1966 ford 427 le mans race engine simulation dyno numbers

[elmariachi]

Originally Posted by patrickt

My overlap at .050 is only 17 degrees. It is 96 degrees at seat-to-seat.

Mine at .050 is 28*.

[patrickt]

Originally Posted by elmariachi

Mine at .050 is 28*.

Yes, your four degrees, at the cam, less of lobe separation is pretty significant. The lobe durations are effectively the same, but you have a higher performance cam than mine. The next step up, back in the day, was the cam that DCDoug has (the "B" cam). As I recall, the LSA on that was 106 but still the same lift and duration that I have.

[elmariachi]

Originally Posted by patrickt

The next step up, back in the day, was the cam that DCDoug has (the "B" cam). As I recall, the LSA on that was 106.

Do you recall what the lift was on that B cam?

[patrickt]

Originally Posted by elmariachi

Do you recall what the lift was on that B cam?

Exactly the same as mine, same duration, same lift, but the LSA was moved down to 106.

[dcdoug]

Originally Posted by elmariachi

Do you recall what the lift was on that B cam?

Wow, you guys went to town on this thread last night.

The lift on my B cam is .526.

EDIT: I can get the rest of the specs tonight if you are interested (don't remember and they are at home). It was a Holman Moody custom grind B cam that my builder had done, so maybe that means it is a bit better on the street that a traditional B cam?

[patrickt]

Originally Posted by dcdoug

It was a Holman Moody custom grind B cam that my builder had done, so maybe that means it is a bit better on the street that a traditional B cam?

There is debate as to whether there was indeed two "flavors" of the "B" cam. Durations for both flavors were 324 seat-to-seat and 245 at .050 with the lift being .525 which comes out to about .500 after you take off your lash. The debate was whether the LSA was the same between the two flavors. Some reports say that the Ford "B" cam was 112 degrees lobe separation, while the Holman Moody "B" cam was 106 degrees. Other reports say that the Ford "B" cam was also 106 and that there are just mistakes in the literature that have been passed down over the years.

[DMXF]

Originally Posted by patrickt

There is debate as to whether there was indeed two "flavors" of the "B" cam. Durations for both flavors were 324 seat-to-seat and 245 at .050 with the lift being .525 which comes out to about .500 after you take off your lash. The debate was whether the LSA was the same between the two flavors. Some reports say that the Ford "B" cam was 112 degrees lobe separation, while the Holman Moody "B" cam was 106 degrees. Other reports say that the Ford "B" cam was also 106 and that there are just mistakes in the literature that have been passed down over the years.

I have an original Ford B cam with the C4-B part number stamped right in the end and had it tested years ago. Separation is at the lower end of the values you mention, something like 106.

[dcdoug]

Originally Posted by patrickt

Some reports say that the Ford "B" cam was 112 degrees lobe separation, while the Holman Moody "B" cam was 106 degrees. Other reports say that the Ford "B" cam was also 106 and that there are just mistakes in the literature that have been passed down over the years.

My lobe separation is definitely 106. Here's the cam card (if that's at all helpful - which it probably isn't).

[patrickt]

Originally Posted by dcdoug

My lobe separation is definitely 106. Here's the cam card (if that's at all helpful - which it probably isn't).

Oh, I believe you. Larry at HM though swears that there were 112 degree LSA "B" cams coming out of Ford -- and he's been grinding cams there since WWII so I'm not about to contradict him. But there are definitely Ford B cams that have 106 degree LSA -- there's no doubt about that. HM did make cams for Ford as well, so it might as simple as "HM ground B cams were at at 106 and when Ford ground B cams they were at 112 and some of the Ford stamped cams were really from HM." I will add that I have never heard of an HM B cam having a 112 LSA. Never.