Thread: 302 questions

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Does anyone have any idea what size combustion chambers these heads have? Its a 72 302 in a mercury comet. I am also curious why the 71 comet 302 2barrel had 210 horsepower and the 72 had 138 horsepower. Are the heads different?
I plan on rebuilding the engine in the car in the spring. I think it will be fun and some good hands on experience. The engine runs, but kind of smokes a little and is pretty gutless. Dont need neck snapping performance, I just want to be able to get on the highway without getting rear ended Thanks

This may help,click on it: www.mre-books.com/interchange/interchange5.html If you are builing a 302 this book is money well spent.

Josh; they went from a closed chamber head to a open chamber head so yes the heads are differant. Call some machine shops and ask for some 67 closed chamber heads off a 289.
These heads with the same pistons will raise your compression from 8.5 to 10.1
This will give you about 235 HP with a good 4 barrel carb.
My buddy down here in florida has 3 set of rebuilt 67 heads for the 289/302 in his machine shop right now. But call some of your local shops to save the shipping charge.
I'm sure some one will have some, I hope this helps you.
This is the book I recomend, to build a street healthy early 302 engine.
Ford Performance, includes all modern ford perfomance engines.

http://www.amazon.com/Ford-Performan.../dp/1884089275
Kurt

the cam will be retarted and dist.set up for emissions along with the lower compression.it could have an air pump. and they went to a different way of rating hp. of engines.

I used to used mallery dual points with weights instead of vacuum advance then I started using MSD's. If I didn't have to run Vac on the dist, I would not. Run Mech.
I didn't think the 72's had emmission stuff on it? A good guy to ask is Pat McCarthy
or Dave Severson. If it didn't come with it don't put it on there or they might lock that car in at that standerd. Man I used to build cars all the time in Vegas that had to pass emmissions. I put carbs, cams, headers all kinds of stuff then just turned it back when I went to have it checked at the emmissions station. Never had a problem with a new motor not passing. Kurt

Bunch of different ways to go on a 302, Josh.... Heads, cam, and exhaust really make the engine!!!! Best OEM type head to find is a '69 351W head, a bit of porting and they'll flow plenty for the street... After an unsuccessful search for a set of them rare buggers, there's a bunch of different aftermarket heads, aluminun or cast iron, that will really wake up a 302..... Bottom end is basic, good specs and finish on the crank, 0 deck the block, flat top forged pistons, good rods, bolts, windage tray, oil pump, etc......

You know Dave I was gonna say the 351w but I got it mixed up with putting the 351C
heads on the 302 with the Yates intake. And the head bolts are bigger so you either have to buy sleved bolts or have the bock re - threaded to except the bigger head bolts.
And that is not mentioning the differant shaped water passages.
I just went back and looked it up the 351w head bolts are1/2 and the 302 head bolts
are 7/16 like I thought, but it is an easy fix anyway. Kurt

yup, just a matter of the right hardware!!

Thanks guys, that does help. What is the difference between open chamber and closed chamber? And please tell me what you think this combo is capable of.

1. rebuid kit from northern auto parts with .030 over hyperutectic flat tops
2. cam upgrade option with the kit is a speed pro with 260 duration and 457 lift int. exh.
3. good clean up on stock heads, valve job and new springs(stock rockers)
4. edelbrock performer intake
5. 600cfm vac. sec.
6. one of those heis with the gm cap and coil and stuff
7. am thinking about using the exhaust manifolds cuz headers seem to be hard to find
8. 2 1/4 dual exhaust
Not set in concrete on anything. This is just a rough draft, but I think I can do this for under 2 grand.

should work ok for a mild street engine...BTW the Maverick headers will work on the Comet, too....

hey Dave, do you think it will make more than 200 horsepower?

If you go to a 4 -V carb and some of the older heads or pop up pistons to raise the compression, you can do over 200 HP easy. Compression is HP, But stay around 10 to 1
to keep it streetable. Kurt

Take a look at this cam as a better choice,Summit Racing SUM-K4400 $99 cam & lifters this has more exhaust duration to compensate for a lack of exhaust flow with the heads you have,it also has the 302 HO firing order.It is the one I have in my 302,very pleased with it.

Thanks Jeff, what year is your 302

It is an '84 302 bored .040(last year for flat tappet) heads are 1965 Hi-Po 289 "K " code mildly ported,RPM intake, Carter Competition Series 625 CFM with an HEI.