Swappin' a '94 longblock in - questions

tbird88

tbird88

Registered User
So, I have a '94 longblock that I wanna back up with an auto and have a few wiring questions. It's goin' into a '91 auto chassis but I got to thinkin' about pinouts and all kinds of other scary stuff so I figured I better ask the experts.

(1) Please tell me I can (somehow) use the longblock as-is concerning the 36# injectors and the crank sensor wiring harness. What I wanna stay away from is havin' to swap an early timing cover/sensor/damper and also injector harness onto this late engine and still be able to simply drop the engine into the '91.

(2) Anybody ever bolt a 4R70W flexplate to an AOD converter? Does it fit?

(3) Is the '91 EEC gonna freak out and why?

(4) Keep the early O2 sensors?

Feel free to mention any and all other possible pitfalls ya might come up with.

'bird
 
Id say yer going to have to swap out the crank sensor...Not sure about the flexplate..And get the correct mass air for 36lbs or use stock 30lb injectors and your stock EEC 91 computer either way..

No easy way around this one..Well if you have an EEC tuner or a chip burnt you c`an use the 36's without a computer swap...But..ya know...
 
Like Damon said, the whole DIS system was upated in 94. To use the 94 in your 91, you will have to swap out the damper and crank sensor. I believe the sensor will fit without changing out the timing chain cover. You wil also want to swap out the AC bracket so your 91 DIS will have it's needed heatsink.

I don't know if we have ever fully resolved the knock sensor issue. The 94 style is physically different from the early style, but the signals might be the same. If you have a VMM and want to keep you may have to swap oil pans. I would use the wiring harnesses from the 91.

The passenger side exhaust manifold is different on the 94.

The 91 did not have EGR, but I am sure you can just remove the 94 EGR and make a block off plate for the plenum.

I'm not sure if the 36lb injectors will cause any issue. Maybe XR7 Dave will see this and update us all on those tuning issues.

Brian has a similar thread in the member's area. Maybe we can all collaborate and come up with a FAQ listing.

http://sccoa.com/forums/showthread.php?t=55027
 
Good idea George let's combine these threads.

OK,the Harmonic Balancer and Crank Sensor are different. If I change the crank sensor can I then simply change the encoder ring on my BHJ balancer or is the balancer design totally different.
 
The 89-93 damper is different from the 94-95 in both stock and BHJ models. The mounting area for the sensor rings are different.
 
I quizzed Vernon on a few points and he brought up a few others. As far as the injectors are concerned, they'll stay, part of the cure for them will be in the chip. Keep in mind that this is basically a drag car under construction, rearend gear etc are for for further discussion down the road. Right now just need to get the engine to function in the car.

in no particular order...
1 - Replace ALL '94 wiring, sensors, DIS with '91.
2 - Replace the '94 damper with '91.
3 - Replace the '94 timing cover with '91.
4 - Use '94 oil pump.
5 - Knock sensor: use '91?
6 - Use '91 frame mounts.
7 - ?

'bird
 
Just use all externals from the 94 motor...the long block bare is a bolt in...Chip fer the mass air with 36lb injectors and yer set


Easiest way to go
 
Shouldnt u be able to use the late model 36# injectors with the stock early style wiring w/o needing a chip?
 
tbird88 said:
I quizzed Vernon on a few points and he brought up a few others. As far as the injectors are concerned, they'll stay, part of the cure for them will be in the chip. Keep in mind that this is basically a drag car under construction, rearend gear etc are for for further discussion down the road. Right now just need to get the engine to function in the car.

in no particular order...
1 - Replace ALL '94 wiring, sensors, DIS with '91.
2 - Replace the '94 damper with '91.
3 - Replace the '94 timing cover with '91.
4 - Use '94 oil pump.
5 - Knock sensor: use '91?
6 - Use '91 frame mounts.
7 - ?

'bird
Click to expand...

What is the issue with the font cover? Is it a mounting issue for the crank sensor?

Also in lieu of a '94 oil pump didn't someone (Melling?) recently start offering a higher volume pump?
 
SCrazy said:
What is the issue with the font cover? Is it a mounting issue for the crank sensor?
Click to expand...
Probably is. Gonna find out today, got an early and late to compare each other against.

SCrazy said:
Also in lieu of a '94 oil pump didn't someone (Melling?) recently start offering a higher volume pump?
Click to expand...
I think it's been available for quite some time now, don't know the # but I think there's a coupla threads on it.

'bird
 
SCrazy said:
What is the issue with the font cover? Is it a mounting issue for the crank sensor?

Hey everyone,

Just got my '90 SC running again this Saturday. It broke a rod about six months ago.

We used a block from an '94 automatic SC

Except for the block, everything else we used was '90 stuff including the timing cover. The crank sensor mounting bracket on the '94 & '90 timing cover are very different. We also used the '90 5-speed flex plate, '90 heads, all '90 sensors & switches, etc., etc. I do have the '94 super charger and intake plenum on that block, but that's a direct swap.

It's my impression that if you put a '95/'95 in an earlier SC, and used the '94/'95 timing cover, you would have to use all '94/'95 electronics including the EEC.

Eddie
Click to expand...
 
