1985 Jeep CJ7 with a 4.0L Carbureted Engine Swap

[rcomm3]

Ok, next question.  Will a ax15 from a 93 yj work with the 88 renix as long as I have the bell housing?  I have the clutch and fly wheel from the ba 10 that was on it.  Also, will the hydraulic clutch system from my T4 work with that trans.?   I guess you all could tell but I have very few mechanics skills but I am mechanical so Im trying to figure this stuff out as I go.  There are very few mechanics and no junk yards within 100 miles so it is difficult for me to grab a donor vehicle.  This means I need to know what Im getting into before I commit to higher dollar items.  Thanks for any help you can give.

[Moses Ludel]

rcomm3...I answered some of this at your other post...The hydraulic clutch master cylinder may work, it's simply a matter of fluid displacement and whether the clutch piston travel and slave cylinder release will take place with the existing pedal throw and master cylinder.  The slave's bore and travel are involved here.  You can compare clutch master cylinder bore diameters (check sizing in a rebuild kit or parts listing) and the piston travel.  They should be similar, and the pedal height can be adjusted slightly to change travel range.

I'm glad to help you sift through any of these questions and challenges.  We'll keep the discussion going...Others will have ideas as well.

Moses

[rcomm3]

So, i haven't been on in some time due to the fact that I was not able to download any pictures.  But.....I now have access to a laptop so now I can post the pics.  to give some background, I bought a 1985 jeep CJ 7 back in September (and paid wwwaaaayyyy too much for it).  I made the classic mistake of actually looking too hard at it and found a whole host of issues.  It ended up needing major body work as well as an engine swap.  I got an 88 renix inline six from a friend of mine and had it totally rebuilt and i have questions posted regarding that in earlier posts,  Here are some of the pics leading up to where I'm at now.

this is what I have for now .....I will post more and then get going with the questions as I have MANY.

[rcomm3]

here are pics of the motor before and after, the old motor and the enormous amount of body work leading to where she sits now.......oh and the last pic is my wifes idea of a joke...the only working jeep at the house.

[Moses Ludel]

All I can say is, "Wow!"  You really brought this one back and then some.  Nice to have a CJ for a 4-to-6 engine swap.  You have bolt-in engine side mounts and no need to cut and weld on the frame like a YJ or TJ Wrangler swap.

Congrats at this point...The scope of the sheet metal work is exceptional!  Keep us posted.  You should be in the driver's seat by Labor Day?  In time for Fall?

Moses

[60Bubba]

I think you'll like the 4.0.  I don't have any experience with one with carburetion, but overall it is a great engine for this chassis.  Enough power for rock crawling and on road use, but not too much to get you in trouble!

[rcomm3]

Thanks, it's been fun learning how to do this stuff albeit rather frustrating at times.  The welding was a trip,  but I can't say im sorry to have finished the welding on the sheet metal, what a pain in the butt.  The body is painted with Chassis saver then I used tintable bedliner for the exterior and the herculiner on the interior.  The engine mounts, once I got that all sorted out (Thanks Moses for your help on that) went on like a champ.  They are the mountain offroad Bombproof mounts.  The intake is Clifford Research kit which included the headers (dual exhaust) carb and fuel regulator and all hardware.  The carb is the Weber 38 DGAS/ES and came all set up from Clifford.  I am using a redline electric fuel pump mounted at the gas tank.  

I have however discovered that I am going to have to use an electric cooling fan instead of the mechanical fan.  Not what I wanted to do but it should work since  I put in an all aluminum 3 row core radiator that is rated for an 8cyl.  I just dont have the space between my water pump pully and the radiator.  I am rewiring the entire jeep with the painless set up  and an additional 7 circut accessory block so I should have plenty of circut space for whatever I need.

60Bubba, thanks for posting on your oil pressure sender.  I learned something there too.  I need to get a fitting for a 90 degree elbow for mine as well as the sender itself.  Which thanks to you I now know that I should grab one for a cj rather than one for the commanche, which is what this thing came out of.  I have all of the old gauges from the 4cyl so I never would have thought of that.  I did, however,  grab a new tach considering the old one was for the 2.5l.  No switches in the back of that one.

