Wondering if any here running flying toilets on 540 plus engine. If so what sizes. If have ever changfed size and found et,please let me know what you went from and to.

I am Working on few future projects.One being new injector with single or two lot smaller flys. Just looking for input from those with MFI as to sizes of injector.

Call James at killer rons

Can but not using his stuff.

Just doing comparison for what I am building. Currant injector is built like Hilborn shotgun, Just think two 5.375 flys too much. The way I built it is too heavy. Withb sucj large flys hard to het good idle seting. Just want to know if the larger toilets feed bigger engine(well small nowdays).

At rpesent I am thinking eithere two 4.375 flys which is same area as bug catcher, or one oval that will give same area.Kind of concerend about single and getting good seal when shut.

Not trashing the one I have way too much work in it and still have d-ported bird catcher on shelf. WOuldmlove to find another bug catcher hat only, Just freaking looks right in place on FED. Hell though about converting one of the two carb hats that look like ral deal and run about 125 bucks, would haqve to get one to look at close to see if can be done. Yeap too much time on hands with this foot deal healing.

Finaly found cfm on site for rons. A 4.1" is 1800. so figre 4.375(bird catcher plys I have should be 200 or so and that 2 dominators equalivilant. So should be good enough.
Try to deign n ew iontak so can change easy enough. If does not work can alway just throw one of others on. Upside to curioyus mind I have options laying around,LOL

The smallest I've run is a 5" Enderle single butterfly, I'm fairly sure they quit manufacturing those so good luck finding a new one for sale. I've also run the accufab 2800 CFM 4 barrel. I have no recent experience with a 4" single butterfly. 

My preference is the Enderle 5" single buttefly because its designed to work with the enderle barrel valve, distrbution block, linkage etc. The accufab is more precise and idle air adjustments can be made with a finer resolution. The 5" single butterfly is more than capable of getting very clean/precise idle mixtures for MFI and methanol NA and Blown. The accufab is primiarly for the EFI market and enables front and rear b/f adjustments, you could spend weeks adjusting air idle if you really like to tinker with things.

I've run the 5" toilet on anything from a 350 to a 598 in normally aspirated applications and the Accufab on a 615 NA. From 500 HP to 1100 HP, all of the big blocks were 1000+hp combos. I also ran the 5" single toilet on a 565 with a High Helix 14:71 (from 10% over to 10% under). All ran fine, no measurable difference going to an edelbrock victor 2 tunnel ram and 3 blade bird catcher on 598 1000 hp combo.

On the 615 1100 hp combo, going from a dart ram with Geradot square hole bird catcher to an edelbrock SV-632 with accufab 4 hole there was some difference, I did dyno both combos (4 years between dyno trips). Torque 905 with tunnel ram and 880 with accufab. 1090HP with tunnel ram and Geradot, and 1120 with 4 hole accufab and edelbrock 632. This is less about the air valve and more about the intake runner length. This resulted in ZERO performance change in the racecar but the intake swap seemed to move the HP a little higher in the range and killed some of the tq which was expected given the DART ram has a very long runner.

The 5" single butterfly is rated at 2500 CFM but if you ever had an opportunity to talk to Jim at Enderle about that, from what I gathered talking to him, that rating wasn't super exact.

So to answer your question....

Assuming your air valve is not restricting air into your motor, you will not see any performance change swapping to a different air valve on the same intake manifold. If you are looking for idle quality and air adjustment at an idle, the 5" on top of a 500+ cubic inch BBC NA or Blown will work fine. If you want to adjust idle air on 2 shafts with a finer resolution, get you an Accufab 4 hole. They make several air flow ratings, pick your favorite. If you want my advise, bigger is better because you never know where you'll use the air valve in the future.

This message has been edited. Last edited by: Triple Nickel,

quote:

Originally posted by wideopen231:
Can but not using his stuff.

Just doing comparison for what I am building. Currant injector is built like Hilborn shotgun, Just think two 5.375 flys too much. The way I built it is too heavy. Withb sucj large flys hard to het good idle seting. Just want to know if the larger toilets feed bigger engine(well small

No such thing as too much, the throttle body is just an air valve and as long as it can supply as much air as the engine is asking for you’re good.

One 4.1”/1800 CFM toilet will be fine on a 540.

With that said if you’re buying one I’d buy a terminator just because they look cooler.

Like I said just getting input for project. Maybe not clear but took for granite everyione here know I am a build it guy. By current hat is my Version of the Hilborn Shotgun two fly. Both are 5.300 inch.

