attacking a monojet

[Barry Donovan]

the regulator

thisis the corrected regulator. still cheap..


as a precaution, I am also going with the tried and true delphi fd0002. I wonlt be doing the 10 to 14psi just yet. if regulator pops a diaghram, it will stay running.
5.7 pounds to 8.7.. I am guessing a 2 pound drop.

it seems to be 20 feet run at 5/16ths..the new pump is also going to get worked pretty hard. the mount I made myself gets a breeze and no electric interference (computer SECC)

so as it stands..
off to do a power steering rack swap, and wait out deliveries.

[Barry Donovan]

12-803bp regulator

ok ..
now I have it deciphered. thanks for help in the other thread.
the last post is worthless.

this will work with any rochester with the 7/8-20 opening

holley 26-73 (7/8-20 to -6an male)
fraggola 499366 (-6an female to 3/8npt male)
right into
holley 12-803BP

I need the bp version. this is getting costly..
two more 3/8npt to add to this for the other two holes. above is just to connect it right up close as I can to the carb.
no gauge..I'll go like grandpa did tuning a carb and play it by ear and foot.

ok griping done about fittings.
I looked up lowes hardware..
assuming it is npt stuff? just look in plumbers sections..should find what I need..
lowes stuff even mentioned gasoline etc.

seems I can hard line it with brass, flare my steel. elbows etc. All cheap.
the unique connection at the carb kinda gets on my nerves..I do not want to spend any more for a special connect. The rest can be cheap.
I will get it up close..and it does cost strangely.

I need to hard line to help hold up the regulator at the inlet side.
the bp model of regulator has inlet where normally holley regulators have an extra outlet. Thisis just right for my setup. in one end, out the other..return is on the bottom.

This may even look normal. looking through pdf instructions. what I want to do right at the carb is exactly as one of their examples of return line usage on the BP model.

update:

found the ever cheaper mr.gasket regulator 2015, replaces the holley part number, mounts the same...and rebuildable.

Total price down to $58.10

I also found the innards to repair these..if the dainty pump in the car won't open it, I have several springs that will make my own regulator out of it.

my last go with figuring this out..that was actually part of the plan to avoid buying a bigger pump..
the pump fitting oe plugs was not cheap for me then, and only marginally cheaper now..I'll make it burn to its own 3 to 5 psi claim.

[Barry Donovan]

fuel mileage too good

I just learned the popping and strange lean, but not deadly..
the pump thinks it is up to speed and stays slow or even off.

that is part of the need for return line..

just got a call..a relative. wanted to now if I would drive 150 miles pick him up, then go another 160 in another direction to drop him off.

having a real excuse of blown power steering, and fibbed about the belt that makes it manual steering without any mods.(it fits alot years of volvo 240, 242, mercedes and on and on) I claimed it was rare. I am a jerk.

that would just add another few miles a gallon...and chance the fake lockup at the pump.

I never thought it would turn into this.

58 bucks for a fuel regulation is another 5mpg and power gain. That is what I get for showing a relative.

[Barry Donovan]

pressure plan #2

working the the pile of space age intelligence when it comes to AN, npt, unf, sae, flared, inverted flared, tube fitting, tube nut, flare nut, pipe fitting, inverted tube, sleeves, caps, plugs and barbs..

I found a 5an flare nut in my parts pile..and am going back to the holley 12-803bp. Found photos of rebuild kit..they really did so something thought out for the bypass. I can tell it conquers the big air gap. The only fault now would be pump too small..and am expecting it.
the end going into carb will allow me to keep the heavy deeper stainless piece that came factory on the monojet. Will grind down a 5an connector to fit the carb.


total cost is now at 90 something again..
seems silly, can't run without it.

anyone know why that fitting does not exist?
absolutely bizarre.
1/2-20 thread from rochester carb into 3/8npt.


can be made from this connector (I am buying 2 of these, 1 side of regulator needs nothing hacked), the other into carb needs grinding...and I am humoring a taper in the end with a drill bit.

5an == 1/2-20 thread...just not correct to fit the rochester inlet without a grind.

another note about the holley "bp" version..
if you remember trying to put a big throttle valve (big carb) on an engine in the past, and it just either had to be pig rich to go, or a serious cough off idle, etc...

the regulator by holley is quite new in relation to years of what was (2005)..it is aimed to fix that old launch problems/coldd start, even hot start. I mentioned my own ricer being there for 30 years knowing about it (regulator built into the carb with a return line- on just 1-3 psi)

I'd love to try this on a v8 ...mechanical secondary slammer. proportionally now on a tiny engine..it is the same fix from the past. that is why they had tiny primary barrels all the way to 8 cyls...for years and years. they can't do it all at once..like ignition timing being off, carbs had a timing too.

imagine 650cfm in one big throttle? no split? if it was mathed to be right...they ought to be able to do that.

the unique problem making a necessity is one I am in..
250-280 cfm is the engines maximum..and it gives it all at once with the one barrel monojet. I love it..alot think injection is the only version that can do that today.
I am building to prove otherwise.

