Yes, another cam question from one of the village idiots. I have a budget build stock H.O. short block with mildly ported 70 351w heads fitted with 1.94/1.6 valves, 1.6 roller rockers, 60cc chambers, aftermarket springs, Weiand Stealth dual plane, 600cfm vac secondary and 9.5:1 compression. Short style headers with 1 5/8 tubes, 2 1/4 pipes. Ignition is Duraspark vac adv with aftermarket coil. It is going in a 2,900 lb Comet with a C4 stock converter, 3.00 rear end gears, 235/60-15 rear tires. I would like to maintain good idle, vacuum, and daily drivability while generating as much tire smoking, stump pulling power as possible without exceeding the 5,500 - 5,800 rpm range, while on the way to church. As it is a car for the kid, I want it to be reliable, hence the limited gearing, ect.. At the same time I would like it to be a little more than a stock H.O. for the street fun factor. I do not really care what it sounds like (lope or not), just want it to move. Also, if it makes a difference, the car is blue. Now I know enough about cams to get myself into trouble, which is why I am seeking more experienced assistance here. Initially I was eyeing 2 cams with similar specs, but very different descriptions. One cam is an Isky 371257-265: RPM Range: 1,400-5,600 Duration at 050: 210 int./218 exh. Advertised Duration: 257 int./265 exh. Lift with 1.6 Arm Ratio: 0.480 int./0.500 exh. Lobe Separation: 112 The other cam is Howards 220225-12: RPM Range: 800-4,200 Duration at 050: 207 int./213 exh. Advertised Duration: 260 int./266 exh. Lift with 1.6 Arm Ratio: 0.480 int./0.496 exh. Lobe Separation: 112 If you have read this far, why the big discrepancy between the power band of these two? Does Isky posses some kind of cam voodoo mojo? For the more seasoned individuals, would these cams be adequate or should I be looking at something a bit more radical that will still provide good idle, vacuum and daily drivability? How much cam is too much given the build parameters? Any helpful feedback is appreciated, even if sarcastic.
Your cams are too weak. I would suggest one of the two following camshafts. The second would require a higher stall convertor and some high quality valve springs. Great price for both cams. https://www.summitracing.com/parts/tfs-51403001/overview/ https://www.summitracing.com/parts/tfs-51403002/overview/ Check out my combination and performance in the "Garage".
For a mostly street engine, stock converter and 3:00 gear you are close... I have a Lunati that's similar to the Howards, doesn't have any issue pulling to 5500.... Car has a 2200 stall and 3:00 gear... I had the small TFS cam in my 5.0 T-Bird, quite the dog off the line with a stock converter and even 3.73 gears(Birdie is a chunky girl, weighs 3700+ with me)... A 2600 stall really woke it up but it'd would have been happier with a 3000-3200... Same cam is now in the 331 with a 3500 stall, I'm yet to fire it off...
When do you think you will fire off the Bird? I'm very interested in how that combination works for you with the AOD.
The cams you described put it in the range of slightly hotter than an Edelbrock Performer cam which is advertised as smooth running, good vacuum, for off idle to 5500 rpm. The next higher range as described by Hotrock would be like a Edelbrock RPM for 1500-6500 RPM. I'm not trying to push Edelbrock products, it's just that they advertise a lot. Let's put this out to the bloggers. Is a Performer level too boring, or is it the right choice for driving your Maverick out to the car show. Is the Performer RPM engine streetable enough or would you only consider it if you went to a high stall converter and higher gears. To keep your son out of trouble you might consider the Performer level. Any other opinions? MD
Gonna have to cool off a lot, maybe by mid/late Sept... Still have lots of small odds and ends to wrap up plus I want to rebuild brakes...
A gear change to something like a 3.55 would be on my short list if I were looking for low end grunt. You WILL feel a significant change in how the car accelerates. Steeper gears will also better compliment a more aggressive cam. You have to look at the entire combination.
If you are building this to give it to your kid...The stock 302 with a proper tune will be plenty for him to get in trouble with. Put a set of gears in the rear...3.55:1(No posi, easier to get in trouble with) is a good ratio to go with and put dual exhaust on it. Dont need to go bigger than a 2 1/4 in id pipe at this stage. You can put a 600 cfm 4 bbl on it with an aluminum intake. He will be quite happy with it. Once he has a few miles of bangin on it this way and can handle it w/o balling it up. Then consider doing an upgrade/build that he will be invested in...Baby steps man...Seen enough kids who couldnt control/handle a powerful car peeled out of em after the fact. Address all the cars safety items/issues first. Get the foundation in good, RELIABLE working order. Then toss around the idea of mods/upgrades. Cant build a house on a shaky foundation. Not trying to be a donny downer here, just saying. We were all kids once...LOL... I Should be dead, considering the things I did with/ in/on cars back then...
I could not agree more and that is exactly what I have been spending the last two years doing. Switched to disc brakes, repaired the power steering, somewhat modernized the front suspension, replaced the rear leafs, installed a Weiand Stealth with Holley 600, switched to a Duraspark ignition. It already had dual exhaust, but it still has factory manifolds. I have a Lincoln Versailles 9 inch that will eventually be installed. It also has 3.00 gears. I do not want to change the gearing, or replace the C4, or increase the stall. What I listed above is what I have on hand and I am just trying to make the best with that. The 302 is tired and burning oil and bleeding water, so it is time to refresh. Hence the H.O. short block with old 351w heads, but I would prefer more than a stock H.O. as far as the cam is concerned. That is why I am trying to size it to this build and determine how much cam could be used without over camming it. Just like you, I am sometimes amazed that I did not kill myself or others with my ignorance and recklessness. I have tried to take that and impart some caution and wisdom into the kid. Hopefully that is the case.
For a street engine it's great... Smooth idle, will easily blow off the 255/60/15, has a small 2K converter and stock peg leg 3:00...
After trying various setups in Engine Analyzer Pro it looks as if the factory H.O. roller is the best bet given the stock gears and converter. In the future if the kid wants more, he can save for some AFR heads and those should yield good results even with the H.O. cam. The H.O. should be a good upgrade from the tired 72 302.
