I tuned every aspect of my engine as I could, ported head, 0.035 quench, 10 to 1 comp, roller cam, ignition curve, dual exhaust with x-pipe, etc... I got 314 rwhp at 5600 rpm and 341 lb @ 4000. Dyno 2000 was telling 400 hp at the flywheel @ 5500 so close to 350 at the rear wheel with 434 lb of torque @ 4000.

But now my intake is not making it!!! It's a performer vortec just a bit better than the stock one. I had no choice because of the hood clearance with the stock air cleaner assembly that I want to keep (stock look).

My car is a summer daily driver and I love taking long trip with it as going to the strip. So my Q-jet is the best carb to do that with an average of 20 mpg on the higway.

I searched without luck for an intake that could flow more with my vortec heads and Q-jet. In fact, you can't have an intake better than the performer (base not rpm) with a Q-jet on a small chevy. It looks like that a Q-jet is not a performance carb. (After seeing my friend cutlass 68 with a 455 doing 11 flat on the quarter with a Q-jet, I got convince otherwise.)

So here my plan, I bought an Edelbrock Super Victor for vortec head, gonna cut the carb pad about 3/4 of an inch and fit the Q-jet on top. That should clear the hood with the stock air-filter a bit cutted.

Anybody done that? I'm a bit worried about cutting a brand new intake!!!

Here some pics of the plan...



Stephan

 

Are you sure you'll be OK with the carb's studs? .. I feel there wont be enough threadsto hold the carb down and if you drill farther inside you'll get into the plenum area.

 

I think I'd be more inclined to remove the divider in the Performer intake and try that before you ruin a new intake. The Victor series intakes are designed for top end power,in the 8000 rpm range. Is your 400 hp 350 even going to get close to those revs?

You seem to be on the fence with your goals in keeping mileage/cruising as well as peak top power.It is next to impossible to have both without overdrive trannies,and fuel injection.

 

There about half an inch of material where the stud will be. I will put studs instead of screw to hold down the carb. If not enough material, steel inserts could be put in to have more clamping force.

But I guess we'll see when the cuting is made.

Stephan

 

I already have remove part of the divider. Same as on the newer performer rpm ones. The real problem with the performer intake is the runner. They are too long and have a small area.

The super victor has been tested in Chevy High performance mag with vortec heads and have given something like 15 hp over the performer RPM intake. All that under 6000 rpm. I give you that the victor jr would have been a better choice for my engine but there not available for vortec heads so the machining would have been extensive.

Keeping it daily streetable with maximum top end is the real challenge.

 

Go ahead and drill the carb pad holes all the way through and tap them as normal. You can measure the depth of the holes and just screw the studs in so they are flush with the inside surface. It would be good to put some Loctite on the studs so that they are sealed and locked in place. Make sure that excess Loctite doesn't get into the airflow path [or wipe it off after installing the studs].

 

In your pics ... appears you're gonna cut carb pad at an angle. If so, maybe you should wait until after angle-cut to drill any holes.

 

Actually, I don't think you are doing too bad. Dyno2000 is notoriously optimistic. 5% error on 400 HP is 380 HP. Then figure 15% drivetrain loss (which is optimistic) and you get 323 HP at the rear wheels.

Too bad you are using the Vortec heads or I would have suggested a Performer RPM Q-Jet. It is working well for me.

 

That's what someone did with my LT1/Z28 manifold. Shaved off about 3/4" and welded on a Q-jet pad. They did a great job of welding and porting. I'm switching to fuel injection and Performer RPM air gap soon, so I may be getting rid of this soon.
Bee Jay

 

Just a suggestion for a little more top end while keeping good port velocity is an old Holley/Duntov single plane. They where designed for the 350" sb motor and higher rpm while very steetble. And it will clear the hood too. But of course u will have to port match the runners and enlong the bolt holes to fit-up.
Unless u have a really large cam (>280* duration) and can spin past 6,500rpm i don't think the Super Victor is gonn'a work - Victor Junoir maybe.
I picked one (Holley/Duntov single plane) up at a swapmeet for pocket change but the studs where bad and need fix.
BTW most dedicated racers will add a 2" spacer to that Super Victor intake. Personally i think cutting up a band new Super Victor will ruin it and have no resale value either. But u may have done more research and know it will work on your combo so good luck to you.

cardo0

 

Yes you're right!

Some welding, cutting and machining will be necessary to fit the carb and I'll wait at the end to position the carb on top of the intake.

Yeah it's not that bad but I feel like there is some left on the table...and that's hard to not go after it!!!

I really liked the Performer RPM on another engine I had. I wouldn't have hesitate if I could have use it.

That intake has been worked a lot! Good luck with the fuel injection. It should be a nice setup.

Stephan

 

Standard head intake would have been a lot of work to fit. With the Super Victor, I only have the carb pad to mofify.

A big single plane will shave some torque but my engine is producing a lot of it between 2000 rpm and 4000 rpm and with my 3.73 rear gear, it won't be too much of a problem. It's a sacrifice to gain (I hope so) something 20 to 30 hp at the top.

Stephan

 

you might consider some of the weiand manifolds not a big name

 

Unfortunatly, Weiand doesn't make a single plane intake for Vortec heads. Too much work involve to make a single plane with standard port intake fit the vortec.

I could have bought a Professional Product to save 50 bucks but my machinist told me to stay away from them since the quality of the aluminium is poor. So is the finish.

Stephan

 

Just curious - You mentioned using the stock air cleaner. Were your dyno test and quarter mile runs done with the stock air cleaner in place? (Nice car - I remember seeing it in Car Craft.)

 

Yes, I have the dual snorkel air cleaner with the stock cold air set-up. I tried without it, and it was worst on the quarter mile. Thanks!

Here a pic: