There's been a lot of discussion about cam specs here, lot's of it pretty technical. Some of it I understand, at least the basics, of lift, overlap, measured height. More duration seems to come with more lift, more overlap causes rough idle with lower vacuum. Lobe centers, which I assume is the center-line difference of intake and exhaust, fully open, confuses me a bit. I've degreed in cams, but aside from following the instructions ( it seems they were normally retarded a couple degrees) I don't really understand what that means or accomplishes. Why not just grind it to go in straight up. Looking at Mummert's site, he has a 280-I-07, and a 280-I-11. The difference appears to be the lobe centers at 107" and 111" respectively. On a street V-8, of say 300 CID, what's the difference driving from, say 1500 or 2000 to 4000 or 5000 rpm? Assuming the heads, manifolds etc. are the same, and compatible to the cam, why does it cause the difference? And finally, how do (real general here) bore stroke/ over square/ under square affect this? I don't like to seem too dumb, but I'm pretty sure I'm not the only one, and there's so many combination out there, there must be some differences of opinion even among cam designers. How about a little remedial education for some of us.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Mike, I know a lot less than you (basically I saw a cam once) actually I have replaced a cam in a 351C, and two in my daughters cars (4 cylinder OHC). In the case of the one in the 351 I asked the parts guy for something better than stock and that was it. It seems to be ok. I anticipate that I will need to buy a cam for the Y-block. I have an ECK block with ECK-C heads (should be a '55 292 according to John Mummert's chart). It came with a 55 Fairlane Club Sedan and was supposed to be rebuilt. Its very clean but I have my doubts. From what I've read it is imperative that the cam have the oil groove so I will have to pull it out and check for that. I don't race. I just like to drive around, make a lot of noise and have fun. What kind of cam do I need. I'm at your mercy.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia