OK, I need some help, I'm a little out of my comfort zone. Usually when I choose a cam I'm looking to maximize efficiency/power and looking to make the whole combo work together. I'm helping a buddy choose a cam based on only two criteria, loud and lopey. With the low compression a long duration cam will be lazy at low RPM so we'll use at least a 4000 stall coverter and a 5.13 gear. The motor in question is a bonestock mid '70's 302 (with a tunnel ram), I'm not allowed to change anything except the cam and springs (and valve reliefs if needed). It will be in a 1960 F100 that's pretty stripped (figure 3800#). I'm thinking somewhere in the 250 - 260 at .050" lift, around .540 lift, with a tight LSA to give a decent overlap and nasty idle. Anybody got any suggestions to help us throw a rod at 7000 RPM? Thanks
On a stock motor, I'd go 220 - 230 @ 0.050" with 108 lobe separation. -Lee Atomic Radio www.atomicpinup.com
Lunati is making a series of cams called "thumper" that is designed specifically to get the "sound" of a long duration race cam, without as many of the draw backs. I saw some comparisons of them - seemed like a good way to go when the exhaust note is one of the primary considerations.
I had the XE282HR (hydraulic roller) in my car and it was rowdy. 232/240 with 108lsa and .544/.565 lift That's gonna run like crap you know. Stock 289/302 heads are NEVER good from Ford. Some better than others but they're all pretty weak, especially on the exhaust side.
Actually the Thumper Cams I am familiar with are made by Comp Cams, and they are Bad Ass. Exactly what your bub is looking for and a retro fit roller at that so you don't have to worry about them going flat with today's oils!
I've yet to try the Thumpers, but have heard good things. Kind of reinvents the wheel though.....companies like Isky and Schneider have never stopped offering the old style grinds. I guess the one advantage to the Comp series though is they make a roller version too. -Lee Atomic Radio www.atomicpinup.com
The Thumpr will set you back three yards for the stick alone, and another three for lifters and such. Flat tappets are still an option, just don't buy the expensive oil that says "2003 and up" on it. I've got the Edelbrock RPM stick and it isn't crazy by any means. 224/234 @.050 So if you want something to snap your neck whilst idling through the McDonalds drive thru, go over to jegs.com or summitracing.com and go to the bottom of the SBF cam list lol. If you want to throw a rod at 7k, get something solid!
That engine is gonna suck. Sounds like a poser engine. A bone stock, low compression, tunnel ram engine is not going to run for shit. No matter what cam you put in it.
A 4000 stall, a 5.31 gear, and stock compression? No offense but it's going to suck. Run a stock converter, a 3.55-3.73 gear and build a better motor. Don't put money into a turd. You'll hate it and then end up spending good money twice.
I'm with ya there, and I don't build motors. That just seems like the wrong combo. The 302 I'm puttin together for my project is .040 over with flattops, GT-40 cast heads with 1.6 roller rockers, torker II, and my cam is smaller than the one you have picked out. Comp Magnum 280. .512 lift, 110 LS, 230 @ .050. I though that was a little big but I have a T5 so I don't need to worry about stall speed.
you might check out some of the FORD MOTORSPORT cams. something like the e303 might work better for you application.
The Comp Thumpr cams are available in flat tappet now as well, much less $$ than the retrofit roller deal. http://www.compperformancegroupstor...Screen=CTGY&Store_Code=CC&Category_Code=THMFW cheers Ed N.
What I like is the 5.13 gear - Hmmm let's see, with a typical say 27" tall tire at 65 it will be spinning 4150rpm! even with a 30" it will probably be right up against the converter at 4000 (with a tighter converter, 3735) That oughta make the motor last real long and the gas mileage will be calculated in gallons per mile!
Is this an off road vehicle? I had a truck with a 454 a TH400 and a 4.11 rear and it would top out at about 75 at 4000rpm and it was screaming.
sound like a pro-streeter. i do agree that other things could/should done just so the rump backs up the thump. i'm starting to look in to 302 stuff for my wifes 63 fairlane but i have made any desisons yet
After you sort the cam thing out whatever you choose. I would cheat a little and put in a set of good rod bolts. 5.13 gears and 4000 stall converter will have this 3800#er wound to the moon. You'll be sweeping up pieces after I speak from experience on this>>>>.
