MustangWorks.com : Ford Forums - View Single Post - f-303 and stamped rockers

MEDIK418 · 03-22-2003, 11:36 PM

I'm running an F-303 in the 89 with ported stock heads. True, they are a bottleneck and a set of TFS heads are coming soon. Slower than stock. . . . not hardly. We'll know for sure tomorrow.
Look at the roller rocker thing this way. Stock springs aren't going to work very long with the F303. It needs stronger springs. I did run the engine for a few weeks with the stock rockers and no valves ever floated up to 6200 rpm. BUT!!! With the heavy valve springs required for this cam, there was too much spring pressure for the stock rockers and they were beginning to wear into the fulcrums. Too much pressure forces out the oil and galls everything. Now. . . .I can't say I noticed any big power increases after the roller rockers but it does rev really easily. First gear will often bounce off the rev limiter often quicker than I can get out of the throttle. (MSD 6AL set at 6000 rpm) but that's more of a traction problem than anything else. I would go with the roller rockers if the F303 was in the future.

03-22-2003, 11:36 PM	#8
MEDIK418 Registered Member Join Date: Mar 1999 Location: Amarillo, Texas, USA Posts: 780	I'm running an F-303 in the 89 with ported stock heads. True, they are a bottleneck and a set of TFS heads are coming soon. Slower than stock. . . . not hardly. We'll know for sure tomorrow. Look at the roller rocker thing this way. Stock springs aren't going to work very long with the F303. It needs stronger springs. I did run the engine for a few weeks with the stock rockers and no valves ever floated up to 6200 rpm. BUT!!! With the heavy valve springs required for this cam, there was too much spring pressure for the stock rockers and they were beginning to wear into the fulcrums. Too much pressure forces out the oil and galls everything. Now. . . .I can't say I noticed any big power increases after the roller rockers but it does rev really easily. First gear will often bounce off the rev limiter often quicker than I can get out of the throttle. (MSD 6AL set at 6000 rpm) but that's more of a traction problem than anything else. I would go with the roller rockers if the F303 was in the future. __________________ 1986 four-eyed LX coupe, 358 Cleveland, Tremec TKO600/centerforce clutch, dish cut Probe forged pistons, comp cams hyd.roller cam, .579/.588@224/230, Edel.performer, 670 holley street avenger, CPR custom built long tubes, ported and polished 4bbl heads, manley valves, beehive springs, MSD peo-billet dist/MSD6AL, fluidamper, 5 lug conv. with 17x8 bullits there's more but it's still not finished yet. Oh, and the oldest boy is turning his 89 GT into a FFR cobra this next summer.