It's pushing the envelope to get 1 HP per cu" in a dependable and drivable pushrod engine, so to expect 400 hp out of a 302 with the changes made is extremely optimistic IMHO. As said it was considered an "economy" engine so it is hampered by it's basic design. The small ports and valves are likely being overwelmed by too much cam and carb which are likely reducing power rather than adding to it.
Blue50, yes there is such a thing as too much of a good thing. An engine is basically an air pump it can only push so much air through per revolution. A carb depends on suction produced by the air flowing thru it to draw and atomize the fuel it needs, and the amount of fuel to air ratio needs to be close to a particular percentage to burn and produce power efficiently. Putting too big a carb on the engine is like trying to drink a soda thru a drain pipe compared to a straw, there isn't enough air speed to produce enough suction to draw the proper proportion of fuel into the airstream. The mixture ends up lean and does not want to burn. The carb is rated by cu ft/min airflow that produces the right amount of vaccuum to draw the right proportion of fuel. If the engine is only capable of moving 450 cu ft/min and you put a carb designed for 750 cu ft/min airflow the engine will fall flat on it's face and probably wont even idle.

And we haven't even touched on the other variables: stall speed of the torque converter, rear axle ratio, tire diameter and width as well as vehicle weight and engine driven accessories.

 

As usual, outstanding explanation by AX. The soda sucking is a good visual.

 

The ford crate motors are a good value. If you are on a budget the previously mentioned explorer motors are a good option.
Only the P heads need the diffrent headers the 96 and some 97 ones use a standard header. The explorer motor has higher compression, the best cast iron 302 head ford ever made and a good intake as well. The cam is for towing jet skis and gas mileage though.

The cheapest option would be to buy a complete Explorer motor, use the long block, sell the intake and throttle body to the mustang crowd ($200ish) slip in a used HO cam or tfs stage 1 roller cam ($20-120) and use your existing intake and carb. I have this basic configuration in my cobra and it dynoed 270 hp and 300tq to the rear wheels (with explorer intake, efi)

It was a really nice motor, well still is but I got crazy and did a $1000 junk yard turbo kit and now it puts out 395hp and 435tq at the rear wheels at 4700 rpm. Then I blow the spark out, need to get a msd box. But that much power is too much except at the dyno and bench racing meets.

 

You can do it and make it dependable but I would suggest that you look into a crate motor. My 93 mustang was making 426 HP at the rear wheels and I drove it at least 60 miles everday in the summer and raced it 2 or 3 times (yea right).

I had way too much money in the engine but it was fun (this is the one that I should have kept).

I have a .030 over 351W /AOD in my 56 and it seems just fine, just need to change to headers from the stock exhaust manifolds.

Chuck

 

Nobody has mentioned the HP increase of a set of Cleveland heads. I was under the understanding that with a few mods they will work on a 302 as they do on a Windsor.
Was I dreaming or is the possible? But the G40 will bolt on and still use the 302 intake.

 

One of the magazines ran an article on the 302 (I think it was Car Craft). They used a stock roller cam HO out of a Mustang GT. They used a set of AFR 185 heads (aluminum)with 1.94 intake valves, roller rockers, a Weiand Stealth intake with a 600 Holley carb, stock roller cam, a set of tri-y headers and stock ignition. this combination was good for over 400 flywheel horsepower and should be dependable. There is a link available but I can't find it right now. -- Chuck

 

What rear end gear do you have?Since you have an overdrive you could go to a steeper gear for that pull you back in the seat feel.

The 93 to 95 Lightnings came with 4.10,s.

 

Pappabill has not answered any of the questions. So I guess we scared him off. Jag

 

Or he's out searching for a new set of heads...

 

Arctic, It requires a unique intake manifold that was pretty pricey but I do not beleive is any longer produced. With much better and more bling aluminum heads available for under $1000 its no longer a good option from a power/price standpoint. Only reason I could think of to really do this now is if you are trying to make a more correct boss 302 clone.

 

So, I've got a Q. Again.

Carbs have CFM ratings...that makes it easy to know how big of a straw you're drinking soda through. BUT (and I'm sure I'm revealing my extreme ignorance here) but how do you figure the CFM possible from the various components of your engine? In other words, how do you know how big of a straw you can handle?

My hope is to get 200-250 rear wheel hp out of my engine by next (not this coming) spring. I figure that'll be powerful enough to make me happy/confident for what I want to do with the truck.

Finally, thanks for all the response--FTE at it's finest!

 

There are rule of thumb formulas based on engine displacement. The added mods except for supercharging won't change the size appreciably for street use since they typically will hurt the flow at low RPMs. You may need to up the main jet sizes some tho. Now if you are just interested in top end HP and don't care if it idles (ever notice how rough an all out carburated drag race engine idles even at 12-1500 RPM?) then the mods start helping to increase the airflow and you can up the carb size a little to what the flow is at the top end RPMs.

 

Using the carb size calculator here: http://www.netscape.com/viewstory/20...php&frame=true
and plugging in Papabills engine 302 Cu in, a max RPM 5000, and 90% efficiency (optimistic) it says he should be using a 350 CFM carb. That in a larger 2 BBL size, his 600 CFM 4 BBL has his engine sucking that sewerpipe hence the poor performance.
a2 BBL carb is not necessarily a low performing carb, there are a number of racing series that are restricted to using a 2 BBL carb, and there are racing 2 BBLs out there.

 

Wow Ax, that means my is even worse on my 289. However, is 5000 rpm normally the top end? I don't have a tach so I'm just guessing that mine revs higher than that. I can tell you that mine runs the best at about 85 mph and up. Jag

 

Wow Ax, that means my is even worse on my 289. However, is 5000 rpm normally the top end? I don't have a tach so I'm just guessing that mine revs higher than that. I can tell you that mine runs the best at about 85 mph and up. Jag