Hi,


Hoping some of the more knowledgeable people here can give me a recommendation on a timing set.


I have a 79 F150 XLT Ext cab 4x4. I got into this project fixing a leaky oil pan. At this point it's turned into a new water pump, timing set, front/rear seals, etc.


I am completely new to this and learning as I go. I purchased a replacement timing set (standard replacement Cloyes set), however in reading the forums here it seems that the consensus is that the 1979 351m has a retarded timing set among other things, which diminishes the performance of the engine. I would like a specific recommendation on what I should do here. I am thinking I should return the set and get something different.


My goal is improve drivability. Think daily driver. For the time being I do not have any plans of changing the cam, getting headers, or anything else. So in the absence of spending a lot of money to change out a lot of parts and rebuild the engine, what would be the best choice for a replacement timing set that does not require me to change other additional parts.


I also thought about replacing with a nylon gear like the original (which is currently chipped, etc) to reduce noise, but those don't seem to be available any longer.


Thank you very much for your help. Please be specific with your recommendation, like providing a make and part number of your recommendation or link to it specifically so I can go into O'Reily with the info and purchase it. I really have very little idea what I am doing, so need you to be specific. LOL And thank you again!!

 

My understanding is that the only timing set that would have the retarded timing built in would be one from Ford that is specific to your vehicle. I other words, the aftermarket sets don't know which vehicle you have so they put the timing back "straight up", which is what you want. So the Cloyes set you have should be perfect. But most aftermarket sets give several positions, so read the instructions and use the one marked "straight up" or "0".

A friend of mine recently did this and was very impressed by the additional power he got with an otherwise stock engine. So enjoy!

 

The set I purchased has only 1 position. There were other options that had 3 or even more key's, but I bought the one with one single position. I can exchange for the other if need be.

Also there were recommendations on double roller, etc. Again, not looking to spend a lot of money, just get what is going to give best daily driver performance and be quiet, etc. I would have gotten a nylon covered replacement if I could find one for sale, but have not been able to. If anyone knows of one for the modified that would be great (found one for the Cleveland).


Also, if I put one back on "straight up" or "0" as you say, do I need to mess with the timing? right now I have the old gears lined up key up pointed to the dimple on the upper gear, tooth to tooth alignment as original. I assume if I put the new one on in exactly the same way I don't need to worry about getting a tool to find TDC or a timing light. obviously double checking all of that would be optimal, but the local shop doesn't have loners on either of those items.

Thoughts? And thanks again for everyone's help!

 

The ones w/o multiple positions put it back "straight up", so you should be good. As for nylon, you don't want it. The manufacturers learned long ago that it comes off, and it can easily clog the oil pickup and destroy an engine.

I don't quite understand how you have the engine and timing set, but your timing set should have instructions. And I would ensure the engine is on TDC on the compression stroke when I put the chain on. Further, don't assume the vibration dampener is correct as many of them have slipped. But, you can't use a timing light. You should pull the plugs and slowly turn the engine over by placing a breaker bar on the bolt on the crankshaft. Put your finger over the #1 sparkplug hole and it will be pushed off as #1 approaches TDC. Use a straw or somesuch inserted through the spark plug hole and touching the piston to determine when the piston is at TDC - all movement will cease.

 

here is a pic of what it looks like now. you can see the key marker line up and each corresponding tooth points directly at each other. if it had slipped, assuming the two point wouldnt be in alignment...is that correct?

here is also of a pic of the new cloye c-3005k set, which appears to have the same markers, etc for lining them up. again, this probably is all basic stuff to most of you. all new to me. first time tearing into an engine ever.

and so you believe that the new set will not be retarded, and the key is already preset to zero, so no need to get one with the 3 keys, etc or anything different.

sounds logical to me. If there are any differing oppinions out there please let me know. my plan is to start putting this back together as soon as I iron this question out.

also if there is any thing else you all think I should do while I have it down this far, please let me know. was a lot of work to get to this point and dont want to have to deal with getting that oil pan back off again, etc.

this is a farm truck I picked up about a yea ago.
what I have done so far, or have planned during this process is:

• new front and rear seals
• new oil pan gasket
• had nut welded in bottom of oil pan to fix cracked plug threads
• new timing chain
• new water pump
• new valve cover gaskets
• fix exhaust leak
• new transmission pan gasket (leaking) and filter
• Replace rubber hoses / rubber sections of fuel line / rubber hoses on power stearing / rubber hoses for transmission cooler / they are all crumbling and leaking, etc.
• one jet in the 2barrel motorcraft carb doesnt seem to put out much fuel and the throttle plunger on the front of it (dont know what it's really called) leaks, so bought a rebuild kit for the carb.
• And everything I have taken off (brackets, pulleys / etc) has all been scrubbed,scoured, and painted to stop the rust an such. It feels like I have spent more on various kinds of spray paint than I have on parts!!!

Everything else I had done to this point was simple tune up stuff/ plugs / wires / belts, etc and LOts of electrical. all the running lights / headlights, etc had been cut off the harness, so rewired all that, etc.
New seal on 4x4 xfr case, leaking around the knuckle going to rear drive

thanks again!!!

