Hello everyone,
I've posted a few times here. I updated my profile. Me --> new to Fords.

Backstory:
I purchased, this year, a 1977 F250 Highboy (Vin starts with F26) without any exact history of what's been done to it. The vehicle came from a vintage dealer who restores and didn't have plans for this truck. Long story short... I purchased this F250 as-is. It runs and just needs some tlc. Engine was rebuilt but don't know when, however I suspect it was more than 10 years ago based on the rust/patina on certain parts. Emissions were removed. It has a bigger cam, but don't know brand/size. There is a Comp vacuum canister (for the brake booster), so I could assume it's a comp cam. The heads are stamped "M" so this is most likely the original engine.

A few other facts.
- HEI distributor (brand unknown)
- Edelbrock 400 intake and Edelbrock 1405
- headers

With some of these details out of the way... this is where I'm at. Part of this tlc is a new cooling system... radiator, water pump, t-stat... etc etc. Radiator leaks. While in there... I looked at the condition of the timing chain and it's really stretched. No nylon gear though which I think means it's been replaced at some point.

Here is my question... how can I determine if this was setup with straight timing or if the previous owner took the 4 degrees out of the timing that Ford likes to do since it's an emission vehicle?

 

Ehewson,

Any offset will be evident at the interface of the timing gear and the end of the cam. You will see 3 dowels on the end of the cam. Take a good look at the gear. You should see if there is a provision on the gear to advance/retard or "straight up" in the way the dowels meet up with the gear. I imagine that some gears do not have a provision for adj, and can only be "straight up". I do not know of any way to check this without removing the gear, but it sounds like you will be working on this thing anyway.

 

Most truck destined engines had a wider 0.72" timing chain, the 1/2" wide sprockets, no nylon overcoated teeth, and straight up timing.

'73 cars with 351C, 351M, & 400s got the narrower 13/32" sprockets and narrower 0.62" chains and nylon over molded teeth with 4 degree retard.

Straight up has the crank sprocket with the timing dot direct in line with a tooth (like in OP's picture), 4 degree retard has the dot not in direct line with a tooth (the dot would be offset slightly to the right of a tooth then). I looked for a picture but never found one of a factory retarded crank sprocket. OP has the wider truck timing chain too, only the narrower ones were used with retarded timing in cars.

You can check by turning crank to one way to tighten the chain on one side, then measure the slack side by pressing it in towards the center with a straight edge and measure, looking for 1/2" or less.

 

My 1979 F250 had a 460 in it with nylon gears. They desintegrated and I put a different 460 in it.

 

I'd install a new timing set straight up. The timing set that is on it does not appear to be of the adjustable type so would have been installed straight up, and yes it has been replaced. Plus, not knowing the specs of cam installed, installing anything but straight up without identifying the cam specs, and then degreeing it, would be futile.

 

Yep... good point. I'll take a closer look at the gears. I think this is just a "straight up" set the PO put on. Also.... you are correct about me working on it for a while. I have parts coming today from summit and rockauto. In NY.... getting colder... so I want to at a minimum get it running before the snow comes.

 

Yep.... 100% agree. I have a double roller coming and plan on just using it straight up.

 

When you take the lower hose off the radiator, jack the rear axle up as high as your jack will go. That will tip enough water out of the block so you don't have water running into the pan when you break the cover loose.

 

I'll be doing mine and a water pump by Spring, maybe sooner depending on our weather. If it gets ... and stays ... cold .... it'll stay parked anyway.

11-20-2024: I checked my slack by turning the crank with a socket back and forth, distributor cap off, etc .... several times. Consistently got right at 1/4" on the 6-7/16" OD harmonic balancer, math says a hair under 4.5 crank degrees. I've researched & it seems 7 degrees is OK, but if 10-12 degrees it's about time to replace it. I am about 80% sure that I used a Cloyes branded set last time (maybe 60K ago), a silent chain version. Likely what I'd go with again.

 

Hey Everyone,
Timing chain replacement is done. Finding TDC with a vac/pres gauge in plug #1 made it easy peazy. I went with a double roller from Summit. I put it straight up. I thought about indexing it, but not now. Honestly... truck ran okay before... so I don't want to introduce too much tomfoolery. I just need to get this truck back to running/driving for the winter.

old left. new right.

 

Double check to make sure the distributor rotor is pointing to # 1 cylinder and the valves are shut for #1 cylinder. The crankshaft will turn twice to one turn of the cam.

Feel free to join the NY Chapter and check out the BS thread. We don't bite....well most of us anyway.
Where located in NY? I'm N of Ithaca.

 

Checking the distributor pointing to #1 is a good call out. Better to to be safe than sorry.

crank twice to 1 cam... make sense.

I am in Orange County. Yeah... I'll look for the NY Chapter and join. Is it a sub-forum here?

 

https://www.ford-trucks.com/forums/forum87/
See if that works. If not, go to the forums list and scroll down to "Regional Chapters"
How is the fire situation down there?

 

Thank you for the link. I'll check it out.

I had a chance to work on the truck after work last night... per your advice.. I did go back into the distributor and the rotor was pointing to cylinder #1.

Fires... not good. Many people displaced. Structure fires. I'm aware of 2 deaths. Thankfully... I'm not effected, for now. I am praying the rain today and tomorrow will help.

 

Update and question below.

Everything is back together. I have to say... I feel like the the engine runs better with the new timing chain. New radiator, new water pump, t-stat, etc etc... all work great. No more leaking antifreeze on the ground anymore. lol

I know there's a ton of information out there on how to handle the seals on the water pump and the timing cover on reassembly. I figured I would add what I did and what worked for me.

• Clean everything really really well! I can't stress this enough. Don't rush it. Take your time.
• Stick a rag in between the oil pan and block to prevent stuff from falling into the pan. It saved me twice.
• Scrap all old seal remnants off. I even lightly sanded a few surfaces (but lightly).
• I used a wire-wheel on a grinder to clean up the timing cover and did both sides. Don't go too hard... just enough to clean up rust, remove paint, and old seals. My timing cover is original... I could tell. It was pitted by the antifreeze.
• I used brake cleaner on a rag and clean all mount surfaces. Great for removing any oils, dirt, etc.
• I purchased FEL-PRO TCS45061 for my timing and water pump gasket set. I've used FEL-PRO gaskets on all my vehicles and I find them to be good quality.
• On all mating surfaces on the timing cover and water pump, I skimmed a coating of Permatex Ultra Black Silicone in addition of the FEL-PRO gaskets with my finger. Not too much... just enough to stick the gaskets, fill rust holes/pitting and sealed it well. Only where the gaskets touch the mating surfaces.
• This might just be a "me thing", but I recommend using the manufactures torque specs. I found that I had to go around the water pump several times and each time a bolt would tighten a little bit until they were all tight.

Question
I checked the timing and with the new timing chain and it was reading 0 BTDC at idle (engine at normal operating temp). I set idle timing to ~12 degrees BTDC. I have an HEI distributor installed by the previous owner and I have no idea what springs were used. I need to set the advance timing. What is the best procedure I should follow here and what would be a good setting? this engine is a mild build with a lumpy cam by the PO. I have no idea what cam, if they installed new springs etc. Looking for a safe setting.