool.gif Neoprene mounts must be changed as well, or you can reuse the old ones (truck mounts are too tall).
/wwwthreads_images/icons/cool.gif An alternative to the above is MORE's bombproof motor mounts.

5) Cooling System:
/wwwthreads_images/icons/cool.gif I6 radiator outlets match the V8's.
/wwwthreads_images/icons/cool.gif If you have a I6 heavy duty radiator (3 core) you can reuse. Some '86s have neck is offset to drivers side, it needs to be replaced to match the fan shroud (I have this problem, don't know why it's a problem... don't know if it's true, that's just what my moonguys learned).
/wwwthreads_images/icons/cool.gif A CJ V8 fan shroud must be used, application is for a '81 CJ7 with a 304 V8 (available from dealer).
/wwwthreads_images/icons/cool.gif A CJ factory seven-blade clutch (viscous) fan is best... from V8 or I6 heavy duty cooling package.

6) Electrical System:
/wwwthreads_images/icons/cool.gif Most of I6 wiring harness is compatible, coolant temp sensor wire must be lengthened.
/wwwthreads_images/icons/laugh.gif TeamRush has pretty much covered the ignition topic in other posts... many thanks Aaron.
/wwwthreads_images/icons/cool.gif Motorcraft modules work with 6 or 8 cyl distributors.
/wwwthreads_images/icons/frown.gif Ancillary mountings may need to be changed. Motorola alt. bracket can be drilled out to accept a Delco alt.

7) Power Steering:
/wwwthreads_images/icons/crazy.gif V8 high pressure hose is needed (although some report that the I6 hose works fine). The high pressure hose has a compression fitting for '80 and earlier, and O-ring for '81 and later.

8) Fuel Line:
/wwwthreads_images/icons/crazy.gif The AMC V8 fuel line is on the driver's side while the I6's in passenger side. A new fuel line will need to be fabricated and re-routed on the left side frame rail, or a fuel line can be pulled off of a 304 powered CJ.

9) Exhaust System:
/wwwthreads_images/icons/crazy.gif The 2 1/8 inch "Y" exhaust pipe from a 304 powered CJ will take care of the exhaust, if you can find one.
/wwwthreads_images/icons/cool.gif Use 2 1/2 inch pipe from "Y" on out.
/wwwthreads_images/icons/crazy.gif Try to get manifolds with engine... especially if using earlier rectangular port heads ('66-'69).
/wwwthreads_images/icons/cool.gif Hedman, among others, makes headers for AMC V8s in CJs, although it appears that they do not make one for my application /wwwthreads_images/icons/crazy.gif...360 into an '80 to '86 CJ7 with the TF999 automatic transmission.
/wwwthreads_images/icons/crazy.gif A drivers side exhaust manifold from an AMC 304 powered CJ may be required. The CJ manifolds (on my best moonguy information) exit past the block on the right side and between the 3 and 4 cylinders on the left. If you need the rear dump manifold, you might be able to find it off another AMC product... the OEM replacement is ridiculously overpriced.

10) Engines:
/wwwthreads_images/icons/cool.gif '66-'69 AMC V8s have rectangular exhaust ports.
/wwwthreads_images/icons/cool.gif '70 and later engines have dog-leg exhaust ports (up to 50% better flow, but only a big gain at higher rpms).
/wwwthreads_images/icons/cool.gif Intake manifolds change with change in exhaust ports '66-'69 and '70 and later take different intakes.
/wwwthreads_images/icons/cool.gif Combustion chambers differ on earlier heads and heads must be matched to pistons to get correct compression.
/wwwthreads_images/icons/cool.gif '70-'71 have 50.60 cc (casting No. 319-6291) combustion chambers. Later heads have 57.92 cc combustion chambers.
/wwwthreads_images/icons/crazy.gif The AMC 258 weighs in at 440 lbs. while the AMC 360 weighs 540. Pre '81 258s weight 90 lbs. more.
/wwwthreads_images/icons/cool.gif Visually all V8 engine blocks look the same as earlier engines. This means that emissions equipment can be placed on earlier blocks and pass visual inspections.
/wwwthreads_images/icons/cool.gif Use the wiring diagram for a '80 CJ with a 304 V8, it will be correct for AMC V8 swaps.
/wwwthreads_images/icons/cool.gif The Computer on later CJs can be taken out.

