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  #21  
Old 09-19-2025, 02:28 PM
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I have a Holley red pump mounted at the tank on the GTO (tripower) and the Chevelle (Holley Dominator or 950HP).

I use them for priming and for periods of high demand. Otherwise I tool around on the mechanical pump.

The Holley pump has been on the GTO for over 60 years and on the Chevelle for nearly 50, with no issues.

GTO has been 12.20 in the quarter, Chevelle has been 9.56 @ 139mph with this set up.

K

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  #22  
Old 09-19-2025, 02:34 PM
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Originally Posted by Keith Seymore View Post
I have a Holley red pump mounted at the tank on the GTO (tripower) and the Chevelle (Holley Dominator or 950HP).

I use them for priming and for periods of high demand. Otherwise I tool around on the mechanical pump.

The Holley pump has been on the GTO for over 60 years and on the Chevelle for nearly 50, with no issues.

GTO has been 12.20 in the quarter, Chevelle has been 9.56 @ 139mph with this set up.

K
Hi Keith. I read that in an older thread about this. What Holley just told me is different. I wonder if the pump has changed?

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  #23  
Old 09-19-2025, 02:40 PM
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OK, both Mallory and Holey tech support say that their pumps (Mallory 110 and Holley red) will not allow the mechanical pump to pull fuel through them if they are off or if they fail. That seems to contradict what people have said here, at least for the Holley. I don't know which is correct but if they won't allow the mechanical pump to pull fuel through in the event of a failure then that's a no go. My intention would be to run it at all times, not just start up.

So now I'm back to either living with the limitations of the mechanical pump, which are not terrible, or going in-tank electric. I was on the verge of doing that a couple years ago but I soured on the idea. One of the reasons was because people advised that you should have the low oil pressure safety switch. I agree that seems like an important part of the system. But people said that the currently available switches were poor quality and not reliable. That really turned me off. But, when the fail, do they fail open or closed?
Regarding the oil pressure safety switch, it's something that is smart to have, but isn't absolutely necessary. Your own risk assessment would need to be done there.

If your intention was to run the pusher pump all the time, you'd need that same switch in that type of environment. I would actually say if you're risk averse, you'd want that safety switch regardless of whether or not you had the pusher pump functioning all the time. What happens when you turn it on at the drag strip, or on the street to have some fun, and you wreck? Same issue.

So if you feel that is a necessary part for an in-tank system, it's also a necessary part for your external pusher pump system.

As far as the quality of those pieces, I have no idea. I do know most of them are designed to activate at pressure below 15 psi, which for some pontiac engine owners is basically any time the engine is at hot idle.

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  #24  
Old 09-19-2025, 02:47 PM
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Regarding the oil pressure safety switch, it's something that is smart to have, but isn't absolutely necessary. Your own risk assessment would need to be done there.

If your intention was to run the pusher pump all the time, you'd need that same switch in that type of environment. I would actually say if you're risk averse, you'd want that safety switch regardless of whether or not you had the pusher pump functioning all the time. What happens when you turn it on at the drag strip, or on the street to have some fun, and you wreck? Same issue.

So if you feel that is a necessary part for an in-tank system, it's also a necessary part for your external pusher pump system.

As far as the quality of those pieces, I have no idea. I do know most of them are designed to activate at pressure below 15 psi, which for some pontiac engine owners is basically any time the engine is at hot idle.
The Tanks inc version says it cuts off at 5psi. The Holley one says 3 psi. I have 20+ psi at hot idle. So that's a pretty good margin there. I just don't want a failed switch to shut off my fuel pump. I don't now if most people run these or not. Seems like with a low pressure system it would be less important than a high pressure system. I'm thinking of it more as a fire prevention system in the event of an accident rather than saving the motor from loss of oil pressure.

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  #25  
Old 09-19-2025, 02:50 PM
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Originally Posted by jhein View Post
This will solve the priming issue and provide a little support for the mechanical pump to overcome the 3/8 line restriction.
Wow - didn’t realize you have a 3/8” line with that power plant - should definitely be 1/2” supply and return in tank with 255 or 340lph and never have to worry again.

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  #26  
Old 09-19-2025, 02:52 PM
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The Tanks inc version says it cuts off at 5psi. The Holley one says 3 psi. I have 20+ psi at hot idle. So that's a pretty good margin there. I just don't want a failed switch to shut off my fuel pump. I don't now if most people run these or not. Seems like with a low pressure system it would be less important than a high pressure system. I'm thinking of it more as a fire prevention system in the event of an accident rather than saving the motor from loss of oil pressure.
Yeah that's typically why they are run, for the accident based issues.

