Thread: lunati VS. Comp Cams

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Another opinion is needed. I was going to purchase a Comp xe268 cam, then I cam across Lunati VOODOO cams. Does anyone have any input about these.\
Lunati 262/268 @.50 219/227 .468/.489 (lsa 112 )(icl 108)
Comp xe268
268/280 @.50 224/230 .447/.480 (isa 110)
I have my vette engine that I have posted about. Will be about 9.0 or 9.3 CP. Standard Aluminum intake, dual plane, with stock converter and 3.08 gears. I am looking to really have some bottom end pulling out. By the way, the stock cam in like .390 lift and something like 220 / 222 duration, real small. Just like peoples opinions. Thanks Hey, if you don't have much to work with, getting the most power out of something is sometimes tough.

Stock converter, 3.08 gear?
I'd be thinkin' one step over the stock cam, something like this....
http://www.cranecams.com/?show=brows...tType=camshaft

I was under the impression that the xe268 cam was to be used for basically stock engines, with stock converters. I want opinons, that is why I posted, but the cam you suggest seems really small. I want to at least notice some power. I am not building a race car by any means, but I have a set of older 350 heads, and cp will be a little over 9.0-1. I am after bottom end power when I pull out in a 81 vette. Like I said, it is a slug now with the stock cam.

If you think a simple cam change is gonna make the motor quite a lot faster, you have another think coming.

In my opinion, you'd be much better off saving up your money until you can afford some AFR 190 heads instead of wasting money on a cam change and trying to crutch-up stock heads.

I am very conservative when I'm suggesting parts for YOUR motor and spending YOUR money, but the cam I suggested is the one I would choose for my motor in the same set of circumstances. Any more cam than that and the motor will be sluggish with the tall gear and stock converter.

I read my post after I posted back to you, and I came off rude I think, and didn't mean to. I am not sure if you understood one thing. I have a set of heads that I got from a friend(machine shop owner) #3973370. They were just done and milled. The engine I have is stock with 76cc heads. I was gonna put these new heads on it, and a cam, intake and carb change. I have headers(factory) and a test pipe for a cat. If you feel knowing that the crane cam you suggested, I will look into. Will the cam you suggested give me a notiable difference, compared to stock? Oh, and these heads were only $250 done, that isn't bad. would I get that much more noticable power if I spent the big money on the AFR heads? I am tring to get the most bang for the buck, but at the same time, I don't want to spend an extra $1000 on heads that might only give me 30hp, verses $250 for 25hp, see what I mean? I was tring to be in area of 300hp if possible.

In the end, it comes down to you calling and talking to the tech guys at your favorite cam grinder. Their service in selecting exactly the right cam for you is free for the asking. I was simply trying to get you to come back to reality a little and spec a slightly smaller cam for yourself. It's always better to undercam than it is to overcam. When you install a hotter cam in a motor, you are moving the operating range up in the rpm range as well as providing more time for the valves to be open. Again, with a stock converter and a 3.08 gear, you will want to be a little conservative with your cam choice. If you overcam it, it won't have any bottom end power and I hear you saying that is what you want from the motor. Call your favorite cam grinder and I think you'll get a recommendation pretty close to what I recommended.

You should be able to make 300 hp pretty easily with most any 350 that is put together with care and paying attention to clearances.

I will do that, and I thank you. Let me ask you this as well. I understand that the more duration you have, The higher up the power band you go. That is why I was looking at the voodoo cams. I noticed that they seem to have less duration that comp cams but higher lift. If you look at my other post, I put some specs there for reference. I agree that if you over cam, you will have the problem you mentioned. I did that 15 years ago with my first hot rod. Sounded really cool at the lite, but a pinto with a miss had me in the 1/8 mile.ha ha. Thanks for your help. I guess I was tring to get the biggest cam possible for my situation. Not only did I not want to overcam, I didn't want to under cam.
What is your opinion. My vette has 190hp stock. If I simply switch the heads to the older 64cc heads, run a thin steel shim gasket to make some compression with my dish pistons, and use the cam you suggested, with a performer intake and a good carb, either my Q-jet which needs rebuilt correctly, or maybe an edelbrock, do you think I will have a noticable increase in power?

