In reply to Dusterbd13:
Yep, I'm sure there's a couple OE examples out there that I could butcher.
And yeah- when I built the first setup the fuel had a pretty weird direction to flow in and it worked amazingly well, so it seems as you said with some vacuum and then some boost it'll go wherever it needs.
In reply to BrokenYugo:
Yeah the fuel puddling thing was something I was concerned about with the old setup and it wasn't a huge issue. It did get loaded up at times, but I never had a specific problem. It'll be right over the downpipe now so I think it will have plenty of heat under it. The one thing I may change is the outlet of the carb sucky box has a little lip on it that I'm not a fan of, I may smooth that out.
In reply to TED_fiestaHP:
Good point about the intercooler, although that's just moving air not fuel at this point. But yeah I'm not afraid of the weird fuel flow. As for the blowthrough carb I have a 4150 holley I plan to modify based on the write up here. A lot of people on the turbo forums have used that with success so I'll give it a try. I will be verifying that my floats are solid, and if they aren't I'll replace them with the correct ones.
I also intend to boost-reference the top of the mechanical fuel pump and use a regulator to increase pressure with boost. OR potentially use an electric pump wired to a hobbs switch that turns on with boost. I'll have to look into options there. I don't know of a good electric pump that can suck fuel from the stock sending unit/pickup and I don't want to sump the tank just yet (mostly because I don't want to explode trying to weld on my existing one or spend the money buying a new one). If anyone knows a decent electric fuel pump that can be mounted external of the tank and will suck from a stock location I'm all ears.
The pump wouldn't have to be mounted inside the tank. The pump on my Maserati is external but mounted low and near the tank. I might have a spare pump as well, I would have to look. To use the regulator that I have you would need a return line, which you might not have. The return line you could T into the current line before the pump, rather than modify the tank.
In reply to TED_fiestaHP:
I'll have to dig into that electric pump situation a bit more, I think I could mount it lower than the tank, but it'll have to flow fairly far uphill to get OUT of the tank if that makes sense. Not sure if most electric pumps will operate like that or not. I did a quick crappy drawing of what I'm talking about.
I'm also curious about running the return to a T before the pump- does this actually work? It seems like an awful small place that could maybe have a backup? Or would the pump just then suck that fuel back up instead of drawing from the tank?
I did just do some reading and if I boost reference the mechanical pump I shouldn't need a regulator- it will just rise with boost naturally. I think the electric pump and boost referenced regulator is a safer bet, especially at higher boost levels, but from the sounds of it at low boost (I'm only running 8psi) a mechanical pump can work.
https://www.bing.com/images/search?view=detailV2&ccid=O5bwwHWF&id=1B8DE52CE99591CAD66DAFE7781D0CEE97C53DC3&thid=OIP.O5bwwHWFtM3-I-M_dROd9AEsDI&q=lotus+esprit+engine&simid=608029772860621395&selectedIndex=47&qpvt=lotus+esprit+engine&ajaxhist=0
Well if that link works, you can see what lotus did, the picture shows the float bowl vent piped to manifold pressure. also shows the fuel regulator.
The pump won't mind pushing fluid up, pumps just don't like to draw fluid up hill. I don't see why the T between the tank and pump wouldn't work. It would just help to feed the pump.
The Maserati only goes to about 10 PSI, if the fuel pressure doesn't keep up, it will suddenly go lean. That you don't want, boost then lean, not good.
Dang that's weird! I plan on using a home made carb hat/bonnet to keep the float bowls happy.
Boost + Lean = Sad.
And the pump will have to draw fluid uphill to an certain extent because it's going to have to go up and out the stock pickup, which will be higher than it technically. The pump can probably be lower than the overall fuel level, but it still has to go up to get out. Maybe I'm overthinking that aspect.
Provided the pump is below the fluid level, it's ok if it goes up and down. It would be slightly better if it just went down to the pump.
http://www.maserati-alfieri.co.uk/alfieri00a.htm Enrico's Maserati info page. On the left, index edge, scroll down and under "biturbo workshop" click on "biturbo 18 valve engine" That will bring up a index of the tech manual, then click on "fuel pipes" and you will see how that was set-up.
I just looked at the tech manual page of the tank, the Maserati has the return going into a T fitting right at the tank, the pump is mounted near the tank, so that should work. It's been done before....
Gunchsta wrote:
I also intend to boost-reference the top of the mechanical fuel pump and use a regulator to increase pressure with boost.
I don't think you need a regulator if you boost reference a mechanical pump. The way a carb works makes a rising rate above 1:1 not desirable, you just want boost pressure+normal carb fuel pressure. The pump itself is self regulating. The lever arm on the pump doesn't push fuel, it pulls on a spring loaded diaphragm and the spring does the actual pumping/pressure generation. By putting boost (edit:and never vacuum, connect it before the carb) rather than atmosphere on the spring side you then have a fuel pressure of boost+whatever pressure the pump normally makes.
(Ignore the "return", that was a controlled leak back to the tank on some cars so the fuel in the pump didn't get too hot at idle)
In reply to TED_fiestaHP:
I'm game to give it a try- I think I'll attempt to reference the mechanical pump first though. Not that I doubt any of the engineering on the Biturbo...
I will look to make sure I can find the parts, once I locate them, if you want them just tell me where to send them. I think I still have a pump and a regulator, this part of the car works, there are many other things that are somewhat questionable. It is a interesting car to attempt to keep running. Some thing I swear they intended to make more difficult to fix. The electrical system is interesting to say the least.