I'd talk with Tanks Inc about it. I don't know much about them, but it seems like a basic hobs switch, these are commonly run in various applications. Is it possible that the people having issues have them installed in such a way that the issue is presenting itself?

My question is how far do you want to go with this? If the only thing you're worried about is a bit of cranking if the car sits for a while, but otherwise you don't have any fuel starvation issues with your mechanical pump, is the juice worth the squeeze here?

My personal preference, but if my car has sat for a couple weeks and there's no risidual oil on the bearings, I don't mind a bit of cranking to get some oil flowing through the engine.

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  #27  
Old 09-19-2025, 02:53 PM
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Originally Posted by grivera View Post
Wow - didn’t realize you have a 3/8” line with that power plant - should definitely be 1/2” supply and return in tank with 255 or 340lph and never have to worry again.
Man, I can literally feel my self-esteem plummeting.

But I know you didn't mean it that way.

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  #28  
Old 09-19-2025, 02:59 PM
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Yeah that's typically why they are run, for the accident based issues.

I'd talk with Tanks Inc about it. I don't know much about them, but it seems like a basic hobs switch, these are commonly run in various applications. Is it possible that the people having issues have them installed in such a way that the issue is presenting itself?

My question is how far do you want to go with this? If the only thing you're worried about is a bit of cranking if the car sits for a while, but otherwise you don't have any fuel starvation issues with your mechanical pump, is the juice worth the squeeze here?

My personal preference, but if my car has sat for a couple weeks and there's no risidual oil on the bearings, I don't mind a bit of cranking to get some oil flowing through the engine.
I don't know but people have suggested that even if I don't have any obvious starvation, it's still happening. I don't know if that only matters for someone who is racing or if would have any noticeable effect in a street only car like mine. So you are running a mechanical pump? I had you pegged for a in-tank guy.

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  #29  
Old 09-19-2025, 03:06 PM
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I don't know but people have suggested that even if I don't have any obvious starvation, it's still happening. I don't know if that only matters for someone who is racing or if would have any noticeable effect in a street only car like mine. So you are running a mechanical pump? I had you pegged for a in-tank guy.
No, I run a FiTech system with an in-tank pump. The EFI controls everything having to do with the fuel system. If the engine stalls, the fuel pump is shut down.

And yes, while you may not "notice" fuel starvation, that doesn't mean it's not happening. There are rich and lean thresholds that the engine will run under. It's possible that your system provides enough fuel that the engine doesn't nose over, but without a wideband, you can't really tell if the engine is singing WOT at 5000rpm while having a 14-15:1 AFR either.

But my point is that if it's not broke, why fix it? If you wanted to move to EFI, you'd pretty much be forced in this direction. If your intention is to keep the carburetor, there's less of a need here, especially if you aren't having any fuel starvation issues.

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  #30  
Old 09-19-2025, 03:49 PM
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I think the Red Holley street pumps are quieter than they use to be. The higher pressure Blue and Black pumps are still noisier though. I would not put a Carter pump to feed a Robbmc, the Carter is a little smaller pump than a Holley. The Holley Red matches up better to the Robbmc.

I have check valves to bypass the Carter pump, which is a kit you can buy. The Carter pumps seem to have the vanes not draw in as easily as the Holley’s for running on just the Mechanical pump.

I just helped a friend put on a Holley Red in series with Carter strip/street Mechanical pump. His electric pump is just on when he arms the NOS system. Otherwise it runs on the mechanical pump all the time, it has 3/8 line, 550+ HP.


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  #31  
Old 09-19-2025, 05:45 PM
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Originally Posted by b-man View Post
10 seconds.

A couple 5 second cranking sessions and you’re there.

I personally don’t see an issue worth spending time and money on.

Carry on.
My Ta unfortunately sits way too long between starts.

When starting my car. I tap the throttle once to set the choke, then spin the engine (while NOT tapping the throttle) for about 5 seconds.

If no cylinders hit, I tap the throttle twice so that the accelerator pump will maybe squirt.

If the accelerator pump squirts, at least a couple of cylinders will hit. It may run then. If not I tap the throttle once and spin engine again. That's usually ALL it takes.

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Old 09-19-2025, 06:39 PM
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No, I run a FiTech system with an in-tank pump. The EFI controls everything having to do with the fuel system. If the engine stalls, the fuel pump is shut down.

And yes, while you may not "notice" fuel starvation, that doesn't mean it's not happening. There are rich and lean thresholds that the engine will run under. It's possible that your system provides enough fuel that the engine doesn't nose over, but without a wideband, you can't really tell if the engine is singing WOT at 5000rpm while having a 14-15:1 AFR either.

