AFR 185's w/E-303: Piston to valve clearance problems?
 

Here's going to be the setup I'm thinking of building. Stock 5.0 short block (crank, connecting rods, and Flat-top pistons), with Airflow Research's 185cc heads. They have 2.02int. with 1.60exh. valves. The e303 camshaft from Frpp has an advertised duration of 282/282 and a maximum valve lift of .498 with 1.6 rocker arms. My question first is anyone running this setup? and the other question is will i have any piston to valve clearance problems with flat top pistons? Oh and the Combustion chamber size on the heads is 61cc. Thanks for any info.

you will have to fly cut the pistons thats why i went with the 165's

185, stock cam,,, 165s, just about any cam...We like the HR266 from comp

As long as the duration measured at .050 lift is LESS than 230 degrees then lift DOES NOT MATTER!!!!!!!!!!!!!!!!!!!! It is WHEN the valves are open, not how much they open that is the issue! You do not have to worry about flycutting the pistons as long as you follow that simple rule. The E-303 cam has a duration of 220 degrees at .050 lift. So that cam is not a problem even with 1.7 rockers. I don't care what heads are on the engine that cam is not a problem.

I dont even think you can slap 185's on a stock block with the stock cam. When I was looking at heads I was told by Summit that I would have to flycut my pistons in order to use them.

The only time that is true is if you have a 1986 5.0. The 86 5.0 had NO valve reliefs at all. 87 and up come with a valve relief already, not much of one but enough. I have installed AFR 205, Edelbrock Perf. RPM, Trick Flow Twisted Wedge, Holley Systemax, Ford Motorsport X and Y heads, Dart heads ALL on stock short block 5.0's of 87' vintage or newer, and with a variety of cam's that as long as the duration @ .050 is NO MORE than 230 degree's then you WILL NOT have a problem! Period! You see with the shorter duration cams (less that 230 deg.) the valve is simply NOT OPEN anywhere near the piston during operation. At least not near enough to be a problem on a Hyd. Roller engine that does not see over 6,300 rpm.

Even with the use of 1.7 rockers. I do not care what the lift #'s are. If the duration is less than 230 degree's @ .050 lift then you can have .750 lift if you want. At that lift the piston is going down the hole on intake and the valve is closing from that lift on exhaust when the piston is comming back up the hole.

I think I'm getting your thinking Technik. When I get my heads back (1.90 Edelbrock's milled .010") with a TFS Stage 2 cam, I will have problems on my exhaust valve right? Since its 224 and 232 with .542 and .563 lift.

so then AFR 205's would work with an E-303?

MM why you going to get or want that 205 afr on a stock Short??? thats a bit well more then a bit over kill