Disclaimer, right up front. I am no 73-79 Ford expert, but have a good amount of mechanical ability. This is my first dent-side as a project, and pretty determined to save it from a life on the ranch. I found this guy set out to pasture~ 1974 F100 custom 4x4 with a 360, C6 auto and I am guessing NP205 transfer case. I did manage to get the limey bastid home after a carb rebuild, points and condenser and a fresh battery. Since then I have had to drop the tank and clean it up (single tank) and am going through the fuel system to r&r it.

I know it's unorthodox, but I wanted to see where the engine was at, so I ran a compression test cold just to see some numbers. Keep in mind it sat for roughly 5 to 7 years, but is is ALL original. The odometer reads 32K, and it's a fair guess that would be 132K. I am also at 7600 feet above sea level and realize the compression drops some for every 1000 feet or so, 3%?

My numbers were as follows:

1. 96
2. 98
3. 103
4. 101
5. 107
6. 100
7. 105
8. 96

I realize those seem a bit low, and with the temps here in the 50's/ high 40's is there concern for this old 360? I am planning to clean up the fuel system and rerun the test hot, but is this incredibly out of range given the circumstances? I will be going through all the gaskets, heads included and scoping the condition of each side... was really hoping to not get in the full blown rebuild yet, maybe later down the road though. Am really wanting to keep it as original as possible! What say the wisdom of the FTE?

 

Keep clean oil in it and run it.

You may consider pulling the valve covers and removing the broken bits of valve seals. You can replace the seals in the truck with the rope in the cylinder trick or compressed air. You need a valve spring compressor, face shield rated to .50 BMG, and some stretching exercises before and after each seal.

Otherwise, pull it and make a 445 out of it.

 

Copy that. Safety third~
I am gonna pull both heads and will redo them on my bench. I am gonna know more in the next several days, am hoping to avoid a re-ring... I haven't bothered with a wet test yet, until I can idle it and warm it up.

 

Given the low compression of the 360, I would run it, then do a wet test. Pulling the heads is a fairly large pita.

Your numbers are well within the per-cylinder variance numbers. Just a little low.

Just trying to save you work.....

 

Appreciate it! It's gonna get a partial tear down anyways and will get some much needed elbow grease and love. Want to clean the engine/ engine bay and everything whilst it is in my shop. The body has seen some abuse, as expected for anything in it's age range.... heck it's only a couple years younger than me and you should see me hobble around. :P

 

Those numbers look too good to have anything wrong with the cylinders. You need a warm test with the carb blocked wide open.

If no improvement, then a wet test. I bet the numbers won't change much from the warm dry test.

If the numbers on the last two test are low, I would look at the timing chain. With at least 132k miles, and 47 years old, the timing chain and upper gear would be well past worn if they are original.

 

Awesome... This is why I am a bit out of my element, but a timing chain kit looks fairly straight forward on these. Would a slack chain let the cam roll a bit off kilter in this 360? Makes perfect sense... between that and the heads/ valve stem seal and whatnot I am hoping to keep the engine in check until rebuild time. Looking at timing chain youtube videos now. Thank you sir!

 

The upper gear in a fiber gear. It wears down smaller, and the teeth gap gets wider. This, added with chain stretch retards the cam timing, resulting in low vacuum, late valve timing, and low compression numbers.

 

Great info... I have been ripping apart toyota/ jap engines for a long time, and mostly 80's/ 90's rigs and am learning a ton about old ford iron in the last week. Appreciate the help sir. Gotta say it's nice to work under a hood with this much space! Will post back here with an update when I get er done.

 

Your gonna do exactly what i did with my FE and im a mechanical noob. Taking the heads off sucks but then you get to clean them, polish the valve seats and get a new head gasket. Everything gets re-sealed and you have some peace of mind, just remember to orientate the head gaskets correctly "front is front" and one will be upside down "front" if i remember correctly. I had a hell of a time finding valve stem seals that fit to my liking, let me know if you run into parts or fitment issues, some of it is still fresh in my head, enjoy

 

Unless you have the equipment to replace the guides, grind the valves and put hard seats in there really isn't any reason to pull the heads . if they're shot they need rebuilt, if they're not you pulled them for nothing. be prepared to take them to a machine shop if you pull them.

 

Well if they are good, then great... I know replacing the valve stem seal's on my bench is far less frustrating than trying to do them on the block. Plus it'll give me a chance to check out the pistons/ rings while I am in there. I actually have hand lapped valves a time or two... Though I admit head work isn't my area of expertise. I typically send them over to the local machine shop. Hoping to avoid the added cost though. If they look good and the valves/ seats aren't roached, I will run them.

 

Thats the current plan my man. Did you happen to pull a compression test prior? And what were the numbers if you recall? Similar, or higher?

 

I did not, I did MIC out everything when I had the heads off. Lots of things I wish I had done differently like a new timing chain. Just didnt have enough experience and know how to think ahead. If your gonna pull the motor, make sure you do new freeze plugs also, flush the coolant cavities... I flushed clumps of rusted goop out of mine and my valve guides were in great shape I did hand grind the valve seats and took my time cleaning the heads, new springs and valves. I invested in one of those small air angle tools and got the brush heads that wont eat into the surface but cleanup everything else. Oh and take your time with every nut and bolt, use heat and PB blaster if needed, I think I tapped and heli-coiled 3 different holes.....

 

Yup, roger that. If they are like any other engine out there I am guessing there's going to be issue's with the exhaust studs. I typically hose these down for several days with some penetrant oil, pray and say some hail mary's for five or six days straight. Maybe even sprinkle some holy water... I will have to yank the t-cover and have a look. From what I am reading though, it's prolly gone slack and will need a replacement.