I'm Driving Like An Old Man!
What's going on here? Lately I find myself driving away from stoplights at a snail's pace. I've got soccer moms trying to run me over-even lifted diesel trucks threatening to do it-and I'm constantly driving down the freeway at or below the speed limit. Is it because of my hair turning gray? Or is it because I'm hitting the Big 5-0 this year? No, not at all. With fuel prices nearing $5 in Northern California, it's the only thing left to try to help out my checkbook. As I've written before, state of tune, tire pressure, alignment-we've covered all the bases except for changing our driving habits. I've also written that lowering engine speed is the best way to increase fuel economy. So I've taken matters into my own hands. With four drivers in my family eating fuel and two tow rigs to get our race cars to the track, I am willing to try anything.
From 1936 through 1968, except during World War II, Mobil Oil Corporation sponsored a fuel-economy challenge known as the Mobil Economy Run. This was a coast-to-coast test that the automakers would heavily promote if their cars did well. Drivers would take stock production cars and compete to realize the best fuel economy. The biggest fuel savings came from driving characteristics. In 1964, Bob Knoll and John Galicki drove a Plymouth Valiant (I know, I know) to a Third Place finish in Class B behind a Rambler American and a Chevy II 100 six-cylinder. As I was saying about characteristics, Bob mentioned, "The trick was to get to High gear quickly and then back off the throttle just a bit without losing speed. I soon found this to be natural, and I still drive that way today." Jack-rabbit take-offs eat fuel, and getting up to speed quickly only to scrub it all off with the brakes eats fuel too. I'm not promoting unsafe driving, but open your mind to what you can do to save fuel.
If you see me on the road, please don't run me over. I'm just trying to save enough bucks so I can stand on the throttle at the race track. Driving this way, you may get there a few minutes later, but you'll have more money when you do get there-and I can guarantee you that you won't have a visit from your local law enforcement. Drive safely.
New-World 30-30 Review
Q I liked your article on the new-world 30-30. I have a CE 302 short-block with untouched 186 double-hump heads that I am going to put into my '69 Z/28. The CE will be bored 0.030-over, and I want to get at least 400-425 hp out of this engine. How much porting will I need on these heads, and will the XS282S Comp Cams get me to this goal? I wouldn't mind using a roller cam if that's what it takes. I also like the idea of the Edelbrock RPM intake (PN 7101). Also, I am planning to stick 4.11s in my 12-bolt. Will this be streetable enough for the weekends? Thanks for the great feedback and a great magazine.
Kent Long
Via e-mail
A The song of a high-winding 302 is very hard to beat! Back in high school, a good buddy of mine, Bill Hasty, had a '69 Z/28 that I did all the mechanical work on. We swapped out the original mechanical camshaft and stepped up to the "bottom of the page" Sig Erson mechanical flat tappet camshaft. What were the cam specs? I didn't even know what they meant back then! All we knew was that it was at the bottom of the page, and boy, did that thing scream. The tach routinely saw 8,000 rpm, and we had some fun!
As for your fantasy build, we'd have your iron headsprofessionally ported. The 186 castings are a good all-around performance head, but you're going to need these heads to flow good air at 0.600-inch max lift when you install a mechanical roller. Brzenzinski Racing Products (Castheads) is well-known in the industry for its cast-iron expertise. The CNC Sportsman porting for Chevy cast-iron heads will result in intake flow numbers around 245-250 cfm, and the exhaust comes in around 175 cfm. This will give you the power potential to knock down the 1.4 hp/ci you'll need out of your little 302.
As for camshaft selection, you're right on point with the Comp Cams XS282S. That camshaft specs out at 244/252 duration at 0.050-inch tappet lift, 0.520/0.540-inch max lift, ground on 110 centers. To pick up an extra 25 ponies, we'd recommend going to the Comp Cams XR280R mechanical roller. This cam comes in close to your choice at 242/248 degree duration at 0.050-inch lift, 0.570/0.576-inch max lift, and is also ground on 110 centers. We would recommend going with a 1.6 ratio rocker on the inlet with a 1.5 on the exhaust. This will push your inlet lift up to 0.608 inch.
To finish off your package, do an old-school trick and machine down the center divider 0.500 inch on your Performer RPM. This will give your engine communication between the two planes of the intake manifold and give you an upper-rpm boost. It will also make your carburetor look bigger to the engine because it will be able to draw from all four barrels on both planes of the inlet. Don't be scared to put a 750 mechanical secondary carburetor on this engine. It will need the lungs to accelerate as quickly as it will want to. And don't forget to give this engine a little compression. The factory 302s had 11:1 compression originally. With the amount of overlap that either of the Comp Cams will give you, I don't think you can get away with 11:1 on our current gas. We'd stick close to the 10:1 range. You could push it a little, but you may find that it will like to rattle below 4,000 rpm.
Now I'm jealous. Good luck with your project.
Sources
castheads.com
compcams.com