Hey guys - been away for a while, hope everyone had a great holiday and new year. I'm frustrated with my '72 - factory 360, bored out to 390 in the 80s, leaking oil (around the manifold I think), smoking, idling hi and missing. I looked at timing and found the indicator about 90 degrees off of the mark, but it still runs (what's up with that?) I just want to get it right, and don't have the facilities or the time to rip into it myself.

Question is - should I have someone rebuild the orginal FE or rip it out and go back in the with new? If new, then what? A 351?

I would also like to go with dual exhaust, but I am worried about keeping the truck true to it's roots. This old girl is a keeper, family truck since '75, stays inside out of the weather, so it's worth it to spend some $ getting it right, and it won't likely ever be sold, maybe shown but not sold.

What should I do? And does anyone know someone in N. Virginia that I can trust to do the work (either way?).

Thanks,

72XLT

 

OK, A little info for you, the 360 and 390 are the same bore block. The 360 is a destroked 390 truck only engine.

The leaking intake just needs to be resealed, nothing more there.

What color is the smoke, blue, black, or white?

Repair the leaks, and if the smoke is black fix the carb. but unless it is going through a whopping amount of oil, drive it. You can buy a lot of oil for what a rebuild costs. IMHO



John

 

John - you are the man, I was hoping you would chime in.

Does "destroking" account for the 90 degree timing change?

The smoke is black, and from the tail pipe I'm getting black splatter that will not wash off the house trim from backing out of the garage (wife is beating on me good about that). What do I need to do the carb? It's a Holly, 4bl, should I drop a rebuild kit or pull it off and take it to a specialist? Could the smoke, discharge and hi-idle be related? It's awfully hard to pin down, the truck runs like a champ @ 55 miles an hour, but sometimes (ZERO predictibility) revs up so high I'm afraid to put it in gear.

But I love it though, the '72 is a real head turner!

Stacy

 

The bore on both engines is 4.05 while the stroke on the 360 is 3.5 inches and the stroke of the 390 is 3.78 inches. Basically the 360 was a 390 block with the 352 rotating assembly. If you want to make your 360 a 390 just find a crank and rods, as the rods are slightly shorter than the 360. They say if you use the 360 pistons on the 390 rods with the 390 crank the compression will go up. Since the pistons are full floating, you can just remove the snap ring and slide the pin out and swap them over to the other rods. A lot of other engines use pressed pins and you have to take them to a machine shop to swap them over. Factory both engines should have been timed around 6 degrees BTDC. My 360 will not run any where near 6 degrees so I have it advanced pretty good.

Personally, my 360 has been a very good engine, although it is far from stock but if I had it to do all over again I would go with the 390. Same mileage as the 360 but lots more power.

What size Holley are you running? Mine is a 750 CFM which I know is way too big but I got a good deal on it. Mine smokes a little an idle but runs great on the high end. Like yours on startup it sprays my wall with black soot that is hard to wash off. It will burn your eyes to stand by it while the engine idles. I personally like Holley's and have all the gaskets, jets, squirters, accelerator pump cams and so on. With that being said I rebuild everything myself but I don’t know your mechanical ability but IMHO there is nothing scary about tearing into a carb. I will say you need to find a good bucket of carb cleaner, most parts stores sell it but it is rather expensive, but once you carb is apart let it soak in the cleaner and it will eat out any dirt that might be stuck in a small passage way. If your carb has any kind of a polish finish I will warn you the carb cleaner will eat it right off as I found out the hard way on one of my carb rebuilds. I am in the beginning stages of installing a 4.6 mod motor with fuel injection to improve the drivability of my old pickup. At this point I have had enough of messing with carbs and its time for a new challenge.

I hope this helps you out some, if not feel free to ask any questions.

By the way you have a real sharp looking pickup. My dad has one the same color that he uses as a farm pickup. However his is no where near as nice as yours. Do you have any more pictures of the inside?

Jeff

 

Jeff - my galery is "72 Ranger" and is @ https://www.ford-trucks.com/user_gal...?albumid=24382. Thanks for the info, I'll get an answer on the carb make model tomorrow.

 

No, destroking accounts for the shorter stroke not the timing. Someone would have to pull the distributer to do that or a timing chain jump.

I have someone else work on my carbs but there is plenty of help here.

Looks like some tune up and sealing will put your sharp looking truck back on the top shelf.


John

 

black soot on the side of the house is something my edelbrock used to cause. ran richer than bill gates. even fouled my plugs and caused erratic idle. i dont know anything about holleys but if you can get some type of tuning kit for it you will be pleasantly surprised with the results. i'm no mechanic. but definitely a do it yourselfer. theres very few people in this world of business that are not out to get you and just after your money. so to avoid all that i hit the books, make many phone calls to my dad and i learn a thing or two about a thing or two and i grab that wrench, hammer, phone crimpers, etc. with confidence

 

btw whats up with the 71 grill?

 

Front end is courtsey of the junk yard. Gat into a banged up a long while back, interchangeable parts, you know how it goes. It's on a long list of things that I need to fix.

 

The 90 degrees off on timing could be that the harmanic damper has slipped ( unless it is a solid one) the rubber breaks down and the outer ring with the timing marks spins. Put #1 cylinder at TDC by piston position and check the timing marks. Asking the extremely obvious, are you checking the timing on #1 cyl (Passenger side front) and not on #5 cyl, that would give a 90 deg. offset.
As for the black smoke, I would say the Carb, Hollys are known for power valve problems after a backfire.

 

I have a 650cfm Holley on my 390, and after rebuild, had to play with jet sizes for awhile. They are pretty cheap, considering you are burning a lot of extra gas with the black smoke and soot blowing out the pipes.

 

Nearly any engine will blow black stuff on startup. Normally it's black water/condensation. The real question is, does it warm up, run right, not smoke, and what about reading the spark plugs?

 

1971 Grille?

The grille shells are the same 1971/72. The 1970 grille shell is different.

1971/72 grille inserts (D1TZ-8150-A right & D1TZ-8151-A left) are identical.

The 1970 grille inserts (D0TZ-8150-A right/left is the same) have an egg crate pattern.

 

Say What?? 71 & 72 inserts are identical? They sure look different to me.


John