The turbo gRoadster 7
12-10-14, 10:06 PM
#51
I got to working on the intake manifold... again. And I took out a little bit more of the front primary port. Its sooooo small. I'm trying to get it up to at least 25mm diameter. I am using an 84' intake manifold so its stupidly constricted.
I also worked on smoothing out the flashing and other imperfections in the intake.
My venturis are almost done. Removing them made there completion possible and made the cut more accurate. I used a micrometer to measure the thickness of the wall of the venturi. The OD of the venturi is 30mm; so if I cut the wall thickness down to ~ 2.65mm the hole should be 24.7 or there abouts.
I also worked on smoothing out the flashing and other imperfections in the intake.
My venturis are almost done. Removing them made there completion possible and made the cut more accurate. I used a micrometer to measure the thickness of the wall of the venturi. The OD of the venturi is 30mm; so if I cut the wall thickness down to ~ 2.65mm the hole should be 24.7 or there abouts.
12-31-14, 08:31 PM
#53
Well. I moved into my new house. Still no internet, but I've got a question.
I finished my venturis. 24.5->24.7 ~ or there abouts. Popped them into the decided carb body (freezing them worked WONDERS no taping necessary pushed them in by hand). Then I went to work on cleaning holes and whatnot. I unscrewed a cap of some sort right above the accelerator pump, and a bar and a small ball bearing thing came out. **** if I know where they came from or how to put them back in there.
Can any Nikki experts figure out what I'm talking about without a picture? Or should I crack my shop manual open?
I finished my venturis. 24.5->24.7 ~ or there abouts. Popped them into the decided carb body (freezing them worked WONDERS no taping necessary pushed them in by hand). Then I went to work on cleaning holes and whatnot. I unscrewed a cap of some sort right above the accelerator pump, and a bar and a small ball bearing thing came out. **** if I know where they came from or how to put them back in there.
Can any Nikki experts figure out what I'm talking about without a picture? Or should I crack my shop manual open?
01-06-15, 07:35 PM
#55
^^ thanks. I wasn't sure at all how it came out... wasn't expecting anything out of that hole. 
I stopped off at the local junk yard and picked up a few items.
A BOV from a Mazda MX6 and the ignition (or at least part of it) from an FC.
Can I run the leading and trailing second generation ignition? I know most people just run the leading ignition and the trailing comes from the existing distributer.
I stopped off at the local junk yard and picked up a few items.
A BOV from a Mazda MX6 and the ignition (or at least part of it) from an FC.
Can I run the leading and trailing second generation ignition? I know most people just run the leading ignition and the trailing comes from the existing distributer.
01-06-15, 09:23 PM
#56
I had success with DLIDFIS because it's a plenty hot spark for the amount of boost I'm running. If I ever need more, I'll look into CDI. As for what you're asking, you're interested in what's called 2GCDFIS. I personally can't say good things about it because a) I don't run it in any of my cars, b) it seems less able to provide a hot spark because at least the primary winding is shared amoung two secondary windings, and 3) it only uses one ignitor, not two, which MUST be triggered by a 5 volt square wave from preferably some kind of ECU, and it's not even close to what a dizzy inductive pickup puts out. However not even a stock J-109 ignitor puts out the right "signal" for it in that the J-109 outputs a 12V square wave but it's inverted compared to what the FC ignitor inside the base of a 2nd gen coil is expecting. What you need is a "transitor trick" to invert the signal back to what the ignitor wants, and condition it as well to work within the "range" of the ignitor, if you will. Like what an ECU can do.
When I realized all the hoops I'd have to jump through for 2GCDFIS, I gave up and passed the info onto the forum. A guy here named Kent took on the task of creating the transistor trick circuit and sent out units all around the world for people to try; he was building them in a tiny apartment in Paris for a while, aparently. That's pretty hard core.
But aside from all that, how does it perform? That's the bottom line in any of those mods, right? Well, the one I installed in PercentSevenC's car burned out the leading ignitor that was feeding it, almost leaving him stranded at a rotary car meet. Fortunately I was there and we McGyverd a way for the trailing ignitor to run the leading spark plugs through the cap so he could drive it home. Turns out it ran better like this.
