i am rebuilding a 87 302 out of a mustang to put in my 94 ranger.
it has flat top pistons with no valve reliefs. i am concerned about valve to piston clearance. i got the 302 as a short block. i have a dual plane ford h.o. intake. i want to put on 58cc heads. i am not sure how big of a cam i can put on with out modifing pistons? if anyone has any good cam-cylinder head combo ideas i'd appreciate it. oh and did all mustang 5.0's 87-92 have h.o engines?

 

how biga cam you looking to get? what do you want from the motor as in drivability? DW

 

just looking for a step above stock on the cam
the 58cc heads will give about 10.1 compression i think?
daily driver but a quick daily driver

 

you should be able to do .475 lift easly with out any clearence problms. go to www.compcams.com
they also have a toll free ## for tech, and recomendations. if you want to play it extra safe go with a standard flepro head gasket, dont use a thin one, with iron heads you wana be care on your compresion ratio or you'll spark know on pump gas. hope this helps DW

 

YEA I WAS PLANING ON ALUMINIUM HEADS THANKS
I SHOULD PROBABLY USE 1.6 ROLLER ROCKERS TOO I THINK

 

What head are you planning on? My new strocker 393's getting AFR 185's Those head are extreamly nice, and kick A.. on the dyno. DW

 

Valve clearance is *very* dependant on the head design and valve size, as well as cam lift, duration, and profile.

I've heard of examples where a high profile cam wasn't causing problems, and a lower profile cam was installed that did cause problems. I think it had something to do with the profile of the exhaust stroke on the cam.

The intake valve reaches maximum lift while the piston is going down, and the exhaust valve while its coming up.

It's not just the lift, but where the piston is when max lift is reached.

 

from what i have read the trick flow twisted wedge head are designed for flat top pistons, may i cam pair those with a e303 grind cam?

 

For starters, are you sure that this is not an '86 short block? The '87 should have small valve reliefs cut in it.

Secondly, all 87-93 5.0 Mustangs used the 5.0HO engine, which uses the 351W firing order. 1993 Mustangs used hypereutectic pistons, while all prior years used forged aluminum.

As far as cam selection goes, valve clearance will depend on the duration of the cam, valve size, heads, and piston reliefs, and to a much lesser degree the lift. Cams with a long duration are more likely to interfere, valves with a larger diameter are more likely to interfere, and unrelieved flat top pistons are more likely to interfere. Heads that have been planed significantly will also be more likely to cause interference.

I ran a set of TFS Track Heat heads with a TFS stage 2 cam (224/232 I/E duration @ .050", .542"/.563" lift) installed straight up on a stock 1990 short block with no problems. The track heat heads have a slightly canted valve setup which increases clearance, but use the larger 2.02"/1.60" valves. True in-line valve heads like the AFR's typically use smaller valves and would probably work too. The stage 2 cam had about .120" clearance on the intake, and almost a quarter inch clearance on the exhaust side, which is fine, but approaching as tight as you want to get.

This cam idled fine and produced plenty of vacuum.

Good luck.

-Matthew