Repectively diasagree on no suht thing as too big. For power maybe I do believe for consistency it can be.

As for 5" being no available it is. Maybe not Enderle's but Chris' is. My lathe can cut any size.LOL Before jumping on I know butterl flys are not perfect round but slight biger top to bottom than across and have that covered with fixture for turning them. I have made them for other injectors for both race and Harley in cutome made throttle body.

I have stack of 4.375 flys out of Enderle bird catchers I mahined out for d ported with square middles. Heck had one of those on shelf that was on car at some point.

I'm assuming when you talk about consistency you are talking about bracket racing..... There is ZERO impact for having an air valve that is too big. Bird catchers are "rated" at 5000 CFM, a BBC at 1000 HP needs about 1400 CFM on the high side, nearly every 1000+ BBC I've owned over the past 20 years had a bird catcher on them at some point in time. They were all VERY consistent. The key to consistency is in the fuel tune up not how big or small the air valve is. This assumes you are not limiting the air needed by the motor with an air valve that's less than 1400 capability.

If you are talking about consistency in part throttle applications, then yes smaller is better, in this case if you want the best configuration, utilize a multi hole air valve. At some point Enderle had a progressive linkage for the bug and bird catchers, but if you are building your own and you are worried about part throttle applications and having the best possible air/fuel mixture and control over the part throttle range, you'll have to work on a progressive linkage system otherwise all your part throttle time will be at 1/4 throttle or less as most big b-flys are capable of flowing enough to make big power at 1/4 of the way open.

could care less about part throttle. As SN I am wideopen full bore to nthe floor most all fo the time. Drive same way race or daily driver.

I have had about every size injector there is on cars. from bug to BAU. Most consistant car/engine combo I have ever owned was bbc with bug.

Guess agree to disagree.

Correct on building own. I am not spending a bunch on something I can make for 5th or less with little work. Not for everyone but what I have always had to do to run. No need for linkage thing proper set MFI will have almolst same throttle as blower car just not quite as snappy.

Not limiting size too much is reason I asked about others using flying toilet since lot smaller than what I have and samller than thinking about building. if they have run it with no issue I know I am good.
A bug is 30 sq in and rated at 3200 cfm I think. A bird is rated at 4200 and 45 ci. Figure one fly should mre than cover 1400 and two flys should be equal to bug.

Was hoping RPM performance had a vacuum sensor so I could check to see if any vacuum at WOT and maybe get one tha would sense a slight positive to let me know is any ram effect. Looks like no such item exist.

quote:

Originally posted by Triple Nickel:


The 5" single butterfly is rated at 2500 CFM but if you ever had an opportunity to talk to Jim at Enderle about that, from what I gathered talking to him, that rating wasn't super exact.

Enderle sure has went downhill since Ken and Jim are gone at Enderle. Total jerks now and nobody seems to know anything.

I agree with going big on the air valve, your motor will only take what it can use and it is not as much air as many think. One motor I had if I remember right was using about 1000 CFM at 775 Hp. Too big of air valve will not hurt anything on mechanical injection but too small will restrict it.

Curly, the story I heard was that when Kent Enderle died, his stepson took the business over, shortly thereafter Jim quit, from there it was downhill. I think alkydigger and good vibrations got together and tried to somehow help the situation and get them back on track. That was a few years ago, I haven't even bothered to ask about it lately so i really don't know where they stand today. Goodvibes and Alkydigger have zero Enderle fuel pump inventory, I wonder is Enderle even in business anymore.

Enderle has the best parts for the money, kinsler is best out there, but they are pricey and who really wants to tune 8 butterflies to set the idle, I don't have time for that. Stacks do look cool though.

quote:

Originally posted by Triple Nickel:
Curly, the story I heard was that when Kent Enderle died, his stepson took the business over, shortly thereafter Jim quit, from there it was downhill. I think alkydigger and good vibrations got together and tried to somehow help the situation and get them back on track. That was a few years ago, I haven't even bothered to ask about it lately so i really don't know where they stand today. Goodvibes and Alkydigger have zero Enderle fuel pump inventory, I wonder is Enderle even in business anymore.

Enderle has the best parts for the money, kinsler is best out there, but they are pricey and who really wants to tune 8 butterflies to set the idle, I don't have time for that. Stacks do look cool though.

