Hey guys,

I own a 1984 F150, 4x4, 351w, automatic C6 heavy duty tranny with stage 2 shift kit in it. It is a project truck. I bought it at an auction quite sometime ago. I got a used, rebuilt 351w engine and put it in...basically rebuilt the truck from the ground up. When I finally got to starting the engine, there was a clicking noise that sounded like the lifters. Here is the rest of the story...

3 days ago i finally got this truck put together. I got going down the highway at about 90kms/hr and went about 16kms and the truck died...got it towed home. Pulled the distributor and the gear on the bottom of the shaft was worn and sheared down on one side. I checked the camshaft for play, it was ok, no wear on the cam from the distributor gear either. Checked to make sure there was no drag from the oil pump by using a speed ratchet, everything was fine.
I had another distributor from an old 351w so I used it and put it in the engine in the truck. timed it, fired it up, sounded great and the clicking noise from before had gone away!!, went for a drive around the block. I figured all was great, so went out on the highway at about the same speed and same amount of distance as the night before, and pop, same thing happened, the truck went dead. I looked at it today, the timing had jumped. the gear on the distributor was ok, but seemed to be wearing as the other one had. so I re-timed it, got everything back into place, and now the truck will not start...turns over, spark is there, fuel is there....
this is the million dollar question

What could cause this to happen??? What can I do to diagnose this situation better...I just want this truck to run...

Sincerely,

banky

 

it has got to be out of time
is there a stock cam in the motor. if not is it a roller cam. if it is you need a steel distributor gear. sounds like your timing chain was not changed when the motor was put together

 

It may also be in the oil pump. I had a buddy rebuild a motor and didn't clean out the old pick like I said he should and guess what happened. Parts of plastic from the old valve stems seals had gotten into the oil pump cause a loss of oil pressure the the pin sheared on the dizzy gear.

 

I did replace the timing chain when i put the rebuilt 351w in. should i be checking it again...it was done properly by a mechanic.
I suppose that is where i should be looking first.

I have heard about the oild pump situation. I have checked it for drag, it seems to be alright. But maybe I should be pulling the motor again and just to make sure all this stuff is proper.

thanks for the info guys.

anymore info would certainly help a great deal...

banky

 

I am not sure if it is a roller cam or stock. The distributor is stock motorcraft, so maybe I will look into the steel gear.

thanks,

banky

 

If you have a 94 or newer 351W motor then you could have a roller motor.

 

don't get the steel gear if you don't have a roller cam. it will eat up the gears. it should not have jumped timing if it is a new timing set. are you sure that the shop is trustworthy. maybe they accidentally put the old timing chain on some new gears. you need the new chain and new gears that come with the set

 

does the motor lope when it idles or does it idle smoothly. sometimes you can tell if it has an aftermarket cam or not.

 

Whats the firing order?
is it 1-5-4-2-6-3-7-8
or 1-3-7.........
if it's the 1-3-7 it's a roller cam and you'll need a steel or bronze gear
if it's the 1-5-4-2..... one and it shreded the timming gear.....somethings not right.......=(

 

how many times did the 351w change it's firing order. i know of the 137 because the ho 302 have the same one.

 

Did you check the clearance between the bottom of the distributor gear and the block with the distributor installed? It seems to be a fairly common problem for 351W distributors to have a clearance issue in this location. This check must be done with the timing cover off.

BTW: All 351W and 302 HO engines use the same firing order.

-Matthew

 

The 351W has nevr changed it's firing order. It was the 302 ho motors that change to the 351W firing order.

If the clearnece between the bottom of the dizzy gear and the block surface I woould think you could clay the bottom of the diizy to get an idea of how clearence you have. It the clearence is tight then some blueing or heavy marker may do the trick. Look to see if the marking is wiped off when you install the dizzy and turn it by hand.

If this is the problem you could drill a new roll pin hole in the dizzy gear to locate it upward more away from the block surface.

 

That's a good idea provided you can either ensure that the clay doesn't get in the motor, or you use something that is soluable in hydrocarbons like playdoh. Obviously, it's best to check this clearance with a feeler gauge prior to bolting the front cover onto the block, but your idea could save a lot of hassle on an already assembled engine.

-Matthew

 

Hey guys,

Thanks so much for all the information. As far as this truck goes, I am stumped!!!

I checked the compression on all the cylinders, all check out fine. So that rules out the timing chain jumping, and like I said, I put a new one in.

As for the firing order, it is 1-5-4 etc...I dont think it is a roller cam, this motor is an 1983 block 351w.

The clearance between the gear and the block I dont know. Can you guys give me some specs for that please. What should it be?
It is an assembled motor, so that does cause a problem, but I will see what I can do.
From what points should I be measuring for the clearance? Where should I be focusing on?
I dont understand the blueing or heavy-marker option? please explain...

With all this said, we have re-timed it, got it back together, tried to start the truck and it will not even start now. Any thoughts on this issue? Realistically the truck should start after being re-timed...Something must be seriously wrong for the truck not to start after that episode.

Thanks again for the info...I will check the clearance and get back to you guys...

banky

 

When blueing or marking up a desired surface you will give yourself something easy to read. Kind of when two pieces of steel are rubbing each other they leave shiney surface from the rubbing. Well when you mark up the bottom of the dizzy gear and spin it you will remove the heavy marker or blueing from the bottom of the dizzy gear and that's only if you have a clearence problem will the markings be gone.

I would guess the dizzy may stick out a bit from the block if you did have a clearence problem?

If you wanted to clay it maybe you could wrap a plastic bag around the bottom of the dizzy with the clay in the bag. Oil up the outside of the bad just so things don't stick and you should also oil up the dizzy gear so you can remove the clay to measure it. I have never done this. It just kind of came to mind for some reason.

Was it the same dizzy that has always been in the motor?