11) Engine Oiling:
/wwwthreads_images/icons/crazy.gif AMC V8s tend to starve the rear crankshaft bearings and distributor gears. The solution is to add an extra line to oil the distributor gear. That topic has been covered on this board. TEAMRUSH, any progress on using a TIG welding tip instead of an oiling line. Don't want to make your own, American Performance (407) 632-8299 makes an oiling kit that sends extra oil to the back of the engine and to the distributor gear.
/wwwthreads_images/icons/cool.gif Drilling 1/8 inch holes (chamfer them) in the lifter valley next to the lifter holes will get oil to the cam lobes quicker. My moonguys are wondering how necessary this step is?
/wwwthreads_images/icons/crazy.gif When you rebuild the oil pump, check the clearances to make sure that they are within specs (.002 or better). Otherwise, you might be wondering why your oil pressure isn't any better than prior to the rebuild when you fire up your new engine. There is an outfit out of Eugene, Oregon called FSRO (541) 461-2335 that reconditions timing covers and sells a gasket kit to achieve necessary clearance. Also, there is a new aftermarket replacement timing cover out on the market, although my moonguys say they are just getting back into production after making an improvement to the initial product.

12) Miscellaneous Information:
/wwwthreads_images/icons/crazy.gif The driver's side inner fender well is different between the I6 and V8 CJs. This only makes a difference if you are planning on running an AIR pump with your 360 swap.

My mooguys /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/laugh.gif/wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/wink.gif welcome any other moonguy crew with better information to correct them.

Did we forget anything?

Jeeper2
'86 CJ7/258/HEI/TF999/Dana44... soon to have a 360 /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif
 
G

·
In the middle of swapping a 360 in for my 304. You have some really good info there.

Headers:
Headman headers that are fenderwell exit for the 304, will work on the 360, with the automatic. You pretty much have to run side pipes though. Also, there is a .04 spacer that is supposed to be between the engine and trans on the amc bolt pattern th400's. When I disassembled the driveline, the spacer was not there. The spacer is needed to mount the inspecion cover and aid in starter mount. I had no illeffects on my front pump. I am putting this spacer in when i put in the 360 though. I got mine from turner 4 wheel drive. It was like $25.00. I do not know if it is 100% esential, but why risk it. This spacer was used on the pre-74 th400's also.

As or the fan shroud... I woul replace the mechanical fan, with an electric one, and then forget about the shroud. It is cheaper, gives a good horsepower gain, and is less stressful on the waterpump, especially if in deep water crossings, inless the clutch is in good working order. I have been running a single 14inch electric fan on my 304 with no problem at all. I have a toggle switch that turns the fan off during water crossings.

Jesse


Ignorance is the first step to knowledge.
 
G

·
I recently did this, I slapped an 83' Waggie 360 into my 85' CJ7 (it had an I6 originally) I used the MORE motor mounts and the CJ's wiring harness. I use the 2 core I6 radiator and it seems to keep it cool.......I rebalanced the I6 flywheel to 360 specs and it works great.......I kept the T5 tranny but have a 727 to swap in when it blows up (so far it is holding up fine).

If ya have any questions shoot me a mail [email protected]......I am not a mechanic but play one on the weekends ; )
 

·
Registered
Joined
·
4,893 Posts
the 304 is an internally balanced engine, the 360, 390, and 401 are externally balanced. this is why the part numbers for I-6 and 304 pressure plates and flexplates are the same. if you build an amc v-8 and balance the engine(who doesn't?) you can get a pressure plate or flexplate for a 304/I-6 and keep the engine balanced

~~Elusive~~
it's sort of still a cj thingy....
 

·
Registered
Joined
·
5,140 Posts
Hey Elusive

not to start an argumment, but where did you get that info?
that contradicts everything ive ever heard,read, seen, or used?
please explain!


OzarkJeep
77 CJ5, in a bunch of pieces right now
 

·
Registered
Joined
·
197 Posts
Jeeper2,

If you remember, probably a year ago or so you sent me a bunch of info on this swap...well, about March 24 I started this adventure and just got done with it about 2 days ago. I spent a week on the engine then Saturday preping the Jeep and pulling the old engine out. I could have gotten the new one in same day, but the parts place gave me the wrong clutch!! I was not happy...anyway, got the motor in on Sunday and spent about a week fine tuning it. You have all the right parts info...but here are a couple of hints to help prevent you from cussing too much. 1)When you disconnect the old motor, do it at the tranny and not the bellhousing...only 4 bolts 2)when setting in the 360, loosen the left frame rail mount to the end of the threads, set the motor in on that left frame mount and then take the right one and work it onto the frame, put the bolts in, leave them loose work the eng mount onto the frame mount put the nut on it and then tighten the frame rail mounts on both sides. It took us almost 5 hrs to get this motor in right. I was also fortunate to have this advice before I started.3) put one tire up off the ground a 1/4 inch or so so that when it come time to line up the splines with the clutch you can do it easily by turning the tire. 4) take the front end of the Jeep off...6 screw and you can disconnect the wires at the wire bundle plug on the firewall. Cant think of anything else at the moment. Please ask if you have questions as it is still fresh in my mind. BTW I had a I6, T150, Model20 set up and all is the same but now with a 360...WHAT a difference a little torque makes...I did get the whole operation on digital camera BTW...I took plenty of pictures to be sure I had something to look back at in case I forgot to mark something, or just needed a reference...

