backfire out the tail pipe question

[davidmij]

BTW, I tried a blob of grease to get the oil pump rod to stay centered - still can't quite get it.

-Dave

[Dakota Boy]

I've had that issue as well. I kept fiddling around, and eventually it dropped into place.

I also dont know the reason for the problem, but I'll be watching this thread for the answer!

[simplyconnected]

The reason it hangs is because the oil pump drive shaft is hexagon. The fact that your distributor hangs is GOOD, because it proves the driveshaft is there.

It isn't 'meshing' with the distributor's hex any more because you pulled it out and turned the distributor. Since you can't turn the oil pump from on top, you can turn the crank (which turns the distributor gear) until the driveshaft and dist once again mesh. Then, the distributor will drop down.

I used 1/3-turn as an estimate. A hex has six sides and the cam rotates half as much as the crankshaft. Soooo... you may need to go a little farther than 1/3-turn. You can't hurt anything by going farther (since the distributor gear is already engaged).

My question is; what caused the distributor to be off??? Was the distributor pulled out? If so, that answers that. If not, you need to check your cam timing in case the chain jumped a tooth. - Dave

[Dakota Boy]

This sort of stuff freaks me out a bit.

I always make some felt-tip marker marks on the distributor (before I pull it) to be sure the marks line back up when I put it back in.

I've recently ordered some books on Amazon that deals with rebuilding/servicing/hot-rodding these old Ford engines, but some of this stuff cant be learned by reading books!

Stuff like: "can you re-use a head gasket?" I know I can on my two-stroke motorcycles... but on a car engine... I dont know...

[simplyconnected]

Don't be disheartened, Dakota. The reason distributor gears are beveled is to make sure the natural rotation pulls the distributor down.

The consequence is, it cannot drop straight down upon installation. So... they make the oil pump driveshaft with a point on the end, and the distributor hex with a 'cup' configuration to guide the point in.

There's a whole lot about engines they don't teach you in the Service Manual. I have found inaccurate torque specs which caused me to break a head bolt. Thank God I got it out.



This bolt is on the end of a Y-Block head and it goes through a water jacket. That's why all the white goop on the bolt. Of course, it was the LAST bolt to torque. Yes, I did use the head gasket over, and it still runs very well. - Dave

[Dakota Boy]

some guy at work said you "never re-use a head gasket", but I'm starting to think he's full of baloney...

[davidmij]

Thx guys, I turned the crank just over a third of a turn each way, but I'll bet if I had the wife push down slightly on the top of the rotor it would have gone. I had googled the problem and saw that on a chevy the oil shaft has a slot - thus with the hex head I figured I needed to turn the engine about a 1/6 of a turn. After reading Dave Dare's post I realize that I need to turn it more like 1/3 (which I had anyway thx to his instructions).
I could get the distributor in when I went past where I wanted to be by one tooth. I'm sure that's because the hex lined up better there. I tried starting the engine again in that position and it backfired out the carb again. Sooo, I need to get it in where it belongs and try it again there. It's dark now so that will be next weekend.

A little history on the car Dave. I bought a 67 LTD for the 390 4 barrel. The owner (a younger guy) bought it 5 years ago to use as a frame for an old truck he wanted to put on it. Since then he had sold the metal trim, 390 emblems, some glass, etc. to another guy. He said he thought it didn't have any spark. He had replaced the coil, points, etc but couldn't figure it out. He said it had gas so he thought it must be a "spark" issue. A few years ago he rolled it outside to make room for another car he bought - it's been sitting there ever since.
I'm hoping I can get it running as is, however if it has serious problems I'm going to keep what I can, block, crank, rods, heads, manifold, etc. and use it and my 352 to build a 390. If I can get a couple hundred for the 9" rear end and maybe the tranny I'll scrap what ever else I can't sell and break about even. Nothing lost other than time. Anyway, that's why everything is an unknown.
Once again, thx for all the input.
regards, Dave J

[davidmij]

BTW again - you should write books Dave. You instructions are a life saver for us rookies.

[Dakota Boy]

X 2

rookies dont know what they dont know.

[simplyconnected]

X 2... rookies dont know what they dont know.

And the more I find out, the more I realize I how little I know.

David; alright, now we're getting somewhere. The engine is an 'unknown'. ALWAYS assume nothing, and start troubleshooting at the beginning (or you will end up doing it twice).

Pull the valve cover off of #6 rocker arms, and follow the instructions. I want to know what the damper pulley reads when those rocker arms are dead level (per the instructions). BTW, you can tell a lot by inspecting the rocker arms, especially if any are oil-starved.

Your distributor will act like it was off a tooth IF your timing chain jumped. Remember, electrical timing (timing light) is referenced to the damper pulley. It has NO regard for the cam timing. The last owner knew there was a timing problem but gave you a story (hmm... I've been here before). I'm hoping things are ok, too. But hey, worse case... a new timing set and a few gaskets won't break the bank.