Got it home, ripped out 2GCDFIS, swapped in a good leading ignitor so it could run through the cap and rotor for a bit until I could fab up an ignitor heat sink plate so we could try DLIDFIS. He came up with a coil holder and I did the wiring. His first drive on DLIDFIS was like night and day better than 2GCDFIS ever was and still noticeably better than stock through the cap. What does that tell you? Tells me DLIDFIS wins, but you don't have to take my word for it. That's just one story. I've got several but I dont want to clutter up your thread. (too late)
When I realized all the hoops I'd have to jump through for 2GCDFIS, I gave up and passed the info onto the forum. A guy here named Kent took on the task of creating the transistor trick circuit and sent out units all around the world for people to try; he was building them in a tiny apartment in Paris for a while, aparently. That's pretty hard core.
But aside from all that, how does it perform? That's the bottom line in any of those mods, right? Well, the one I installed in PercentSevenC's car burned out the leading ignitor that was feeding it, almost leaving him stranded at a rotary car meet. Fortunately I was there and we McGyverd a way for the trailing ignitor to run the leading spark plugs through the cap so he could drive it home. Turns out it ran better like this.
Got it home, ripped out 2GCDFIS, swapped in a good leading ignitor so it could run through the cap and rotor for a bit until I could fab up an ignitor heat sink plate so we could try DLIDFIS. He came up with a coil holder and I did the wiring. His first drive on DLIDFIS was like night and day better than 2GCDFIS ever was and still noticeably better than stock through the cap. What does that tell you? Tells me DLIDFIS wins, but you don't have to take my word for it. That's just one story. I've got several but I dont want to clutter up your thread. (too late)
02-10-15, 09:44 PM
#60
Cool! Same here.
I must say there is another person on the forum, bumpstart who was also recommending a semi-locked and posted pics and info for how to do it, but he went about it in a let's say slightly less easy way.
He says his way is reversible, but I didn't like the idea of welding washers on it, or having to grind them off when you're done. Others have said their washers were too thick and interfere with the weights. I wasn't interested in any of that. I wanted easy and not reversible so there is no chance of it ever failing. You can't get any more easy and reliable than the way I did it, in my humble opinion.
I guess since I have some spare distributors, my way made more sense to me. Just swap a dizzy in for NA use. Then swap another in for turbo use. Pretty easy.
Obviously keep them clearly labled (I just used a sharpie but I could come up with a more permenant mark if needed). No need to tear it down to swap components, which can be kinda time consuming, or worse grind off all your hard work! If I ever needed to, I could file the slot all the way out to stock length and it'd be back to stock advance. So I suppose it is reversible, if you're willing to put in the effort.
I must say there is another person on the forum, bumpstart who was also recommending a semi-locked and posted pics and info for how to do it, but he went about it in a let's say slightly less easy way.
He says his way is reversible, but I didn't like the idea of welding washers on it, or having to grind them off when you're done. Others have said their washers were too thick and interfere with the weights. I wasn't interested in any of that. I wanted easy and not reversible so there is no chance of it ever failing. You can't get any more easy and reliable than the way I did it, in my humble opinion.I guess since I have some spare distributors, my way made more sense to me. Just swap a dizzy in for NA use. Then swap another in for turbo use. Pretty easy.
Obviously keep them clearly labled (I just used a sharpie but I could come up with a more permenant mark if needed). No need to tear it down to swap components, which can be kinda time consuming, or worse grind off all your hard work! If I ever needed to, I could file the slot all the way out to stock length and it'd be back to stock advance. So I suppose it is reversible, if you're willing to put in the effort.
02-11-15, 06:21 PM
#61
A dremel tool took the excess off of my weld.
I used a brass strip of metal and clamped it on the back of the advancer arm. Welded away with flux core then puled the brass off. Flux welds don't stick to brass. I love that trick.
I used a brass strip of metal and clamped it on the back of the advancer arm. Welded away with flux core then puled the brass off. Flux welds don't stick to brass. I love that trick.
02-12-15, 12:41 PM
#62
Whatever works!
I had to use a dremel with a tiny stone to make the welded slot big enough to fit the round file in there. Then went the rest of the way with the file. Also a bench grinder was used to flatten the welds before filing so it couldn't interfere with the advance weight.