[Moses Ludel]

3 hours ago, rcomm3 said:

Thanks, it's been fun learning how to do this stuff albeit rather frustrating at times.  The welding was a trip,  but I can't say im sorry to have finished the welding on the sheet metal, what a pain in the butt.  The body is painted with Chassis saver then I used tintable bedliner for the exterior and the herculiner on the interior.  The engine mounts, once I got that all sorted out (Thanks Moses for your help on that) went on like a champ.  They are the mountain offroad Bombproof mounts.  The intake is Clifford Research kit which included the headers (dual exhaust) carb and fuel regulator and all hardware.  The carb is the Weber 38 DGAS/ES and came all set up from Clifford.  I am using a redline electric fuel pump mounted at the gas tank.

Mounts look good, no fuss swapping engine types on a CJ.  Glad you got the fuel pressure regulator for the Weber, they need it to keep the needle seated.     

I have however discovered that I am going to have to use an electric cooling fan instead of the mechanical fan.  Not what I wanted to do but it should work since  I put in an all aluminum 3 row core radiator that is rated for an 8cyl.  I just dont have the space between my water pump pully and the radiator.  I am rewiring the entire jeep with the painless set up  and an additional 7 circut accessory block so I should have plenty of circut space for whatever I need.

4.0L serpentine belt water pumps vary in stick-out height.  Compare a YJ Wrangler 4.0L water pump to an XJ and ZJ application for the 4.0L.  You should find that the YJ Wrangler water pump and pulley will work with a mechanical fan and shroud.  If you do have sufficient clearance for the 3-row core radiator (be sure), try avoiding use of an electric fan. 

60Bubba, thanks for posting on your oil pressure sender.  I learned something there too.  I need to get a fitting for a 90 degree elbow for mine as well as the sender itself.  Which thanks to you I now know that I should grab one for a cj rather than one for the commanche, which is what this thing came out of.  I have all of the old gauges from the 4cyl so I never would have thought of that.  I did, however,  grab a new tach considering the old one was for the 2.5l.  No switches in the back of that one.

Keep an eye on the CJ sender, it's the right one but has a small orifice prone to clogging.

 

[rcomm3]

Having it going by Labor Day would be fantastic.  I hope I can live up to that.  

The electric fan is really just to get it going. I am still planning on the mecanical fan but I need to do some more research on it.  Here is the crux of the problem.  Originally on this motor the mech fan was mounted to the side and there was an electric fan to the other side due to the shape of the radiator.  I am moving the fan to the center and the water pump mount has a wider spread on the bolt pattern at approx 3in.  I have yet to find a spacer with that diameter and with the 1 1/8 pilot that I would need to mount it.  I ws going to remove the fan clutch and run the fan constant with a spacer because with the fan clutch alone, the fan would hit the idler pullys.  Plus the foot on the clutch barely fit with the wider bolt pattern on the water pump.  I even called flexalite to see if they made something to help me and they did not have anything and did not know where I could find what i needed.  Even with all of that said, the ultimate goal is to have a mechanical fan but for now, this will have to do.

I do have a carb question.  Do I need a fitting and hose on the float bowl vent or can I leave it as it came from the factory?

[Moses Ludel]

rcomm3...Check out the various serpentine belt water pumps for a 4.2L or 4.0L.  The serpentine belts began at the end of the CJ era and also ran on the 4.2L YJ Wranglers.  Easier to find the right water pump and pulley system.  There are V-belt drive water pumps (normal rotation) and serpentine belt water pumps, which have reverse rotation impellers.  Make sure you use a pump with the correct rotation for your belt system.  Your current pump sounds like a 4.0L XJ Cherokee type.

Can you take a picture of the Weber bowl vent?  I'll gladly comment on whether it needs a hose relocation with filtration.

Moses

 

[rcomm3]

Ok, here is the pic of the carb.  The bowl vent is in the center of the pic.   I also got my new tunnel cover and shift boots.

[Moses Ludel]

rComm3...So the vent is the raised casting above the bowl with the round opening that faces toward us, right?  Is there a pipe thread at the opening?  Did the instructions talk about venting to a vapor canister?  Use of a hose with a remote filter on the end?  What keeps fuel from sloshing out of this vent opening and down the carburetor and manifolds?

