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My 73xr7 conv is running just fine... but(always a but) I want it to run finer;) .

Its a 2v cleveland all stock.

Will the following mods be sufficient to make dangerous street noises?:

*Aussie heads-do these just accept standard/stock spring/rods/valves?
*Headers w/dual ehaust. Which brand headers (w/AT & AC)What size tubing? Flowmaster 50's OK?
*Intake upgrade. Should I go with a matching aussie 4bbl intake. A Edel Performer 2v or a Weiand xcelerator?
Matched w/ a Performer series 500CFM
*Is a cam and roller rockers really needed?

All input welcomed and appreciated.

Ed
 

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Cleveland advice... FWIW

The problem with your 73 351C-2V is that is a low compression motor. To get any serious gains out of it you'll need to bump the compression up a bit. Either get a set of Aussie 2V heads that have the smaller chambers, or find yourself a set of quench 4V heads.

OK, when you have done that, the next thing you need to do is feed that thing. That means camshaft. The mistake that too many people make is to go too large on the cam. Even a .500 lift cam is a big jump from your 2Vs stock .407 lift.

Now the engine is capable of breathing, but you're restricting its intake. Get a 4 barrel intake matched for either your 2V or 4V port size heads, whichever you're gonna be using. If you go aftermarket aluminum, you'll be taking around 55 pounds off the nose of your car! Stick with nothing bigger than a 600 to 650 CFM vac secondary carb for a mild street engine. The brand of carb is up to you.

Now that you've got the engine breathing in OK, you've got to get it to exhale. Factory duals will help a great deal. Long tube headers are better left to the street/strip cars. If you do want headers, stick with a small tube diameter to help out with low RPM torque. Make sure you have a balance pipe between the two sides too. It will also help with torque.

Exhaust size? Even the stock size should be good for the street. Use a quiet muffler so as not to attract too much attention to yourself. Make sure you run tailpipes to the rear of the car, too. Turndowns behind the mufflers will make the car much louder and annoying on long high speed drives.

What I have just described to you is about what I have in the closer-to-stock of my two Cougars (not counting the parts car here). With its stock exhaust, but using generic Turbo-style mufflers, it ran 14.80s -- with its 3.25 posi and factory high stall 4V 'CJ' torque converter. Add a set of 3.70 rear gears I have it down to 14.40s. Not bad for a 3800 pound car with stock cast iron intake and exhaust manifolds, eh? It does run of of steam above 5200 rpm, so that's my shift point. Oh, it will rev higher, but it ETs slower if I shift higher.

BetaCat has just a bit of a low rumble at idle. Just enough to let the street squirrels (nowadays I guess you have to call them 'ricers') that you've got something going on under the hood.
 

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351 c

tou can take your engine and add 4-v intake , carb , headers, and ofcouse, exhaust. thats only if your bottom end is good. this combo worked good in my 70 std.3.25 rr end. geoff
 

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Interesting 351C ideas. My '70 is a 351C-4V. When rebuilt, it was detuned to a 9.0:1 ratio. At the time, I figured the gas available now-a-days just isn't what it used to be. Apparently, the 4V big valve heads didn't have enough room for the hardened seats, so I'm stuck adding lead at every fillup. A minor inconvenience. Recently, I added an 600 CFM Edelbrock Performer w/electric choke. Seems to run somewhat fat out of the box, though to date I haven't played with the jetting. What would be my next move if I keep the Cleveland? A Performer intake, and HEI? I'm going to keep the stock exhaust manifolds since headers tend to develop leaks and create unwanted noise. A convertible has enough of that. Other ideas in the works is to get more of the HP (~250 I suspect) it does make to the rear wheel (i.e. electric fan, aluminum driveshaft, etc.). Maybe I should start my own thread...

Steve C.
 
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