[RocktimusPryme]

Originally Posted by Formulajones

Well, what you have is working for you, I don't know if I'd mess with it. Unless you foresee an issue or maybe want to add an EFI setup or something, I'd just enjoy as is.

It's hard for most to get past the price point for an in tank setup and I completely understand that.

Ill second that if you arent having issues dont mess with it. However, if you are looking at building up your fuel system anyway, putting in bigger lines ETC. That is where the cost difference becomes less of a factor. Its not as if building a beefy mechanical fuel system is cheap. And as I said earlier, I think the baffled tank means almost as much as the in tank pump. You can buoy a stock tank with a hydra mat or something but those arent cheap.

I totally get staying with a mechanical pump if thats all you are chaning. But if you are looking at your fuel system and saying "This is all inadequate", I really dont think you save much by staying mechanical.

BTW the Robb MC fuel regulator is a little less than that Aeromotive one, works great and comes from a small American company.


At the end of the day, with my high effort street car, I can say that several people here told me not to bother with the mechanical setup. I did it anyway. Even tried to do it the right way. Big nasty pump, 1/2 feed line, 1/2" pickup. Then went with an even bigger pump, added a regulator and a vent line. And now guess what, I had the same issues I was warned about. Went electric. Its just take any questions out of it. Its going to work, end of story.

I very much agree with Tom that you should build for your situation and not based on the internet. That said, the reality is that its a copycat world here. There are lot of us with similar cars, and similar goals. How many E headed 461s are there, ya know? May as well use what works from very similar situations.

[TCSGTO]

Originally Posted by RocktimusPryme

Ill second that if you arent having issues dont mess with it. However, if you are looking at building up your fuel system anyway, putting in bigger lines ETC. That is where the cost difference becomes less of a factor. Its not as if building a beefy mechanical fuel system is cheap. And as I said earlier, I think the baffled tank means almost as much as the in tank pump. You can buoy a stock tank with a hydra mat or something but those arent cheap.

I totally get staying with a mechanical pump if thats all you are chaning. But if you are looking at your fuel system and saying "This is all inadequate", I really dont think you save much by staying mechanical.

BTW the Robb MC fuel regulator is a little less than that Aeromotive one, works great and comes from a small American company.


At the end of the day, with my high effort street car, I can say that several people here told me not to bother with the mechanical setup. I did it anyway. Even tried to do it the right way. Big nasty pump, 1/2 feed line, 1/2" pickup. Then went with an even bigger pump, added a regulator and a vent line. And now guess what, I had the same issues I was warned about. Went electric. Its just take any questions out of it. Its going to work, end of story.

I very much agree with Tom that you should build for your situation and not based on the internet. That said, the reality is that its a copycat world here. There are lot of us with similar cars, and similar goals. How much E headed 461s are there, ya know? May as well use what works from very similar situations.

I get what you’re saying. If you look at the internet too much you’ll constantly second guess yourself.
I think the main reason the mech pump has worked as well as it has is the -10 feed line which is basically a garden hose.
I’m still going to mount a fuel pressure gauge where I can see it now just out of curiosity as this setup may be nearing its limits in my application. If pressure starts to drop you may not be able to feel it but there could be a performance loss.

[Skip Fix]

You would not think a 180 HP 7.8:1 400 with just a 228@ 0.050 cam and 2.56 would have fule supply problems but mine sure did.

[scott70]

Hmmm...i used to run 11.7 at 115 mph in my 70 gto. 800dp holly, t2 intake, Carter mechanical pump,factory 3/8 fuel line with a bone stock fuel tank. Pulled hard the whole way.

[Formulajones]

Originally Posted by Tom Vaught

The vehicle with the Tanks,inc system is Naturally Aspirated currently.
That being said, I agree a 255 l per hour efi pump would support that deal.
But I like doing Boost upgrades and if I choose to mount a Vortech Supercharger
on the front of the engine down the road, I don't have to mess with the fuel system.

I've been contemplating the exact same deal. That's one reason I went overkill on the Chevelle fuel system. I've already went with a boost friendly Super Sniper EFI that will support 1250 hp. Currently running it NA. I'm going to do a 502 sitting here, and it will either turn into a 509 with a set of pistons to bump the compression using my AFR heads and stay N/A, or I may leave it a 502 with the 9:1 pistons and bolt on a Pro Charger with mild boost. Either way, the fuel system is ready.

[Formulajones]

Originally Posted by Skip Fix

You would not think a 180 HP 7.8:1 400 with just a 228@ 0.050 cam and 2.56 would have fule supply problems but mine sure did.

I've found that cars with very numerically low rear gears like that are the worst for it. Really long pulls through the gears really puts a strain on the fuel system and if it's already marginal, it will certainly show itself with a 2.56 rear gear. Some don't even get out of first gear, lol

At 5500 rpm you're nearly doing 70 mph with a 2.52 first gear LOL

[hdinch]

I switched to the RobbMC 1100 last year from the carter high flow pump. I am running a street car, 73 bird with a 461 and 3.73 gears. I was running low 12's prior to the fuel pump change. I had to make track adjustments on the RobbMC pump on the last run it made an 11.90. Also running a 1/2 line and pickup. This motor is around 525 hp. This spring I had a 150 shot put on the car and had it dyno tuned for test runs. The pump would keep up but had to be turned all the way up. I have not been to the track this year due to Covid and also my local track closed so I have yet to be able to test it myself. So all that being said...I am happy with how this pump is running and I was not quite sure if I was having fuel issue's but I knew I could not use a 150 shot with what I had.