I had to use a dremel with a tiny stone to make the welded slot big enough to fit the round file in there. Then went the rest of the way with the file. Also a bench grinder was used to flatten the welds before filing so it couldn't interfere with the advance weight.
02-12-15, 06:19 PM
#63
So the next step is the TFIDFIS. To which I am hesitant.
I am NOT an electrical engineer.
I understand I am taking the signal from the pickups (the red and green wires), and using that signal to the HEI's then send off the burst of energy to the coils. BUT there is only one set of red/green wires for the Leading and one set of wires for the trailing ignitions. What separates the signal from Rotor one to the signal for Rotor two. Or do they fire at the same time?
I can follow the diagram posted here on the board and probably achieve the desired result, but I'd like to know why.
I am NOT an electrical engineer.
I understand I am taking the signal from the pickups (the red and green wires), and using that signal to the HEI's then send off the burst of energy to the coils. BUT there is only one set of red/green wires for the Leading and one set of wires for the trailing ignitions. What separates the signal from Rotor one to the signal for Rotor two. Or do they fire at the same time?
I can follow the diagram posted here on the board and probably achieve the desired result, but I'd like to know why.
02-12-15, 08:47 PM
#64
Sounds like you're trying to do DLIDFIS. Use that as your search term and you'll come up with lots of information dating back over ten years.
I've used GM HEIs for DLIDFIS a number of times. They work great. What you're doing is you take the original red and green wires from the dizzy leading pickup, then Y them in parallel to go to the trigger terminals of the ignitors. The wire colors for all 81-85 dizzies are:
green wire to W terminal
red wire to G terminal
If you have an 80 dizzy, reverse the polarity. Easy stuff.
The other ignitor terminals go to the coils and are industry standard and are self explanitory to some extent:
ignitor B to + coil terminal ignition ON
ignitor C to - coil terminal and tach signal (if desired)
Think of them as B stands for battery, and C stands for coil. Confused?
The C terminals are easy. They go directly from the ignitor to the coil negative terminal ONLY. No parallel hookups. No other wires should be hooked up to these except a tach wire, but to only one of them. However your stock trailing coil already has a tach signal wire so you're good. Just keep each ignitor C terminal and each coil - terminal separate from its neighbor.
The B terminal needs power whenever the key is in the On and Start positions. Easy to check with a test light. Turn key on and check that it lights up. Actually check both coil terminals (+and-) because they should both light up as this is a protection circuit for the ignitor and coil to prevent them from constantly charging, overheating and quickly failing. I learned this the hard way when my MegaSquirt didn't employ this type of protection. Eep!
Getting back to what I was saying, the B terminals of both ignitors need to be hooked to both coils along a common wire. See the main difference here? These wires are ok to hook up all together compared with what I said about the C terminals above, which must remain separate. This matches the diagrams you'll see.
You don't have to be very good at wiring to make DLIDFIS work, but some basic skills with a crimper and wire stripper are a good idea. Ever wired in an aftermarket fuel pump? Or maybe even a stereo? Yeah, it's about the same.
And to answer your specific questions about how it all works, yes the leading sparks for both rotors spark at exactly the same time. Kind of mind blowing, right? Actually you can spark both leading plugs at the same time due to the spark plug location in the rotor housings, beuing below the bump of the figure 8 trochoid shape. You can't spark both trailings at the same time; also based on plug locaton. If you did, it would ignite the incoming mixture. To test what this feels like, simply hook up T1 and T2 backwards and try to drive around the block. It's happened to me, peejay, divindriver and I'm sure there are some others too embarassed to talk about it.
DLIDFIS and other variants run in what is commonly called "waste spark" for piston engines where the spark for the piston that is not at TDC but rather in its exhaust phase is "wasted" as it's not really doing anything for power in a piston engine as they only have a 180 degree power stroke. However in a rotary I've determined that the so called wasted spark isn't really wasted at all and actually adds a little bit of power and certainly cleans up emissions and makes for easier hot and cold starts etc. When you eliminate the cap and rotor from the equation and directly spark the spark plug, all that energy required to jump the gap in the cap and run through two high tension wires, is suddenly all available to light off even way lean or way rich AF mixtures. This is also great for boost, which I discovered last year.
