Anyone running the lunati 703 voodoo cam?

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MerlinsMopar

MerlinsMopar

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I am building another 340 thats now .040 over 10.2 compression with scat rods and 65cc j heads with 2.02s and I bought the lunati cam after talking with them, it seemed like the way to go. I also got the springs and lifter package with comp cams 1.5 rockers.
I have always ran purple shafts or racer brown cams but ran into vacuum issues with the brake booster so this cam was supposed to have decent vacuum for the brakes but perform well also.
Anyone that used the 703 voodoo chime in on your thoughts please. I don't want to install this cam if it isn't up to par. My resto has power brakes and they have to stay that way.
Thanks!!!
 
Honestly, I solved that issue decades ago. I just convert everything over to manual brakes and never look back.

They actually stop better IMO.

Having said that, I’ve never used that cam, but the numbers LOOK power brake friendly.
 
yellow rose said:
Honestly, I solved that issue decades ago. I just convert everything over to manual brakes and never look back.

They actually stop better IMO.

Having said that, I’ve never used that cam, but the numbers LOOK power brake friendly.
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I am keeping it that way due to being a numbers matching car. I guess you have to sacrifice 1 for the other. Stock cam just isn't going to cut it tho.
 
I have that cam and honestly its marginal. I think I get around 15" at idle so you may need a vacuum reservoir.
 
dano said:
I have that cam and honestly its marginal. I think I get around 15" at idle so you may need a vacuum reservoir.
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Seems like 15 inches should run the brakes...but it’s been a long time since I’ve had to deal with that. Seems like once you got down to 10ish inches of vacuum was when things got sketchy.
 
I have that cam in my 340, it makes 15" it is an ok cam, does have a decent lope.
I have manual disk brakes, but it should pull enough for a booster.
 
MerlinsMopar said:
Does it make good power? How is the lope?
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I've driven it very little with issues not related to the cam and just got the car running again but it need aligned and the carb tuned to be driven. Lope if fair, it's there and noticeable but not the "I'm ready to die at any point" lope.
 
It makes decent power, not much low end though, but I only have 3.23 gears and a 4-speed.
 
yellow rose said:
Seems like 15 inches should run the brakes...but it’s been a long time since I’ve had to deal with that. Seems like once you got down to 10ish inches of vacuum was when things got sketchy.
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Same here. Last power brake vehicle I built a engine for had a pretty mild cam (20" at idle) for 1/2 ton 4x4 truck application. I think booster size matters too, small boosters might be less efficient.
 
I run a 703 in my 340. With the initial at 16* it is at 12-13" of vacuum and it does have a decent lope. I run manual brakes
 
Im going with the 702 in my 360 with similar combo. It's supposed to have good vacuum for power brakes.

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I will tell you how I came to my decision on the 702, the 703 was my first choice and I talked to my machinist who is a cam wizard and he was looking at the @50 duration he said I'd like to see that number a touch lower for your combo, so I showed him the 702 which was my 2nd choice. He said thats the winner in my book! We talked and discussed 50 other cams and he said I think your best with the lunati. He told me whenever im planning an engine build and going through the motions to pick the cam i like the best and go one size smaller. For a street car of course im sure racing cars is a different process.
 
Yes I have the 703 in my 340 4 speed with 3.91 gears. 15” of vac with tq LD340 dual plane intake and headers. Sounds good, lots of pull and I’m all in with 35 degrees of timing. I could add a few more degrees but it got cold out and I got lazy. Lol!
 
Syleng1 said:
Yes I have the 703 in my 340 4 speed with 3.91 gears. 15” of vac with tq LD340 dual plane intake and headers. Sounds good, lots of pull and I’m all in with 35 degrees of timing. I could add a few more degrees but it got cold out and I got lazy. Lol!
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With power brakes? If so, is stopping power reduced?
 
I run that can in a 360 with a 3.55 gear, 17*initial timing, 35 total. A custom built 3500 stall converter with power brakes and A/C. Brakes work fine. I had to make a throttle kicker to kick up the idle with the A/C on but it works. That cam runs great on the street but the A/C kills it. Your power brakes will work fine. You do need more converter, at least something around a 2500 stall. I'm not a fan of Lunati's super heavy spring pressure so I went a different route but I'm running W2 heads with long valves so I have more to choose from. It will pull good from around 1600 to 6200 rpms. So yes, your brakes should be fine. Hope this helps.
 
Hellrats said:
I run that can in a 360 with a 3.55 gear, 17*initial timing, 35 total. A custom built 3500 stall converter with power brakes and A/C. Brakes work fine. I had to make a throttle kicker to kick up the idle with the A/C on but it works. That cam runs great on the street but the A/C kills it. Your power brakes will work fine. You do need more converter, at least something around a 2500 stall. I'm not a fan of Lunati's super heavy spring pressure so I went a different route but I'm running W2 heads with long valves so I have more to choose from. It will pull good from around 1600 to 6200 rpms.
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I questioned why I needed dual springs for that cam. Seems like they would beat the seats up into the head after a while. I have a 4 speed with 3.23 gear but might change the gear to 3.55 or so being that I like to launch from stop signs etc. I will have to talk to my machinist about that. I am running a racer brown ssh-44 in my other motor and love that cam. I know it wouldn't work the brakes tho, hence the lunati. This is the reason that I posted the thread and all the info is really appreciated. Thanks for your reply!
 
You will need the dual springs so you don't float the valves but I really don't think you need the seat pressure that they call for. But on that note, yeah talk to you machinist and let him make the call. That's what I did and he was correct. You'll have fun with that cam and a 4 speed!
 
MerlinsMopar said:
I questioned why I needed dual springs for that cam. Seems like they would beat the seats up into the head after a while. I have a 4 speed with 3.23 gear but might change the gear to 3.55 or so being that I like to launch from stop signs etc. I will have to talk to my machinist about that. I am running a racer brown ssh-44 in my other motor and love that cam. I know it wouldn't work the brakes tho, hence the lunati. This is the reason that I posted the thread and all the info is really appreciated. Thanks for your reply!
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More valve seats have been killed from too little spring load than too much. When the valve hits the seat it needs to hit it once. If the spring load isn’t enough for the mass of the valve train and the valve hits the seat and bounces it will pound the valve job right out of right quick.

I had a cam grinder tell me several years back if it was possible to get a spring with 340 pounds on the seat and 340 over the nose that’s all he’d use. That of course is impossible but his point was seat pressure won’t kill a flat tappet cam. The over the nose load will, but not seat load.
 
cawcislo said:
I believe that cam is 226/234 @0.050, .494/.513 lift, 110 LSA.
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Thanks cawcislo, I run the Hyd. roller Comp version. Lunati seemed to have a stuck on stupid piss poor attitude towards getting me THAT exact cam to me for a LA and kept sending me a Magnum version for my LA block. Then they didn’t want to refund my money for a couple of months.
I managed the best of 17-ish inches of vacuum. I run manual brakes & steering. So a NEED for vacuum wasn’t there. But it’s better to get all you can.
DF443940-1A64-4DC5-B30F-3AE4389609D7.jpeg
 
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