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Intake For 468 BBC

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Intake For 468 BBC

Postby mitchmc » Thu Aug 15, 2013 8:45 pm

Hey everyone I haven't posted here in awhile, but now am having trouble finding answers on a suggestions for which intake to use on my motor. BLock is a 454 .060 over with four bolt mains. It has:

-Steel GM crank
-Eagle H beams with L-19 bolts
-SRP forged pistons with a tight quench (.038 quench making it 10.3:1 Compression)
-990 Casting Heads with little to no work done
-Comp Solid Roller Marine Grind 285CR-8 with comp roller lifters
-Can't remember the PN off the top of my head for valve springs, but they are appropriate to run to 7500 + rpm, so nothing light
-Dart intake
-Quick Fuel Q-950

This was just a motor I bought until I decide to build a bigger one and thew it together with the parts I could find to complete the build. I run this combo on 91 octane pump gas with no issues with detonation (due to tight quench I'm thinking) Combo makes 620hp from my calcualtions spinning it to 7200rpm. Car is a 69 Camaro weighing 3600lbs with me in it and runs high 10.90's at 122-123mph. I also drive the car on the street occasionally. Maybe 10 Times or so a year.

Now for the kicker. Putting it together I knew the dart intake had abnormally small intake ports which was odd. On a tight schedule I bolted it on as it was, and made a mental note that I would check it out later. Well its been two years of good running and I finally decided to pull it off and deal with it. It turns out that the intake is an oval port Dart instead of a rec port!! No wonder they looked small. I feel like I am giving up some power in this area, although I'm sure this whole time it wasn't bad for tourque. So question is, what do you guys think? Which rec port intake should I bolt on? I'm thinking of picking up a 454-R Edelbrock as it seems to have good results, thinking the dart rec port version might be a little big. Let me know what you think, and if there are any other suggestions for cams, that would be good as well.
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Re: Intake For 468 BBC

Postby pdq67 » Thu Aug 15, 2013 9:06 pm

I want to say that E-Brock sold a dual plane C-454 rect. port intake that was very good. They had a 396, 427, and a 454 back then.
And you should be able to cut the 2-plane wall down on the 454 if you want.

But it's been years so please bear with me..

I do know that GM removed the wall from the L-88/ZL-1 engines dual plane intakes because they didn't want to tool up for a low volume single plane back then.

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Re: Intake For 468 BBC

Postby rally » Thu Aug 15, 2013 9:11 pm

I have a 468 setup. I use the Vic Jr Rectangular Intake. 4150 base. You say you found out you had a oval port Dart Intake? Those Dart Ovla ports can be machined to match your Rect Port Runners. This was a trick used by drag racers using these. Those oval port Dart Intakes have different runner sizes which will speed up port intake velocity going into the runners. Dart Intakes make slight more horsepower than the Vic Jrs. Anyhow i use the Vic Jr because of hood clearence on my 69 Camaro with a factory cowl induction hood. My opinion if you port match the intake, dont take a whole lot of material out of your intake runners. It better to have them a little smaller for better intake port velocity. This is what a good Edelbrock Tech guy i know well. He knows his stuff.
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Re: Intake For 468 BBC

Postby mitchmc » Thu Aug 15, 2013 9:19 pm

I was thinking about doing that, but there is just so much material to take off (close to 1/2"), I think I will just end up messing up the shape of the port and creating a "pinch" area halfway up the port. This is of course unless I reshape every port perfectly. From my knowledge this will create good air velocity in the "pinch" area, but as soon as the air hits the bigger area that I have port matched to the head, not to mention the bigger port in the head itself, the velocity drops off and turbulance occurs. Someone can correct me on this if I am wrong. I hear what you are saying for sure, just don't know if I have the experience to re shape the whole port. And by the time I take that much material off I will have a lot of time into it, and I think I would be farther ahead just buying a rec port and port matching it instead? Maybe I'm wrong. Definately open to those kind of suggestions!

Forgot to mention its 4200 stall in front of a well built TH350, and I am not all that worried about street manors. When I drive it on the steet it isn't very far or for very long. Mostly what will make the ET's go down and the MPH go up! Thanks.
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Re: Intake For 468 BBC

Postby wyrmrider » Thu Aug 15, 2013 9:38 pm

Perfect question for Big Joe
my 2c
MPH may go up with larger rec port mfd
ET may not, it may go down without redoing other parts of your combination, gears, cam, compression etc
you may actually have a pretty good combination given the rest of your parts
where do you need more power
how fast do you spin the motor
rec ports take more rpm to work and do not like to work at low rpm
you have the heads fooled, high velocity blast into the big void of an intake
maybe the heads think they are filled, if they were they might work better :)
dual plane manifold should work better unless you redo everything
as for cams
do you have a guess as to your head flows, what exhaust?
trans, gears, converter, tires
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Re: Intake For 468 BBC

Postby rally » Thu Aug 15, 2013 9:40 pm

Yes for sure port matching is a lot of work like you said. Its an old drag racers trick with that Dart Oval Port Intake being machined and ported to work with the Rect Heads. Get results with that setup though. Yes if it were me why not buy a Rect Port Intake like you are saying. Why dont you wnat to use another Dart Intake? Dart Intakes amke about 10% more horsepower than the Vic Jr will. But you have to have clearance to use a air filter. This is why again i had to use the Vic Jr. Dont get me wrong, Vic Jrs are damn good intakes.
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Re: Intake For 468 BBC

Postby mitchmc » Thu Aug 15, 2013 10:05 pm

Car is 4200 stall as stated above with TH350 and 4.10 rear with 28x9 mickeys. I am capable of spining the motor to 7500 or even a little higher without valve float, so not scared to rev it. Open exhaust at the track (old style cut outs with the 3 bolt flange right behind the headers). 1 7/8 Headers. Oh, and no air filter for this motor. Don't have clearance with the current intake, and don't have much desire to use one.