I started calling it "late leading" just to confuse people who may have been aware of Mazda's late trailing or third spark plug in the 787B, but that term never really caught on. But it really is a late leading spark, and it really does improve all that I've said and more. It is certainly not wasted.
By the way, all FC and FD leading ignition systems have a wasted spark coil with dual outlets for both leading plugs which spark at the same time. However it's not really as powerful as having two individual ignitors and two separate coils like DLIDFIS. Study the FC leading coil you have. Notice how it has only one ignitor to power two spark plugs. The FC ones work well enough for most setups it seems, even FD guys use them, but if FC and FD guys start making serious power, they either have to go to CDI or two separate leading coils and then either single leading sparks per rotor face, or sometimes late leading or "waste spark", depending on how high the RPM vs coil charge time they need and how much energy is required to jump the gap, such as under high boost or with exotic fuels etc. You know, whatever works. Remember you're looking for two spark events per engine revolution. This is how stock and DLIDFIS works. Only the FC stock trailing coils and aftermarket single-spark leading coils will have one spark even per engine rev or rather one spark per rotor face. Sorry if any of that was utterly confusing. I don't know how to explain it any other way.
As for me, DLDIFIS with GM HEIs or stock J-109s and stock Diamond coils work just fine. Oh and stock 81-85 NGK BR8EQ-14 spark plugs. No need for anoying motorcycle plugs that require a thinwall socket.
I've used GM HEIs for DLIDFIS a number of times. They work great. What you're doing is you take the original red and green wires from the dizzy leading pickup, then Y them in parallel to go to the trigger terminals of the ignitors. The wire colors for all 81-85 dizzies are:
green wire to W terminal
red wire to G terminal
If you have an 80 dizzy, reverse the polarity. Easy stuff.
The other ignitor terminals go to the coils and are industry standard and are self explanitory to some extent:
ignitor B to + coil terminal ignition ON
ignitor C to - coil terminal and tach signal (if desired)
Think of them as B stands for battery, and C stands for coil. Confused?
The C terminals are easy. They go directly from the ignitor to the coil negative terminal ONLY. No parallel hookups. No other wires should be hooked up to these except a tach wire, but to only one of them. However your stock trailing coil already has a tach signal wire so you're good. Just keep each ignitor C terminal and each coil - terminal separate from its neighbor.
The B terminal needs power whenever the key is in the On and Start positions. Easy to check with a test light. Turn key on and check that it lights up. Actually check both coil terminals (+and-) because they should both light up as this is a protection circuit for the ignitor and coil to prevent them from constantly charging, overheating and quickly failing. I learned this the hard way when my MegaSquirt didn't employ this type of protection. Eep!
Getting back to what I was saying, the B terminals of both ignitors need to be hooked to both coils along a common wire. See the main difference here? These wires are ok to hook up all together compared with what I said about the C terminals above, which must remain separate. This matches the diagrams you'll see.
You don't have to be very good at wiring to make DLIDFIS work, but some basic skills with a crimper and wire stripper are a good idea. Ever wired in an aftermarket fuel pump? Or maybe even a stereo? Yeah, it's about the same.
And to answer your specific questions about how it all works, yes the leading sparks for both rotors spark at exactly the same time. Kind of mind blowing, right? Actually you can spark both leading plugs at the same time due to the spark plug location in the rotor housings, beuing below the bump of the figure 8 trochoid shape. You can't spark both trailings at the same time; also based on plug locaton. If you did, it would ignite the incoming mixture. To test what this feels like, simply hook up T1 and T2 backwards and try to drive around the block. It's happened to me, peejay, divindriver and I'm sure there are some others too embarassed to talk about it.
DLIDFIS and other variants run in what is commonly called "waste spark" for piston engines where the spark for the piston that is not at TDC but rather in its exhaust phase is "wasted" as it's not really doing anything for power in a piston engine as they only have a 180 degree power stroke. However in a rotary I've determined that the so called wasted spark isn't really wasted at all and actually adds a little bit of power and certainly cleans up emissions and makes for easier hot and cold starts etc. When you eliminate the cap and rotor from the equation and directly spark the spark plug, all that energy required to jump the gap in the cap and run through two high tension wires, is suddenly all available to light off even way lean or way rich AF mixtures. This is also great for boost, which I discovered last year.
