[glhs#116]

So, in another thread, I basically have to replace my cam in my mostly stock 1971 455HO because of wear on the cam gear. Naturally, if I can step up at the same time I would want to. I chose the Lunati Voodoo 10510702 basically because I hear good things about the Voodoos and it seems still not too far off the spec of an 068 (.05 lift duration). Other considerations are that I need to still pass emissions and intend to get a manual overdrive one day and obtain decent economy. It is primarily a fun daily not a racer. But I see so many people putting the bigger 703 and 704 in smaller engines that I am a little worried. After all, I know that too small is just going to be a recipe for detonation and finicky tuning.

Is it too small? There is a decent 2.5 exhaust with H pipe on the car and I do have good Harland Sharp rockers on the BBC rocker studs with poly locks.

Sam

[steve25]

So you have 1.5 rollers now, or 1.65?

[glhs#116]

1.5

[Formulajones]

I certainly wouldn't be afraid to try it in a stockish 455.

Is yours still a low compression ratio? 8:1 or so?? If it is this cam will work fine and shouldn't pose any detonation issues if everything else is up to par. I'd PM Paul and ask him where he would prefer the install position. If I remember right he says they work best about 6 degrees advanced or a 106 ICL on this one.

It says choppy idle but looking at the specs I doubt it will make much noise in a 455, especially installed on a 106 ICL. Would work nice with a stock converter and mild gears.

[dataway]

If you have to ask ... then yes it's too small

Hey .... someone had to crack a joke.

[72projectbird]

That car still needs to pass emissions? Jeez

[shaker455]

Originally Posted by glhs#116

So, in another thread, I basically have to replace my cam in my mostly stock 1971 455HO because of wear on the cam gear. Naturally, if I can step up at the same time I would want to. I chose the Lunati Voodoo 10510702 basically because I hear good things about the Voodoos and it seems still not too far off the spec of an 068 (.05 lift duration). Other considerations are that I need to still pass emissions and intend to get a manual overdrive one day and obtain decent economy. It is primarily a fun daily not a racer. But I see so many people putting the bigger 703 and 704 in smaller engines that I am a little worried. After all, I know that too small is just going to be a recipe for detonation and finicky tuning.

Is it too small? There is a decent 2.5 exhaust with H pipe on the car and I do have good Harland Sharp rockers on the BBC rocker studs with poly locks.

Sam

Sam,
I used the 703 in a 69' Trans Am RAIII 400 and and on the engine dyno it made 380hp.
for you cubic inch i would not recommend any less than the 703 if that's your intended route.
Jeff

[glhs#116]

Originally Posted by 72projectbird

That car still needs to pass emissions? Jeez

In Qatar? Yes

[Formulajones]

Originally Posted by dataway

If you have to ask ... then yes it's too small

Hey .... someone had to crack a joke.

It's not the size that matters, it's how you use it.

[glhs#116]

Originally Posted by Formulajones

It's not the size that matters, it's how you use it.

You see my dilemma. I don’t want to, er, slide it in if it isn’t going to satisfy... Erm, within the constraints mentioned that is

Sam

[gtofreek]

That cam will have a smooth idle in a 455. The 703 has a smooth idle and makes plenty of vacuum in a 455. The 702 will probably be all done by 4800-5000 RPM. It is small, IMO, for a 455. If you go with it, I would install it on a 106° ICL.

[glhs#116]

Originally Posted by gtofreek

That cam will have a smooth idle in a 455. The 703 has a smooth idle and makes plenty of vacuum in a 455. The 702 will probably be all done by 4800-5000 RPM. It is small, IMO, for a 455. If you go with it, I would install it on a 106° ICL.

So, even though it is bigger and tighter (110 I believe) you think the 703 should pass emissions, street well and pull a tall gear on the highway?

As per installing on a 106 ICL, is that where it should end up anyway?

[gtofreek]

Originally Posted by glhs#116

So, even though it is bigger and tighter (110 I believe) you think the 703 should pass emissions, street well and pull a tall gear on the highway?

As per installing on a 106 ICL, is that where it should end up anyway?

I put the 703 in a 9.2:1 455 that was basically stock with iron D-port heads. It made 400 HP from 4700-5200 RPM, and made like 528 ft. lbs.. According to the customer, it makes 14" of vacuum at 5000 ft. elevation. Works his brakes good. It has a real good idle also. The Lunati description of the 702 cam as being choppy idle is totally wrong. I put that cam in a 328 and it wasn't choppy. It will be baby smooth in a 455. The 703 was smooth in a 455. The 704 has a slightly noticeable idle in a 455. The 702 will probably come out somewhere in the 108°-109° range if you install it straight up. But there are so many variables that could affect the cam timing that it is best to degree them. The Voodoos are especially sensitive to where they are installed. They like to be advanced at least 4-6°.

[shaker455]

Yes degree the cam.
my 703 cam key way was cut in the wrong spot and I had to get a 9- keyway chain to correct it.
Personally I would step up to the 704 for the 455 but that's me.

[Blued and Painted]

U don't want to damage/melt the cat converters with unburned fuel.

[glhs#116]

Originally Posted by Blued and Painted

U don't want to damage/melt the cat converters with unburned fuel.

