4.0L Head and EFI swap

[carguy87]

Recently pulled an old tired 4.2L out of the Eagle for a rebuild and thought, why not?  So here I am rebuilding it with a 4.0L camshaft and cylinder head and putting the EFI setup from a 1995 Jeep Grand Cherokee onto it.  I'll have more pictures and info as I go along.  I will hopefully have some great numbers afterwards too, planning to dyno it before I change to a Mega Squirt system and do any radical changes.  Little about my car, 85 wagon, it was a stock 4.2L with computer bypass, stock carburetor, TFI upgrade with 60k volt coil, ENVALVE, smog and vacuum gutted to my preference(4WD selector, EGR, and intake valves on the air cleaner), 3.53 gears, and 3spd. auto with lockup. I averaged around 16-17mpg and 19 highway.  Doing this as I lost compression in number 3 cylinder.

[Jurjen]

Good to have another 4.0 head project here.
Using the 4.0 camshaft is a good idea too.
Did you have the water sockets in the head welded up?
What are your plans for the exhaust manifold?

[carguy87]

I used JB Weld on the water jackets.  For now I am sticking with the stock 4.0L header and modifying the exhaust to route the right way.  Once I get the rings set and the engine broken in, I'm planning on switching to a Mega Squirt system, higher flow injectors, and putting a small Turbo on it to beef up the old girl and see what I can do without going too overboard.  Of course with the Turbo, I'll have to switch to an electric fan and probably a serpentine belt to keep it from slipping too much, but that is in the future.

[Jurjen]

I have electric fans, on a homemade frame:

[DaemonForce]

Woah that looks really nice. Are those tornado fans by any chance?

How does the whole thing sound when it runs?

[Jurjen]

No tornado fans, just some cheap fans from the evil bay, 80Watts 1250 CFM each.
They are still offered on the bay for about 15$ each.
I wanted to test if they had any influence on the fuel milage.
No measurable influence as far as I can say.
What I did notice is that they are never running, as long as you go faster than 15MPH they will never switch on because of engine temperature.
They are very quiet because of thet S-shaped blades.

[carguy87]

How much did that setup cost you? I might have to get some measurements from you   Are those 3 solenoids by the battery what you wired in to control them?  I would probably wire them into my 4.0 harness and fuse block to get rid of that code and keep it at it's happiest temperature.

[eaglefreek]

I installed a dual fan setup from a Chrysler vehicle. It works great under normal circumstances however, when it's over 90 degrees or up inclines, it gets really hot. I also didn't notice any difference in MPG. Carguy, do you have any experience with Megasquirt?

[Jurjen]

That set-up cost me about a $100. I have two relais switching the fans.
One relay is operated by the coolant temperature, the other by switching on the A/C.
The frame was made from left-overs from the company I work for.
It was intented as a temporary test, but since it functions very well, it stays in for the time being.

[carguy87]

Wow, it's been hectic here with my new job and the holiday weekend.  I finaly got some time to work on the car yesterday.  I managed to get the engine put together, painted, installed in the car, and most of the electrical installed.  I thinned out the harnesses quite a bit, but I got in a rush and couldn't thin down the harness going to the tranny and inside the vehicle yet, but what I did pull out gave me a lot more room.  For my CPS I welded up some angle iron to hold a piece of flatstock above a hole I cut into the transmission housing.  I will hopefully get a chance to run the plumbing and rest of my vacuum lines tomorrow as I finally have a day off.  I'll add updates and hopefully some pictures of the process in a couple days.

[eaglefreek]

So your using the factory computer first and then switching to Megasquirt later? The CPS won't be used with Megasquirt, ha e you figured out which way you'll trigger the MS?

[amcinstaller]

http://amccars.net/cgi/yabb2/YaBB.pl?num=1180803230/30

your megasquirt should work the same, or at least close. this one is turbo, and a 4.0.

[eaglefreek]

http://amccars.net/cgi/yabb2/YaBB.pl?num=1180803230/30

your megasquirt should work the same, or at least close. this one is turbo, and a 4.0.

Tom modified the distributor to trigger the Megasquirt. He's quite the smart guy.

[carguy87]

Debating on the MS trigger.  I am either going to use the distributor like many have, or my favored option, switching to a coil on plug setup like the newer model 4.0's and running a reluctor ring on the crank dampner to trigger the MS.  Right now giving it a proper break in is on top of the list though. Finaly got a few hours to do some work on it yesterday.  I was able to mount the fuse box and fab up a mount for my fuel pressure regulator, I wanted to put it up in the engine bay to keep it accessible and more accurate at the rail.  I also got my radiator, fan, and rest of my plumbing back in.  Pulled out the cable to rig up my transmission pressure actuator, just used the cable housing from the donor 95' Jeep and made a bracket to mount to the back of the tranny, I then went to the local Tractor Supply and grabbed a length of same size cable that was long enough to mount to the actuating arm.  Had to stop work to check out another side job and because I ran out of Fuel Injection hose clamps (I was 3 short ).  Hopefully Friday will be the break-in day.  Maybe post pics Saturday and a short description to keep everyone from guessing, lol.

[tougeagle]

Your project has me interested... I wanted to get some numbers down on mine so bad, and I was just a week or two away from doing it. MAKE SURE you get teh right size injectors the first time, should be no less than 24lbs/hr. I think I may have toasted the ring in the one I sold from a super lean condition at some point in time. Take it to a mechanic with a OBDI capable scan tool and have them check your fuel trim once it's running.  I'm very interested in the numbers...