I started calling it "late leading" just to confuse people who may have been aware of Mazda's late trailing or third spark plug in the 787B, but that term never really caught on. But it really is a late leading spark, and it really does improve all that I've said and more. It is certainly not wasted.
By the way, all FC and FD leading ignition systems have a wasted spark coil with dual outlets for both leading plugs which spark at the same time. However it's not really as powerful as having two individual ignitors and two separate coils like DLIDFIS. Study the FC leading coil you have. Notice how it has only one ignitor to power two spark plugs. The FC ones work well enough for most setups it seems, even FD guys use them, but if FC and FD guys start making serious power, they either have to go to CDI or two separate leading coils and then either single leading sparks per rotor face, or sometimes late leading or "waste spark", depending on how high the RPM vs coil charge time they need and how much energy is required to jump the gap, such as under high boost or with exotic fuels etc. You know, whatever works. Remember you're looking for two spark events per engine revolution. This is how stock and DLIDFIS works. Only the FC stock trailing coils and aftermarket single-spark leading coils will have one spark even per engine rev or rather one spark per rotor face. Sorry if any of that was utterly confusing. I don't know how to explain it any other way.
As for me, DLDIFIS with GM HEIs or stock J-109s and stock Diamond coils work just fine. Oh and stock 81-85 NGK BR8EQ-14 spark plugs.
No need for anoying motorcycle plugs that require a thinwall socket.
02-16-15, 04:59 PM
#65
Mock build! 
Finally, I got a 5/8" flange adaptor, and the turbo JUST squeezes in there. I might get some asbestos and cover that hot side to keep if from frying the intake.
As for money I've dropped a TON on this project. By far this is the most expensive thing I've ever done. $400 spent on exhaust piping and fuel pumping the past couple of weeks... ouch. Well, its almost done.
Finally, I got a 5/8" flange adaptor, and the turbo JUST squeezes in there. I might get some asbestos and cover that hot side to keep if from frying the intake.
As for money I've dropped a TON on this project. By far this is the most expensive thing I've ever done. $400 spent on exhaust piping and fuel pumping the past couple of weeks... ouch. Well, its almost done.
02-18-15, 05:14 PM
#66
Got my Mallory Comp 140 in the mail. I bolted it to a spare fuel cradle I had lying around. I don't know where that cradle came from but it sure showed up at the right time so I'm not complaining.
As for the Mallory 4309. I'm thinking of mounting it to the keg. I've never seen anybody do this, I tend to see them mounted to the firewall. Is there any reason for that?
At anyrate I'm going to dead head it to the carb. Two lines from the regulator to the two bowls. and a fuel pressure gauge on top.
I'm still contemplating where I should put my reference for the fuel pressure. Taping the bowls seems the most logical, because that is where the fuel pressure resistance is. However that is more difficult than just going from the carb hat.
As for the Mallory 4309. I'm thinking of mounting it to the keg. I've never seen anybody do this, I tend to see them mounted to the firewall. Is there any reason for that?
At anyrate I'm going to dead head it to the carb. Two lines from the regulator to the two bowls. and a fuel pressure gauge on top.
I'm still contemplating where I should put my reference for the fuel pressure. Taping the bowls seems the most logical, because that is where the fuel pressure resistance is. However that is more difficult than just going from the carb hat.
02-18-15, 08:10 PM
#68
Damn, I knew there was a reason why everybody else was doing it that way.
EDIT: wait you mean the pump or the regulator?
The pump mounting is gonna prove challenging then. I'm trying to dream up a way to mount it upright, but there just isn't a lot of room down there... I guess just forward of the tank maybe past where the axle moves.
EDIT: wait you mean the pump or the regulator?
The pump mounting is gonna prove challenging then. I'm trying to dream up a way to mount it upright, but there just isn't a lot of room down there... I guess just forward of the tank maybe past where the axle moves.
02-18-15, 08:21 PM
#69
OK... I see the pump must have fuel in it all the time. NPT fittings on the bottom.
I might cut a 2" hole in the floor and have the pump half in the car half outside of it. Then FIRMLY bolt it to the frame rail. If I recall correctly the frame rail runs right along side the pump cage.
