1966 ford 427 le mans race engine simulation dyno numbers

[Ibr8k4vetts]

Originally Posted by Gunner

Needs mufflers, air cleaner, water pump and alternator to be an apples-to-apples sim. Fan, too, for 60s tech. (When did electric fans become common?)

I believe the originals had e-fans, But I could be wrong!

[Gunner]

Originally Posted by vector1

rocker arm ratio 1.76

Just noticed this. Isn't 1.73 standard, even on the Le Mans engines?

[Woodz428]

Originally Posted by Gunner

Just noticed this. Isn't 1.73 standard, even on the Le Mans engines?

Adjustables are 1.76 and non-adjustables are the 1.73. All the solid lifter engines had the 1.76 rockers.

[lovehamr]

Originally Posted by Ibr8k4vetts

I believe the originals had e-fans, But I could be wrong!

Yup, not to much room for a WP mounted fan on a GT40.

[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.

[dcdoug]

Originally Posted by patrickt

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.

Interesting, I wonder if he ground my cam? My engine builder (who is in his 60s), said he had a friend at HM who is "even older than he is" grind my cam. Sounds like the same guy.

[patrickt]

Originally Posted by dcdoug

Interesting, I wonder if he ground my cam? My engine builder (who is in his 60s), said he had a friend at HM who is "even older than he is" grind my cam. Sounds like the same guy.

Probably. I think Larry is in his late 70's.

[vector1]

looking at the cam that was used in the program and what you guys are discussing, it sounds as if the cam used in the program is not correct.

if someone wants to post the cam specs you guys are discussing i'll put them in and see what happens, but it will not probably change the numbers much, just the rpm at where they happen.

optimizing the current setup, centerlines at 104/100 for a lsa of 102, dur. 248/242, gross valve lift .706/.670. that is a pretty agressive solid lifter and don't know if it could be done, looks like roller territory.

549 tq @ 5000/566 hp @ 6000,

aggressive solid roller--248/248 .722/.722 lsa 102

556 tq @ 5000/574 hp @ 6000

with this roller cam and typical street single plane intake

566 tq @ 5000/603 hp @ 6000

the two above examples are with 10" of idle vacuum, all examples are with production water pump only, normal windage, and production design pistons and bearings.

[patrickt]

My "K" cam, and Doug's "B" cam are very similar. His cam is essentially the "big brother" to my cam. Here are the specs:

K cam
intake/exhaust duration at .050: 245/245
intake/exhaust duration seat to seat: 324/324
Lobe Separation Angle: 114
Maximum Lift at the Valve: .525 less lash of .025 for an effective .500


B cam
intake/exhaust duration at .050: 245/245
intake/exhaust duration seat to seat: 324/324
Lobe Separation Angle: 106
Maximum Lift at the Valve: .525 less lash of .025 for an effective .500

[vector1]

need the centerline of either the intake or exhaust, otherwise i'm just guessing on where to clock the cam.

[patrickt]

Originally Posted by vector1

need the centerline of either the intake or exhaust, otherwise i'm just guessing on where to clock the cam.

Try giving the K cam four degrees of advance making the ICL 110 and the ECL 118. For the B cam, try two degrees of advance making the ICL 104 and the ECL 108.

[elmariachi]

If you'd be so inclined, here is my Comp 294S, installed with 5* advance:

Adv Duration 294 int./294 exh.
@ 050 inch Lift 248 int./248 exh.
Lash 0.022 in.
.605 lift
Lobe center angle 110
Lobe separation 106

[vector1]

b cam at 2 deg. advance--

517 tq @ 4500/514 hp @ 5500, avg tq 456, avg hp 370,


b cam optimized for max avg hp at 0 deg. advance--

518 tq @ 5000/520 hp @ 6000, avg tq 455, avg hp 372

both above with 12" idle vacuum

k cam at 4 deg. advance--

508 tq @ 4500/512 hp @ 6000, avg tq 455, avg hp 372

k cam optimized for max avg hp at 6 deg. advance--

512 tq @ 4500/517 hp @ 6000, avg tq 456, avg hp 372

both above with 16" idle vacuum

the choice to optimize cams is between max avg tq, max avg hp, max tq, and max hp, which moves the numbers around slightly. max avg tq and max avg hp being similiar.

also using 12.5-1 compression

[patrickt]

That's interesting. BTW, elM's Comp Cam has the advertised 294 duration at .006 at the lobe, it's not seat to seat. When you tell it to run mufflers that are not restrictive, what does that do to the HP numbers?

[elmariachi]

Patrick, how does that compare with "reality?"

[patrickt]

Originally Posted by elmariachi

Patrick, how does that compare with "reality?"

I think it's a little bit high, but not terribly so.