Hello everyone. I am new to your boards, but feel I am a decent mechanic. I have a few questions for all of you. I own a 92 Explorer that I use in the mountains. I pulled out the 4.0 and installed a 78 351W with a c-4 tranny. I took the 351 out of a 78 T-bird. Here is my problem. The engine does not seem to make any real power. Driving down the road, it does not want to go over 60 MPH. Even sitting in the driveway, when you rev the engine it does not sound quite right, I am sure you know what I mean. A well tuned engine just has that sound. Mine has a dull ness to it. I brought the electronic ignition from the T-bird and put it in the exploder too. I am wondering if there is actually a way to not have it wired right? Here is another little tid bit. When I put it in, it had a 2 barrel carb and a motorcraft carb. It ran OK, but not all there. I put a holley 2 barrel on it, and it livened it up a little, but not quite there still. Now, I have a stock 351W 4 barrel intake with a holley 4 barrel. It still runs exactly the same. The engine will spit and sputter at times, and pop through the carb. What is weird, when it does start to act like it is loading up, it will pop out the carb and then run smooth for awhile. Does that make sense? I am here because I am at my wits end, and really wanting to get everything smoothed out this weekend if possible. Any advice or help would be greatly appreciated.

 

If a 4.0 made the thing move a 351w ought to really go. I'd say you have some tuning issiues to deal with.
Have you put a timing light on it to check the timing? What are you running timing wise? Have you tuned the carb? Does it have an egr valve on it and is it working right?
What size exhaust are you running?
Give us some more information so we can figure this thing out
Clint

 

I am with 71swissaqua, sounds like when you replaced the distributor you put it in 180 out, I'd be sure that is correct before I moved on. Did you use the right firing order when you put the plug wires on? Good luck

 

Ok, this weekend I replaced the distributor. Pretty much had to as the old one was froze in the block and I could not adjust it at all. Dropped in the new dist. on Saturday. Drove it around on Sunday. It really seems to run smoother now, but it could be my imagination. It never popped back through the carb or anything though all day.


About my timing. I cannot really put anything on it. Everyone will yell at me for this, but I am using a harmonic balancer off of a 84 302. I put it on the 351 so I could use the serpentine belt. By doing this, I do not have timing marks to time off of.

You asked if I had tuned the carb. It has reacted the same with 2 different 2 barrel carbs as it does now with the 4 barrel. Also, I cannot do much with the 4 barrel as it is a stock carb, so the adjustments are not there.

Yes, it does have a egr. Do I have to hook it up? I have not ever hooked it up, should I?

Exhaust size? It is the stock manifolds going into 2" dual exhaust into 2 flowmasters. It should be free enough.....

So, to recap, it does appear to run better with the new dist. I need to tune it a little more though as it is hard to start right now. It did run pretty good, but I think I am still lagging in the power department for sure. 65- 70 was all she wanted to do. It also got pretty warm when I was making it work.

 

Well not knowing your timing, I still think that your timing is way off, a symptom of timing too far retarded would be overheating.

Do you have a vibration that doesn't seem to go away?

The 84 distributor (302) is for a 50oz balance all 351w used a 28 oz, so slowly your adding premature wear.

If by adding the new distributor you mean it may run better but your not sure then I would say you installed it using the old distributors base timing as a starting point. So if it were timing it would still be off.

You might consider starting over, get the right balancer, install it, take number 1 cylinder and find top dead center on the compression stroke, once you determine tdc then purchase timing tape for your balancer at any autoparts store, install it with the 0 under your pointer. Then rotate the engine to where the pointer is pointing at 6-8 BTDC (btdc will be to your left facing the front of the motor) loosen the distributor and take the cap off and see which terminal the rotor is closest too, make a mark straight down from the terminal to the cap base, remove cap rotate the distributor until the rotor is pointing at your mark, tighten down the distributor, install cap, the mark is your number 1 cylinder go from there with your firing order/spark plugs, reinstall plugs, make sure everything is secure, your initial is set. I would bet it runs a lot better now.

 

The balancer will not hurt me if I leave it, will it? I did not know I could buy timing tape. That would help out alot. I will stop and pick that up tonight.

What about that egr? Should I hook it up?

 

change the balancer now, very bad on bearing,crank and all moving parts

 

If the egr isn't hooked up I wouldn't worry about it, just be sure that where the emisson were hooked to the engine, like the intake or carb or back of the heads be sure that those ports are blocked off.

Well what your doing is your rotating assembly is off balance so your adding wear and tear to the bearings that normally wouldn't be there. Your engine but I wouldn't do it. Good luck

 

Do any of you know what year of 351w has the correct harmonic balancer? This one has 4 bolts to hold the single pulley. This would not effect performance right? Well, until the bearings go, and rods are sticking out, but right now it would not really, right. Well, I guess it could have an effect..........

 

big effect but not sure on the years of 351's

 

All the 351w dampers are the same balance so any should work. I just looked in summit and it states all 289 and 351w's they both used the 28 oz balance so I would say any 351w would do the trick.

 

The one I took off of the engine only had 3 bolts for the pulley. I will call around and see who has what available. Do you all really think that the balancer would have an effect on how the engine is running.

The 4.0 that was in it before seemed to move the rig alot better than this 351 does. That is sad.

 

timing and balancer, do a compression test

 

I will pick up the tape tonight, and try to get it timed tonight. The balancer may take a little longer.