Serves me right for buying second hand. No instructions. :P
I might cut a 2" hole in the floor and have the pump half in the car half outside of it. Then FIRMLY bolt it to the frame rail. If I recall correctly the frame rail runs right along side the pump cage.
Serves me right for buying second hand. No instructions. :P
02-18-15, 09:14 PM
#70
Id recommend against the pump being inside the car because of fire hazard. The pump does need fuel running through it upright for cooling reasons or it could burn out or suck air. I mounted it between the driver side rear axle and storage bin area. 4 holes drilled in the body with through bolts and 10mm nuts with washers. This was on a friends Holley RB setup.
02-18-15, 09:56 PM
#71
I'd recommend against that fuel pump because I don't know how well they work. I'd go with an MSD 2225 because that's what I used and it works for a blow through Nikki. Don't get a walbro what ever you do, just don't.
I'm in the middle of redoing my fuel system to more closely follow Mallory's instructions where you've got a 5/16" send and a 3/8" return. I originally set it up wrong. It was 2012 and I'd never done this before. So now I'm in the middle of redoing everything.
Well, not everything. I'm keeping the Mallory 4309 and just swapped some fittings around. I'm keeping the current 3/8" hardline that was a send, and replumbing it into a return. It will join the stock line going into the tank.
The car's orignal return which is 5/16" on a GSL-SE, is being repurposed as a new send so I had to do a little cutting on it. I don't have the car's original send anymore.
It would have made life a little easier.
The MSD fuel pump is getting relocated closer to the frame rail so I can mount it to it to reduce the anoying fuel pump noise inside the car. Dom't use the stock stud that hangs down because it connects to sheet metal. This sheet metal acts like a speaker.
Believe me you don't want to cut a hole in the floor for a fuel pump. Sheesh! If the noise doesn't bother you, the potential fire hazard should. Just get another pump that will work with a Nikki blow through.
Anyone else ever used a Mallory fuel pump? Are they ok?
Are you sure you want to plumb a fuel line directly to each banjo bolt fitting on the carb? I know bad83 did, but do you think you'll need it? Especially just starting out? Why not use the stock fuel rail? The fuel system can only flow as much as the smallest orifice, in this case the hole in the seat where the needle fits/seals it. If you try to feed it with some huge fuel line(s), what will happen? It will flood out every time.
My setup was prone to flooding after a boosted run. I was told this is because larger diameter fuel lines hold a lot of fuel, and when you let off the pesal and the pressure drops, all that excess fuel has to go somewhere. If it can't go back to the tank, the only other place it can go is in the carb leading to a common flooding issue.
I was told my fuel send line was too big. Or my return line was too small. Turned out it was both. My send was 3/8" and my return was 5/16". This is opposite of what the instructions that come with the Mallory 4309 recommend. So I spent the better part of the day today, tearing everything down while trying not to spill gas on myself or anything else. Then I got to work engineering a new setup while trying to use what was already there, just repurposing it, as mentioned above.
I think when I'm done I might post a pic or two in a build thread. Should I?
I'm in the middle of redoing my fuel system to more closely follow Mallory's instructions where you've got a 5/16" send and a 3/8" return. I originally set it up wrong. It was 2012 and I'd never done this before. So now I'm in the middle of redoing everything.
Well, not everything. I'm keeping the Mallory 4309 and just swapped some fittings around. I'm keeping the current 3/8" hardline that was a send, and replumbing it into a return. It will join the stock line going into the tank.
The car's orignal return which is 5/16" on a GSL-SE, is being repurposed as a new send so I had to do a little cutting on it. I don't have the car's original send anymore.
It would have made life a little easier.The MSD fuel pump is getting relocated closer to the frame rail so I can mount it to it to reduce the anoying fuel pump noise inside the car. Dom't use the stock stud that hangs down because it connects to sheet metal. This sheet metal acts like a speaker.
Believe me you don't want to cut a hole in the floor for a fuel pump. Sheesh! If the noise doesn't bother you, the potential fire hazard should. Just get another pump that will work with a Nikki blow through.
Anyone else ever used a Mallory fuel pump? Are they ok?
