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Topic: Biggest cam, but still open headlights?

in Forum: C3 Engines


Biggest cam, but still open headlights?

Posted: 11/3/05 5:52am Message 1 of 8
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Edgewood, KY - USA
Joined: 10/26/2003
Posts: 339
Vette(s): 1981, Black/Black, Engine bumped to about 400HP.Ext/int mostly stock.

My winter project is to rebuild the 350 with flat top pistons, vortec heads, 9.5/1 C.R., performer intake.  My engine builder suggested "an RV-type cam, for torque and to keep the vacuum level up".  I want low-end torque and I certainly want to have enough vacuum to raise my headlights, but I also want a little roughness to the idle and I want the power curve to continue to maybe 5,000 or 5,500 RPMs, not the dismal 4,000 with the stock motor (at which point the power nose-dives.)  I was thinking more along the lines of the Lunati Voodoo 60102.  Will this cam provide me the vacuum I need?  Lunati suggestion with this cam is "improved valve springs and roller rockers recommended".  Are the standard Vortec springs strong enough for this cam?  Other thoughts?  Thanks in advance for your input! 




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Biggest cam, but still open headlights?

Posted: 11/3/05 6:57am Message 2 of 8
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
I can't answer your questions directly, but my '69 427/435 has an L88 cam installed, and while the vacuum is low, the headlights do open and close, though it generally takes a couple of seconds before they pop up, and they do pop up and down smartly. The big headache is low vacuum for the power brake booster, so it takes real leg effort to press the brake pedal to haul the car down.

You can always install a bigger or additional vacuum reservoir tank for your headlights if necessary.


Biggest cam, but still open headlights?

Posted: 11/3/05 11:38am Message 3 of 8
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Virginia City, NV - USA
Joined: 1/19/2005
Posts: 314
Vette(s): 1979 Coupe, white in color

Chesh, I went with the Lunati Voodoo 60101 after talking to a Lunati tech rep. I plan on running EFI some time and don't want to run into low vacuum problems. The rep told me the came would give me good performance and does have a lope at idle. I haven't installed it yet due to just getting over some medical problems.

Dave




Biggest cam, but still open headlights?

Posted: 11/3/05 7:33pm Message 4 of 8
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WEST SENECA, NY - USA
Joined: 12/3/2001
Posts: 2379
Vette(s): 1981 Blue Ice Met. w/pearl ghost flames TKO500 5speed. LS1 Swap 3.45 Dana 44.

chesh,

If you run an "RV" cam you will not be taking full advantage of those vortec heads. Now I'm not telling you what cam to chose or buy, but I can tell you that I run a pretty healthy cam in mine. (LT4 HotCam to be exact.) And I have no issues with vacuum problems what so ever. (Headlights open and close ok). And that cam is strong from 2500 to 6000 rpms.

We have talked via PM about Vortec heads. If you buy the original Vortecs -Part # 12558060 (casting #10239906 or #12558062) they will only handle .480 lift. You will need to mod them just as I did mine, if you are going to run a cam that comes close to .480 cam lift.  Which cost a few bucks.

Now, if you go with the new updated small port Vortecs Part #25534421, they will handle up to .530 lift no mods required. They already have 3/8 screw in studs and the valve springs to handle the high cam lift.

BTW, They do make a large port Vortec head Part# 25534431. But that one is better suited for high rpm racing. Small port is better for street.

Sarge





GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.
3.54 Dana 44
'69 "N11" Sidepipes
Borgeson Steering Box
Born 8/1981
Sequence #3975




Click here to see more pics of my Vette on CarDomain.


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Biggest cam, but still open headlights?

Posted: 11/4/05 5:19am Message 5 of 8
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Edgewood, KY - USA
Joined: 10/26/2003
Posts: 339
Vette(s): 1981, Black/Black, Engine bumped to about 400HP.Ext/int mostly stock.
Thanks guys.  Sarge, that was exactly my concern - that the "RV" type cam would disappoint me.  Your info and assurances were exactly what I was looking for.  Thats a bunch! 


Biggest cam, but still open headlights?

Posted: 11/4/05 5:22pm Message 6 of 8
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Cadiz, KY - USA
Joined: 8/26/2002
Posts: 249
Vette(s): 74 Convertible

See mcspeed.com and click on "killer lights" and change to electric headlight motors.  Then you can put it whatever cam you wish.  Looks like you don't care about NCRS survivor status so change them.  Electric is no more expensive than replacing all of you vacuum parts.

I have the electric headlight motors on my 73 and they work great.




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Biggest cam, but still open headlights?

Posted: 11/5/05 8:06pm Message 7 of 8
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CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
I have the VooDoo 60102.  Just another step up.  I have good vacuum and a decent idle, very slight lope, but not much.  And I have the stock torque converter in a turbo 400.


Biggest cam, but still open headlights?

Posted: 11/15/05 8:59pm Message 8 of 8
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Columbia, TN - USA
Joined: 10/5/2002
Posts: 92
Vette(s): (1) 1971 Roadster, (1) 1971 Coupe (2) 1977 Coupes, (1) 1972 Coupe, (1) 1998 Coupe, (1) 1997 Coupe
The important thing is to make sure that your headlight door vacuum system is in good condition with NO vacuum leaks.  Good luck.   proracr38671.8748958333


in Forum: C3 Engines


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