[Barry Donovan]

regulator wi/bypass..fittings $$

I have been rummaging randomly for several days trying to get this down to a price wirth a rusty fendered rod knocking 1987 subaru...

and getting the real parts.

as of now, barb s to be local (return line barb) expecting no more than 2 bucks for the plastic at .25 inch, it is going to a rubber line anyway.

the two stainless 5an to 3/8npt are now down to 8 bucks for the pair, free shipping.

the regulator 12-803bp is $64 rounded up.

as of this edit:

just under $75

total fuel hack, carb, my own machining, my own rebuild cleaning and time

is just over 100..

keeping this all under 200 is a realistic goal.

I'll edit this as time goes along..(not buying right away)

[Barry Donovan]

lucky air boot

still not blaming the monojet for anything...I noticed the boot to plenum was quite a sloppy silicone dangling hack I made in the cold months. Finished it off today..the thin stainless is a nice finale. No more silicone in the air stream. Fighting off belligerent noise with harleys going by..self conscious over valves smacking to the stuff it can't even burn..the battle goes on.

thinking of the popping noises on the long trip, remnded me of a silicone event I had with this engine in the past. This engine freaks over silicone. 1 part per million trillion..absolutely freaks over silicone. Silicon tin bearings is probably the culprit. pcv gas side of things means it cannot be in the air stream. The sloppy mess I had here in photo gave it every reason to choke on some silicone. Cleaned this up today, lucky fit. the inside of plenum has a real clamp and stopper..like an inverted way to hook up. the thin clamp is for a transaxle boot. Noticing what the overpriced blue silicone turbo boot does with grip..very grippy.. I know I’ll get away with this here. A ridge on the plastic tube locked it right in with no clamp. the clamp is extra. Clean appearance? Clean enough.


more fuel regulate stuff
still browsing around.. I was going to go for a vacuum assisted fuel regulate, as the same vacuum fitting on the carb is the retard catcher at distributor. That would be interesting to put fuel and timing on the same thought of catching off idle, same line at carb. pump would send a quick squirt, the timing the quick retard...and bam..probably burning tires. just kidding, this aims to do the opposite. no surges are the goal. I am driving like an old race car with a stage setting most of the time right now..it is annoying, to me that is not right.

here is a quote describing it for fuel injection:

• • When the engine is suddenly under heavy acceleration, the vacuum drops off momentarily and then recovers within a very short period of time. This sudden drop in pressure during acceleration also affects the fuel pressure, as the injectors are suddenly opened longer. The fuel pump takes a second to catch up with the pressure, so the fuel pressure regulator reacts to the drop in vacuum by closing the fuel return line momentarily. This gives a momentary boost in fuel pressure.
    
    

being a carb is a draft all the time.. I will most likely go old school with a return. the blip off idle goes away as of now, at 40F and above. I can conquer the rest with fuel regulator and no vacuum..the curioisty really has me second thinking my goal.

it would be interesting to see how far a carb type cfm could go with todays gadgets however. Try a 350cfm on a 108ci and see how much of the blip certain setups would get conquered..

[Barry Donovan]

setting up for pump



with welder, I made the 3 prong male end base for this last year..very strong. the circles you see accept a foam or rubber, then just zip tie to the base. will get photo when new pump is in. I did not have to humor subarus setup..but I had just paid a decent penny for a direct fit pump as I recall.
saving connector and plate allows me to use nearly anything. I also have the height needed for the holley stand up versions (I do not like those) , as of now the delphi fd0002 is first choice. keywords.."solenoid" and 5.7psi-8.7.
the pump above ran for 24 years..only to die to a filter fail in slow mode. The new slow mode should be a hum of 5 psi.

A tip for this model car..when the pump needs to be bigger, the pig is dead. back to traditional runtime.

[Barry Donovan]

fuel plan 3

going for pump..maybe spend more for a better one..
I know how to regulate on my own, don't even need a gauge.

regulator stuff on a shelf.. hunting down a much better grade pump...
opinions on carbed pump for rochester, understanding solenoid?
I suppose that is hard to do too..the opinion would need to know the cams, compression, bore, stroke, main jet, etc etc..

today was 82. yet another wy too warm to make sense.

I would swear the carzy alloy knows the crazy sun.
go for a decade the same engine..the sunspots start happening. wow.
be prepared to go rocket scientist.

carb is well, even cool. it does its job.(the best yet in 15 years for this engine and I).

very unusual fuel demand.. maybe less cylinders does need more. big engines got the overlap to keep on sucking it in.

I also found via bangshift product page the newer model number for a Holley regulator, and a spot for a gauge..