I knew one of them died and other quit or retired but been a while and was not sure which one. Sure know it is not the same there and would not be one bit surprised if they went out of business. Hate to hear that.

quote:

Originally posted by Curly1: I agree with going big on the air valve, your motor will only take what it can use and it is not as much air as many think. One motor I had if I remember right was using about 1000 CFM at 775 Hp. Too big of air valve will not hurt anything on mechanical injection but too small will restrict it.

The same can be said for EFI as well. I recently went from a Rons 4” toilet (1435 cfm) modified with a TPS, to an EFI model 1150 cfm four hole from Rons. The switch slowed my car down 0.035 initially. I have sped it back up by 1 and am still slowly moving the EFI map to see if more can be had. This is on a small EFI 388 N/A that couldn’t use everything a 1150 provides much less a 1435.

quote:

Was hoping RPM performance had a vacuum sensor so I could check to see if any vacuum at WOT and maybe get one tha would sense a slight positive to let me know is any ram effect. Looks like no such item exist.

there will be no vacume at wot

quote:

Originally posted by wideopen231:
Was hoping RPM performance had a vacuum sensor so I could check to see if any vacuum at WOT and maybe get one tha would sense a slight positive to let me know is any ram effect. Looks like no such item exist.

They do

I am not going to spend the time or money to prove it but I think from my experience a carb will have a little vacuum at wide open. Carb has to have air flow through the venturi to siphon the fuel into motor. I THINK (could be wrong?) that a carb will always have a little vacuum even at wide open and if carb is too small it gets worse. I believe it needs that vacuum to draw the air and fuel through the venturi fast enough to pull the fuel.

Mechanical injection does not have much if any vacuum wide open which to me is why they usually make more power than a carb. We are still talking little if any vacuum.

I believe that a forward facing hat like Enderle may have a little positive pressure at high speed. The reason I think that is because on dyno get good tune but on the track the motor requires a little more fuel. And the rear cylinders need more fuel than the front which tells me it is getting some small amount of ram air effect. Even that is very small numbers. There was not any noticeable ET difference in 1/8 mile by getting fuel perfect so that tells me horsepower gains are minimal. Still I try to get it right because it may help on consistency and weather changes, plus easier on motor to have fuel same in all cylinders.

It is my belief those differences are very small, probably for a forward facing scoop to have any real noticeable power improvement the scoop would probably have to be 5 foot across or something crazy like that.

At that size motor may make more power but the scoop to catch enough air to make any difference would also act like a parachute. Also something like that would have no effect at low speeds. Basic thinking is boost will make more horsepower and vacuum at wide open is costing you a little all assuming you have right fuel ratio. Naturally aspirated I think we are talking very, very small numbers on vacuum and horsepower and horsepower is why we are having this discussion. To prove any of that would need 8 O2 sensors, vacuum sensors, good data logger and lots of testing. Also there are other variables like cam, how much heads flow, how well exhaust works. If you have small cam or restrictive heads the changes will be small.

Which brings us back to original question about size of the throttle body on mechanical injection and I believe bigger is better there. Unless it is a street car with tall gears and tight converter.

If the carb is sized appropriately (capable of flowing slightly more air than the motor needs), vacuum in the manifold would be zero. I doubt the sensors available for racing applications would be able to detect any "vacuum" created by simply having boosters in the way if carb is sized appropriately. The air flow past the booster is what creates the draw to pull fuel out of the bowls, not "vacuum". If you have vacuum in the manifold the air valve (carb and or injection) is TOO SMALL.

Ram effect is a real thing, but I have the same experience as Curly and have never seen a positive impact from it in drag racing with all sorts of different combos. My current 250 blower application in a dragster has the top of the enderle bird catcher injection hat 4"+ below the top of the roll cage, directly behind the blow shield, essentially in a void of air, behind the driver. For the weight and application it runs with every other 250 combo I've read/heard about. There may be measurable improvements in comp/ss/prostock type applications but i've not seen any real gain from forward facing scoops.

quote:

If the carb is sized appropriately (capable of flowing slightly more air than the motor needs), vacuum in the manifold would be zero.

My EFI system uses a MAP sensor and have never seen it greater than 97 kPa at wot being N/A engine. I use a foam type air cleaner and unsure (doubt) if removing would increase. To have no vacuum, one would need to see 101 kPa on that scale.

The 4” toilet I was using produced slightly better ET when compared to the 4 hole throttle body that is presently on the engine. Both throttle bodys are much larger than the needs of that smaller sbc. Both the heads and intake have had porting.