Author Topic: Blow Through Carbs Holley vs Edelbrock  (Read 20852 times)

0 Members and 1 Guest are viewing this topic.

Offline SPARKY

  • Global Moderator
  • Hero Member
  • ***
  • Posts: 6924
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #15 on: November 28, 2012, 12:05:09 AM »
The fuel pressure regular must be boost referenced.
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline Dynoroom

  • Global Moderator
  • Hero Member
  • ***
  • Posts: 2195
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #16 on: November 28, 2012, 12:09:46 AM »
The fuel pressure regular must be boost referenced.

Some carbs need the power enrichment port boost referenced too........  :cheers:
Michael LeFevers
Kugel and LeFevers Pontiac Firebird

Without Data You're Just Another Guy With An Opinion!

Racing is just a series of "Problem Solving" events that allow you to spend money & make noise...

Offline Buickguy3

  • Hero Member
  • *****
  • Posts: 1026
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #17 on: November 28, 2012, 09:15:42 AM »
   Here's another thought about a draw thru carb. When you use a draw-thru system with an intercooler, and the 5-6 feet of piping and associated stuff, you are providing a perfect charge in the entire system. Should you break an intake valve or valve spring,------------- well, we've all seen what happens to a top fuel engine when that happens. The other thing is that when you shut off the engine all of that fuel settles out in the manifold, piping and intercooler which really confuses things on restart. Buick got away with this system in the 70's because the carb was mounted on the side of the turbo, and the turbo was mounted on the manifold directly. Total distance about 12". Incidentally, the fuel rich environment on these cars destroyed the center section bearings and seals and diluted the oil to the point that they lost the bottom ends on a majority of the cars. Most dealers were reluctant to even trade them in because they knew the problems. Hope this helps your decision. The Salt Cat 1 car was a blow thru system and would have worked fine had we had more education on what we were doing. It was a very steep learning curve. If you can't use EFI, go with a blow thru.
   Doug  :cheers: :cheers: :cheers:
I keep going faster and faster and I don't know why. All I have to do is live and die.
                   [America]

Offline Dynoroom

  • Global Moderator
  • Hero Member
  • ***
  • Posts: 2195
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #18 on: November 28, 2012, 10:06:09 AM »
Yep, this draw-thru twin turbo, chargeair cooled engine still holds the record in D/BGMS set back in 1988. Ran it for years until EFI came along......
Michael LeFevers
Kugel and LeFevers Pontiac Firebird

Without Data You're Just Another Guy With An Opinion!

Racing is just a series of "Problem Solving" events that allow you to spend money & make noise...

Offline JustaRacer

  • Full Member
  • ***
  • Posts: 258
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #19 on: November 28, 2012, 11:08:49 AM »
   Here's another thought about a draw thru carb. When you use a draw-thru system with an intercooler, and the 5-6 feet of piping and associated stuff, you are providing a perfect charge in the entire system. Should you break an intake valve or valve spring,------------- well, we've all seen what happens to a top fuel engine when that happens. The other thing is that when you shut off the engine all of that fuel settles out in the manifold, piping and intercooler which really confuses things on restart. Buick got away with this system in the 70's because the carb was mounted on the side of the turbo, and the turbo was mounted on the manifold directly. Total distance about 12". Incidentally, the fuel rich environment on these cars destroyed the center section bearings and seals and diluted the oil to the point that they lost the bottom ends on a majority of the cars. Most dealers were reluctant to even trade them in because they knew the problems. Hope this helps your decision. The Salt Cat 1 car was a blow thru system and would have worked fine had we had more education on what we were doing. It was a very steep learning curve. If you can't use EFI, go with a blow thru.
   Doug  :cheers: :cheers: :cheers:

Interesting.  You'd think the fuel could not breach the turbo seals because the oil pressure normally exceeds boost for most spark engines.  What killed a lot of various turbo cars was owners who did not know that you must let the turbo cool down prior to shutting off the engine.  The turbine shaft is very hot, and can coke the engine oil.  As of late, GM got around this by using watercooled center sections.   



My doctor told me to go out and kill people.
Well, sort of.  He told me to reduce the stress in my life.

Offline Buickguy3

  • Hero Member
  • *****
  • Posts: 1026
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #20 on: November 28, 2012, 03:49:39 PM »
   Justaracer,
   You are correct on the reasons for center section failures. Lack of oil changes and owner error. I don't think the dealership sales force in general should have been selling them as they were no more educated on turbos than the owners.
  Doug  :cheers: :cheers: :cheers:
I keep going faster and faster and I don't know why. All I have to do is live and die.
                   [America]

Offline barrybill

  • Jr. Member
  • **
  • Posts: 30
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #21 on: February 02, 2013, 07:46:36 PM »
The Turbotech forum has a 6 page discussion on AFB blow through Carb set up. Scroll down quite a few titles till you see something about blow through. Lots of good info.  Barry

Offline redhotracing

  • Full Member
  • ***
  • Posts: 279
Re: Blow Through Carbs Holley vs Edelbrock
« Reply #22 on: February 19, 2013, 12:03:41 PM »
A fellow forum member (greenjunk) ran a SBC a couple years ago blowing twin
70's into a carb box... He was running a standard Holley 950 carb, presumably
jetted rich, using a referenced fuel pressure regulator to handle delivery. Made
great power, enough to crack several 4 bolt main blocks...  :evil:
Luke- Winston Salem, NC
Loring 2 Club- 201.252 (2010)
Ohio 2 Club- 203.712 (2013)