Cnc ported intake worth much power?
Thread Starter
Pro
Joined: Apr 2005
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From: Batavia IL
Cnc ported intake worth much power?
Well I am finally getting ready to drop my 496 big block into my car, I was holding out on my intake selection cause I couldnt decide if I wanted to try to keep it under the hood or cut it open. i decided to cut and make the space needed. I was looking at the super victor 4500 manifolds and noticed the cnc ported ones available. I have already spent alot of money so the price seems like a drop in the bucket now. the engine is going to be revved like crazy. its got a full forged bottom end, AFR 335 cnc heads, 11 to 1 comp, 1050 dominator, solid roller cam (.690/.690 lift 255 int @.50 263 exh @ .50 285/293 advert 110 lsa)
thanks guys.
thanks guys.
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From: Lakeland, FL
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The CNC ported intakes might be worth 20+ HP. However, you have to be sure that the ports on the heads are at least the same size as the ports on the intake. You will actually lose power if the ports on the intake are larger than the ports on the heads.. Ideally, you'll make most power if they are a perfect match. The CNC ported intakes are usually matched to a specific gasket. If you match the heads to the same gasket, you'll make a lot of extra power!
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
I bought one of the Victor CNC ported intakes. It's a joke...
All they do for the "CNC Porting" is that they go into the port with an endmill and machine about 1/4" depth of the port to the correct size/location of the FelPro gasket. At the end of the 1/4" depth, they leave whatever sharp ridge the endmill happens to leave. So you have to go in with a grinder and blend all the contours to make the "CNC" milling usable at all. For the money they charge, you're a heckuva' lot better off just doing your own port & gasket matching with a grinder and some porting tools - you have to do the work anyway with the poor quality "CNC POrting" done by EDL.
Lars
All they do for the "CNC Porting" is that they go into the port with an endmill and machine about 1/4" depth of the port to the correct size/location of the FelPro gasket. At the end of the 1/4" depth, they leave whatever sharp ridge the endmill happens to leave. So you have to go in with a grinder and blend all the contours to make the "CNC" milling usable at all. For the money they charge, you're a heckuva' lot better off just doing your own port & gasket matching with a grinder and some porting tools - you have to do the work anyway with the poor quality "CNC POrting" done by EDL.
Lars
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Joined: Aug 2001
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Well I am finally getting ready to drop my 496 big block into my car, I was holding out on my intake selection cause I couldnt decide if I wanted to try to keep it under the hood or cut it open. i decided to cut and make the space needed. I was looking at the super victor 4500 manifolds and noticed the cnc ported ones available. I have already spent alot of money so the price seems like a drop in the bucket now. the engine is going to be revved like crazy. its got a full forged bottom end, AFR 335 cnc heads, 11 to 1 comp, 1050 dominator, solid roller cam (.690/.690 lift 255 int @.50 263 exh @ .50 285/293 advert 110 lsa)
thanks guys.
thanks guys.
Is this a clutch car ? Auto ? what rear gears ?
What do you mean by rev like crazy ? How high are you comforatable spinning it ? Have you purchased the cam ? Believe it or not the cam could be a little small (duration at .050) if you really want to rpm it like crazy and it is a clutch car with deep rear gears. Looks like a good cam for an auto.
Race Director
Joined: Apr 2003
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From: Tampa, Florida
HOTROD magazine just tested 3 handported manifolds. The best made ~20 hp over a non-ported intake. Keep in mind these weren't CNC manifolds like Lars is describing. They got the full plenum, runner, gasket matching port jobs. Not one made more power below 4400rpm.
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
True, but it totally depends on the combination. A friend of mine was the guy who ported those intakes.
Thread Starter
Pro
Joined: Apr 2005
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From: Batavia IL
Th400 with manual valve body and a Tbrake. 4500 stall converter. I wish to shift around 7200 rpm or a little more. I am not married to a cnc intake if you got any better suggestions, it just needs to be 4500 flanged. gear is 3.73 with a 28 inch tire, car is around 3000 lbs. I am able to gasket/port match also. I am going to try this cam out, and maybe go bigger later this summer.
Last edited by Tumarr; Jan 17, 2008 at 10:29 AM.
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Safety Car
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Th400 with manual valve body and a Tbrake. 4500 stall converter. I wish to shift around 7200 rpm or a little more. I am not married to a cnc intake if you got any better suggestions, it just needs to be 4500 flanged. gear is 3.73 with a 28 inch tire, car is around 3000 lbs. I am able to gasket/port match also. I am going to try this cam out, and maybe go bigger later this summer.
I thought we were talking about a street car (vette) that weighed around 3500 lbs. For your combination that cam is a little small.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
One very important thing to remember is the intake has to line up properly with the heads. I have seen a perfectly ported and gasket matched intake put on gasket matched and ported heads and when you look down the runner you can see a ridge on the top or bottom where the two pieces meet.
This can be as simple as a lousy intake alignment or the heads have been milled etc. So unless you get the intake to mate with the head perfectly you will lose allot of the benefit of the porting
This can be as simple as a lousy intake alignment or the heads have been milled etc. So unless you get the intake to mate with the head perfectly you will lose allot of the benefit of the porting
Thread Starter
Pro
Joined: Apr 2005
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From: Batavia IL
Well I guess I'll for now use this cheap hurricane intake I have and play around with the port myself and see if I can reach my goals with that. It will be a fun learing experience. I am hopeing for low 10's or high 9's on motor. Then some spray after that. I got the feeling I will be experimenting with several cams also. I wanted it so I can drive on the street but track perfomance is priority. I got a trailer for it so I dont need to drive it very far. I'll keep you guys posted on the progress.
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I would think a Vic R would suit the 496 the best. The latest Team G Weiand is a good one too it seems, but may be a little large.
The Super Vic would do OK,but for your heads, converter, gears and cam, I think the Vic R would outrun it.
Plus the 335's have a unique approach angle and port matching them is critical. Often needing epoxy in the intake to make them perfect.
Too bad you're not putting all of this on a 540 or larger! The 315's might be a little better on a 496, but since I like large heads, I'd have picked the 335's too so I could *grow* into them a little!
Who's cam is that? Got any .200 duration numbers?
I can tell you that the higher I spin my 540...the better it runs. But there is a limit of course. Those rear gears aren't going to allow big RPM at the end unless converter slips a lot..so I think the smaller intake will pull harder and recover better on the shifts.
For example, ML67 is making 702 RWHP with just a Vic Jr and a 4150 carb on his 540 with 335's. It's been hand ported professionally, but it works killer!
JIM
The Super Vic would do OK,but for your heads, converter, gears and cam, I think the Vic R would outrun it.
Plus the 335's have a unique approach angle and port matching them is critical. Often needing epoxy in the intake to make them perfect.
Too bad you're not putting all of this on a 540 or larger! The 315's might be a little better on a 496, but since I like large heads, I'd have picked the 335's too so I could *grow* into them a little!
Who's cam is that? Got any .200 duration numbers?
I can tell you that the higher I spin my 540...the better it runs. But there is a limit of course. Those rear gears aren't going to allow big RPM at the end unless converter slips a lot..so I think the smaller intake will pull harder and recover better on the shifts.
For example, ML67 is making 702 RWHP with just a Vic Jr and a 4150 carb on his 540 with 335's. It's been hand ported professionally, but it works killer!
JIM