[Dustya]

Currently collecting data on the Fuel pumps to try to find a compatible upgrade for us. If anyone has any information please feel free to provide it.

2.0T - Ac Delco - HPM1015
Inlet Header Length 4.500 MM
Connection Type Female
Mounting Hardware Included Yes
Gasket or Seal Included Yes
Housing Material Stainless Steel
Maximum Flow Rating 37
Inlet Diameter 0.177
Inlet Diameter 4.500 MM
Inlet Type Female Threaded
Outlet Type Female Threaded
Outlet Quantity 1
Outlet Diameter 0.177
Outlet Diameter 4.500 MM
Mount Hole Quantity 2

By design Our pump is very similar specs wise I have no clue.

3.6L - HPM1027 I cannot find technical data on our pump but.. This Ac delco pump is used in about 50 different applications and is direct replacement for All 16 17 3.6l LGX applications Buick Cadillac and Chevrolet

Our pump is used in the CT6 3.0tt LGW Application as well.


6.2L - ACDELCO HPM1035
Mounting Hardware Included Yes
Gasket or Seal Included Yes
Housing Material Stainless Steel
Inlet Diameter 0.374
Inlet Diameter 9.5 mm
Inlet Type Tube
Outlet Type Threaded
Outlet Quantity 1
Outlet Diameter 0.551
Outlet Diameter 14 MM
Mount Hole Quantity 2

6.2l Zl1 - ACDELCO HPM1036

By Design the SS and LT4 Pumps are much different then the 2.0t and the 3.6l I do not believe we could swap out for either of these.


Cadillac ATS-V 2 parts # found ACDELCO HPM1013 and ACDELCO HPM1030

Data for the HPM 1013
Inlet Header Length 6.400 MM
Connection Type Female
Mounting Hardware Included Yes
Gasket or Seal Included Yes
Housing Material Stainless Steel
Maximum Flow Rating 41
Inlet Diameter 0.251
Inlet Diameter 6.400 MM
Inlet Type Male Quick Connect
Outlet Type Female Threaded
Outlet Quantity 1
Outlet Diameter 0.251
Outlet Diameter 6.400 MM
Mount Hole Quantity 2

By Design these are very similar to the 2.0t and the 3.6l pumps. And there is a possibility the ATS-V could be a direct Swap need to find more technical data on our fuel pump first.


As with all Ac delco parts there seems to be alot of confusion with alternate part numbers and data I am starting this thread to record and update all the information I find.

[Jason@JacFab]

Good info, thanks for posting!

I guess let me add to this as its fuel related, I measured the stock stroke on the 2.0 HPFP at .300"... I measured the lift on the fuel pump lobe on the camshaft that drives the pump at .160"... This leaves about .14" of available stroke left in the pump... Now ZZP currently sells their "upgraded" 2.0 camshafts with a total lobe lift of .200" stroke. (still leaving .100" of stroke avaiable")... NOW you obviously don't want to attempt to take up that whole .300" of stroke available in the pump as it could be put in a coil bind situation and you'll probably break something, BUT a guy could probably take it up to say .23-.25" of usable stroke in theory.

You'd have to do some research on the LGX pump, and fuel pump lobe to get some numbers, but theoretically if numbers allow (similar to mine above, you know), could have someone regrind the fuel pump lobe of the cam shaft, and remove material out of the base circle to get that additional pump stroke out of it.

The fuel pump lobe on the LGX looks to be a 3 lobe, design? where as the LTG is a 4 lobe (its basically a square on the camshaft)... It took me a while but I finally found a place that can theoretically regrind the LTG cams for me, but more importantly, they can do the fuel pump lobe, removing material from the lowest point before the next ramp, to increase the fuel pump stroke. I should have my cams back within the next 1-2 weeks... If it works out for me, it may be doable on the 3 lobe LGX cam to gain you some more headroom in the fuel department.

[Dustya]

Originally Posted by Jason@JacFab

Good info, thanks for posting!

I guess let me add to this as its fuel related, I measured the stock stroke on the 2.0 HPFP at .300"... I measured the lift on the fuel pump lobe on the camshaft that drives the pump at .160"... This leaves about .14" of available stroke left in the pump... Now ZZP currently sells their "upgraded" 2.0 camshafts with a total lobe lift of .200" stroke. (still leaving .100" of stroke avaiable")... NOW you obviously don't want to attempt to take up that whole .300" of stroke available in the pump as it could be put in a coil bind situation and you'll probably break something, BUT a guy could probably take it up to say .23-.25" of usable stroke in theory.

You'd have to do some research on the LGX pump, and fuel pump lobe to get some numbers, but theoretically if numbers allow (similar to mine above, you know), could have someone regrind the fuel pump lobe of the cam shaft, and remove material out of the base circle to get that additional pump stroke out of it.

The fuel pump lobe on the LGX looks to be a 3 lobe, design? where as the LTG is a 4 lobe (its basically a square on the camshaft)... It took me a while but I finally found a place that can theoretically regrind the LTG cams for me, but more importantly, they can do the fuel pump lobe, removing material from the lowest point before the next ramp, to increase the fuel pump stroke. I should have my cams back within the next 1-2 weeks... If it works out for me, it may be doable on the 3 lobe LGX cam to gain you some more headroom in the fuel department.

