wanted ask around to see what a good retro roller cam would be for a early 302 my car will have 3.00 rear gears and c-4 tranny with 27 inch tires this will be a mild build with gt40 heads unless I save up for the AFR 165. LAter on I might change to 3.40 gears but for now im keeping the 3.00 so if I do go with the 3.40 I have a mild 2500 stall I would install list of parts 600 edelbrock carb performer 289 intake headman long tube headers possibly gonna change to a street demon 625 carb
You're better off buying a full-sized roller cam and using link bar lifters than using a small base circle retrofit cam, wider variety of grinds and the small cams have been shown to bend and twist at rpm. Also they almost never match their advertised specs. The downside is you "usually" have to pull the heads to install/remove the link bar lifters. And don't be afraid to save some money and buy a good used roller cam. Unlike flat tappet cams, they don't normally wear out unless something went wrong. I picked up the Comp XE cam in my signature used for $125 shipped to my door. And, BTW, I have the 625 Street Demon on mine and love it.
The difference between a roller and a non-roller block is the height of the lifter bosses. That's because the roller lifters are taller than flat tappets. Unfortunately this also comes at a weight penalty and forces you to use heavier springs to help compensate. And moving up from there to a retro-style link-bar lifter will add insult to injury in this case. That costs some power drain and additional wear over time.. negligible as it may be or seem to some folks. If you simply drop roller lifters in the non-roller bores, they will stick up so high that the oil bands won;t align properly and they'll starve for oil and die rather quickly. Basically, it's like shopping at the convenience store.. and easy "drop in parts" aren't necessarily always best and often cost more. On the plus side of things.. the push-rods usually get a bit shorter due to the taller lifter cup height within the retro rollers and therefore end up lighter to help off-set the added weight of the taller link-style lifter to at least some degree and flexing is also reduced in that trade. But.. this is a mild build and flex wouldn't be any measurable issue here when the proper .080" thick wall push-rods are used anyways. And as for the flexing issues of small base cams.. the very same thing goes for the reduced base circle cams in milder applications such as this one. Plus the roller cores are already stronger/harder and maybe even torsionally stiffer than the old flat tappet stuff was to begin with anyways. You still get the added power of the roller cam.. just costs you more cash and the total power gain isn't as good as it could have been with the shorter/lighter OEM style parts and reduced base circle cam. And there are TONS of small circle cams out there. If you don't see the one you want?.. which is highly doubtful .. most mfgrs will grind it up for you at no additional cost. The simplest change is to use a reduced base circle cam, and stock ford lifters and retainers(spider and dog bones --- comp and many others have these kits). You'll need to to make two small changes to your block. First, you'll need to drill and tap two 1/4" holes in the galley. They only need to be about 1/2" deep. They are directly over the cam bearings, so don't drill too deep. You don't need the bosses cast into the block. You may also need to clearance the galley around some of the lifter bores so the dog bones clearance correctly. Both of these small jobs can be done with the assembled engine. Just be extra careful about chips and shavings. Also be sure to use some red loc-tite on the spiders bolts and check what disty gear you'll need to use for the cam you've chosen. Some need hardened gears.. and some don't. As for the cam choice? With those conservative gears I would stay a bit smaller than what many may recommend if you plan on the GT40's(especially in un-ported as-cast form) and use a more aggressive ramp design(how fast the cam opens the valve and amount of overlap will help offset the inherent weaknesses of the heads). If you do plan on upgrading to the AFR's?.. then you could go a little larger without dropping too much low-end torque and response and the cam could be milder in the amount of overlap needed to improve exhaust scavenging. Basically, we're forced to throw more duration and added overlap at weaker heads(weaker exhaust ports also typically need a split-duration cam design) than we are with better heads having superior exhaust flow and better flow balance(I/E flow ratio). It's a complete package and needs to work together which requires proper foresight of future upgrades or you'll never completely hit the bulls-eye. Both those head and gear combo's will need a different cam choice to maximize what you have at any particular moment so plan and choose wisely. A general and quick rule of thumb is to look at the advertised duration and compare those with the @ .050" numbers. The closer the spread is between them.. the more aggressive the ramps will usually be. Just keep in mind that the more aggressive ramps will need a bit more spring than typical cookie cutter cams, Ford's alphabet cams included, to keep things under control. For off-shelf stuff, I like the Comp Cams Extreme Energy and Lunati Voodoo stuff myself. From there on up, I always prefer the custom grinds.
I just have several flat-tappet blocks laying around and the 5.0 roller blocks seem to be getting ghard to find,good info about retro cams I didn't even realize cause I haven't heard of anyone using them much thanks for info guys BMCDAniel I have heard a lot of good stuff about the street demon carb I really want one
While you're saving for the heads and carb, save some extra for a better intake. The one you have now isn't much better than the stock intakes.
Chris Moore (aka grabbergt) has some retro lifters and an x303 cam he took out of his 302 and would probably give you a good deal on them.
