Guess I'll use the VR-4

What do you think Speedy?
Dart 331, forged rotating assembly, internally balanced, out of box TW heads, custom cam, vic jr, 9.0-ish cr, pump gas, 3000 stall c4, 4.10's, and a 3200# car. Yes, carb'd 650:)
Questions:
What 8 rib blower/pulley combo will give max blower rpms at 65-7000 crank rpms? How can I visually check the VR-4 to make sure it is in good working order and set the preloads on it? I bought this off of Brians88lx, he's the guy who kept blowing head gaskets, and I trust that it is good, I just want to check.
Jesse

To test the ball drive load put a torque wrench on the front pulley bolt and read your in/lb. I myself would use a 3.75" blower pulley and 6 3/4" crank pulley. This combination will give you estimated 8.5psi on a 331 ci engine with stock TW heads. Now I figured this on a stock FI profile cam. I don't have any Dyno numbers or boost psi numbers with a carb loaded into my Dyno Software. I have noticed on the Procharger setups that a 10psi kit for FI is only 8psi with a Carb with the same pulley sizes. I am not sure what causes the PSI difference on the carb.

You think that is a safe speed with the cast impeller and oil cooler kit?
Jesse

Your at 48k at 6000 rpm and you could rev higher but I doubt if your car will be making any power after that, you probably would just be putting stress on the motor.

Hi, Just to chime in, You may find the 650 dp not to be enough on that set up with the supercharger. I had my carb built by a shop that builds blow-thru carbs only and they recommended a 750 for my 302. If you go to Fordmuscle.com there's a real good series on building a blow-thru stroker motor, including the fuel system. When you go to the site search High on carbs.

Speedy, I could just change the cam out to make power up there? I know the intake will go up there.
Jesse

What is your cam specs, do you have the cam card that you can give me everything or scan it and send it to me and I can Dyno your combination.

:angel:

.499/512@.050 219/225@.050 112 lsa
Need anything else?
Jesse

If you can find a 4" pulley you could see what happens boost wise at 6800 rpm, I myself see 10psi at 6600 rpm even in this heat "94" with my 3.75" and I am at 54k+ rpm on the VR4 and have had no problems with the unit. Your Carb as stated above is to small if you go over 5350 rpm the Dyno says you need a 850cfm in a supercharger application to have enough fuel at 6800 rpm.

You have no probs with the unit, but you have a billet impeller...I have the cast one. Why 6800? As for the carb, does it take into account changing jets and drilling PCVR's to gain more fuel under WOT than at idle? What kind of numbers did you come up with? 4" blower pulley, which crank pulley?
Jesse

I put in 6800rpm because you said 6500-7000rpm so I split it in the middle. Cast impeller will still hold up just like the Novi2000 at 60k rpm. Of matter fact I will give everyone a clue in who is reading this topic, The First Novi 2000s had the VR4 Billet impeller but because of cost was changed to the cast and that is why the VR4 unit is cast also...Cost. I didn't go into the Carb settings just pulled in a 650cfm. All my boost measurements are with a 6 3/4" crank pulley. The dyno software has you at 435 whp but shows you choking at 5300rpm. My guess will be you will be really lean when you hit the 5000rpm mark. Without a Supercharger it is showing you to be using a 625cfm carb and to use a 850cfm with a 1400cfm supercharger at 6800 rpm @ 10psi.

Also, the Stealth intake isn't good for blow-thru. You'll need to use a single plane, such as a Vic Jr.

Vic Jr, as was stated in original post:)
Speedy, how is my 331 with bigger heads "making" lower numbers than your 302?
Also, with a Dart, I am going to a solid lifter cam for a steeper ramp and not having to purchase the $400 link-bar lifters. So, I won't be going with the FI profile, although it does favor boost so much;)
Jesse

My cars have come close with the Electronic Dyno Software to my real Dyno numbers but I have every number needed to complete the total reference charts. I put what I had for your car and using default on other things. I can give you reasons but most don't like what is said...lol
1. First your automatic eats power up. Lots of Power
2. Carb to small which it shows when I put a larger carb in the graph.
3. Just being a Carb seems to lower the numbers, when I put your car with a EFI running a Edelbrock Performer 'R' you gain 23 hp from 4200-6500rpm.
4. The software to generate WHP numbers has a Standard Transmission only causing a 12% power drop and a Automatic with your stahl a 22% drop.
5. You will know your real numbers by either putting it on a Dyno or at least taking it to the track to reverse engineer your 1/4 runs into horsepower.
6. I have so many hours on a Dyno using a Tuning Device that I have a every horsepower that this car can give.