The customer service for this company is great and will help you with any issues related to the pump. One thing I had to due was create my own plumbing....running up from the factory passenger side for my bird. Not sure how others have done this but I had to get creative with my fittings to keep sharp bends out of the equation to and from the RobbMC pump.

[RocktimusPryme]

Originally Posted by hdinch

The customer service for this company is great and will help you with any issues related to the pump.

That is 100% accurate. Robb is as standup as they come. Always answered email questions promptly and has very reasonable prices for rebuilds and inspections of his products.

Even if I would advise going to the in tank type systems, I would still get the regulator from Robb.

[Formulajones]

I'll likely go with a RobbMC mechanical pump on the nomad for the time being.

I've been waiting for the EFI ready tank from Tanks Inc. They finally have a picture of it and a projected date at the end of September for availability. I'll go that route when it gets here.

[chrisp]

Carter HP

[421mike]

Originally Posted by tom s

1/2 in from tank to the Carter,3/8 from the pump to both AFBs.Tom

Thanks Tom, I kept running out on the top with just the carter but think the fuel line was too small.

[Tom Vaught]

Mechanical Pumps work on the principal that the fuel tank and Atmospheric Pressure provide a given flow "Delta" thru the fuel line size to the Mechanical Fuel Pump.
Atmospheric Pressure being around 14.7 psi at sea level.
So if you disconnected the line and let it drain into a pan you would have Atmospheric Pressure acting on the square inches of surface area in the gas tank with the control factor being the tank vent size which atmospheric pressure and air mass has to flow thru. You plug the tank vent you get no fuel flow.

Then you have the Fuel Pump which is actually a LIFT PUMP that receives the fuel from the tank and lifts it to the carb inlet. From the factory the lift pump has a range of fuel pressure to the carb capability. If the fuel pump size, the needle & seat size, and the float settings are correct the fuel system works perfectly for a given horsepower capability designed by the Engineers for that vehicle.

So if you follow Tom S suggestion with the 1/2" feed line (and pick-up in the tank)
you now have less restriction for the fuel to flow for a given pressure and more fuel
volume in each foot of fuel line transferring fuel from the tank to the mechanical fuel pump.

If you have dual quads you have twice the carb fuel volume requirement that the fuel system has to support. The correct fuel pump and the lower restriction of the 1/2" fuel line helps with that situation.

So I would follow the suggestion of Tom S who has worked out the requirement for a happy engine with dual quads on a street car.

Tom V.

[Dragncar]

I have run a Holley mech 80gph to 12 flat. But done something weird but it worked. I just wanted to find out if it would. The car still has the steel 3/8 line in the tank with sock off. The tank also has a 1/2 line going to a generic 140gph "Black" pump. I have a Mallory 3/8 Return regulator.
Well I tried the electric pump to the secondaries only, the return regulator makes that possible. And I have that old Holley mech pump going to the primaries.
It worked, no issues. I figured the 80gph pump would keep up with just the primaries or half the carb. And the 140gph going to the secondaries would be more than enough. It all runs fine. Car did not immediately run any faster I was just trying to figure out if the 140gph pump was keeping up.
Car did eventually run almost 2 tenths fast but that was when I went to drag radials vs bias.
The engine did have this little "gurgling" sound at far top end. I figured it was at the 80gph pumps limit. I am kicking around buying a new 120gph mech pump for the front.
But have one a Langers old BG 400 electric pumps. Think I am best off doing that but still want to try the 120gph mech + 140gph electric to see if it works. I know, kinda weird.

[Formulajones]

If you use the generic 10hp per GPH rule, that 140 pump you have will support all the power you'll throw at it without the need for any mechanical pump in the system. I'd run that solo and call it done. Have done that for decades on one of the cars here with all stock lines well into the low 11's.

My only issue with those external pumps is I tend to only get about 4-5 or maybe 6 years out of the pump before the brushes are gone. Got tired of rebuilding pumps which is why I started going the in tank route years ago.

[Skip Fix]

On mechanicals I wonder how many companies have actually switched to a ethanol resistant material for the diaphragm? Figure unless you can find ethanol free you get that degradation of the rubber.

[Formulajones]

Originally Posted by Skip Fix

On mechanicals I wonder how many companies have actually switched to a ethanol resistant material for the diaphragm? Figure unless you can find ethanol free you get that degradation of the rubber.

I've always wondered that Skip. I've had good luck and not so good luck with mechanical pumps, but can't contribute any of that to ethanol.

The stock AC pump is still going strong on my Formula and it's been on there for 22 years now. Long before I think they cared about ethanol compatibility. For the last 15 years ethanol fuel is all that car has seen.

