Pre 79 vs. Post 79

[Anonymous]

Please excuse my ignorance as I am young and fairly new to engines in general.
I have a 66 coupe with a '81 200. I have restored the interior 100% and have now turned my attention to the engine. It runs well although the emissions control openings were plugged very primitively.
The question arose when I looked up the advertised hp for the 81 vs the 66 200. I was shocked to find that the 66 was rated at about 120 hp and that the 81 was only around 86 hp. This info was also confirmed by the Ford Falcon Handbook. My Questions are:
- is the hp back up now that the emmisions is off?
- Is the 81 a better, stronger, engine than the 66 original?
- Was the 81 still using a c4 with no overdrive? Since the engine matched the trans.

This is my first post and I would really appreciate any help that can be offered on this subject.

 

[CobraSix]

They had different standards.

The 66 motors are Gross, basically a theoretical number based on the engine displacement. This is the engine power with absolutely no parasitic loses, like Alternator, AC, PS, anything. I think around 1970 or so, they switched to Net Power, which is what Has been used since for determining power. The numbers are the same...

Slade

 

[xctasy]

Thats right! The net figure is about 16 to 35% less than the gross figure, depending on. It was nothing for a 60 's to early 71 car to be rated 40% higher gross than the 1972 on wards net readings.

Ak Millar in the mid 60's found around 67 hp at the wheels, which is around 85 hp net at the flywheel, or 120 hp gross at the flywheel.

Despite the emission controls, the smog 1981 number is about the same as the 1966. It has a much better head, huge valves, better valve seats, and 21 years of development to boot. The smog controls take about 16 to 20% of the power out of the engine, but there is a 16-20 % boost just in the head alone. When emission gear is plugged, it can sometimes make the car run too rich, so be aware of that if the fuel consumption is heavy.

The 1981 log headed 3.3, or any 200, is a sweet piece of machinery, with reserve strength to go right up to the 150 hp mark with only minor modifications. Mustang Geezer is a prime example, but Import Killer, Mustangaroo ,Jimbo65, and others are working there rides. The GT200 of Azcoupe is another beacon. Ricsmol's, 200stang, 66Sprint, dudes from south of the boarder and some other Comete and 'Coon punters (Not to exclude a bunch of others, sorry, ya know who you are!)

Well done on the fine choice!

 

[CobraSix]

(Not to exclude a bunch of others, sorry, ya know who you are!)

yeah...me...

Slade

 

[Anonymous]

Things to look for on that '81:
1. Does it have the Holley 1946 Carb or the Carter YF carb? If it has the Holley and the EGR is blocked off, it will be running rich, very rich. It's also nearly impossible to tune this out, because the passages in the carb control this richness, rather than the jetting. The Carter can be retuned easily.
2. Do you have 2 catalytic converters or just 1? If you have 2, replacing them with just one (or simply removing the little one that's located on the header pipe near the engine, replace with a pipe) will improve power and gas mileage, while still being legal. Many California cars had the 2-converter exhausts on them.
3. How many miles does the catalytic converter have on it? If it has more than 70,000, replace it. Your power and MPG will improve.
4. The C-4 tranny is common behind these engines. If you have occasion to work on it, get the torque converter upgraded or rebuilt with one that has all-welded vanes inside. This will improve the power transmission to the rear wheels (noticeably!).
5. This applies to the 1946 Holley carb (maybe others, too): the electric choke is pre-heated with a pipe from the exhaust manifold that goes into the choke housing. Inside the exhaust manifold is (was) a small coil of tubing that heated the air in the pipe. The bottom end of this little coil of tubing comes out the bottom side of the exhaust manifold and goes back up to the side of the carb, usually through a rubber tube (this is the clean air that feeds this 'choke heater system'). The problem: gas addidtives like MTBE eats away the little coil of tubing inside the exhaust manifold. This causes very hot exhaust gasses to end up inside the choke housing, which WILL warp the top plate of the carb. This causes the power valve to fall open inside, causing very rich fuel mixtures, rough idle, etc., etc. You can check yours by trying to adjust the idle mix screw on the carb: with a warmed-up engine, slowly turn the screw in until the engine dies. If it never dies, even with the screw all the way in, your carb is junk. A rebuild will only fix it for a few weeks, because the top plate is warped so much that the rebuild gasket will only seal for a little while, letting the power valve leak again very soon. It will have to be replaced, and the choke heater system changed.

 

[Anonymous]

81 might be a C5. Is it a low mount starter?

 

[CZLN6]

Howdy Pacman:

And welcome to the fold. A couple of more big differences between the "66 and your '81 200 engine.

The '66 was rated at just over 9:1 compression, while the '81 is at 8.2:1. That difference alone is good for 4 - 6 hp. The other improvements to the '81 head more than made up for the difference.

If you got the whole engine you will note that the '81 has electronic ignition. It is called "DuraSpark II". In addition to being electronic (No points) it incorporates both vacuum and centrifugal advance. A much better system than the vacuum advance only distributor in the '66.

After exploring the carb issues described by Mark P. above, take a good look at the ignition system. It is a very durable system, but needs periodic maintanance. The cap and rotor are the main wear parts, next would be plug wires. Spark plugs are cheap and should be checked often. If you haven't replaced them in a while, do so and look at them as needed. They are a window into your engine. Plug reading will help you determine how your carb tuning is going. gap the new pluges at .050" with the electronic ignition system and tune from there.

After all is up to par, set the initial advance at 5 degrees more than stock calls for.

Enjoy.

Adios, David

 

[Anonymous]

MarkP, you mentioned a pre-heat pipe for the carburator. I currently have a YF without an electric choke but with a heat pipe as you described. What years did Ford start putting the electric choke on the YF's? This is an upgrade that I would like to preform on my Mustang.


-Chris

 

[Anonymous]

Thanks to all for the help and insite.
To clarify some points brought up, The carb has an electric choke, and I believe that it has a low mounted starter consistent with 81 engines. However, the distributor most definatly has points. This seems unusual since an 81 engine should have electronic ignition. The thought occurred to me that it is an 81 head on an earlier block but again the starter seems to be low mounted(to the best of my knowledge).
I suppose that the distributor could have been swapped?
Also, The trans. seems to be a c4 since it has an 11 bolt pan. I also changed the trans. fluid using an 81 c4 filter and gasket which fit perfectly.
I will do some research to try and clarify the problem. I appreciate the ideas. Thanks.