[BDH79T/A]

I had Jim's book. It was VERY informative and helpful. I haven't been able to find it since moving 3 years ago.

[BDH79T/A]

That Lunati 262/268 was one in my top 5.

[tom s]

FWIW,what ever you do make sure you have good 1 pc valves.The advantage of the hyd roller IMO is less worry about a FTC going flat and having to put additives at oil changes.One flat cam will wipe out ANY savings you have done.If this car-engine is planned to have awhile now is the time.If maybe a short time then maybe not.Also you dont have to have headers on a street car.I have a 455 with the SP and use the RA manifolds.Good luck with your project.Tom

[Mike]

Crower 60243. Love it

[Squidward]

I run the 702 Voodoo in a 350. It got a little soft on the very bottom end of the rpm range due to size of cam/engine. But I am sure a 428 would own that cam. I agree with 68404 springs. I run the 703 Voodoo cam with Crower cam saver lifters in a 400. It is very streetable, although vacuum is around 13". Again, I'm sure that cam in a 428 would behave much better, more like the 262 would behave in a 400.

68404 springs bind at .950 with installed height of 1.6, so these springs would support the lift of either the 262 or 268 Voodoo cams, as long as your valve seal-retainer clearance is adequate.

I have a narrow frame of reference with little other experience in cam use beyond stock cams, XE262, and Summit 2800. But I loves me my Voodoo.

[BDH79T/A]

Thanks Squidward. What kind of compression are you running on the 400? You running an auto or 4 speed?

[Formulajones]

I built a 428 with 13 heads 20 years ago. I ended up needing a 16cc dished piston, zero decked, with the heads coming in at 76cc, and a .039 head gasket to get a target 9.7:1 compression ratio.

I ran a few different camshafts in it over a period of several years. My favorite was the summit 2802, no rhoads lifters. I installed the cam at 108* ICL. It idled smooth, stock converter, and 3.07 gear. Plenty of vacuum for the power brakes. I ran the Crower 68404 dual springs with it and used 1.65 rockers on it. It was a strong runner off idle to 5500 and cruised around like a stocker, ran on pump gas just fine with 34 degrees of total timing.

Like Squidward mentioned, he likes the Voodoo camshafts. I hear nothing but good things about them. I never got to try one in the 428 but I have some engine builds coming in the future that I might just stick a Voodoo in.

[ponchjoe]

I just finished a similar build but with a 455. I decided against the noisy Rhoads and talked to gtofreek and went with the voodoo instead. I used the 704 but would recommend the 703 for the 428 or the crower 60243. You might want the 703 ground on a 112 but I have power brakes in my car and haven’t notice a problem and I’m still tuning.

[gtofreek]

This Voodoo cam in a 428 has very mild manners, but oh boy, watch out when you step on it!
http://www.lunatipower.com/Product.aspx?id=1776&gid=287

Here's a video of it.

https://www.youtube.com/watch?v=z9ly_yH0ZZ8

[tempest1964]

Paul, I thought about your build with this Lunati cam. How do you think it would do think it would do with a 3.08 gear?

[ponchjoe]

I’m planning on doing the 704 with a 3.08 this winter, may need a small stall but will find out after the change.

[grivera]

Whatever you do, use forged rods

[Steve C.]

The Voodoo 262/268 hyd flat tappet cam with a 1.5 rocker ratio is stated to have 0.468 valve lift. If used with the Crower 68404 valve spring in conjunction with a true 1.600" installed height it would in theory be 0.182" away from coil bind at that valve lift.

Do your homework regarding distance from coil bind with it. I have no personal experience with that cam but I'm aware of what is often touted about distance from coil bind, example here:

A comment from a cam tech article, the topic was the importance of checking installed height and coil bind.

"Obviously if you try to lift the valve past solid height, then something has to fail. However, now we know that if you are too far away from solid, you will not be able to use the coil interaction over the nose to reduce surge. Depending on the application, it's ideal to have the spring come to within 0.060 - 0.120 inch of solid over the nose."

Possibly Paul Carter might chime in on this since he has quite a bit of experience with Voodoo cams. That and maybe with a hyd flat tappet it's not as much of an issue. Also I know he has opinions on proper seat pressure with them and I see that spring is rated with 113 lbs seat pressure.

.

.

[Steve C.]