 

That timing set should work well. And, it should go on fairly easily. However, since the new timing set will offset the cam by a few degrees from the original timing set you will probably have to rotate the cam slightly to get everything to align. And, close isn't good enough. It has to be correct or the engine won't run correctly.

As for something else to do while you are in there, just use new gaskets and take your time. It isn't rocket science and it sounds like you are learning quickly.

On the carb, I suspect the thing you are talking about (throttle plunger) is the accelerator pump. When you open the throttle on a carb the air reacts much more quickly than the fuel can due to the difference in density. So, they use a pump to squirt fuel in during the movement of the throttle. One problem with the Autolite/Motorcraft carb is that it uses a Holley-style accelerator pump, and they tend to leak. So, you are wise to replace it.

And the jet you spoke of is probably the accelerator pump discharge nozzles. You should clean them out when you rebuild the carb. HOWEVER, do not enlarge them by running something hard through them. I use a piece of copper wire as copper is softer than the brass the nozzles are made of. And, don't lose the little needle and possibly a small weight that sits in the passage below the screw that holds the nozzles on.

Oh yes - the slippage I spoke of is in the harmonic balancer. It sits on the end of the crankshaft and the crankshaft pulley bolts to it. They are made of an inner chunk of steel and an outer ring with a layer of rubber bonding them together. However, the 35 years of heat, cold, rotation, and chemicals has frequently broken the bond and the outer ring may have slipped - and then the timing marks on it are wrong. So, when doing something as delicate as a timing chain swap I don't use the timing marks on the balancer unless it is new.

 

steeIhead,

Yes, I think you've got a handle on it! If aftermarket timing chains are anything other than "zero" or "straight up" they do so by having additional keyways that are marked +2, +4, -2, -4, etc. Hopefully this will improve your engine's performance. Obviously it is a needed repair! Those nylon coated gears do have a nasty habit of coming apart.

Sounds like you're getting this truck whipped into shape!

Make sure you get a can of carb cleaner to spray out all of the passages in the carb while it's apart. All those passages can get varnish buildup from gas sitting in there and engines not being run often enough.

Good catch Gary Lewis! I was trying to think of what jets he was referring to - and that's it, tha accelerator pump nozzles!

 

Been there, done that. Rebuilt the 2150 and drove 5 miles and the engine wouldn't hardly run. Turns out the junk in the fuel system had plugged the nozzles - in spite of having two fuel filters on the system. Those nozzles are tiny and easily plugged.

 

thanks guys!

I got a can of ChemDip to soak the carb parts in. that's what the guys at o'reily said to do. Pace I am going the carb project is still a couple weeks out still.

after I finish with this part of the engine, i'll hit the transmission pan next and then the xfr case, and then I should be....drip free. Unless I mess something up with the gaskets.

I bought the following gaskets

• standard paperish felpro gaskets on the water pump and timing cover (notes I read somewhere said to use a very thin layer of rtv on them)
• cork gaskets on the oil pan and transmission (was told to use 3m yellow trim & gasket adhesive on between the pan and gasket, and not the gasket and engine to help keep gasket in place when seating as well as strengthen the bond and prevent leaking)
• I put rubber gaskets on the valve covers incase I need to remove them. glad I did cause while the engine doesnt smoke at all, it does give a puff at start up and I've since learned that is a valve seal issue which will require replacing.

thanks again everyone!!!

 

Before you put the pan and valve covers on you should massage them, gently, with a hammer to take the dents out where the bolts have been. Just lay the edge on the edge of a table and use a hammer to take the dent out. Again, gently.

And, don't leave the carb in the ChemDip too long or it'll strip the plating off the carb.

 

I started to laugh when you said massage them gently, with a hammer....LOL

good idea though, they are pretty flat right now, when I set it on the garage floor face down it sits pretty even on the concrete, but the bolt holes may have some bend there, i'll definitly do that.

how long is too long with the chem dip. I figured I'd take it apart one weekend and stick it in there and then plan to put it back together the following weekend! so I am glad you said something! How long is too long? are we talking a couple hours, or a day?

 

The solution should say on it. But, I'd say 2 hours on just a dirty carb, and maybe overnight if it is badly varnished.

 

This might be going a little far but I would pull the oil pump and make sure the oil pickup was clean of the nylon teeth that are missing on the cam sprocket. Also how was your oil pressure before? I would replace the oil pump with a stock pump, but it is to easy for me to spend other peoples money.

 

If the oil pan is off it is very easy to see if the pickup screen has plastic on it. You wouldn't have to pull the pump itself to do that.

 

Ok, everything was sounding good until you said I probably would need to rotate the cam slightly...not sure how to go about doing that. also on the timing, since I have never set the timing on anything.....the idea of doing it without using the timing marks is a little daunting...not sure what to do there either.


That being said the harmonic balancer seems pretty solid. in spite of all the gunk elsewhere, it was fairly gunk free and the rubber has cracks, but still feels rubbery and doesn't seem to have any give, even if I try twisting the inner portion while holding the outter firm. So hopefully that is not an issue here.


Your comment about adjusting the cam is concerning though, how do you adjust the cam? is that another way of saying adjusting the timing?