With all this said I am thinking the single plane will work better than dual plane for my goals. Like I said street manors are out the door, even though it does still get driven on the street :D

The dart rec port I was thinking might be a little big, but spinning this high maybe it will work? This is where I'm in need of experienced opinions. Definately open to all other suggestions, thanks for the replies and advice so far!
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Re: Intake For 468 BBC

Postby MileHighMan » Thu Aug 15, 2013 11:37 pm

mitchmc wrote:Car is 4200 stall as stated above with TH350 and 4.10 rear with 28x9 mickeys. I am capable of spining the motor to 7500 or even a little higher without valve float, so not scared to rev it. Open exhaust at the track (old style cut outs with the 3 bolt flange right behind the headers). 1 7/8 Headers. Oh, and no air filter for this motor. Don't have clearance with the current intake, and don't have much desire to use one.

With all this said I am thinking the single plane will work better than dual plane for my goals. Like I said street manors are out the door, even though it does still get driven on the street :D

The dart rec port I was thinking might be a little big, but spinning this high maybe it will work? This is where I'm in need of experienced opinions. Definately open to all other suggestions, thanks for the replies and advice so far!



For what it's worth,,,My combo was very simular to yours....I went from a holley HP-1000 carb and Dart 4150 single plane manifold,,,to a Edelbrock Vic jr rectangle port with 4500 flange and 1050 Dominator....I already had larger 2 1/8 Hooker super-comp headers,,and I picked up right at 3 tenths,,and three mph.....Also my shift points were at about 66-6700 rpm...Dan...
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Re: Intake For 468 BBC

Postby rally » Fri Aug 16, 2013 7:04 am

1050 Dom carb is to big for my application. Unless your making upward to 700 HP its a waste.
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Re: Intake For 468 BBC

Postby MileHighMan » Fri Aug 16, 2013 8:58 am

rally wrote:1050 Dom carb is to big for my application. Unless your making upward to 700 HP its a waste.




I agree the dominator carb and intake sounds to big...How would you explain my results????.....3 tenths and three mph would indicate a siginificant power increase......Dan....
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Re: Intake For 468 BBC

Postby alteredu » Fri Aug 16, 2013 9:13 am

I ran a very similar combo to yours last year. Used a Eddy 454R manifold that I port matched to the -2 Brodix heads. Also, NO a 1050 is not to big. I ran a 1050 at altitude and it was just fine. It was reworked by Gary Williams. If you use a 454R a 1 inch Wilson works very well with that manifold. I tried a bunch of spacers and that one worked the best.
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Re: Intake For 468 BBC

Postby mitchmc » Fri Aug 16, 2013 9:56 am

I have DEFINATELY tossed the idea of a dominator around. Especially reving as high as I am. Unfortunately the funds are not there right now to purchase one, and the 950 I have is a pretty nice piece and really should do the job sufficiently. Looks like the 950 and the Edelbrock 454R are winning so far. Great input guys I knew there must have been a few with a similar combo that had tested a few intakes before. I can only hope I gain 3 tenths like MileHighMan. Guess time will tell. Keep it coming with the input and suggestions!
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Re: Intake For 468 BBC

Postby fdicrasto » Fri Aug 16, 2013 10:25 am

Sounds like you have a possible torque monster right now and I wonder how you can control wheelspin with the low first gear and small tires. That would lead to the next conclusion. The single plane rectangular port & 1050 carb like mightyman and alteredu got results with might work great with your combo by actually killing low end torque and resulting in better #'s everywhere. That's not saying this is a proper combo( dinky headers , etc ) but it just may be right for what you are doing now. Phil D. Just a note; 622 hp does not seem to calculate with info about car.
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Re: Intake For 468 BBC

Postby mitchmc » Fri Aug 16, 2013 10:40 am

Car hooks with zero wheel spin. Old traction bars from who knows what, worn out leaf springs, but it works. Almost pulls the front wheels off the ground (you could maybe fit a piece of paper under them, but still counts, haha) with nothing except drag shocks on front. So until this doesn't hook any longer, I won't change it. Oh and this is all through the stock 10 bolt with the 4.10 gears. I know, I know. It is destined for failure. But until it does, I'm good with it.

And maybe your right, 620 might be a touch high, but a hair over 600 should be accurate. I used to have access to a mph to hp calculator that was very accurate in most cases, and I think at 120mph or 121mph it was around 595hp?

I don't think a rec port single plain will kill tourque that much in the 4200 rpm range. Will it?...

The step is so huge from the intake to the head, I just do not see it being good for any sort of power. It HAS to be creating some turbulance which is in turn killing some of the potential torque this intake is made for. Again, no expert here. Just trying to picture it in my head.
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Re: Intake For 468 BBC

Postby Abbottracingheads » Fri Aug 16, 2013 11:02 am

It is hard to beat the 2907 Edelbrock for this application. The only other one I would consider is the Profiler Sniper Junior.
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