Help! Anyone know the gross lift Ford 302 ???

I need to know the gross maxium lift for a 1983 Ford 302 w/4 speed trans . It is all stock and came from a Mustang donor car . Does anyone know or where I can find out ? I want to get a cam and don't want to go over the Max Lift . Thanks for your help ! Jim

 

I would call ISKY or comp-cams !!!!

 

Yeah call the tech guys at comp or even the guys at Summit.

 

Thanks ! Figured I would try here before I call one of the cam people .

HAPPY HOLIDAYS TO ALL !!!!

 

As for the 'max cam that will fit in your engine', my experience says if you are not at all interested in dealing with valve to piston problems, take whatever cam the cam company tells you is the biggest that will work, and go about 15 degrees of duration smaller, or call a 5.0 specialty parts joint, and go by their recommendation. Major cam company mostly only test the snot out of Chevy 350s, and _maybe_ 5.0s, but not necissarily. A specialist in your engine will _know_, not be making an educated guess.
Can you tell I've had customers run into trouble with that before?

The nuts and bolts:
Technically, max lift is irrelevant. It is physically impossible for the valve to hit the piston when the valve is all the way open, unless your cam timing (timing chain) is WAY off or breaks (in which case amount of lift is mostly irrelevant).
Why? Because by the time the valve is all the way open (for the sake of argument, let's say you are building a ProStock big block, and that is over 1" of lift), the pistons is several inches down in the hole from top dead center, and so still over an inch away from the valve at 1" lift. It is duration and cam timing that cause valve-to piston interference. In most cases, valve-to-piston interference happens between 1/3 and 2/3 of the max lift, and while yes, max lift does affect this, it is MOSTLY when the intake valve starts opening (or when the exhaust valve closes) relative to TDC that determines if you will have a problem. If you are under 1000 HP, the difference in lift _at the point of interference_ between the stock cam and the biggest cam you can get, is probably less than 5%.
So really, what you have is a max duration vs cam timing, not a max lift. Within that max duration vs cam timing, you could have a wide range of lifts depending on the intended use of the cam and the grinder.
For example, 2 cams we get (big solid lifter stuff, because that is the only thing we get from Comp) a Comp and an Isky with about the same advertised duration and the same cam timing (within a few degrees) are within a .005" of each other for valve-to-piston clearance (measured, not estimated). However, the Isky has almost 15% more gross lift and makes about 7% more power on the dyno. Since the Isky opens the valve faster, it has more lift with the same duration (and therefore makes more power), without hurting the valve to piston clearance.
Another of the big solids we get from both suppliers is the other way around (the Comp is better). In both cases, there are pros and cons to both options, but that is irrelevant here.

I just thought I would throw that out there just in case anyone cares what really determines that stuff and why

 

CadDaddy42 ,
I do understand where you are coming from . I need to explain better , what I am referring to is how much lift on Stock Rockers , not the adjustable ones and flat tap lifters . I know you can only go so far before the valve train will have to be changed . That is what I am trying to find out . I want to get a good cam for the street for my 55 Ford that has good low end torgue and has that great hotrod sound . I have a 83 Ford 5.o with 4/speed and 4:10 rear . The engine is stock with 600 Holley . that is the way it came from the factory . Thank for the time and help !
MERRY CHRISTMAS & HAPPY NEW YEAR !!!

 

Really nice, investment cast stainless, roller rockers - 1.6 or 1.7 - About $200.
The cheapest aluminum roller rockers on the market - probably under $100 on E-bay.

That being said - my guy said the biggest totally safe cam, considering both your stock valvetrain and valve clearance, would be the Isky 264 Mega. The 272 non-Mega is a possible answer, but would be pushing it. The 264 Mega is about 0.480 lift with the stock rockers. Because it's an '83 HO, it may or may not have springs that can handle that cam (and even if it had the good springs, they may be wasted). You'll want to pull them and test them on a spring tester to make sure they do not coil bind, and that they have enough pressure (they may all be weak from mileage, or a couple may be REALLY wasted from sitting with the valve open for a long period of time - no real way of knowing unless you know for sure the donor car was relatively low mileage and never left parked for a long time. It's best to test them on a tester, not by bouncing the valves off of your pistons
And of course, you'll need new lifters, since an '83 shouldn't be a roller cam.

Whether or not it will run well with the intake / heads / exhaust / gear ratio you have, is another question entirely. Putting a big cam in an engine with stock intake and heads is often counterproductive, but I don't know what you have and I'm not really a Ford performance expert. Lots of concepts are universal (such as 'mismatched components = poor performance'), but the specifics of what components are a good match, is really best left to a Ford expert.

Merry christmas