Please share the series Weber and whether there is an OEM application for this carburetor for a given engine/vehicle model?  I'd like to explore what vehicle manufacturers do with this vent for both emissions and to reduce risk of gasoline fumes under the hood.

If you're unclear about a model application, share the casting number, I'll do some exploring.  The carb kit instructions did not address this vent?  If you purchased the kit from Clifford, it might be worth a call there to see what they recommend.  I'd like to know.

Moses

1 hour ago, rcomm3 said:

 

[rcomm3]

Moses,

I found only one casting number on the carb.   It says  38DGASM and then below it 16B.  The port is not threaded so it would have to be a press in vent fitting, I think.  I haven't called Clifford yet but I plan on it tomorrow.  The casting number was located just below and to the side of the vaccum advance port on the carb next to the idle screw.  I don't think there is an OEM appliction for this because I don't think the renix motors ever had carbueration. I THINK they were all fuel injected.  The instructions did not mention anything about the vent and the model is the 38 DGAS/ES.  If you need me to I can post a pic of the number.  Thanks for your help.

Rick

[rcomm3]

I have another problem as well.  I started this in October and that is when I took off all of the fender support struts, aaaaannnndd now I cannot for the life of me figure out how they go back on.  I have 4 of the 6 on but there are 2 more that, well I just don't have a clue.  Do you have a diagram on how they went in?

[Moses Ludel]

rComm3...Is this actually a vent?  Does the port go through the air horn (casting top piece) and into the fuel bowl?  Take a peek inside the passageway.  

This could be a solid casting.  Logically, if this passage opens into the bowl, fuel could slosh out of the opening, and fumes would vent to atmosphere.  Please confirm by looking into this passageway; see if it actually opens into the bowl.  You can gently probe with a strand of fine wire if necessary.  You're simply checking for whether the passageway opens into the float bowl.

Moses

 

[Moses Ludel]

Regarding body supports (struts), here are factory diagrams.  As a PDF, you can zoom-in for details:

'81-up CJ Body Panel Supports.pdf

Let us know whether this answers your riddle...

Moses

[rcomm3]

Moses,

Ok, the port only goes in so far then stops.  It doesn't seem to go all the way through to the bowl unless there is a right angle somewhere and it goes down but I couldn't find any evidence of that.  I had a hard time seeing anything in there as it seems to back pretty far.

 

In other news, I just finished (pretty much) installing the painless wire harness and am getting ready to get the motor started for the first time.  I was looking at the rear and the vent hose has come ouyt of the port.  I tried to get it back in but it appears the threads might be stripped on the axle end.  Is there a fitting that just pushes in or will I need to find a fine threaded tap?  Just to be sure, the vent hole for the rear axle is over by the passenger side tire right?  Thanks

 

Rick

[rcomm3]

Oh and 1 more thing.  What direction does the oil pump turn in order to prime the motor?  I thought it was clockwise but I just want to make sure.  Thanks

[Moses Ludel]

Hi, Rick...The oil pump rotates the same direction as the distributor shaft and rotor: clockwise.  Your 4.0L oil pump is driven by the tang at the bottom of the distributor shaft.  The camshaft turns the distributor drive gear.  With the distributor removed, use your priming tool to rotate the oil pump's drive shaft clockwise.

Glad you have determined the Weber carburetor design.  Makes sense that this is not a vent, as it would be threaded or have a press-in port pipe if a vent hose were required.  It's likely just a casting blank on this application.  The bowl vent is probably one of the ports inside the air filter area.  This would be emission compliant and prevent fumes from wafting to atmosphere.

AMC-Jeep CJ7 Rear Axle Vent.pdf [This is a generic Mopar parts catalog diagram; the vent fitting may be on either side of the axle, depending upon the AMC Model 20 application.  Often, there is a brake tubing junction on one of the axle tubes that will dictate the vent position.]

The rear axle vent hose fitting on an AMC/Jeep Model 20 rear axle is Mopar part number J5353494.  This part has become obsolete in the system; however, there are vent fittings that press into an axle tube and also fittings that would thread into an axle tube.  If you can confirm which type vent fitting you have, there are different remedies for a loose fitting.

