keep in mind i have stock heads....for the time being... but stock none the less Xtreme Energy XE268H Hydraulic Flat Tappet Camshaft & Lifter Kit Lift: .509''/.512'' Duration: 268°/280° RPM Range: 1600-5800 or Xtreme Energy XE274H Hydraulic Flat Tappet Camshaft & Lifter Kit Lift: .520''/.523'' Duration: 274°/286° RPM Range: 1800-6000 with the 520 and 523 lift clear a 9.5:1 flat top piston with recesses?? these are the 2 options i have narrowed to in my exhausting search for the next cam.... anyone have experience with the 274H cam? thanks
yes...they have recesses in them....not sure how deep they go.....hell...i dont even know what name brand the pistons are....i got them from the shop that did the engine work....i told him i wanted 9.5:1 compression and he got them for me... i assembled the block myself....and i dont remember a name on them...but i do know they have cut outs in them...and they are flat top....
yeah...but i dont want to spend 200 on a cam and lifters kit and the cam wont fit the heads...then i HAVE to buy a new set of heads...i want new heads...just cant afford them.....real tight budget suck real bad...
Ran almost the same cam, only an Erson, in lots of 302's with your type pistons. .512 lift and same duration. Installed it 4 degrees advanced and never had a problem. As stated before, I did clay the engine before final assy. to verify clearance, this should be done on all aftermarket cam and head changes. Stock rockers and springs will work, but that is iffy too. I had the non adjustable Ford rockers, and after tightening the nut down to spec's on the shouldered stud., the engine ran very sluggish with that cam, ended up getting some 5.16th's posi lok nuts and setting the rocker arms at zero lash. Woke the old girl right up and spun it to 6500, never had a rocker problem as I had surmised at first, using the posi lok's. With years of changing and seeking more HP, roller rockers and screw in 3/8 studs and guide plates, came into play. Now use rollers with 7/16th's studs and roller cam 300+lb springs. Me thinks you will be fine with what you have in mind. JMO
I have had piston to valve contact at .501 lift with TRW L2482 forged flat top pistons with about .008 deck clearance with .042 gasket using 1.94 & 1.60 valves in factory heads. The problem wasn't the depth of the valve reliefs, but the diameter of the reliefs. The valves were hitting the pistons on the flat top just outside of the reliefs. They would have cleared stock size valves. Two aftermarket pistons that I am using that will clear with big valves are Keith Black 115 and Sealed Power H273CP. They have huge reliefs both deep snd wide.
i have stock heads so i would imagine that the reliefs wont interfer.....now if i get different heads....and bigger valves...then yeah...that would be a problem
You really need to decide on your heads first, then pick a cam. Often stock heads won't allow valve lifts anywhere near what an aftermarket head can handle. For many stock heads .500 lift is max. Even if you could lift the valve higher the ports won't flow any more air. A cam that works with your stockers might only choke a good set of heads later. Intake and exhaust flow rates at intended rpm, compresion ratio need to be known to pick a suitable cam. Those things are largely dictated by the heads. And everything in the flow path needs to be matched; carb/intake, heads, cam, exhaust. Save up for the heads first.
What BMC said. The cam is NOT your problem. If you can't do heads, don't throw money away thinking you can cam lousy heads into being good ones. You can't. PERIOD. If you want best gain for a little money work on the rear end as many people have already told you. You have the worst possible heads you can put on a 302, until you fix that, messing with intake, carb, cam, exhaust, is just .......d. Did I say it plain enough? Sorry, but you got great advice and you come back talking about how putting a cam in it is the answer. It just ain't so. You've done everything but start at the beginning. Which is heads or the rear end.
Trust me, he doesn't have the worst. The XE cams are designed to work with the poor exhaust on stock heads. As for valve clearance, my cousin's 289 with AFR 165s, 1.9 intake, 1.6 exhaust, 1.7 roller rockers and Comp 270H .500 lift with 1.6's, .531 lift with 1.7s and no valve clearance issues. 9.8:1 compression.
I would also consider the fact that you are running a C4 A/T. Do you have a stall? Mine is 470/474 lift at .050 with 280/290 duration and it will not idle in gear without feathering the gas. I usually push it in neutral at stoplights. I agree with Dave, clearance should be fine. Seth
i have the XE256H cam.....484 lift.....2500 stall ....and it idles awesome....pump the gas one time...turn the key....vwoom...idles...even when its cold... trust me everyone..i hear everything you are all saying...and i have been making my decisions from experience from all of you.... i know the heads and cam and intake and rear end all need to be changed...i am trying to find the cheapest thing first... the rearend will cost me about $1000 ...for gears..rims and tires...and leafs and shocks...etc.. intake....cam...will cost $450 and heads....$800 and up... trust me...i hear you all
IF you already have a non-stock cam that 'idles awesome', I would leave it be and save my $ for a head upgrade. My heads are pretty stout pieces even for modified 351W(1970) pieces and it makes all the power I want. My cam is smaller in lift than yours and I am probably putting about 265 on the ground (est). I would save for a head upgrade. Even if you bought late model 5.0 heads (iron) from a junker and modified them you will probably be ahead of the game. That is unless there is something you don't like about your cam. Mine is a 351W/302 HO firing order cam, it hits pretty hard. Keep in mind, If you are running stock heads now, even with your cam, and change to an adjustable valve train (ie. roller tipped rockers) your lift geometry will likely change. In other words changing from stock stamped rockers to 1.6, 1.65 or 1.7 ratio roller tipped rockers can often have the same effect as installing a higher lift cam due to the difference in geometry. Then, your 'will it clear' issue will return, but likely you will be okay with 1.6, maybe 1.65. Seth
I agree, the head upgrade would be more power, but it isn't cheap power. The XE268H should not have much worse low end than your current cam. the 270H didn't cause any problems in the Fairlane with big heads and at the time a crappy intake and carb. Even after all of that is sorted, 650dp and Edel Air Gap intake, 6901 long tubes and 18 inches of pipe afterwards, she purs like a kitten at just over 800rpms... ok, maybe a really mean, hungry pissed off kitten, but no idle problems. As for the E7 heads, I think you guys are a little off. The E7's aren't any better than early 70's and late 60's heads, same valves, smaller exhaust ports. STManser, you said 77 F150 heads with 56cc chambers? the only problem is the exhaust ports, which are not that much worse than the E7's I've dealt with. A port job and you can surpass the E7's easily. The biggest problem with late model 70's heads was the 69cc chamber... just sad really...
