427Hotrod

Do you recall the idle vacuum you had with that 406? Mine is around 6-8 inches at 1000 rpms in gear. (3000 stall) Just curious.

Also,...mines a flat tappet solid. How much do you think I'm actually losing over a roller like the one you tested? In the future,....I may see a roller cam................

 

I'm of the same mindset of V2racing. If you ignition is not right, it doesn't matter what you do to the carb. I also believe that any carb can be modified to run on even the most radical combinations.

So if your dizzy and carb are out to lunch a change to a roller cam will be maybe less out to lunch.

I have the MSD E-tech dizzy, But I consider the Crane pro-billet to be far superior because it has better timing choices.

In one day you can try all kinds of timing to suite any motor with just clicks on a dial.

http://www.summitracing.com/parts/cr...1501/overview/

 

How much room do you have under the hood? A 4-hole carb spacer might help. It's a Corvette, though, it was probably all you could do to stuff the Performer RPM manifold under there, right?

Scott

 

Either add more gear or less cam the rest will pizz you off $$$$

 

I don't have a vacuum reading. We didn't ck it..but he's been driving it just fine with the WCFB's. It idles clean etc.

Shoot a note to "Devildog" here on the Forum. I'm sure he's checked it and would be glad to tell you about it. We originally planned it for a non-O/D trans..he later installed a TKO. It's a little rowdy for mega low rpm cruising in 5th with 3.08/3.36's..but does fine overall.


Depending on how good the flat tappet is...might be 20-30 HP? Could be more or less depending on how close they are to optimum. I tested a real good flat tappet against a real good solid roller in a 555" a while back. Made 820HP with the flat tappet and 850 with the SR.

JIM

 

I switched from a 1/2" open spacer to a 1" four hole, it definitely made the low end better, but it also seemed to take a little from the top end.

 

Wayne,
How hard is it to change the boosters?

 

Kind of funny you mention that. I actually considered 4.56 gears,.....but I like to be able to actually drive the car. For the same money as a gear swap,...I could do the roller cam.

Gkull
I have a MSD ProBillet HEI that I tried all the limiter bushing combinations, and also three different vacuum cans.....As a last resort I locked the timing at 36 degrees,....means my initial is also 36 degrees. It did help quite a bit compared to what I started with.

That lead me back into the carb where I played with IFR and air bleed jets for a while. All told,...my original 3310 now has a Proform body, QFT billet metering blocks, QFT billet throttle plate, has been rejetted numerous times, and I guess the fuel bowls are about the only thing left that was from the 3310..........

L88 hood,..........Hummmmmmm,.....Could try spacers.

 

On my 400 with an rpm air gap and the one inch spacer I fit a 3" filter under my L88 high rise and have about 3/4" to spare.

 

I had K&N make one three inches tall for my oval filter, and if I remember right,...might not have room for spacers now that I think about it.

 

I had to buy the tool it's the red thing that looks like the end of a screwdriver in pics it's got four pins coming out the end that line up the the four holes in the booster. Cost about $12,234 from BG for a $3 tool, (over estimating a bit but you've read Home Wrecker on the side of a car before. ) but I have the best of the best in that engine. 4 years now and it runs like day one.

What concerns be is spending money for little return, putting something on that you can't even feel, when I'm at 7 grand going down the strip I doubt the motor know what carb is on it, spending money for little gain really bites my *** that's why I picked everypart down to bearings when I built my 427ci and it came up with the numbers I expected.

The HP per dollar goes ballistic once you get into the 550-650HP range in a smallbock and I'm not talking about an Fleabay pile or crap motor, I had brand new parts from reputable companies re-machines that's probably why I take it 7500RPM 4 years later with only a spring change, if you ever sat in the passenger seat of mine at in 2nd gear at over 7000RPM it happens so fast that I have I time to boot you out before you crap your pants.

Getting back the downleg vs annular, this is where you should notice a difference driving around town, a little more response and Tq, not a heck of a lot but enough to to make you want to stay with annulars.

One last thing is to make sure you have spun in boosters before you go any further.

 

Thanks Wayne. I'm not for sure about my boosters being spun in, it is an 950 hp main body.

 

Been researching carbs and EFI systems recently ,looking for the lastest and greatest.The new Street Demon carbs have been getting some great reviews right out of the box.Two sizes 625cfm & 750cfm.Carb has smaller primaries,larger secondaries sorta looks like a modern Qjet.Bolts up to a square bore or spread bore manifold.Polymer fuel bowl available which keeps fuel cooler.Smaller primaries for cruising ,larger secondaries when you wanna stomp on it.Efi looks great but 2K buys a lot of fuel,and more upgrades!
http://www.summitracing.com/parts/dem-1904/overview/

 

No clue.

What is spun in boosters mean? I plan on sending the whole carb to Quick Fuel when I get ready to put the Vette away for the winter, and have then go though it.

 

If I were getting 460 rwhp out of a 383, I wouldn't change a thing. Please let me know how the FAST Fuel System works out for you.

 

Spun in are threaded and can be replaced with that tool. Cheaper carbs have pressed in boosters and hard to change them.

 

I spun that 383 to its max a few to many times and busted the crank, so I am building a new 427 now, and that is what I am putting the EZEFI 2.0 into.... They do make a EZEFI 1.0 for 550hp and less.... With the 427 I am shooting for 650 hp before I hit the NOS... And up to 1000 with NOS, thus the reason for the 2.0 system