Yes, it does help to move the distributor (slightly) while turning the crank. The distributor should drop right down. Do it after verifying your cam timing. - Dave

[davidmij]

Thx Dave D. I'll do that next weekend.
Before I put the 390 in my T-bird I want to try to get it running so I can see what all it needs, etc. That way when I do pull it I can work on everything a lot easier, new oil pump, rebuild the carb, hoses, etc, etc. I'm sure it's all a lot easier to do with the engine on a stand.
Right now i can't readily see where the timing marks and even the damper pulley are? I think my 352 has a different looking setup. Basically I think the 390 is part of a pulley, and the 352 has a disk with the marks. I'll buy a cheap timing light too - gonna need these tools eventually anyway.

thx, dAve J

[davidmij]

OK, had a half day off today and did some more work.
Had a heck of a time getting the distributor in where I wanted it, but I got it. Tried to start it and it did the same thing, spurting and coughing out the carb. I pulled the valve cover (drivers side) and leveled up the number 6 rockers by hand turning the crank. At that spot the rotor is in between the number 6 and 2 cap towers. Does this mean I am still off by a tooth?
One more problem - there is no timing pointer on the engine to check the timing - this might explain a lot - obviously someone was messing with the timing at some point. So, with the #6 rockers level and the rotor pointing ~ at tower #6 the timing marks on the damper are at about 11:30 as I look from the front of the engine. Does that make sense? Should they be more towards the the bottom? I was thinking maybe the distributor was put in 180 degrees off. But I believe from what you said Dave Dare that it does a 720 degree cycle so it is probably OK.
The good news is the rockers all have clear clean oil on them, and all the valves are moving and not froze. There is some sludge on top of the rocker that pivots on the pushrods, at least on a couple of the middle ones. I posted some pix.
So Dave, will I have to have someone weld a spark plug like you described to find true TDC? Or could I just mark the damper by turning the engine till the #1 piston is at top, and turn it around until the #1 is at top again and it mark it again - then measure? I'm able to find the top quite easily and accurately by putting a solid wire in the spark plug hole and cranking with one hand until I feel it come to a stop with the other.

Thanks in advance, Dave J

[simplyconnected]

...The good news is the rockers all have clear clean oil on them, and all the valves are moving and not froze. There is some sludge on top of the rocker...

Thanks for the pictures, Dave. To me, looking at the pictures, I can't imagine anyone putting heads back on, this dirty and gummy. If this engine was overhauled, it was certainly a very looooooong time ago.

With the #6 rocker arms at the end of Exhaust Stroke and the beginning of Intake Stroke, when they are dead level, your distributor should point directly at #1 spark plug tower. Yours is waaaay off. The important question is, why.

Sounds easy enough to pull the distributor and correct it to point at #1, and that should put you in the ball park. But, where exactly is TDC?

TDC needs to be found for two reasons; to verify your cam is timed right, and to time the spark. Do it right, and do it once. By skipping the correct order, you will do this job several times before finally doing it right.

So, let's find TDC. You need a positive stop, not a visual indication. I normally make my own for free, or two sources come to mind:
http://www.summitracing.com/search/P.../?Ns=Price|Asc
and eBay. You may get lucky and find one in a local auto parts store. Be sure of your spark plug threads before ordering.

Timing pointers can be purchased from just about any of the parts houses or you can make one out of heavy wire, firmly held down by any block bolt (or two). After all, the pointer should never touch anything. - Dave

[davidmij]

Thx Dave, I was just happy to see that the clean oil I put in it was being pumped through the head, and that none of the valves or lifters were stuck. This engine is quite a mystery indeed, a LOT of "whys". The valve covers have been painted with "poor mans chrome" (silver paint) along with some of the corrugated plastic wire wraps. It also had a "Nascar" sticker on the air cleaner cover, hence, I think someone, (probably a kid) was trying to make himself a hot rod back in the day. Anyway.

It's good to know that the distributor is about 180 off, maybe I can get it to at least run now.

Thx a million for the web site, I'll get the piston stop and timing pointer and work this per your instructions - hopefully soon. I REALLY appreciate your input, not just for this car, but for my 92 F-250 and it's 460 motor too. I'd be lost without your help.
Oh, also, I was looking at the end of the distributor rod to get the hex lined up with the oil pump shaft. I noticed it was kind of worn on the inside, like metal gets if it's been hammered. I had to clean up the burrs with a knife to get it to go in on the tooth that I wanted. I'm just telling you this so you'll know that I know that I need to re-work the motor. I do plan to do that now that I have seen how rough it is. It'll happen when I pull the motor and can work it on a stand.

Once again, thx a ton for your help.
Regards, Dave J

[simplyconnected]

Without hesitation, RUN to the auto parts store and buy a new oil pump driveshaft. Rule of thumb: whenever changing your oil pump, get a new drive shaft too.

All oil (from the bottom of the pan) goes through your oil pump BEFORE it gets to the filter. That means, bits of metal and everything else gets munched-up inside your oil pump rotors. Well, guess what drives the rotors...

Ford used 1/4" shafts for many years. Then, they went to a 3/8" hex for the 351W. 1/4" is too skinny. Buy a good, name-brand shaft. Apply lithium grease on the shaft before installing.

In my last post, I meant to warn you that spark plugs come with different threads (so you know which positive stop tool to buy). 14-MM threads are common to Ford cars, but check yours before you buy.

I hope this helps, Dave. No need to thank me, I'm just relaying info from the REAL Ford Engine Designers, who freely taught me. Good luck. - Dave