Four barrel EFI

[ozconnection]

Playing around with throttle bodies.....

 

 

 

 

[BJSZED]

Nice setup ! Very interested in how the delayed secondary throttle plates will work. I have a 4 barrel throttle body setup which works very well at low and high revs, very smooth. All my throttle plates move at the same time.

 

A couple things to watch out for is correct pcv operation with a dual plenum intake. And double check if your getting a proper ported vacuum signal for your distributor. Because of the small cubic inches, the throttle plates are more closed at idle and cruise which can affect the ported vacuum signal. I had to re-drill lower in the throttle bore.  

 

Anyway, I always like reading your posts, great job !

Edited December 25, 2016 by BJSZED

[ozconnection]

Hi BJSZED,

 

Thanks for your input man!.

 

On the Clifford manifold, the PCV is positioned exactly behind the plenum divider in the manifold so that three cylinders receive half the gasses, the other three receive the rest...make sense?

 

Ported vacuum signals are not used for this setup. At the moment the distributor is locked at 30 degrees. The throttle body configuration is setup on my track car so it really doesn't really need an advance curve for the track as it rarely ever drops the revs below 3.5K rpm

 

Having said that, my next round of modifications will include a balancer 36-1 timing wheel to allow for adjustable ignition timing. The car gets driven to the track so some low speed tractability will be useful in those circumstances.

 

The engine is managed by a Megasquirt ECU.

 

Cheers!

[BJSZED]

Looking forward to the updates !

[Mayolives]

ozconnection...........I'm sure I'm not the only member that would like to know more about your EFI system. I'm ready to spring for some parts to install on my 3.1, stroker that has an Arizona Z Car, four barrel intake.  I've been reading about the various manufacturers of EFI systems but they all say they are the "best" one to use! I really need some first hand experience and direction.  

[BJSZED]

Any updates ?

I've been checking on Auszcar but thought I would harass you here for us North Americans. Interested in how your plenum divider in the Clifford manifold worked out. Did it improve low end torque? I would think the delayed secondary's would be an improvement as well.

[John Scott]

Kind of related, but I'm about ready to jump on the Holley Sniper efi. The smaller unit supports up to 650 HP.  I plan to keep my Mallory 140 pump and regulator in case I want to go back to carbureted. I'd use the Mallory at low pressure 7 psi to feed a FITech fuel command center, high pressure sump mounted in engine bay. Already have had the wide band 02 for years. 

It seems they add more features to the sniper every day. Data logging, Blow through, spark control, more tuning control, new 8 injector for serious HP etc. Anyone else considering this unit?

[BJSZED]

I think the Sniper is for 250 hp plus.....if you do it, make a thread. Almost went that option as well.

 

Also, a better option than the fuel command center is the Rob MC Powersurge, no float or wonky vent set-up....it's fed the same with a low pressure pump. Some guys are gutting the command center float and setting it up like the Rob MC unit.

Edited May 9, 2017 by BJSZED

[John Scott]

Interesting unit. I'll look into it as well. I'm a little concerned with their tiny 1/4 return and .055" diameter restriction hole in the "IN" port . You still have to run a line back to the tank.

 

The MC Powersurge: PowerSurge is intended for street and drag racing applications where the engine is not at or near full throttle for more than one mile at a time. If you are using the PowerSurge for other applications (speed boat, circle track, road racing, top speed contests, etc), the size of the return line from the PowerSurge to fuel tank must be increased and the restriction in the "IN" port of the PowerSurge must be enlarged. Contact RobbMc Performance for details.

It sounds like they have ways of tweaking this for long term WOT etc.

Advantages I can see for the FITech CC is the float system lets me retain my -8return line on my Mallory 3 port regulator, and just feed the sump with the healthy 140 pump set at 7 psi. Nice to see what in and out pressures are with included guages, built in regulator 58.5 psi.

There's always sucking up and just crawling under and adding a Holley FI pump in place of my other. I just hate to mess up all the hard lines and fittings..

Lots of head scratching coming, no doubt. I plan on going over my system with Holly tech before committing to anything. 

[BJSZED]

I have the FCC and it is not all roses. Definitely not suitable for any kind of circuit racing due to the float.

 

The vent from the FCC is really a return, do not run it into any factory vent line that is for burning off fumes as you will be sucking raw fuel into the intake manifold. Ask me how I know ! Run the "vent" line from the FCC to the factory return line and let the factory vent line act as a vent.

 

Also, since there is no high pressure fuel return to the tank, the fuel recirculates inside the FCC and heats up which then can boil. This is why people are removing the float and running the "vent" as a return which keeps the low pressure side flowing cooling the fuel. Fitech is now offering better set-ups like the Rob MC unit...check them out. The FCC works but may need some tweaking, many reviews on-line. 

 

Like I said if you go TBI, start a thread. As you can tell, I'm serious about it ! lol.

[BJSZED]

Ozconnection,

 

Have been reading that TBI systems generally run better with an open plenum instead of dual. Especially, if the fuel is injected below the throttle plates ?

Seems to be the case with V8 engines but not all. Mine runs fine with the Arizona manifold but would be interesting to try a Clifford one day.

[John Scott]

They both sound like a can of worms, the more I read. 

Might just be better to run an inline EFI Holley pump in the rear,the 12-600 and 12-800 are suitable for hotter locations. 

• Compact (7.5” long x 3” wide x 2.75” tall) for easy installation on frame rails or other tight areas

 

and the new Holley return filter up front. 

They fit -6-8. Would save me a lot of plumbing, no vent, just my -8 return already in place.

1 line in. 1 to FI, 1 to return. Sure is a lot smaller than the sumps anyway. 

• Holley EFI Filter Regulator; Combines Fuel Filter/Regulator Into 1 Assembly; 175 GPH; 10 Micron Filter; -8AN Ports; Internal Regulator Preset At 59.5 PSI ;

Edited May 11, 2017 by John Scott

[BJSZED]

Yep, good solution and no venting issues

[John Scott]

I need to drive my gas tank down to less than 6 gallons, then I can pump out with the fuel pump. I have only been out once this year, once last year to spank a GTR.

I'm one of those guys who has drilled and tapped the entire HP Carburetor, metering blocks, power valves,air bleeds, tapped and put in my own bleeds, bought a wide band and tuned for weeks. My carb really works well perfect 14.5:1 cruise, 12.5 WOT, no flat spots, idles 1100...nearly 30 mpg, with a +.600 lift 244 @ .050 108* cam.... weather changes much, so does the tune. Blah.  The art of carb tuning is dying out. I'm tired of the smell in my garage. 

You know, I can't wait to toss it on the shelf forever!

[BJSZED]

Yep, it is a lot easier...want to try 12.6 to 1, type it in to the handheld, done.....easy changes, can have different tunes for different goals, mileage etc...easy! Look forward to the Sniper write up...........

[John Scott]

Downloaded the install pdf. This is getting even simpler.

So just a fuel pump couple of filters and return line from the EFI unit which is internally regulated. No sumps, regulators, vapor lines.  

I'll start a new thread when I purchase.