"they seem to have less duration that comp cams but higher lift."

Yeah, this reminds me of the "extreme energy" cams where they maximize the lift for each degree of cam rotation. To my way of thinking, there has to be a mechanical limit there somewhere and I'm thinkin' that there will be some pretty horrific pressures encountered between the lifter face and the cam lobe, possibly enough pressure to wipe off the lube and allow metal to metal contact. I keep hearing more and more stories about cams failing and I can't help but wonder if some of this max lift theory isn't responsible. It's getting to where you can't talk to anyone who hasn't experienced a cam failure. Of course, some of it can be traced to using too much spring pressure on start-up or improper preparation or improper lube, etc.

"If I simply switch the heads to the older 64cc heads, run a thin steel shim gasket to make some compression with my dish pistons, and use the cam you suggested, with a performer intake and a good carb, either my Q-jet which needs rebuilt correctly, or maybe an edelbrock, do you think I will have a noticable increase in power?"

You'll want to measure the deck height when you get the heads off (block deck to piston crown) and use a gasket which will give you as close to 0.040" piston to head clearance as you can get. My guess is that you won't be able to get as close as you want. I'd guess that the piston is down in the bore by at least 0.035" at TDC and the thinnest gasket you might put in there is 0.016" for a total quench figure of 0.051". Still, it's better than using a thicker gasket and having a dismal quench figure. If you don't know the cc's of your dish pistons, you really should cc them while the heads are off. If you are not familiar with how to do this, read this paper I wrote on the subject....
http://streetmachinesoftablerock.com...opic.php?t=124
You really need to know your exact static c.r. before ordering the cam.

But to answer your question, yes I think you'd have a nice running car. One addition I would definitely make is a good set of 1 5/8" headers with duals and an "X" pipe.

Hey Richard. I did what you said, and contacted both Crane and Comp Cams. They both agreed that the xe268 was too big for what I wanted, and Comp suggested the XE252 cam, and Crane suggested a cam close to what you suggested. Good work. Now, can you tell me this. Compared to the stock cam I have now, once I install the new cam, and heads with a thin Gasket .016 and install a NON computer carb ( I have an electronic Q-jet with a really slow dumb computer) Should I notice a difference from what I have told you. I mean, am I gonna have to try to notice it?? I know I sould like a pain, but I am on a budget for this car. I can't dump too much money into it, because it isn't worth much, but at the same time, when I goto sell it, I want it to be at least a little impressive for a buyer.Honestly, what kid is gonna buy a SLOW VETTTE????
One more thing. Guy at work GAVE me a holley 750 single feed electric choke Vac secondaries...GAVE... Now I feel that is too big a carb, but is it possible to remove the metering block and jet it down? Any suggestions? Some guys say keep the Electronic Q-jet,and the slow computer,and the Electronic advance Dist. Other guys say put the Holley on it, and a Vac advance Dist, and lose the computer. What do you think??

I love Q-jets, but I don't particularly like ELECTRONIC Q-jets. Heck, I don't particularly like electronic ANYTHING on a car except ignition. I know I'm just a rusty old relic, but I just can't get wrapped around electronics for fuel management. I'm still a carburetor kind of guy and I probably still will be when they shovel dirt in my face.

My "need for speed" self says use the Holley. It's a vacuum secondary unit, so it will only feed the air/fuel to the motor that the motor asks for. Your reference to "jetting it down" makes it sound like you could make the carb smaller by changing jets. I've seen and heard this reference before and would like to advise anyone who thinks it is possible to make a carb smaller in this manner......it just ain't so. The way a carb is sized is by the square inch area of the venturi(s). Unless you change the venturi(s), you cannot make the carb larger or smaller. You can change the relationship of air to fuel with a jet change, but that's all you will change.

My need for obeying the law says that you should check with the Pennsylvania authorities before you do any of this, particularly about removing a computer-controlled carburetor.

If you are able to install the Holley on a Performer intake, use the Crane or Comp cam that was spec'd for you by the tech guys and install headers, "x" pipe and duals, you'll notice a significant change in acceleration that you can feel in the seat of your pants.