But my point is that if it's not broke, why fix it? If you wanted to move to EFI, you'd pretty much be forced in this direction. If your intention is to keep the carburetor, there's less of a need here, especially if you aren't having any fuel starvation issues.
And that's the thing. With no O2 sensor I have no idea. Plus you guys all correctly predicted the future with the 18' wheels and suspension. As you now have said, maybe soon I'll have a sniper TBI sitting on top of a Torker II or something like that.

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Old 09-19-2025, 09:33 PM
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If you’re likely/eventually installing efi, do it right. Install the in-tank pump with a universal bypass regulator like the Aeromotive 13301. It comes with a spring for low psi carb application and a heavy spring for efi. Once you convert to efi, simply install the heavy spring.

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  #34  
Old 09-19-2025, 09:44 PM
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10 seconds.

A couple 5 second cranking sessions and you’re there.

I personally don’t see an issue worth spending time and money on.

Carry on.
Agree, this subject has come up before and I've said the same thing.
We have to ask ourselves what constitutes a crank time that's too long? I see this as pretty normal and just part of old car life. Everyone has gotten used to there new EFI cars I guess.

I figure if you crank 3-4 seconds, stop, pump the throttle a couple times, crank another 3-4 seconds you should be there. That's just not a big deal.

If youre really set on an electric pump, just go all the way and do a tanks inc setup, put it in the tank and be done with it. With a car that has the HP you've mentioned in the past it should honestly already have a solid fuel system like that. A mechanical with 3/8 line isnt going to get it done.

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Old 09-19-2025, 09:51 PM
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This is the solution to the Hobbs switch issue. I've got 58k miles on mine. Works great.

https://www.revolutionelectronics.co...Fuel_Pump.html

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Old 09-19-2025, 09:52 PM
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Originally Posted by grivera View Post
If you’re likely/eventually installing efi, do it right. Install the in-tank pump with a universal bypass regulator like the Aeromotive 13301. It comes with a spring for low psi carb application and a heavy spring for efi. Once you convert to efi, simply install the heavy spring.
Well, so the main reason I changed my mind on the Tanks inc in-tank pump system last time was the fact that the oil pressure cut off switches were said to be of questionable quality and prone to failure. I didn't like that. Then someone mention NOS units but those are harder to come by and getting worse. So that kind of soured me on the whole deal. Maybe I overreacted to that a bit. So I'm reconsidering it now. First I need to know if the switch fails open or closed. That's important. But also, one could easily wire in a bypass switch so that if it fails open, you could literally restore power with the flip of a switch. So unless someone here knows the answer about how they fail, I'll be calling tech support tomorrow to find out. But, if I can wire a bypass switch, then it doesn't really matter. Also, I don't know how important everyone thinks that is. It seems like a good safety feature but also seems like it would be extremely rarely needed. I guess that's just a personal decision.

Oh, that regulator looks nice but Tanks inc also makes a carb pressure regulator for half the price that can be upgraded for EFI pressures for $21. I don't know if the Aeromotive is that much better. Maybe it is?

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  #37  
Old 09-19-2025, 09:58 PM
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Originally Posted by VCho455 View Post
This is the solution to the Hobbs switch issue. I've got 58k miles on mine. Works great.

https://www.revolutionelectronics.co...Fuel_Pump.html
Now that looks like a great solution. Thanks.

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Old 09-19-2025, 10:13 PM
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Thinking about either of these safety switches, either tach based or oil pressure based, when do the come into play? Basically, when the motor stops running. No tach signal means it's not running, no oil pressure means it's either not running or it will be stopping very soon. But how often in an accident does the engine stop running? Probably not if it's a rear or side impact. Maybe not even if it's a front impact, at least not immediately. And if you're running soft lines, then what is the likelihood they're going to fail in any case? So just how important are these devices?

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Old 09-19-2025, 10:46 PM
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I recently did the same as Keith Seymore with a Holley Red in line. 3/8 braided line with under 400 HP. In n out at the bottom of the tank. If my car sits for 3 or for days the QJ fuel bowl dries up and the pusher for priming makes for a quicker start. The mechanical has no problem drawing through it. Typically I only need it when I'm winding it up to 5500 rpm or so. I'll hear it when I'm priming. When driving I won't probably because of the loud exhaust. (my 461 with close to 500 hp has 1/2 line, 550 Robb pump, no pusher, no problems)

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  #40  
Old 09-20-2025, 12:15 AM
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And that's the thing. With no O2 sensor I have no idea. Plus you guys all correctly predicted the future with the 18' wheels and suspension. As you now have said, maybe soon I'll have a sniper TBI sitting on top of a Torker II or something like that.
Modifying your car to the way you want it is the fun part of this hobby! I think a Holley sniper would be great. I’d choose a northwind over a Torker II though. You can still use the shaker with the northwind btw. You just need that drop base deal.

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