LPG Eagle from germany

[germaneagle]

Hi Eagle Freaks

This is my first post here, so let me show you my old Bird with some details of the LPG conversion i made to spare the some money ;-))
What you think about my projekt daily driver? When have some questions about the conversion pls feel free to ask !

cheers leinex

[Prafeston]

Nice ride! I like the BBS wheels. So it runs on propane?

[carnuck]

Looks like the system I'm putting in my '84 Jeep J10 with 4.0L (another one later for my Eagle with 4.2)

[eaglefreek]

Welcome. Nice to see another Eagle from Europe.

[germaneagle]

At the moment it is a cheap venturie gas system from Zavoli (Italy) without a extra gas CPU. In Germany we need the old venturie system because the german TÜV accept only the old kind technic - the car is registered as an oldtimer.
I planned to convert with a megasquirt injection and a 4.0 head swap or a complete conversion with AW4 / NP242 and the cherokee 4.0.
I have an offer for an 1989 Renix Cherokee near to me for only 400€. so I hope to by this for conversion. Is it the right choice for doing that?
Idrove the conversion as a monovalent system so no need for benzin since i build the propain system.  So i can pull out the fuell tank and replaced the bomb gas bottle in the trunk and placed under the car to have the full room in the trunk.
btw the BBS Rims are from my old Cherokee...they fits very nice on the Eagle with 215/75-R15.
I cut the fenders in the front and rear to match with the 235/75R15 but have no luck with the german TÜV... so i need th smaller one's.
What kind of drive shafts i need for the complete drive train, with the AW4 and NP242? it is a couple inches longer than the stock i think.

[eaglefreek]

I've got the Aw4/NP242 combo in my Eagle. I had the stock front shaft made longer and used a rear shaft from a 2wd Grand Cherokee and had it shortened. Since used Jeep parts are probably scarcer there, you can have the Cherokee rear shaft made longer. It just costs more because they just reuse the ends and add a whole new tube. The Renix 4.0l aren't much different power wise than the HO's and since you're using Megasquirt it's probably not much of a difference between the two. I have a Megasquirt system sitting in a box waiting to go on my car some day.

[germaneagle]

my past plan was to convert only the head and take the megasquirt injection, but with the increase of power it does not hurt to convert with the AW4. Did i need a different axle ratio in front or in the back? my front diff is a bit loose in the place where the left drive shaft comes out to the wheel. At the time it make no noise but an overhoul becoming apperent. Ive heard of an eventually direct swap from any Ford or so for the front diff. Is that right? Or only the gears matched from that - it is not clear now for me. the car comes from suisse originally, so it is possible that the towing gears or mountain ratio is installed - how could i find out from outside? how could i balanced the shafts when shorted or made longer? It is possible to made that for myself but normaly it is need to balaced the shafts to avoid hopping the whole thing like a rockers head ;-))
 I think the old renix system is nearly the same power as the HO's, perhaps it is a bit different in the intake manifould, but the newer HO manifould is only better at higher rpm.
The megasquirt part is as well new for me so we see who would win that fight ;-))
I have an different PCM layout - miniMS or kdfi - on my desk who is only a copy from megasquirt's origin design, but worked with the same software ( tunerstudio). This make the things a bit harder to work because there isn't much howto's out there for these systems.
Here are some pics of my past plan...

[germaneagle]

Everyone here who need some pics or infos about my 4.0 Head swap? I have the engine opened for convert the head, have milled the head for higher CR ( 10,5:1 ) - the LPG has 110 oktane!
at now i portet the inlet channels in the valve area a bit, and close the water channels with liquid metal. also changed with the 4.0 cam.
The megasquirt like EMS is at my bench for prepairing and testing - need to fabrikate some adapters for the trigger wheel...




Here is the milled head



the chain is absolutly warn out....



the engine bay is a bit messed up....



this is the old 4.2 head who is very dirty - but more than 30 ys old and since 1.5 ys my daily driver with LPG conversion - notice the colour of the outlet valves all hot with gas operations - perhaps they drive a bit lean in some conditions...

[carnuck]

Keep in mind the timing set for 4.0L comes in 2 designs. Renix (87-08/90) and HO (09/90 up) and the HO version has timing retard built in to cut the cam back and lower the VE (volumetric efficiency) of the motor to kill ping and do away with the EGR on the Renix motors. The 4.0L also has a cam button with a plate built into the 4.0L timing cover.

[germaneagle]

Hi carnuck!
Thanks for the hints! I have allready bought the timing set from the 258 engine. Is that right in my case? Did i have any problems to line up right the timing with a 4.0 cam? I have to search in google to see the extra plate parts from the HO system..... perhaps i need a adjustable timing wheel to be exact in timing with the cam?
Did you have any experiance with milling heads? perhaps i need shorter push rods or spacers under the rocker arms to prevent open valves with the milled head. Ihave milled 0.05 from the head, so it can go into trouble here. I find the head gasket in the 258was thinner than the 4.0 gasket who planned to install. the 4.0 gasket is in paper / metall mix and the 258 was only metal. but in compressed state the paper gasket is a bit thinner than now - so i have no clue where i end up here.
And oh i have big problems to pull the lifters out of the block, won't pull the oil pan for help to push out the lifters. They are sharp as a knife in the cam driving area. Perhaps have to grind the new lifters was another way to get the right position for the valve train. ( sorry my english is a bit of german taste  )
furthermore i noticed that the valve springs in the 258 are stronger in diameter an thickness that the 4.0 ones - the rockers looks nearly the same - only small differences in the form, but with the same ratio ( i read there are 6:1 and 7:1 parts possibly in stock). So where is the way to go with the springs? And where are the difference with the two cams? Where i can find reliable specs from the cams?

[eaglefreek]

I'll answer a few questions. My 4.0L head was also milled .0050 and I used the 258 pushrods without shimming the rockers.  I used the 4.0l valve springs and head gasket. I went with 3.54 ratio when I changed to the AW4.
Now a question. You mentioned making a trigger, what are you using for ignition for the Megasquirt? EDIS?

[germaneagle]

Yes i have a EDIS 6 for testing here, with 36-1 trigger wheel. in theory you could use a hall or VR sensor direct into megasquirt and it is the preffered method who is recommended at the megasquirt site, but my last experiance with direct driver to the coil was a burnt PCB, so i change to the Edis system who is normaly running out of the box with a wasted spark setup ( coil from a Ford explorer). the last test was with a hall sensor in an Cherokee distributor with my own fabricated window plate,  but there is a better solution with a Ford distributer i think, but in germany it is a nightmare to get the right parts from american cars, so i went to my own fabricated plate last time who you can see here.



So i went to the edis system - it is to make live easyer and prevent the PCB from cooking 
The goal for this setup where to get the right cirquit/sw parameters (PWM) for the low Z Injectors i need for the LPG system ( 2Ohm).
My head was milled 1,3mm or 0.05 inch so the Problem is bigger than yours to prevent the push rod problems....i think. I read about spacers in a jeep forum or adjustable rockers, but the rockers solution was very expensive and rare to get in germany. So i have to look, eventually shorten the push rods myself.

[germaneagle]

So guys
the porting is nearly done !





later i have to clean this up to see what i've be done here... what a mess ....

[germaneagle]

update

i've ported the head and grind my valve seats.

The water port all closed with epoxy metal, you could see here:



I'm curious if this stuff really holds.... we would see what happens soon...

[eaglefreek]

I've heard others use it without issues. I chose to have mine welded. It cost me $150, but I have the peace of mind that it won't fail.