12-841 with bypass

the gauge hole alone is worth one less fitting.
$94 retail is not bad after my obsessive hunt for one with a return line.
subtract $15 for the guage fitting being built in..and add a unknown value of getting that much closer to the carb.
I hold off for this regulator..
and its billet 6061-t6..I don't know my alloys. must be good.

the 300 dollar pump is still a tease being a trochoid (my engine oiler has something just as extreme)..
sigh

[Barry Donovan]

fuel plan 4

in the land of working with nothing, where nothing works for long…
I finally came to my senses. This would be a cost of much less than 100 for regulator, pump, t-fittings. Use the very low pressure regulator on the return line. The connection to regulator will be on the top side of fuel line if it needs a mount hanging off the carb. A .25 inch oem return line.. I’ll be lucky if it accepts the 1 psi setting on a 6 pound squirt from the delphi fd0002. I did learn this is not a fulltime return..it kills the expansion of slow, and the quick squirts of cold and hot start…and when purge is working, popcorn noises of air.
this is my final thoughts on this.. I post how my hacks go on you tube.

came to me while sleeping.
lack of vent can for some hours, as if my mind likes air to function.

[Barry Donovan]

my own regulator

another ingenuitive burst of hillbilly genius..self declared.

I finally just got up and did something. I gave the fuel tank and the carb its own connections at the vent can. above is the setup that worked before putting in a real restrictor on the t-fitting that returns. the mig welders tip is plenty. The t-fitting being at 5.16ths native fuel line size has no restriction on this setup..that was my last mistake, I restricted the whole thing on previous setup. Being it started right up, I go with this for time being. the cough,and odor that is left is definitely crap from not flowing right.

.035 inch, and 1.5 inches long. Started right up lively…
The only excuse now is that pathetic emission generation 1psi runtime fuel pump…

subarus hitachi had a regulate thet never stopped..in fact if it did..car would not start. I am not only back to that original seeper..it is much more controlled. The cough in the throttle has an old HG fail in it..I bet I bunged the vent line...and it never quite cleaned itself.

to get this fuel injection full return line setup really going will just need a bigger pump, if it all. of course bigger pump will get the cheapy regulator if the time comes.

[Barry Donovan]

yet a plan #5 (fuel regulate)

I was browsing around, found a little post about a little beetle with dual 44mm..

lost fuel on grades.
hmmm.

at 43mm I am doing the same.
for the beetle dune buggy..
the cheap vacuum assisted regulator fit the bill. low pressure, I guess the nameless brand functions a long day.

today upon running, the vapor lock is not there..throttle takes a bit longer to come down..(as if a dog box monojet takes a long time to come down) I don't really know what the problem was, let the vent lines really get going.. I got sick a little. that problem is really resolved as of now.

so startup can be improved, and long haul hard throttle.

having a very precise progressive vacuum spot on the monojet working its way to 20Hg, this should dial in the assisted version like a clock. the progressive goes from zero to 20..full in at just less than half throttle. Awesome to see on gauge (I am easily amused).

It will be interesting to see if I set the idle at something silly like 1psi, and watch the fuel pressure change to higher on the gauge as the engine demands more...
kinda cool thought. I did see an example on you tube (turbo v6)

the regulator I refer to was an option once already.. now back to it. cheap on ebay.

another mind changer was finding the little simple dial by hand regulators die at 5 pounds or greater...user reviews were great if it was a scooter or <3psi weber.

in fact from what I read.. I would not even try one.

I am cheating cost due to a 5/16ths ricer piping..and the regulator is simply that realm that makes one wonder.(I would not go big as the ad claims there either) Holley and aero stuff exists tough for a reason.

[Barry Donovan]

monojet with return line


it is a pressed fitting. Snugly so. I am not sure of legality..I found gas connections are barbed to have no clamps, or threaded..or clamped. pressed in is usually for vacuum lines.
Being I had a exactly 4mm drill for the 4.5 mm fitting.. this is sealed with no glues, then gets hit by the 7/8 fuel inlet nut. if this is legal, I am going to put this right in.


idea 2. this one hit the float bowl.. too close.



this is best idea..but wall of monojet is thin. the fitting is tapered..maybe give it a helper. silicone or epoxy?

don't want to risk just yet..maybe think of a bulkhead fitting to go through the whole thing with a nut?
ultimate purge/surge spot.

I did find I can put the "jdm yo" regulator on carb with 5an to 1/4 npt or 1/8npt, and make my own return out of that...
and this chevette carb is no longer for sale it is donated to science.