If this is a press-in fitting with a hole close to 1/8" pipe thread size, one solution is to cut fresh threads with an 1/8" pipe tap.  (Use extreme care not to let axle material slough into the housing; grease on the tap threads and a shop vacuum can help here.)  An 1/8" steel or brass fuel nipple with 5/16" fuel/oil resistant hose and a hose clamp will take care of the axle housing end.

The upper (typically plastic) vent has a one-way pressure cap that prevents moisture and debris from entering the hose and axle.  I like to mount this capped vent at the upper wheel well, out of harm's way and high enough to stay above water during moderate stream crossings.  The vent relieves axle pressure (essential to prevent seal leaks) while not contaminating the axle.

Moses

[rcomm3]

Ok, some more progress even though it is "oh my gosh" hot out.  I got the vent re-attached to the axle although it took a 3/8 tap.  Apparently the hole has been tapped before.  The wiring harness is in and the 7 circut accesory block is in as well.  I've got some new pics to post.  

Moses, I got the process for timing from another post but is there a way to determine whether the #1 cylinder is at TDC on the compression stroke without taking off the valve cover?  And since I don't have a mark for the #1 cylinder, do I just set the distributer rotor where I want the #1 position to be?  Then make the wires correspond.

Oh yeah, I figured out the whole fender strut issue......Feel like such a dope.

 

Thanks,

Rick

[rcomm3]

look, what I found....the owner won't sell but he also won't do anything with it.  Gosh that kills me.   Maybe the next project.....or stay married....HHHMMMMMM

[Moses Ludel]

Go for staying married...I still rubberneck at a clean FJ40 'Cruiser or a mint CJ-8 Scrambler...I get over it, though, and we'll celebrate our 40th anniversary in November...

Moses

[rcomm3]

Well, last thursday came and went and no joy with starting the motor. As soon as I hooked up the battery cables, the parking lights came on.  Turn the headlights on and the parking lights go out.  Try to turn the engine over, and all I get is a click.   So I now know I have gremlins.....Great.  After a few calls to painless and some advice from friends, I have found out that painless wired thier harness wrong. The hazards and the turn signal flashers were switched.  So I chased down what controlled what on the turn signal switch and switched the wires on the switch.  Ok, that works, then the electric fuel pump isn't.....crud.  Well I figured that out but now it doesnt shut off and Now I found fuel leaks at the regulator....damn.  Ok, no problem, I'll just fix it later because I have also found what I think is a bad master cylinder on my clutch.  I changed out the hose and now I can't get any pressure to pump the fluid to the slave.  It seems to have pressure on the first pump of the pedal and then nothing.  It goes to the floor and there is no resistance unless I leave it sit for a while then repeat.  one pump then to the floor.  I looked at where the push rod goes into the MC and it appears that the seal might be broken.  Sooo as far as starting it, well not this week.  Maybe next.  Has anyone had this issue with the clutch before???

[Moses Ludel]

12 hours ago, rcomm3 said:

...I have also found what I think is a bad master cylinder on my clutch.  I changed out the hose and now I can't get any pressure to pump the fluid to the slave.  It seems to have pressure on the first pump of the pedal and then nothing.  It goes to the floor and there is no resistance unless I leave it sit for a while then repeat.  one pump then to the floor.  I looked at where the push rod goes into the MC and it appears that the seal might be broken.  Sooo as far as starting it, well not this week.  Maybe next.  Has anyone had this issue with the clutch before???

rcomm3...Sounds like you need to bleed the clutch hydraulic system before condemning the MC.  The seal you describe at the MC sounds like the dust boot on the pedal side?  No signs of fluid leaking from the pedal side of the cylinder?  While the dust boot is purposeful, it is not the fluid seal.

There's likely air in clutch hydraulics from the hose changeout.  If you have a bleeder valve at the slave cylinder, bleed the system like you would brakes.  If no bleeder valve, try bleeding at the hose connection to the clutch master cylinder.  This can be a two-person chore, with one pumping the pedal and holding it down while the other "cracks" the hose connection at the clutch master cylinder.  Keep fluid level up in the MC while you bleed the system.

Moses