I also run a repop AC pump on our Z that's daily driven. Bought that 4 years ago. Don't know if it's ethanol friendly or not but it's seen almost 35k miles now with nothing but 10% ethanol and still working fine.

Then there is the issue of the mechanical pump dying on another car that is driven pretty frequently. That pump was 25 years old. So I went through a pair of Carter mechanical pumps on that one from Napa just last year. Neither pump got me out of the neighborhood before they died. By the time I took the second pump back for another replacement, he just looked at me and said "I'll just give you a refund" LOL I went down the street and bought a different brand mechanical and that one has been fine now.

On the Nomad I can't seem to get a stock mechanical pump on that one that shows more than 3 lbs. of fuel pressure. Unfortunately the frame and engine mount setup on that car doesn't allow room for a decent pump. Used to run a short Holley pump on that one in the 80's and daily drove it which worked fine then, but today that stuff has just been hit and miss for me, some are okay and some aren't. Since I daily drive this stuff reliability has become more of a concern and I'm to the point I don't really trust the mechanical stuff so much.

I've just gotten to the point where I'm putting everything in the tank now and ditching the mechanical idea all together. Eventually I'll get all the cars switched over as Tank's Inc keeps coming out with new tanks. They now have a Nomad tank scheduled to hit the market in September.

[FrankieT/A]

Originally Posted by Formulajones

I always go to the 400 LPH pump in the Tanks Inc deal, and I run 1/2" feed and return lines the full length of the car, with an Aeromotive 13301 regulator. I've installed several of these for people as well as our own cars for years without a hiccup.

It'll support over 1,000 hp so it's overkill for most street stuff, but the fuel pressure will never flinch.
This setup is on dad's 724hp GTO and I use it on my 600hp Chevelle as well. And when we converted both cars over to Holley Sniper Stealth setups, all I had to do was swap the spring in the regulator for EFI pressure and it's ready to rock.

You can tame this setup down with a 255 pump for those at or under 600hp if you wish, but for about a $60 difference I just prefer to step up to the 400 LPH pump and call it done for anything I throw at it.

Matter of fact, my 70 bird that I daily drive still runs it's stock fuel system with an original AC delco mechanical pump that is now 21 years old. I've gone 13.10 @ 104 with this setup (corrected 12.76 at 106) with a bone stock RAIII 400 in the car. I'm to the point the age on the stock pump has reached it's limit with me and I don't trust it. Rather than screw with another mechanical pump where reliability lately with me has been hit and miss (actually more miss) I really don't trust them anymore. So I'm just converting the car now to Tanks Inc, 1/2" lines, probably a 400 LPH pump, and be done with it. Totally overkill for a car that doesn't even make 400hp, but I can do any engine I want in the future and never have to revisit the fuel system.

Exactly what I did...Except Sniper, I have FITech. And FJ has a point, any future modifications and the fuel system is good to go.

[389]

RCI fuel cell with a sump, run dual 3/8" steel lines from the sump up to a tee in the mechanical fuel pump.

[Dragncar]

Originally Posted by Formulajones

If you use the generic 10hp per GPH rule, that 140 pump you have will support all the power you'll throw at it without the need for any mechanical pump in the system. I'd run that solo and call it done. Have done that for decades on one of the cars here with all stock lines well into the low 11's.

My only issue with those external pumps is I tend to only get about 4-5 or maybe 6 years out of the pump before the brushes are gone. Got tired of rebuilding pumps which is why I started going the in tank route years ago.

It was just a experiment I tried and got lazy and never went back to how it was with just the 140gph electric.
I have heard of the 10hp per GPH rule but.... no one in their right mind would try and make over 1000 HP with a single 140gph pump. Not trying to compare myself with Langer but that BG 400 pump of his I bought, he runs 2 of those things making his 1300 some odd horsepower. Plan was to put new brushes it it and run it. But not sure if I would need to go to a 5/8 fuel line for the pump either. Not interested in doing that right now. But it was 100$ so I bought it.
I have always understood having extra fuel capacity is a good thing in a race car. I lot of guys have had great luck running 2 Holley Blue pumps.
I agree the BG 400 is overkill for me. I would feel a 180-200 gph pump for what I am trying to would be about right. New engine should make 680 to low 700s for horsepower.
What is the total cost for a in tank system ? I agree that the cooling effect of a in tank pump is a benefit. But some cars are a real pain to change the pump in the tank. I had a Chevy pickup that was a pain. I have this Honda beater that you can change the in tank pump in 20 minutes. (very well designed car IMO) I had this Sirocco with a Bosh mechanical injection 120psi electric pump that was just outside the tank. On a Vegas trip I was pulling my hair out trying to figure out my engine problem. Ended up buying a pump at a Kragen, and driving one rear wheel up on the concrete tire stops in their parking lot, changing it on the spot and driving back to Nor Cal.
Next engine will make another 150+ HP so I want the fuel system to be right for it too.

[firechicken]

I run 2 Holley blues to feed my 800ish hp engine. They are switched separately and I only have one on when cruising on the street. Drove to the track one time and forgot to turn on the second pump before my first pass. Leaned out at 1000ft and popped the head gaskets at 15 psi boost. I'd say 10hp/1gal/hr is not a great formula to follow.