Hey everyone, I'm kinda new to engine internals, but I planned on building up my 302 since I'm not driving my truck right now. I've got a completely stock 302 2 barrel in my 1976 F100. About how much lift from a cam would the stock pistons allow without being notched? I plan on replacing my current pistons with forged stock style ones, and want a cam with alot of duration (for that nice lopey sound) but the one I'm looking at has .540 intake and exhaust. Could I have that much lift with stock style pistons?

Any help would be appreciated

-Dan

 

might have enough room, but check it anyways. I ran an XE274 on a stock 76 MII 302 but I did the valve train.... springs, studs etc. as you should as well with a cam that big. What cam is it? duration has a lot to do with it to.

not sure the lift of that cam but it's up there.....

 

It's a Lunati -- Advertised duration 310/310, Lift 540/540, Grind no SPM1-285-300.. Summitracing.com sells it as LUN-30605. I know, it's a full race cam. And yes, I planned on new rockers, springs, etc. Again thanks for the help. I may just have to talk to Lunati or a local machine shop to see about the piston-valve clearance.

-Dan

Hemi> P.S. I looked online (a quick google) and it looks like A) Comp no longer makes the XE274 for Ford Windsor and B) The lift on the XE274 is about .490

 

Brand: COMP Cams
Product Line: COMP Cams Xtreme Energy Camshafts
Part Type: Camshafts
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,800-6,000 RPM
Intake Duration at 050 inch Lift: 230
Exhaust Duration at 050 inch Lift: 236
Duration at 050 inch Lift: 230 int./236 exh.
Advertised Intake Duration: 274
Advertised Exhaust Duration: 286
Advertised Duration: 274 int./286 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.520 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.523 in.
Valve Lift with Factory Rocker Arm Ratio: 0.520 int./0.523 exh. lift
Lobe Separation (degrees): 110
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: No
Grind Number: FS XE274H-10
Quantity: Sold individually.

Camshaft, Hydraulic Flat Tappet, Advertised Duration 274/286, Lift .520/.523, Ford, Small Block, Each

 

the machine shop is going to tell you to check it......you can do it with the heads on.


make a solid lifter or buy one, I made one by filling an old hyd lifter with washers. set the rocker to 0 lash and then put .100 shim between the valve stem and rocker (holds the valve open .100) and turn it over. if it hits the piston, well you need to do some grinding.

 

If you are replacing the stock pistons anyway be sure to get pistons with valve eyebrows. You'll still need to check for clearance though.

 

thanks for the help guys.. I've been watching gas prices rise steadily and now I think I may run an Edelbrock Performer or performer rpm cam, carb, and intake combo.. Gas mileage isn't that important on my truck, but I still want decent mpgs.. I plan on driving it to work once a week or so (50 miles round-trip) and don't want to go broke just for the full race cam

Thanks again

-Dan

 

http://www.compperformancegroupstore...Category_Code=

Kinda expensive, and it takes the retrofit roller setup to work, but they designed it to do what you're looking for.


Pete

 

.540 lift is pushing it with stock pistons. Even the FRPP F303 .512 lift hyd. roller for a 5.0 says to check for clearance. The E303 .498 lft does not. So, anything over .500 should be checked.

 

His limiting factor here isn't the pistons, but rather the pressed in studs in the heads. Any can bigger than a Comp Cams 268H will require screw in studs and guide plates, in addition to the springs & retainers.

 

MPG what's that? I get maybe 8 with my truck.....but it pulls to 6300..I like it.

 

I have one of those in my 460

 

That thumpr seems expensive, but a good choice.. I also like the idea of converting to a roller.. I really don't need a full race cam anyway, but I just love the sound of 'em. Thanks again for all your help guys.. Looks like I'll be saving up for this one..

Problem is the thumpr has almost as much lift as the Lunati cam I was originally looking at.. (531/515 on Thumpr, even more on ***** Thumpr) but I think I may just go with a whole comp cams valve train and pistons notched to my needs.. I think the final effect would be well worth it.

Thanks for all the info

-Dan

 

Do your heads have bolt down rockers on pedistals or the ball type with a stud and nut?

 

BTW.. all the flow data I have seen on stock Ford heads says they start falling off after 0.500" lift.. even ported with bigger valves, so a cam with more lift than this is not buying you anything.