71. No cats. I pass emissions anyway, currently, if the carb and ignition are in good tune.

Sam

[glhs#116]

Originally Posted by shaker455

Yes degree the cam.
my 703 cam key way was cut in the wrong spot and I had to get a 9- keyway chain to correct it.
Personally I would step up to the 704 for the 455 but that's me.

Y’all are great. 703 ordered. I guess I can use the 702 for decoration. I will check where it comes out. I do prefer a stock link chain timing set like I have installed but there is a multi keyway roller chain set on my shelf if it comes to that...

[steve25]

If it where me and with your your emissions concern I would run the smaller Cam but step up to 1.65 rockers and get your 111 CC heads whacked .060" on the deck and the Intake flange if such work can be done in Qatar?

[Cliff R]

Most emission testing is done at idle and part throttle cruise rpm's. This is where tight LSA can get one into trouble as pulling the lobes closer together increases overlap and effects cylinder scavenging at low rpm's.

Cam manufacturers go that direction with their camshafts mostly for the "bling" factor as tight LSA puts more "authority" in the exhaust sound. It also pulls power down in the rpm range and narrows up the power curve, so "felt" performance is more exhilarating that a wider LSA cam with similar specifications.

I can't provide a lot of feedback on the Voodo cams because I have very little direct experience with them, and none of it was with Pontiac engines. I did get to spend a LOT of time with a customer in the past couple of years who built what he thought was a very stout running 350 Olds engine using one. It had 9.5 to 1 compression and a smaller Voodoo camshaft, aggressive idle note, "felt" very strong driving the vehicle, easily roasted the tires whacking the throttle, etc. As good as it seemed when the car finally hooked up, which was often well into 2nd gear it was seriously lacking at that moment to the shift point, IMHO. I said nothing to him about it, instead we contracted to have me drive the car to our local track for testing. Good move IMHO, because despite how good a vehicle "feels" by the seat of your pants, the drag strip number will tell you EXACTLY how much power it is making/effectively using.

Anyhow, I was proven correct at our first drag strip outing. The first two runs resulted in spinning the tires most of the way thru the 1/8th mile and lackluster ET and MPH, converting the numbers like high 16's at best a little over 80mph. I then changed tactics and did a "John Force" burnout, which resulted in perfect traction. What a complete TURD all the way down the track. I considered ordering a Big Mac and a Coke and having it delivered so I could consume it before the end of the run, yes, it was that slow!

Jump ahead to the next season, with my help we built a new engine, 10.7 to 1 compression, custom ground cam from Lunati, 222/222 on a 114LSA (basically a copy of the GM 327/350hp cam).

No more "bling" in the idle quality, nearly dead smooth, strong vacuum, smooth/strong power right off idle, power curve flat as Kansas, just keeps on pulling until you feel like moving the shifter. Mid-20's for fuel economy in the owner 1984 442 with 3.73's out back and the rebuilt (done here) 200-4R with one of our custom converters in it.

It's now SOLIDLY into the 13's at the track and I suspect with DOT's or slicks we'd see some high 12's with it. I'd also bet anyone reading this it would pass emission testing w/o the first problem anyplace.

The new found power is mostly linear compared to the first engine, so it doesn't throw ALL of it at you right off idle and roast the tires to death. Instead it just pulls like a freight train clear across the load/speed range, and the car is very quick, and strong in at gear at any vehicle speed.

Now for the bad news, with all that said the owner is NOT completely happy with it......because it doesn't have any "attitude" at idle and it doesn't get any attention at car shows and cruises like it used to with the lower compression engine and tight LSA camshaft!....LOL

As far as how all this relates here, emission testing throws a trump card at you especially with a low compression engine. Camshafts that are going to fully exploit the available power of the good flowing HO heads are NOT going to be less than 230 @ .050" and about 280 @ .006". I've built more of the HO and 455 SD engines that most who will read this. Despite their EXCELLENT potential, the relatively "low" static compression ratio makes it difficult to "have your cake and eat it to" with them.

The best cams I've cam up with for them are all at or over 230 @ .050, and hydraulic roller designs so we can keep seat timing down for improved idle and low rpm power, but have enough cylinder filling abilities at higher rpm's to utilize the excellent flowing round port heads. Most have been ground on either 112 or 114LSA saving the tighter LSA for the stick shift cars as idle quality is not quite as important. We combine these camshafts with 2 valve relief pistons and very tight quench, and cut the heads just a bit to get closer to 8.8 to 9 to 1 compression which also improves power at every rpm plus more vacuum at idle with longer seat timing camshafts.

For what you are doing here staying small with the cam will greatly improve emission test results, but certainly is not going to exploit a lot of the potential of the excellent 455 HO engine..........IMHO...........Cliff

[Tom Vaught]

Originally Posted by Cliff R

Most emission testing is done at idle and part throttle cruise rpm's. .........IMHO...........Cliff

That was true for many years but the last 10 years or so manufacturers have had to run a Emissions Test (75CVS), a F.E. Test, a WOT Test, a A/C On Test, an Evaporative Emissions test, and in some cases on heavier vehicles a heavy load test.

But the majority of older Performance vehicles only had to do the CVS/FE/Evap tests and as Cliff posted were mostly light load testing. .

Tom V.