tomcowle

I'm doing a single plane intake conversion on a LT1 and I'm wondering which intake "fits" better than some others. I'm using a set of factory LT1 head castings and the engine will be naturally aspirated.

My reason for asking is that I have a super vic 2975 sbc intake and in my opinion it is too large for a 355" engine utilizing a hyd roller turning 6500 or less. I have access to several other single planes but I don't feel like measuring them all.

Does the victor E have smaller runners?

mdacton

vic-e is too short.

You should go super vic. it will work good. injected or what?

tomcowle

Injected? .....Me?? lol!

Naw, I have a 350" lt1 I'm doing as a pet project. It has factory ported heads and it will have a hyd roller cam, looking for 10.90's with it NA.

I'm eyeballing a new holley strip dominator intake right now however I'd love tp hear from others.

mdacton

If I could do it all over I would have gotten a super vic and a dominator flange. I'm shooting for 10.90's too. I am using that vic-E with a 1" spacer. and blocked off the injector holes... redneck pc. of junk...

AdioSS

since you're staying under 6500, the dual-plane Performer RPM AirGap is pretty good intake. If you have room, then a tunnel ram can make really good numbers.

WS6T3RROR

For that type of engine and combination i'd say the gm bowtie single plane will kill about anything. Although I am not a fan of any of thier stuff the world products motown is also a killer with some reworking. Pro products hurricane (i know its chinese ) will work better than the vic jr in my experience.

Honestly though if you already own a super vic... its kinda tough to beat. It will actually work alot better than people give it credit for if you dont cam the living **** out of it.

Its kinda hard actually to pick a bad intake when it comes to racey small blocks, everything still has to work together though.

I disagree about the tunnel ram, it'll be about the same to 6500rpm and then put the hurt on a single 4 pretty bad by 7k or so.

tomcowle

The victor E and the victor jr share identical dimension from what I've found. (they are on the smallish side) I think only the bowtie vic is smaller.

You can absolutely kill an engine by putting too large or too small intake on it, I'm trying to keep the velocity up in this engine with its limited rpm/cylinder head capacity.

automotivebreath

I ported a set of LT1 heads a while back ~255 CFM for a stock 350 CI
bottom end running a victor E, a carb. and a a small bullet hyd roller.
The car runs great, nice intake.

mdacton

how great does it run?

I want to know.....cause thats about what I have...

tomcowle

I think the Victor E in unported form is too small for a 383, in my opinion. The super vic 2925 (i think thats the number) seems to be the better match with some clean-up especially with a full blown set of heads. The victor E maybe be a great choice for FI because your only flowing air thru it.

WS6T3RROR

I always run a way larger intake in the case of fuel injection. In that situation its only there to hold up the throttle body and its all much less sensistive. A worked super victor or motown intake is usually what I pick in those cases, all I want it to do is not hurt headlfow any or even improve it. No need to worry about fuel puddling etc etc etc in that type of situation. Plus the intake charges, the velocity isnt as important in the intake because air has no real mass to speak of without gasoline mixed in. In efi the heads are still very important just like with a carb because fuel is added by then, but a carb needs a well designed manifold to take care of the intake charge and have a good amount of inertia developed from high intake velocity.

Stroked96Bowtie

^^^Interesting point...

I have a set of heads and a vic-e at the machine shop now getting bolt holes matched and the intake will be CNCed to match the intake runners on the heads.

The CNC guy suggested only matching the heads and not porting the plenum to help keep velocity up through the intake runners. Only CNC about 2in up into each intake runner. Im running some pretty big heads and this was mentioned to help keep the velocity up and help with lowend power.

NJLT1SS

Here is a side by side pic of a 4150 and 4500 series intake:



Here is my intake, its World Products Motown intake with a Dominator flange:



Its being topped off with a Wilson elbow and Nick Williams 90 MM TB. Im just waiting for a new MAF, should be running tomorrow



Nick

WS6T3RROR

Charge motion goes out the window with fuel injection. The fuel is basicly most of the mass of the intake charge, and therefore dictates the momentum the charge has.

I always port the plenums, i lay back the dividers a little because most of the time the center cylinders get choked by them. I also made a nice big radius on the ears and lay them down and back and if its a 4150 flange super vic I put it in the mill and hack a whole bunch right out of it around the flange. Those little lips that kick out right under it dont do anything but cause trouble. Most of the time if i really care how the engine runs I get out the welder on the "ears" so I can get them where i want and the shape they should be. The changes I make to a plenum are usually done with several spot checks on the flow bench connected to the head. Once you have done them a few times you can get it pretty close just from memory and eyeballing it. When the flow with and without the intake is really close, I quit, thats as good as she gets.

automotivebreath

I'm very familiar with engine and the the car. It a stock body Firebird from the
late 80s, weighs about 3200 lbs. Runs a glide with a 3500 stall and a 456 gear
with 9 X 30 tall slicks.

The best time to date is 10.50s at 126, that was with a lower gear in the rear.
The RPM was too high, the 456 slowed it down to the 10.70s.