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Whats this "tune-up" I keep hearing about?

3.2K views 16 replies 11 participants last post by  spinn  
#1 ·
So I finally bought myself a properly "aged" car. 1966 Fury III 4-door with a 318 poly and a 727. Drove it everyday for the last couple of months, no problems other than 16 mpg. I've heard that these can get 20mpg, and that would be nice.

It smelled strongly of gas when it ran, so I put on a open air cleaner (my attempt at tuning ;) ). I also ran some B-12 in the gas, sea-foamed it, and cleaned out the plugs. Mileage went from 16.5 to 15.5... Wait, what?

I'd like to tune the carb (never seen one up close, let alone tuned one) and replace the distributor with one that doesn't have points, whatever those are.

I'm familiar with most modern car stuff, not afraid to do any of it, just never had something this "mechanically classic" before. I suppose I could pay someone to tune it, but I've never had someone else work on my car, and don't plan on starting now.

I have heard that a later LA distributor will "drop in," then I heard some talk of boxes and coils, and how to wire it all. Doesn't sound like drop-in to me...

My plan of action is this:

1) adjust valves (I can probably handle that)
2) replace distributor, wires, plugs, maybe new coil?
3) pray to Flying Spaghetti Monster that I don't need to tune the carb
4) tune the carb

Where do I start with this distribution business? My goal is reliable street use, with an eye for gas mileage. I'm thinking LA non-points stock-replacement distributor, maybe an upgraded coil, and some modern tech plugs to match both. No idea where to start. Is there some 'box" that needs replaced or added? What about "lean-burn"? Can I use a lean-burn ignition and tune the carb a little lean for better mileage?

I'd appreciate any direction, just keep in mind I'm a total n00b here.
 
#3 ·
mrunexpected said:
My plan of action is this:

1) adjust valves (I can probably handle that)
2) replace distributor, wires, plugs, maybe new coil?
3) pray to Flying Spaghetti Monster that I don't need to tune the carb
4) tune the carb

I'd appreciate any direction, just keep in mind I'm a total n00b here.
No worries, we'll get you through this...

1) Don't adjust the valves. Its a very long complicated story, but your 318 has hydraulic lifters. Its a little piston that gets filled with engine oil and its like a shock absorber between the cam and the valves. They're kinda a set-it-and-forget-it thing. If you have a valve ticking, something has gone wrong and adjusting it won't help. If its ticking, let us know and we can help you out. If its not ticking, then they don't need to be adjusted.

2) an upgrade to the ignition system is a good idea. Start with plugs, wires, cap, and rotor. Also check the points for corrosion. Then read up on how to time the ignition including setting point gap. Ignition timing is set by loosening the distributor hold-down bolt and turning the distributor housing while watching a timing light. Its possible that your gas smell is from timing that has slipped and gotten a little behind the game. Back in the day, all of this was standard procedure for a "tune up" every 10,000 miles. If that doesn't fix the problem, move on to something else.

3) Ask the FSM to send me a hot 21-year-old asian chick.

4) Tuning the carb isn't the end of the world, but for a noob it might seem that way. I know it was for me. Carburetors work mechanically. The amount of fuel that gets sucked into the engine is relatively fixed by the size of the orifices that let fuel through. If a carburetor changes its amount of fuel delivery over time, something about it has become gunked up, clogged, or otherwise stopped mechanically doing its job. In that case a good quality rebuild should do the trick. That will leave you with minimal tuning to do on the carb. But trying to tune a carb to fix the problem usually ends up just making things worse. You would be trying to use external adjustments to fix an internal failure.

Do an ignition tune up first. There is nothing really wrong with a points ignition. It is a little weaker spark sometimes and it can be a little more maintenance-intensive. Stepping up to a later distributor is not a bad idea, but its not your smoking gun on the MPGs.

Get a good general auto repair book and read up. Tackle things one at a time. You'll do fine.
 
#4 ·
Curtis has it pretty well pegged. Only thing i would ad is check the dizzy for top bushing wear,cam lobe wear and if OK then set the Dwell THEN set the timing. Dont forget the special moly grease to put on the dizzy cam to lube the spot where the points block rubs the cam , so as to slow down wear and keep the points adjustment lasting longer.
 
#6 ·
The lean burn system used a small controller , and an oxygen sesnor and was a troublesome setup to say the least. You could upgrade to a chrysler early electronic system. the mid seventies cars is where you will find one. Go to the pick a part and get the dizzy and the module and the wiring and mod it up. That would get you out from under the POINTS thing alltogether, you just have to decide if it is worth it to tckle all the work involved.
It would be a no brainer for me , but I do that junkyard stuff in my sleep. :D
 
#8 ·
I totally agree with what latech has said.
STAY AWAY from that "Lean Burn" crappp.

OEM Chryco electronic ignition was usually very reliable.
Be sure to use a ballast resistor, and to make sure it is working.

Image

I hate to say so, but it was a fairly common replacement item.
When it fails ... no spark.
 
#9 ·
latech said:
The lean burn system used a small controller , and an oxygen sesnor and was a troublesome setup to say the least. You could upgrade to a chrysler early electronic system. the mid seventies cars is where you will find one. Go to the pick a part and get the dizzy and the module and the wiring and mod it up. That would get you out from under the POINTS thing alltogether, you just have to decide if it is worth it to tckle all the work involved.
It would be a no brainer for me , but I do that junkyard stuff in my sleep. :D
A '65 would not have the lean burn system. That was a '70s thing. However upgrading to the Mopar electronic ignition system and ditching the points distributor is a good idea. They're pretty much bullet proof. If you get the 4 pin orange box electronic system you'll only need a two pin ballast resistor. If you're going to get one out of a wrecking yard just get the ballast resistor that's on that car.
 
#10 ·
Is it a poly or late 318?

One of the best HEI system is a frankenstein of GM and MOPAR.

Use the GM 4 pin module and the Mopar single pickup factory HEI. The result is no mess or wires, and the best performance ever.

looks like this.
 

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#11 ·
form everything I've seen, 318 poly's have solid lifters, so it probably does need adjusted. its why its got reusable gaskets and only 2 bolts per cover.

this is a POLY, not a 318 LA. its got scalloped valve covers, and looks big-block big.

ok, so forget the lean burn. just a "regular" distributor sounds like what I need. I really do want to use this thing every day, and spend my tinkering time on something more...worthy. so i really want to ditch the points. i have little interest in originality. I want reliable, efficient, cheap, and easy in that order.

what is the advantage of the gm-chrysler hybrid distributor vs just a 70's "regular" chrysler distributor? I need to get some sort of module/adapter for it right?
 
#15 ·
#16 ·
mrunexpected said:
well, how do i tell for sure?
(Assuming that engine hasn't been run for a little while, but that the block is still warm to the touch.)

I'd think that if you were to remove a valve cover, then use a wooden hammer-handle or something similar to press (fairly hard) on the pushrod side of the rocker arm ...

If it "gives" a little, it's a hydraulic valve lifter.