[Barry Donovan]

return line built into monojet



if you guessed the end of a hollowed throttle cable you have won. This is the winning hack for today. could be good for 800 to 10,000psi..maybe even more.


winner. I can even make a mistake drilling. Having a reduction of my choosing (the squirt of .035 seems to be doing well) I can go back to the dual outlet regulators, one end being for a gauge..
this also purges as close as one can possibly get to the carb...by building into the damn carb.

my fuel main jet is so small..it locks in like a vpor lock (as previous posts mention) makes cold starts difficult.
this setup here gets a hole through the spring loaded filter...this way it acts as a bypass for filter gone clogged. Dual purpose.

I guess I may not need a regulator..trimming the end inside filter hole..where filter is spring loaded..as filter gets loaded spring will press the opening closed, forcing shot to the bowl.
the purge needs to happen in those mysterious inbetweens...this will get it.

became enthused enough to attack this with 30 minutes of light left. got it in.
can't use filter anymore..the sube is extreme there in the filtering anyway. The original had no filter either, at the carb. A small seep, no drip..could be fresh install..let some minerals get it. have some gas proof silicone anyway. Very tight connect..pushing boundaries of alloy squish. A bit cockeyed, installed by hand drill and eyeball..no problem. I knew there is margin of error. Cough is reduced, while engine still cold when it is at its worst. I could not make it pop either, no backfire. This is somehow related to valves smacking around.. I could hear it in the changes, and the way throttle felt..right away. as if to be vapor locking all the way to the chambers. This was just one relief..

As this gains density, it shuld be real nice. I noticed the copper mig welders tip is much colder in the new return spot..must be very busy. I hit a sweet spot no doubt.

float is now the regulator..quick let downs have a place to go. the tiny main jet can work after all.

next test is dead cold start.
aside from regulator, purge and surge..it is a bleeder for nominal runtime. Big pump is welcome...

[Barry Donovan]

no regulator needed

I can't even recall of this problem first time around..maybe a motorcycle, big carbs. A dodge omni with a holley rings a bell..

air just right..fuel was never right.

this did fix it, went for a ride oin the highway seems very wimpy, but casually full..all valves tinging, not lifters..this is combustion. I found a boat load of old something. analyzing old carb I found the vent line for gas tank never worked.

describing a tough engine is useless.
stubborn is a better adjective.

the monojet was as close as a missing purge to being perfect.

I did look through the years of them..from log dead of old, to first chokes.

I think I went for the best choice. late 70s..a progressive port.

on a personal note. A tooth I hung onto for 39 years is now off to the tooth fairy. this car and what I found has something to do with it...

some go for 1 case as jewed as can be. If I had a dollar for everytime the world needed a lawyer...

there is other means to lawsuits... monetary not necessary.

enough rambling.. like the engine this is on.. it will be getting better.
vapor path cleaned up will be something special.

this whole time toughening everything was the battle getting cleaned out now...almost 6 years later.
the runaround of spaghetti tangled hoses long gone still left confusion.

I was glad to take this on.. I must admit I am getting older, not as bold on the subject of conquering potential..but just going lazy and with the stampede of "all there is".


all there is left only one with self balance. my battle goes on..the ricer engine in my favorite hot rod forum.

[Barry Donovan]

custom return line/regulate final


looks like it belongs. the round bottom of the monojet. The final for this was a stainless steel helicoil (exact fit- after trimming the hook pf course) in the inside to act as a washer, to get piping away from back wall of exit. As this is in cathode mode, if part of the carb accepts anode..its got some stainless to munch on...match the rare needle and float bowl seat. The spacing was necessary as the chamber forces heavies to process eventually, get it into the float bowl. If this does not happen, the tank fills up with the imperfections. Near the glimps of red is the .035 mig welders tip..the golden copper. I also took thelining out of the throttle cable ending, this was plastic, used as a cable keeper. Now return line is a bit bigger I.D. size. This sealed nearly perfect first try yesterday.. I gave it some silicone (gas resistant) to finalize.

lack of depth perception..but the in and out lines are down bottom of course. It occurred to me..the vent is actually the why the purge part of the regulation works. So the float is now real regulate, the vent actually has something to vent..and that goes to vent can, to come back in a smaller amount, after processing. This was another reason rochester forced the heavier, or non fuel stuff to go into float bowl. the engine heat, vacuum shredder, pressures..all the things a carb does in a large way splits that up to keep running.

the return line, from a throttle cable ending..is many tmes stronger than the brass, and has a nut on the inside. This can do big fuel pump now.

back to the scooter worthy dial regulators..the return line is a good candidate, if the .035 welders tip is not what I want. So far it is proving to be good.

the odor is less incinerator today...I must have been cleaning up the unusued, or lack of busy, vent/return lines all along. if this was an original 25 year poison.. I'd give this car away.(I have seen that event locally on cars with similar problems)

today it is not likely..the slob dump of injection is a panic mode most like today (I do -it knows when to dump). Carbs can't do that. they will hover in perfection for a century of teeth breaking before it does not stop.

getting into a return line system that functions is a sure modern thing to do.