Ahhh, thanks:) It sucks sooo much being poor....I have all of the pipes and everything I need, all that is holding me back right now from slapping it on is the carb hat and the pulley's/belt...that's it!
Jesse

DO you need a carb hat?

As in am I in do I need one to run, yes...can I afford it right now....talk to me in August:) I am wanting a CSU hat, I have heard nothing but good things about them, next would be the EV hat.
Jesse

Well I have something maybe better than both. I will check at the shop but I can give you a PAxton Polished hat if I can find it and I have a bunch of 1" spacers laying around also. I will look tomorrow when I go in and if you purchase something else I just ask you send mine back because I can give it to someone else. Thanks

Speedy,

Do you have a better tbi hat then the stock Paxton hat ?
The VR4 outlet is bigger then the Paxton hat inlet.
I might be interested to :cool:

Here you see some pictures of a similar carb/tbi hat

How does your truck run? Do you have any track or dyno numbers?

Speedy, that sounds good, but not until next spring. I won't have any time to install it before I deploy so it'll have to wait until I get back, but I would definitely like to try it if only for comparison against the EV or CSU hat. Might make a good write-up.
Jesse

I did not do a run (yet)

The Paxton VR4 hat is a 3.5" opening and I did not have time to look today I will try tomorrow. I had 3-VR4 hats at one time and sold two of them a few months back.

You mean the outlet from the blower is 3.5"? I thought mine was 3...maybe I shoudl remeasure:)
Jesse

The inlet on my Hat is cone shaped but is 3.5" after the hose ribs the main opening is 3" but they call it the 3.5" Hat in the old catalog so people would see it was for the VR4 I guess... I will take measurements when or if I find it tomorrow because my older son thinks he sold it to a guy making a turbo kit but I don't remember that transaction so he probably sold it and kept the money...LOL

OK, let's dig this post up...I still plan on running this combo but I need cam recommendations....what do you think will make the most power and torque reverse engineering from the shift point of 6800? In other words, keeping the shift point at 6800, what kind of cam specs should I be looking for?
Thanks guys,
Jesse

compcam 276HR
276 280 .544 .560 114*
Rpm Range 2000-6000
Part # 35-312-8
It is Hydraulic roller for Carb with a blower
I had this cam in my dual VR4 carb engine and it pulled to 7500 rpm and did not float and the power is just crazy.
The motor is now in my friends boat has 170 hours and runs at 6000 rpm and when he pushes the throttle the boat lifts like a car on slicks up to 6800 rpm. He uses a jet drive and even with all that load it will do idle(1000rpm) to 7000 rpm in 5.5 seconds. It really is a cam to look at.

Cool, thanks!
Jesse

Update: So everything is going as planned, ordering all the parts as I type...3.5" blower pulley, smooth idler pulley, and 7" crank pulley, all 8 rib, now I just have to find a belt.
Question: Should I go ahead and get a good dampner while I am putting the crank pulley on? I have heard some nasty things about crankshaft vibration and I'd like to do it right the first time, any recommendations?
Thanks in advance,
Jesse

Anyone on this thread anymore?
Jesse

Still around...lol

Quote:

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Originally Posted by Orion_134

....Should I go ahead and get a good dampner while I am putting the crank pulley on? I have heard some nasty things about crankshaft vibration and I'd like to do it right the first time, any recommendations?...

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Another question, is the tensioner used on the supercharger's belt system a stock-type spring-loaded tensioner?
Thanks,
Jesse

No, it is a push down style with a locking bolt.

And the dampner?
Jesse

You still use the stock unit that moves over to the air condition bracket area for the main belt.

Maybe I should have use a different word...the harmonic balancer. Should I go ahead and upgrade my harmonic balancer because of the combined loads put on the snout of the crank by the supercharger?
Jesse

Harmonic balancer does not matter because the pressure usually snaps off the front of the crankshaft.

IOW, the damper is there to control vibration from rpm and load but, not the kind that the belt imposes on the crank. It can't help you there.

F=MA