/wwwthreads_images/icons/cool.gif
JK
O|||O
78CJ5 360
 

·
Registered
Joined
·
4,893 Posts
i just bought a flexplate for my 304 and it is neutral balanced, i looked the part numbers up for 304, 258, and 360.
the 304 and 258 are both the same.. both neutral balanced, but the 360 has a weight welded on it and holes drilled in the other side. i looked at my 304 pressure plate and compared it to my 258 pressure plate, i know that you can't tell the balance by looking at them, but they are identical.. so, unless the 258 is externally balanced or the 304 is balanced some other way than the torque converter, flex plate, or pressure plate, i don't see any external balancing. I'm not saying I'm right, I'm just saying what i know

~~Elusive~~
it's sort of still a cj thingy....
 
G

·
From what I understand from my engine design classes. The I6 engine is balanced, by its geometry. Having 6 cylinders all inline makes the engine balanced as it is firing. I know my 304 has a harmonic balancer on the front of it, just like my 360. I have always heard that the 304 was externally balanced. Plus the 360 and the 304 share the same crank, right, so how could one be internally balanced, and the other externally balanced?

Jesse

Ignorance is the first step to knowledge.
 

·
Registered
Joined
·
5,140 Posts
i see the conflict there, Ive seen different part numbers for 258/304 flexplates and flywheels

also the flywheel on my 304 had a weight and holes drilled into it to balance.

but a 304 and a 360 use the same crank, so i ssume its externally balanced too

OzarkJeep
77 CJ5, in a bunch of pieces right now
 

·
Registered
Joined
·
4,893 Posts
perhaps the harmonic balancer is enough on the 304?.. i know my 304 was balanced and blue printed, and i am happy to get the neutral balanced components for it. you could be right... i am thinking about it..i don't think they ever put the tf727 behind a 304.. i know the waggoneers used the 258 and the 360. maybe when i ordered a flexplate for mine, and i told them that i didn't want the 360 flex plate, they gave me the only alternative(258). but i looked in the book myself and saw that the 304 and 258 were listed as the same part# when i went.. but i see your point about the cranks... i just don't know

~~Elusive~~
it's sort of still a cj thingy....
 

·
Registered
Joined
·
6,870 Posts
Now you know how hard it is to collect the information to do an article like this!!

And NOW you know how hard it is to process this much information and make it comprehensible...

Keep up the collection of information, and post it again in about a week or two when you have the upgrades...
--------------------------------

As for the raging 304-360 crank balance debate...
The balancing guide that came with our balancer says that,
ALL AMC ENGINES ARE EXTERNALLY BALANCED.
(That may or may not be specifically true. I suspect any printed source.)

Just because the flywheel or flex plates will interchange from the 258 to the 304 doesn't disprove that...
Casting the counter weight on the rear crank shaft flange is still an external balance.
Countering with a harmonic balancer is an external balance.

My experience is limited to the 360, and it ABSLOUTELY IS EXTERNALLY BALANCED.
I have 304 and 360 harmonic balancers here, and there are big differences.
I did notice the missing weight on the 304 flex plates...

So Many Cats, So Few Recipes...
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #13 ·
Amen to that TeamRush /wwwthreads_images/icons/crazy.gif

Thanks for the encouragement. I know that the swap bit is weak on trannys to go with the swap, but I've been going the "adaptorless" route and would like to keep it that way. Once an adaptor enters the picture, then Chebys seem to find their way into the engine bay.

Did you ever get around to testing out the TIG tip thing to oil the dist. gear?

Later,

Jeeper2
'86 CJ7/258/HEI/TF999/Dana44... soon to be a 360 /wwwthreads_images/icons/cool.gif
 

·
Registered
Joined
·
6,870 Posts
This will never make it into parts mikes board, because it's a custom install, and there is no way to mass produce it, and therefore make any money off of it...
I see they have not one, but two different versions of my Ford Cap/ TFI upgrade over there for sale...
No mention of where they got the information....
--------------------------------

I drilled the left (odd) bank lifter gallery plug in the front at an angle directed at the fuel pump eccentric and the distributor gear.
I threaded the plug, and screwed it back into the block.
I screwed a 0.024" mig welder tip into it.

When the oil pressure is up, it sprays a continuous stream of oil on the top crankshaft gear.
That oil is slung out to the timing chain, and applys a continuous supply of oil to the timing chain.