In reply to TED_fiestaHP:
Appreciate it, thanks! I'll let you know. And I commend you for even dealing with it, they must be marvelous to drive when they work right.
You can stick an in-tank Walbro 255 lph pump on the end of the factory Dodge sending unit if you want to - they're small enough to fit through the factory sending unit hole. Main problem is sealing up the wiring connection.
Or you can do what I did for my latest round of mods. Get a cheap replica fuel tank (you can get an OK repro tank for under $100 for these cars now) and weld a Wal-Mart bread pan under it for a sump.
I need to start a build thread of my own. I thought I had one here but can't seem to find it.
In reply to MadScientistMatt:
Hmm... Any reason you couldn't drill a hole in the top of the sending unit, pass the wires through it, then superglue it back closed around the wires? or some better kind of epoxy/jb weld? Maybe a connector on either side? I'm very interested in this, I like the 255 for it's reputation and price. How do you mount the pump to the existing sender?
Although frankly welding a sump onto a $100 tank doesn't seem that bad either. EDIT: Just looked these are like $80 on eBay now. I think I'll probably just put a sump on it when the time comes.
And I would love to see a build (or even just a couple pictures in here if you want to share) of your car. I've read some turbo slant builds on slantsix.org but always like to see more.
OK I looked and I have a spare pump, pressure regulator and a intercooler. If you want them, just let me know where to send them. The pump would mount external, since it is the Maserati pump. The regulator would use a return which could T into the feed line for the pump, same as the Maserati set-up. Just mount the pump as low as possible and it should work fine. The feed connection on the pump is 1/2 inch hose, which is odd size, but I have some of that as well.
In reply to TED_fiestaHP:
Sweet! what are the dimensions of the intercooler? I was looking a bit after work last night and I don't have a ton of room to work with up front unless I loose the hood latch.
Well I would have to measure it... But I actually have 2, the idea was to put them across the front of the Bi-turbo, and they almost fit. So from memory.... maybe 26" wide and 5" tall or something like that. To get them to fit I would have had to cut to much metal. The idea was to put them across the front of the radiator, but the idea didn't fit as well as I had thought it might. Right now that silly car won't start anyhow.... Ignition switch.. I think.
That was about the size I was looking at on eBay and I wasn't sure I had enough room (without cutting a lot) either. I had actually been thinking about just running an early 2000s VW intercooler for my front mount. I think they would be about the right size and I should be able to come up with one pretty easy.
https://www.bing.com/images/search?view=detailV2&ccid=vOpZAzaE&id=A09352720058856209898E87B5BBE47AF4EFA181&thid=OIP.vOpZAzaEZxtph67v7w_rVQEsDh&q=maserati+biturbo+engine&simid=608002748918728846&selectedIndex=25&qpvt=maserati+biturbo+engine&ajaxhist=0
The intercoolers are not huge, from this picture you can see where they almost fit. The Bi-turbo has a turbo low on each side and the idea was to go forward across then up to the carb box. I can send you both, maybe you can route both of them together.
In reply to TED_fiestaHP:
I've looked at a couple pictures and one looks like it might be able to work somewhere. I'd gladly try it out but I don't want to be wasting rare and valuable Maserati parts on my silly Dart. Honestly, no sarcasm. I'm super afraid of NLA/oddball parts so I'd hate to wreck your stash of extras.
A single one like this is what I think would work well for how my setup is taking shape in my head.
The intercoolers are E-bay items, not rare Maserati parts. Just a long rectangle with a tube connection on each end. I have never seen the ones you just found a picture of... So those must be rare!
The pump and regulator are used parts that I kept as spares, the intercoolers are something that almost fit, so it's just all stuff sitting here not being used. If you put it to use that would be great.
I can take some pictures over the weekend so you can see better how the intercooler might fit.
Gunchsta wrote:
In reply to MadScientistMatt:
Hmm... Any reason you couldn't drill a hole in the top of the sending unit, pass the wires through it, then superglue it back closed around the wires? or some better kind of epoxy/jb weld? Maybe a connector on either side? I'm very interested in this, I like the 255 for it's reputation and price. How do you mount the pump to the existing sender?
This was something I did on a Chevy C10, not my Dart, but the sender dimensions are pretty similar. I tried several wrong guesses with glue that left the cab smelling like gas fumes all the time (yes, this tank was behind the driver's seat and not under the bed) before I would up taking some rubber grommets and a screw that was almost exactly their ID, then attaching ring terminals on both ends of the screw. Still occasionally had the cab smell like gas though. But gasoline-proof bulkhead connectors aren't cheap...
Getting the pump on the end of the pick up tube was just a rubber hose and hose clamps. Zip tying the pump and pickup tube to a length of metal tubing could give it some extra support - I did not do this myself though.
In Reply to TED_fiestaHP:
Ahhh ok great, then yeah I'm all over it! I can paypal you the cost of shipping plus a little extra for your time.
Shoot me an email at gunchsta@gmail dot com and we'll figure out the particulars.
In reply to MadScientistMatt:
Hahaha- Love that it was on a C10 with the tank in the cab. Hope you're not a smoker...
Looking at how cheap tanks are I think I'll eventually sump one, but in the mean time I may try the Bi-turbo pump.
I wish I didn't want parts from one of the most notoriously unreliable cars on my car.
