Join Date: Jun 2001
Location: 35.753983 N, 91.634603 W
Re: 351 windsor intake manifold question
I think you will be pleasantly surprised by how much more responsive the RPM is over the Victor Jr-especially on a mild engine like yours.
The Victor Jr is an excellent intake manifold for the 351w, but it really shines at upper RPM ranges, 5000-7500 is about where it's doing it's best. From about 1000 RPM to about 5000-ish, the RPM absolutely KILLS the victor Jr in responsiveness, fuel economy, and the butt-o-meter dyno. This is speaking from experience.
I like the air-gap myself, but the regular RPM did give me better MPG because the intake ran hotter (which atomized fuel a little better)....BUT, the regular non-airgap style also had a tendancy to boil the fuel in the Edelbrock carburetor.
I can tell you this: Mine was mild. 9.5:1 compression flat tops, iron heads, 750 4 barrel Edelbrock carb, typical headers/exhaust....1.94/1.50 valves in the ported iron heads. Nothing special-probably made max HP about 350 HP and probably around 5500 RPM. Pretty much a turd in my opinion. Originally I built it with a Victor Jr hoping for good top end HP, and the top end was decent. No race car but decent. 5000 to redline (about 6000 RPM max). I traded it for a RPM non air-gap. With the Jr, it would not spin the tires off idle (C6 with 1500 stall speed...about stock). With the RPM, it would spin all the way through first and well into 2nd gear from a dead stop. Overall responsiveness for "street driving" was excellent-it felt like a different engine.
Now if I had kept and and bumped the compression up to about 12:1, put a big solid roller in it and a 4500-5000 converter, the JR would have worked great. But then you get into race car territory....and that wasn't the intended purpose of that old ragged 351. I just happened to have the Jr intake laying around from a previous project that worked better with a super victor.
Real world comparison. I'll say it again-the victor JR is a great intake, it's just not great for a street-type car/truck. Surely someone out there might trade their RPM for your victor jr. I've done this twice-once on a 351w and once on a 302. The 302 with a victor jr (in my case) was a turd, but it woke up with the RPM. Just lost exactly 1 mph on the drag strip, but picked up some ET. And drove 100x better on the street.
Now if you were running methanol, a Jr works great for that....but you're also talking about roughly twice the volume of fuel running through the runners; assuming carburetion. Our stuff is all injected now and it doesn't make that much difference with intake design. Some difference but not night-and-day like on a carb'd motor.
GET OUT & VOTE THIS NOVEMBER!!