"I shoot for 130-135 lbs. on the seat[with a 30° intake seat], and 330-340 lbs. open spring pressure on that Voodoo cam also. You can go less seat pressure if you have 45° seats[still shoot for 110-115 at least]. I wouldn't go less than 320 lbs. open."

Paul Carter post 51 here:

http://forums.maxperformanceinc.com/...130-135&page=3


.

[72LuxuryLeMansLa.]

Originally Posted by Steve C.

"I shoot for 130-135 lbs. on the seat[with a 30° intake seat], and 330-340 lbs. open spring pressure on that Voodoo cam also. You can go less seat pressure if you have 45° seats[still shoot for 110-115 at least]. I wouldn't go less than 320 lbs. open."

Paul Carter post 51 here:

http://forums.maxperformanceinc.com/...130-135&page=3


.

I'm glad you posted that link. I enjoyed reading that thread again.

[Formulajones]

Originally Posted by grivera

Whatever you do, use forged rods

I used stock resized rods with ARP bolts in my combo I listed above, and raced the crap out of it for more than a dozen years without issue, lol

[Will]

That Voodoo 262 is the smallest cam I'd run. Anything smaller than that is just leaving power on the table.

If you don't mind spending a little money, I'd get the Crower 60243 & Rhoads Lifters.

[Formulajones]

Originally Posted by Steve C.

The Voodoo 262/268 hyd flat tappet cam with a 1.5 rocker ratio is stated to have 0.468 valve lift. If used with the Crower 68404 valve spring in conjunction with a true 1.600" installed height it would in theory be 0.182" away from coil bind at that valve lift.

Do your homework regarding distance from coil bind with it. I have no personal experience with that cam but I'm aware of what is often touted about distance from coil bind, example here:

A comment from a cam tech article, the topic was the importance of checking installed height and coil bind.

"Obviously if you try to lift the valve past solid height, then something has to fail. However, now we know that if you are too far away from solid, you will not be able to use the coil interaction over the nose to reduce surge. Depending on the application, it's ideal to have the spring come to within 0.060 - 0.120 inch of solid over the nose."

Possibly Paul Carter might chime in on this since he has quite a bit of experience with Voodoo cams. That and maybe with a hyd flat tappet it's not as much of an issue. Also I know he has opinions on proper seat pressure with them and I see that spring is rated with 113 lbs seat pressure.

.

.

I think what you're saying, if I'm reading you right, is that it's been found more beneficial to run the springs closer to coil bind. At least that's what I've been told anyway. Has something to do with better valve control and harmonics blah blah etc....

I ran the 68404's at a 1.6 install height using the 2802 and 1.65 rockers, worked great. That's .512 and .536 lift
With a coil bind at .650 I'm .138 away on the intake and .114 on the exhaust. Seems I had room to go which is why I tossed on the 1.65's.

[Steve C.]

Often stated the safety margin of .060" (or more) is necessary to avoid the dangers of coil bind and over-stressing the spring.

This from the Reher-Morrision website:

"Both the Spintron and the dyno have convinced me that a valve spring performs best when it runs in a certain relationship with the cam lobe. Installed height and the distance from coil bind are both critical. In the good old days, we’d set up the valve springs at the installed height that produced the seat pressure we wanted, and then add a .030-inch or .060-inch shim when they lost pressure. I now believe that’s the wrong approach for a high-end racing engine. In a perfect world, the spring should operate at its optimum position from coil bind regardless of its pressure. Valve springs are very complex components; evaluating a spring on pressure alone is like choosing a cylinder head solely on its airflow while ignoring velocity and cross-sectional area."

And another comment on the subject:

"When choosing a spring, it's best to get the spring that comes closest to "coil bind" (without reaching it) at max lift. This helps reduce or eliminate spring "surge", where the harmonics increase due to not using the whole spring."

From all this just keep in mind MOST consider the 0.060-inch figure the minimum allowable clearance, some will go slightly less.. And related you will hear or read from some that the further from coil bind you keep the springs, the longer they will last. My opinion on that last statement is due your research.

.

[Steve C.]

A fwiw, this specific coil bind subject was based on a 1.600" installed height for conversation. The obvious, in all likelihood they will not all measure the same.
One example for the intake installed height (before shims) on a set of heads:

1.980
1.970
1.935
1,960
1.963
1.950
1.950
1.955

Within another thread the statement / opinion was made that .015" across the heads was a acceptable variance. That I have not verified.

.