[1967Tempest]

Originally Posted by 77 TRASHCAN

Dave,
The plain stock blue Fel-Pro head gaskets will work fine for your deal, no need to splurge on the 1016's

Bought them in the kit..

[Blued and Painted]

Originally Posted by Cliff R

just stated facts about this particular engine build. We've done a lot of them here, so not guessing about any of the results from the end product......Cliff

Thats why ALL your posts are a must read even if it is regurgitated. Thanks Mr. Cliff..

This is not a cam recommendation.

[1967Tempest]

Does anyone have any shootouts Lunati 704 Vs. Crower 60919?

Or equivalent?

These are my front runners.

Thanks!!

[Steve C.]

VooDoo 10510704 and Crower 60919.

Although similar in .050 duration, the difference between them is like night and day !

For interest input the Advertised duration and Lobe separation here:

http://www.wallaceracing.com/overlap-calc.php

These are the valve timing overlap ranges that are most likely to work correctly based on input from David Vizard ( take it with a grain of salt. Similar published info will vary )

trucks/good mileage towing 10-35 degs overlap
daily driven low rpm performance 30-55degs overlap
hot street performance 50-75 degs overlap
bracket/oval track racing 70-95degs overlap
dragster/comp eliminator engines 90-115 degs overlap

Besides the big difference in seat duration note the valve lift !

It also won't be exactly apples -to- apples if they are not rated at the same tappet lift, which I believe they are not. But it will serve as an idea for interest and/or conversation.


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[Steve C.]

And as long as I'm touting David Vizard, this info published by him below might be of interest as you note the amount of valve lift between the Crower and VooDoo lobes !

VALVE LIFT.
"A 2-valve cylinder head typically continues to flow more air up to lift values equal to as much as 0.35-0.4 times the valve diameter. The reason for this is that there is a flow pattern transition period that takes place at a lift value of about 0.25 of the valve's diameter. When this point is passed, if the port has been modified to support flow in this lift region, the valve efficiency actually starts to increase. This is the reason why a 2-valve engine responds to high lift." "If you want to build a street motor with the most power without a sacrifice of idle and low speed qualities, then lift is the most important factor to maximize, not duration. The best street cams are those that seek to maximize lift while only adding a minimal amount of duration."

Bottom line, the engine wants all the lift it can and thrives on it so run as much as mechanically achievable or prohibitive to you because of cost and/or budjet limitations (such as in a purchase for solid roller cam, longer valves to increase installed height, stronger springs, etc.). Obviously if it's a street application or race application will have a bearing on the situation, most here would be hesitant to run 0.700 lift on the street.


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[1967Tempest]

Very true.

Since I currently have a recommended spring and retainer set-up for the Crower cam, I should take that into consideration.

Like previous stated, I would have to verify that the current head set-up will work with said Voodoo cam.

Lot of information here. Good to cause the cam is a PITA to swap out of you make the wrong choice.


Should I not even consider factory headers? Am I destined to put a set of headers on this?

THanks again!!!

[Steve C.]

Stated - "Since I currently have a recommended spring and retainer set-up for the Crower cam, I should take that into consideration."

As noted be sure you know your actual spring pressure. Will it be adequate with a VooDoo lobe ?

Remember to always check new valve springs before installation. Do not trust what a catalog states and understand they will probably lose some pressure after run in.

Example, recently Skip Fix checked some brand new Crane valve springs and found the seat pressure was about 19 pounds less than what was published. They were tested at the actual installed height on the heads.

Spring tensions often vary measurably within the same production runs; therefore, it is recommended that each spring be tested on an accurate spring tester and the spring installed at the recommended seat pressure.


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[1967Tempest]

Good to know.

Like i've said, gotta make sure all the ducks go quack before I select. I would hate to spend all this cash and have a slug...

[Chicagogoat]

IMO that 704 voodoo cam should be fine as long as your current spring package can fit up to .540-.550 lift to give you that .040 cushion. You need to stick with a 1.5 rocker ratio and you'll be fine with that cam. As Steve said the spring rate has to jive with the manufacturer recommended profiles so most of the time your best bet is to change the springs to match the cam, double check them to make sure, then you should have no issues. I'm running the 705 cam with Rhoads lifters and KRE-D's and I'm pretty happy with it all around. I'm a firm believer of what Cliff advocates, running "bigger" cams on big inch Pontiacs to get the most return on investment. Also running as much lift as you can "get away with" goes hand in hand with pushing for bigger cam profiles. Yes different heads, CR, induction, converter/gearing weigh heaviest on cam selection. But so does the driver's tolerance for mean sounding cams

[gtofreek]

What heads, and valves are you running? That 704 Voodoo cam is a bitch to setup springs for with 1.65:1 rockers if you have stock length valves in a D-port head. I did it, but it was very touchy, and springs had to be assigned to specific valves so they wouldn't coil bind. With RAIV length valves in D-port heads, it shouldn't be a problem. With 1.65 rockers, it's like .555"/.580" lift!

[gtofreek]

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.

[77 TRASHCAN]

Dave, have you worked your heads yet, to determine the assembled height of the springs?

[1967Tempest]

Yeah, the heads are on the car now. 6X-4 CC'ed at 94 with Crower 68404 springs with the corresponding retainers and 7* keepers.

I cant remember the installed height off the top of my head.

[gtofreek]

Originally Posted by 1967Tempest

Yeah, the heads are on the car now. 6X-4 CC'ed at 94 with Crower 68404 springs with the corresponding retainers and 7* keepers.

I cant remember the installed height off the top of my head.

There is an easy way you can make a degree sign after a number. Simply hold down the Alt key while typing 0176 on the number pad, and wah lah, the degree sign appears!

[Firebob]

What about running stronger springs? Like some hyd roller springs(355-360 open) on the likes of the 704FT cam. Trouble??

[gtofreek]

Originally Posted by Firebob

What about running stronger springs? Like some hyd roller springs(355-360 open) on the likes of the 704FT cam. Trouble??

If the seat pressure is under 140, I'd say they will be fine, but I would break it in with the inner springs removed.

[Firebob]

Thanks Paul. Since this is a sort of Voodoo recommendation thread...
Say a 455, 30 over, Ehead round ports(290@.600), Doug's 1 7/8. Would the 704 be a decent cam or would I be better off going a bit bigger? Mainly street with some road track time a couple times a year.

[gtofreek]

I put the 704 in a similar engine. It was only 9.5:1 compression with E-heads. It has a pretty mild idle. If you have 10:1 compression or better, I would suggest the 705 if you don't mind a little choppy idle. It has 241/249 @ .050". If you are lower compression, the 704 would be good if you don't like/want a choppy idle.

[Firebob]

CR should be right at 10.5-10.6 with 75cc chambers and 13cc piston volume@ .012 Below deck. So you think the 705 might be the better choice?( By the way I love a choppy idle.)

[gtofreek]

Yes, for that compression, I would go with the 705,