Hi,

I have a '65 F100 with a 240 6 cylinder. I've had this truck for a little over a year, and I'm just now getting under the hood. I use it mainly for taking trash to the dump, but now I'm interested in making this truck a daily driver.

I think I may need to rebuild the engine. How do you know if this is required?

I'm seeing a lot of oil / grease around the 5th and 6th cylinder spark plug area. I also get backfires (I think out the exhaust) on high rpm decelerations.

Also, there is an oil leak at the intersection of the back of the engine and the (clutch/transmission/??).

Obviously, I'm not a mechanic. :-( I'm trying to learn, though.

I installed new points/condensor/plugs/wires/rotor/cap; and set the dwell and timing. It seems to run pretty good (except for the backfires)... also going up steep hills, the truck can't keep a speed much higher than 45 mph.

A note on the tune-up. I tuned up per the specs in Chilton's, and the backfires were frequent and loud on deceleration. (timing set at 6, dwell at 40). I moved the timing to 10, and the backfires were not so bad, but are still present. I suppose I'm reluctant to move the timing any further from the spec.

If a rebuild is in order, how do I go about finding the right shop for this job? I live north of Santa Fe, NM. If anyone has a recommendation for a reputable shop (in either Santa Fe, Espanola, or Los Alamos), I'd appreciate it!

Another question: I'm interested in converting the 240 to a 300. Would this be difficult for a good shop, or would I be better off finding a 300 and rebuilding that...

Thanks,
Daniel

 

First thing is to see if you have decent compression in each cylinder. Do a wet and dry test. You take comp. reading dry, then do it again with a squirt of oil in each cyl. Compare what you get between each test. If you don't get any change after the wet test, I'd say there's a valve problem. Most likely you have a valve cover leak causing the oil back on #5 and #6. Also I'd suspect a rear main leaking if you have oil in the clutch area.
I would also check to make sure the distributor is in properly. It could be off a tooth on the shaft, making it look like it's timed properly, but not. Bring the crank damper up to TDC on the pointer and pop the dist cap. Look to see where the rotor is pointing. If it's 180 degrees off of #1, bring the crank around 1 complete turn. See how close it is to where #1 is. You can mark the base of the dist with a yellow crayon where #1 is to make it easier. I've seen them run being off, but you couldn't time them correctly. It would also contribute to the backfiring.
If you want to convert to a 300, pick up a pre 75 one. They are identical looking and will be a direct swap. Either way, I'd rebuild the one you want because that truck is probably just plain old tired out.

Barry

 

Got any holes in the exhaust system? That could cause backfire on decel.



Bobby.

 

Are the backfires through the carb or the exhaust?
Popping out of the carb is a valve adjustment issue and out of the exhaust usually means timing issues. Althought both symptoms could be evident from either condition, I suggest static timing the engine to deterime if the timing chain or gears are worn to the point of needing replaced. If this is your problem, no amount of tweaking is going to get rid of your problems.

I agree with the compression tests as well. This will determine your ring condition, valves, head gaskets and even the block if cracks are present. Side note: When doing the comp test, make sure to pull the ignition wire, wire the throttle full open, and make sure your battery is fully charged. Only crank the engine 4 or 5 revolutions with all spark plugs removed. Record the highest reading for each cylinder.

 

Ditto what everyone else has said. Sounds a lot like timing, so you ought to clarify that first.

The rear most leak may be from the rear crank main seal. You neglect to mention how much you are leaking. Do you get puddles? Only some oil and dirt on the sides? Do you have to add oil? How much? Some leaks should be lived with. Compression test may help find one in the head.

Regarding rebuilding -- if you are thinking of a 300, you are better off finding a good used engine, or buying a crate (factory rebuilt) engine. At least in terms of money. Did a little searching recently -- about $1100 for a rebuilt bottom and heads. You will put that much money in a full rebuild VERY quickly. Especially, if you are desiring a 300, it is just cheaper to get a different engine than to convert a 240.

Of course, if you are thinking of putting together a performance 300, say with a higher compression via 352 pistons, 240 head, performance camshaft, etc. Then a custom rebuild may be just the option. But didn't sound like that is what you are looking for.

I kinda doubt you need a full rebuild anyhow. Better hammer out the timing issues, consider a duraspark or Pertronix swap AFTER you have the timing correct, consider rebuilding your carb as well. Is it a 1101 Autolite with spark control valve? Do you have shop manual for 65?

Consider posting/looking over at fordsix.com as well, as you will find that most 61-66 folks are not 240/300 literate. No offense meant, especially to the other posters in this thread. But the 240/300 was only available in 65 and 66. Lessens you chances. I get a lot of good stuff out of the 67-72 forum as well, as they had the same engines for a lot more years.

later......

 

Yes, I think it's the main seal that's leaking. It is not leaking much (to the ground anyway), however it is very dirty. I'm seeing a few drops on the ground after idling for extended periods and sitting still.

I haven't been losing or burning much oil. But, then again, I don't drive the truck very often - only a few miles a week. I'd like to begin driving it more, though.

The rear differential leaks a bit, too. :-(

Daniel

 

I think the carb is an Autolite 1101. Is that the same as the Ford 1100? The only manual I have is Chilton's. And it is not specific enough for me, since I have very little experience working on cars. I'll need to check the Chilton book again, but I think my carb looks like a drawing of a Ford 1100. But then, the carb tune up instructions refer to the Autolite 1101... no mention of Ford 1100.

Anyway, it's a single barrel carb with the oil bath air cleaner. There's a tag on the carb, I'll get the numbers from it when I get home from work...

Thanks,
Daniel

 

In addition to these leaks, there are a few other small leaks in an area that I don't know the name for, so I'll descibe it... I can't seem to find a good diagram in Chilton's for this engine. :-(

Theres a rectangular plate across the side of the engine beneath the sparkplugs. This plate has 6 bolts (presumably attaching the plate to the engine). The bolts have what appear to be rubber washers. Several of these washers are disintegrating and leaking oil.

Can I just remove this plate by removing the six bolts? Get a new gasket for it, new washers, and replace? What is this plate called? Is there a specific order and torque for tightening these bolts? I can't find any info about this in the Chilton book.

I see that I'll be needing a real shop manual for this truck, eh?

I'll be placing an order for one tonight.

Thanks,
Daniel

 

This side cover is probably the lifter or pushrod cover. (been a long time since I worked on a 6!). This cover can be removed and rtv used to seal it. You can also cut your own gaskets from cork or rubber gasket material found at most auto supply stores.
The gaskets should also be available if you do not wish to make them.

 

There aren't any holes/leaks at the exhaust manifold that I know of (how would you detect a leaky exhaust manifold gasket?).

However, the exhaust pipe/muffler assembly is very loose and rusty at the connection to the exhaust manifold.

Daniel