WhiteThunder, it sounds like you have had a chance to see both covers and I have not. I do have notes from a post made in the past that the earlier cover had been superseeded by the later cover part number (F4SZ 6019-DA) and the early one was no longer available. I understand they look different, but are you positive the newer one will not work with the older crank sensor? This could really be an issue if the new cover will not work with the older style motor. (Fast ED N, are you out there? LOL) We should get this part straightened out as to what will work.

The Melling Oil pump is M246.
 
George,

We took a close look at the '90 timing cover and the '94 timing cover. The '94 timing cover will work if you use the '94 harmonic balancer. But then we figured we would be using the '94 crank sensor and that may or may not match up with the '90 EEC.

The '94 harmonic balancer has "gear-looking" wheel that the crank sensor reads. It looks a lot like the ABS geared wheels the brake system reads. The '90 has a "three-window" opening that the crank sensor reads as the harmonic balancer turns.

The '90 crank sensor bracket is separate from the timing cover. On the '94 timing cover, the crank sensor bracket is built into the timing cover.

Overall, my mechanic and I were concerned about going with any '94 engine sensors, which we didn't know would or wouldn't work with the '90 EEC. Sure didn't want to find out after the engine was in.

Hope this helps. If you have any other questions, drop a line.

eddie

blackthunderbird@comcast.net

'97 LX Sport
'90 5-speed SC
 
I realize what the crank sensors look like on the two different models and you and your mechanic are absolutely right that you cannot use the newer style crank sensor and sensor ring wiith older model DIS system. The DIS was completely updated in 94 and is not compatible with the early style.

What I was getting at is that Ford now only supplies one timing chain cover that is supposed to supercede the early model and be able to work with either the old or the new style crank sensor and appropriate sensor ring. That is what I was trying to confirm or deny. Maybe that replacement number I quoted is different from what came on the 94-95 and will work with both and maybe what came on the 94-95 originally will not.

It sounds like you have seen them both and are saying the older style crank sensor will not fit the late style timing chain cover. I hope that new number will fit both or the early guys are looking at another obsolete part!
 
It will be interesting to find out if the new and improved timing cover works on '89 - '95.

In my situation, a rod broke in the '90 block. A friend gave me a '94 block and we just bolted up all the '90 stuff on the '94 block. Seemed the least complicated way to go.

What I recall is that the older crank sensor wouldn't fit in the '94 timing cover mount.

eddie

'90 5-speed SC
'87 LX sport
 
All of the 89 - 95 3.8 Bird timing covers, including SC, change up to F4SZ 6019 DA. This newer number doesn't include the oil pump, which used to come with the original part numbers.

The parts listing doesn't give any indication about a modified casting to accommodate both early and late crank sensors. So unless somebody can get an 89 - 93, and 94 - 95 cover side-by-side to eyeball them, I can't say if they would be interchangeable or not. If someone was to purchase the latest number new from Ford, it should be OK for any 89 - 95.


cheers,
Ed N.
 
Thanks for all the input on the timing cover. I think the mistake I made was making the leap to "assume" the new item was the same as the 94-95 original part.

It now seems that the 89-93 and 94-95 original timing covers will not interchange, but the new part will work with all years. So if you are putting a newer block in an older car that has the original timing cover, you'll need to swap the covers to mount the crank sensor.

Hopefully Tbird88 will give us some pictures. Anyone have a pic of the newer number that Ed posted?
 
Timing cover does not need to change

I did a swap of a complete 94 longblock into my 93SC...(I used all my 93 sensors and harness), the difference is that the crank sensor for the early model has a seperate bracket that will bolt onto the late model cover (the threaded holes are there for the bracket on the 94 cover but are not used with the 94 sensor, mine were all gunked up with road grime and were hard to see) whereas the 94/95 sensor bolts right to the cover. The other difference as George pointed out earlier is the knock sensor is different, I dont know how much effect it has on performance if any.
 
I have done the same swap in my sc only with a 5 spd. you have to change the crank sensor and the damper, i left the 94 sc, injectors, tb, and i have not yet flash tuned it or put a maf on it, it runs strong but runs a little rich. i have a c & l on the way with a 36 # sampling tube, ill let you know if it solves the problem of running rich. BTW i put 35000 on it so far and havent had a problem, and i used the later style O2 sensors. Even though its running way rich when you get on it, it still ran a 14.9 on street tires.
 
fast Ed N said:
All of the 89 - 95 3.8 Bird timing covers, including SC, change up to F4SZ 6019 DA. This newer number doesn't include the oil pump, which used to come with the original part numbers.

The parts listing doesn't give any indication about a modified casting to accommodate both early and late crank sensors. So unless somebody can get an 89 - 93, and 94 - 95 cover side-by-side to eyeball them, I can't say if they would be interchangeable or not. If someone was to purchase the latest number new from Ford, it should be OK for any 89 - 95.


cheers,
Ed N.
Click to expand...


Thanks Ed.

I bought a new front cover in December '01 for my '89 and the number you gave above is the number on my invoice from that time. Looks like I have the universal front cover and will just need to swap sensors.

Hard to believe but it looks like I came out on top this one time.

Brian
 
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