Good information thank you! as I have been researching what the ats-v guys have been doing seems just a cam lobe that gives them 10-15% more and methanol no know upgraded fuel pump for them as far as I could find. Just seems crazy!

The whole grinding the cam lobe etc.. is def not in the realm of my knowledge. I would probably go ahead and purchase an OEM one to have sent out.

Please forgive my ignorance here so the idea is to get the pump to open more ? in my head it worked the other way around push it in further giving it more pump effect.. But I guess the idea works both ways.. and the whole grinding makes more sense.

Also was spying on your LTG Site gonna try out some of your TCM tricks.

[DSX_Camaro]

Back from when GretchenGotGrowl's car was a thing, he used the LF3 or LF4 HPFP in his LFX and it supplied him with enough fuel, I think, for his 600+whp current target. It needed like a Ferrari lash cap (you might be able to pm Rhino GPI I think it was) but if you are so lucky as to be able to use it, I would definitely say try that route. Not super hopeful though.

[Jason@JacFab]

Originally Posted by Dustya

Good information thank you! as I have been researching what the ats-v guys have been doing seems just a cam lobe that gives them 10-15% more and methanol no know upgraded fuel pump for them as far as I could find. Just seems crazy!

The whole grinding the cam lobe etc.. is def not in the realm of my knowledge. I would probably go ahead and purchase an OEM one to have sent out.

Please forgive my ignorance here so the idea is to get the pump to open more ? in my head it worked the other way around push it in further giving it more pump effect.. But I guess the idea works both ways.. and the whole grinding makes more sense.

Also was spying on your LTG Site gonna try out some of your TCM tricks.

Definitely just try to have an oem cam fuel lobe reground. If this current company im working with works out for me and they can actually do it, i might be able to have them do a cam for the LGX also?

The pump doesn't really "open" per say, think of it like a small engine, or compressor... It has a piston inside of it, and the fuel pump lobe makes it go up and down... So like a STROKER motor, if you increase the stroke, it will increase the output. OR like some of the other GDI people out there are doing, if you can disassemble , bore it out and put a bigger piston in it, again more output (ie BIG BORE) motor.

I know the LTG HPFP can't be disassembled, its a welded unit. Not sure about the LGX? I know that an LFX pump can be disassembled. I also think that LT1 pump comes apart, as Lingenfelter offers one with a bigger piston thats like $1500, call it a big bore, its a direct replacement for an LT1/4, they claim it flows 30% more fuel than a stock LT1 pump, and 10% more than a stock LT4 pump.

[Dustya]

Originally Posted by Jason@JacFab

Definitely just try to have an oem cam fuel lobe reground. If this current company im working with works out for me and they can actually do it, i might be able to have them do a cam for the LGX also?

The pump doesn't really "open" per say, think of it like a small engine, or compressor... It has a piston inside of it, and the fuel pump lobe makes it go up and down... So like a STROKER motor, if you increase the stroke, it will increase the output. OR like some of the other GDI people out there are doing, if you can disassemble , bore it out and put a bigger piston in it, again more output (ie BIG BORE) motor.

I know the LTG HPFP can't be disassembled, its a welded unit. Not sure about the LGX? I know that an LFX pump can be disassembled. I also think that LT1 pump comes apart, as Lingenfelter offers one with a bigger piston thats like $1500, call it a big bore, its a direct replacement for an LT1/4, they claim it flows 30% more fuel than a stock LT1 pump, and 10% more than a stock LT4 pump.

I might just order a OEM fuel pump.. I read your thread on the LTG pump and it being welded..But even if the LGX can be taken apart where would I even find a bigger piston for it or would it have to be made ? as for the CAM let me know ill happily purchase one to send out.

[Jason@JacFab]

Originally Posted by Dustya

I might just order a OEM fuel pump.. I read your thread on the LTG pump and it being welded..But even if the LGX can be taken apart where would I even find a bigger piston for it or would it have to be made ? as for the CAM let me know ill happily purchase one to send out.

I’m guessing it would have to be made, OR possible a larger one from a different hpfp could be used? But then you’d be buying 2 (expensive?) pumps just to make one, and I’m assuming you’d still have to bore out the lgx pump somehow to work with the larger piston. Maybe I’ll look for a cheap used LT1 hpfp on eBay and see what’s involved in doing such a thing, as we know it comes apart.

I’ll keep you posted on the cam thing.



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[Jason@JacFab]

I just bought an Lt1 hpfp off of ebay. Not for i4 or v6 purposes per se, but I will be taking it apart, attempting to replicate something similar to the LPE big bore pump, and sending it to a guy with a ZL1.

Will be a good learning experience for future i4 / v6 stuff.

[Jason@JacFab]

It would seem that many companies are modifying the Lt1 and LT4 fuel pump to fit smaller engines after doing some research. I received my LT1 pump and have already started modifying it, of course I'll do the LTG first since I've got a bunch of them laying around here, but I can also do one for the LFX as I still have a spare LFX engine. I'd need an LGX fuel pump to take measurements off of to make one fit that.