Are you sure you want to plumb a fuel line directly to each banjo bolt fitting on the carb? I know bad83 did, but do you think you'll need it? Especially just starting out? Why not use the stock fuel rail? The fuel system can only flow as much as the smallest orifice, in this case the hole in the seat where the needle fits/seals it. If you try to feed it with some huge fuel line(s), what will happen? It will flood out every time.
My setup was prone to flooding after a boosted run. I was told this is because larger diameter fuel lines hold a lot of fuel, and when you let off the pesal and the pressure drops, all that excess fuel has to go somewhere. If it can't go back to the tank, the only other place it can go is in the carb leading to a common flooding issue.
I was told my fuel send line was too big. Or my return line was too small. Turned out it was both. My send was 3/8" and my return was 5/16". This is opposite of what the instructions that come with the Mallory 4309 recommend. So I spent the better part of the day today, tearing everything down while trying not to spill gas on myself or anything else. Then I got to work engineering a new setup while trying to use what was already there, just repurposing it, as mentioned above.
I think when I'm done I might post a pic or two in a build thread. Should I?
02-19-15, 09:15 PM
#72
Na, I didn't want to cut a hole, just haven't been under there in a while and I didn't know how much room I had to work with. If I can make it work with out cutting i'll go that route. And if I was I wouldn't have the whole thing in the car, just the top half with like a rubber tube cut in half to stop the rattle.
I went with the Mallory because that's what the instructions for the 4309 recommended to use for boosted applications. 40#s pressure with the MSD pump seemed excessive.
As for the plumbing I'm thinking about just getting AN -6 lines to and from the tank. Figure I should have enough fuel coming and going fast enough flooding won't be an issue. The two lines is just because I have two separate holes in the 4309. If it doesn't work I'll plug one up.
I went with the Mallory because that's what the instructions for the 4309 recommended to use for boosted applications. 40#s pressure with the MSD pump seemed excessive.
As for the plumbing I'm thinking about just getting AN -6 lines to and from the tank. Figure I should have enough fuel coming and going fast enough flooding won't be an issue. The two lines is just because I have two separate holes in the 4309. If it doesn't work I'll plug one up.
02-19-15, 10:10 PM
#73
I was told to get an MSD pump so that's what I did. This was after the walbro could only be lowered down to 5psi with the mallory. Again this is with the wrong size send and return lines under the car, but I still doubt the walbro would have gone much lower. The MSD pump could get all the way down to 2psi sometimes, but would sometimes go no lower than 3psi. It depended on a number of factors such as moon phases and the number of neutrinos passing through it in that particular second.
The guy I got my mallory 4309 from, said his setup with an MSD pump and 5/16" send and return lines could get down to 1psi.
This was after the walbro could only be lowered down to 5psi with the mallory. Again this is with the wrong size send and return lines under the car, but I still doubt the walbro would have gone much lower. The MSD pump could get all the way down to 2psi sometimes, but would sometimes go no lower than 3psi. It depended on a number of factors such as moon phases and the number of neutrinos passing through it in that particular second.The guy I got my mallory 4309 from, said his setup with an MSD pump and 5/16" send and return lines could get down to 1psi.
02-19-15, 11:13 PM
#74
Well, I guess I'm also playing the safe game. The Mallory has an AMAZING resale value. Second hand about $100. So the worst that can happen I **** can it for what I paid. 
Also, this isn't always accurate, the Mallory is more expensive; so better quality?? I think the Mallory is more designed specifically for a blow through application. High volume low pressure. The MSD seems is more apt for a TBI; like MSD's aftermarket TBI system.
At anyrate we'll know soon enough. Got some exhaust piping in the other day. Got my gas for my MIG. Got rebuild kits for carburetors.... all I need now is to get off my fat behindus and DO SOMETHING!!!!
Also, this isn't always accurate, the Mallory is more expensive; so better quality?? I think the Mallory is more designed specifically for a blow through application. High volume low pressure. The MSD seems is more apt for a TBI; like MSD's aftermarket TBI system.
At anyrate we'll know soon enough. Got some exhaust piping in the other day. Got my gas for my MIG. Got rebuild kits for carburetors.... all I need now is to get off my fat behindus and DO SOMETHING!!!!