If your going to thro your money away on a gernade try speed pros 310 duration 522 lift hyd. cam lifter chain kit like $100.00 on the net. If its gonna be a gernade make it a cheap one.
Or PAW for $60 cam, but if you go over 0.500" lift you may be up to dual springs and I am not sure you can get ones that fit without machining the heads.
holy crap you kidding me? I hate those edelbrock carbs. Ive had at least three and swapping to a holley is like a whole different mota.. I think I have two edelbrocks laying around here somewhere holding a door open or something, you want to buy a couple?
I would opt out of the build myself. With a stock 302, you need a Weiand Stealth or a Performer intake, an Autolite 4100 off of a 352, a set of hi-po manifiolds and a Lunati Voodoo hydraulic. The smallest one they make. Its 207°/213° @.050 and 250°/256° seat to seat. Its very agressive. The 302 will be lucky to break 8:1 with very wheezy heads, and this cam gives it some power from idle to 5000, where a hydraulic dies, and you need a solid to rev any higher without breaking things, but the heads are done anyway there. It won't be a poser, it won't have any rumpety, but it will run like it should and do it on dog piss for fuel. It will have a nice smooth idle with just enough grump to make you wonder if its a 351. It is going in a heavy pickup, you need more cubes if you want it to have attitude and run right. How about a 390? You can build one pretty cheap, put a Comp 282S (236°@ .050 solid) with flat tops at 9.5:1-10.0:1, and it will have the balls to back up the idle. A 460 can be done even cheaper, though it will pass everything but a gas station.
Too bad you are so far away, I would take them off your hands. They can be a good carb for everyday use. I don't have anything against Holleys though, but AFBs work pretty well when you get them dialed in and they run for a very long time once you do. There really isn't anything to wear out on them, and no gaskets to dry up and leak. They can also sit alot and not get pukey like most carbs. I have let one sit for a year on the truck, fired it right up, topped off the tank and had it do just fine. If I had done that with a Holley it probably would have burnt when the needle and seat jammed. But the Holley will make more power, it just wont do me any good if the car is on fire.
2nd bill b. that would be a cool combo, huge cams in the wrong place suck alot and run worse than stock cams!
Exactly. Mine has been un-touched since its first setup 4ish years ago. Runs great. Was my daily up until a month or so ago.
my dad does have an edelbrock on his nailhead and it runs good, they are a decent carb for the bolt on a drive crowd, but I have yet to see one on a car at the dragstrip doing anything faster then 15 seconds. Usually if you see a well built car that is doing 13's or faster, chances are it has a holley or demon on it.. as far as the cam is concerned the tighter the lobe seperation the lumpier it will sound. Like 108 degrees for example would be lumpier then a 110.. get something in the 240 range duration and a 110 or less lobe seperation..
Wow, my first post that stayed around longer than 15 minutes! Thanks guys for the replies. Unfortunately you guys are reinforcing for me that I may not want to get involved. The buddy I'm helping plays with cars quite a bit, but never on the performance side, I'm trying to explain to him what happens when you mismatch components badly. I'm thinking that the only way I really want to do this deal is to scrounge some GT40 heads (at least, maybe something better) since the current heads would need springs anyway but most likely a valve job and guides too. For the record, the truck will only go a couple of miles at a time and get dragged to the dragstrip every once in a while so the driveability really doesn't matter. Anybody got any good SBF heads to unload? Thanks
Check on eBay or local yards for some cast GT-40s. They usually go pretty cheap around $300-$400 or so. Thy flow well over stock and will work with all stock pieces. Gt-40Ps flow even better and are found easily as well, but the angled plugs limit your header selection from slim to none.
Huge cams and low compresstion don't play together well. Nothin' like having a badass lumpy idle and have it fall on its face when ya put some foot in it. Make him do it right or bow out. He may say he'll be happy but he won't.
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