When the slots in the gear pass by, (half of the gear is open) the oil stream lands on the distributor gear and fuel pump eccentric, (both of which run virtually dry other wise).

I found the Hobart brand of mig tips are made of a better grade of brass, and have convenient flats that help in screwing it in.

Entire cost of the upgrade, $2.
Entire time for the upgrade, under 30 minutes, but I already had the front cover off the engine.

1. Figure the angle from the plug to the distributor gear.
2. Remove plug from block.
3. Drill hole in plug.
4. Thread hole in plug.
5. Reinstall plug, taking care to aim threaded hole at distributor gear.
6. Screw in MIG welder tip.
7. Drink a six pack while commenting on how smart you are!!

----------------------------------

Better print this out now before parts mike's sponsors want $49.95 for the instructions.

"I Have The Body Of A God... Buddha"
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #15 ·
Wow, now that is cool. /wwwthreads_images/icons/cool.gif

My moonguy crew /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/laugh.gif/wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/wink.gif is so excited that they can hardly wait to rip that timing cover off. Thanks TeamRush. This is a significant addition to the AMC oiling system. While I'm at it, the moonguys want to know what you think of lifter valley line that some install on the 360, and/or drilling holes in the lifter valley to get oil to the cam lobes quicker.

As always, your help is much appreciated.

Jeeper2
'86 CJ7/258/HEI/TF999/Dana44... soon to be a 360 with Duraspark /wwwthreads_images/icons/cool.gif/wwwthreads_images/icons/smile.gif
 

·
Registered
Joined
·
2,209 Posts
This may be the wrong direction, ( I know NOTHING about AMC V8's) but the whole internal/external balance thing brought up memories. Big Block Chryslers could be both internally OR externally balanced. Motors with forged steel crankshafts are internally balanced, while motors with cast iron cranks are externally balanced. I don't know if this applies to the AMC motors but it was worth spitting out if it makes sense to anyone.

Mike H.
1983 CJ-7 Laredo
1999 Dakota 4x4
/wwwthreads_images/icons/cool.gifo[[[[o
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #17 ·
Just re-posting to move it up to the front. I would have thought that this post would have generated more feedback.

If I was a horse, they would have shot me years ago... /wwwthreads_images/icons/tongue.gif
 

·
Registered
Joined
·
6,394 Posts
/wwwthreads_images/icons/tongue.gif The reason nobody's posting is that they are in awe of the range and scope of this post and the technical stuff in it. We did the oiler upgrade before TR thought up the idea of using an inside squirter. I just expanded upon the PM idea of an external oil line to the timing cover for in-service engines where you don't want or can't pull the front end off. We have a pictorial that we have sent to several guys to assist in making this oiler upgrade, and if you would like to see it I will send you one. We also have a crankshaft oiler enhancement in the works, and the first week in MAy we are going to try it on the 304 in the SNOJEEP. We are going behind the engine plate with a shunt that ties the two oil galleries together. The oiling system on the 304 must have been designed by a child....they could have just copied a Chrysler and done fine, but no..../wwwthreads_images/icons/frown.gif. I'll let you know how our shunt turns out. It is a lot less risk than the internal shunt that the boys from FLA install./wwwthreads_images/icons/crazy.gifMy moonguys/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/crazy.gifkeep mumbling something about getting it right from the factory.....I think they are remembering the big double-rocker Chrysler days.....sigh....now them was engines......heavy, yes.....but boy did they RUN!/wwwthreads_images/icons/laugh.gif

CJDave
Quadra-Trac modified by the crack moonguy/wwwthreads_images/icons/wink.gif/wwwthreads_images/icons/smile.gif/wwwthreads_images/icons/tongue.gif transfer case team.
 

·
Registered
Joined
·
422 Posts
Discussion Starter · #19 ·
CJDave,

I think your talking about a rear crossover? If so, I found a guy who has a picture of just such a beast on his web site. I'll post it on Monday when I get back to the office and can peruse my hard copy.

If I was a horse, they would have shot me years ago... /wwwthreads_images/icons/tongue.gif
 

·
Registered
Joined
·
197 Posts
What else are you looking for Jeeper2? I think it has been pretty well laid out for you. BTW, I am not sure what your plans are, and some who are more technically proficient than me may argue this with me...but I dont think, unless you plan for this engine to see the 6000-7000 rpm range, that you need to improve the oil system in the 360. For most purposes, the original configuration is sufficient. I would like to see more on the preferred clutch type though for those mounting to original CJ trannys....

/wwwthreads_images/icons/cool.gif
JK
O|||O
78CJ5 360
 
1 - 20 of 28 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top