Fuel Pump Replacement?
#21
Drifting
Thread Starter
I was referring to some GM FPs. They come in different prices. The more expensive mech FP have a higher gph rating.
I have AC and I'm going in from under the motor.
I just bought some PB blaster, see how that works?
Thanks for the suggestion.
R
I have AC and I'm going in from under the motor.
I just bought some PB blaster, see how that works?
Thanks for the suggestion.
R
#22
Le Mans Master
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#24
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Remember, as soon as you get the pump plate off the pump pushrod will try to fall out. That's where the bolt on the front of the block helps. You remove the short bolt, install a longer one with exact diameter and threads. Just snug it. It will hold the pushrod in place for you when you install the new pump. After work is done, replace with the shorter bolt.
#25
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Crank It Over To #1 TDC Before Removing Fuel Pump
Remember, as soon as you get the pump plate off the pump pushrod will try to fall out. That's where the bolt on the front of the block helps. You remove the short bolt, install a longer one with exact diameter and threads. Just snug it. It will hold the pushrod in place for you when you install the new pump. After work is done, replace with the shorter bolt.
But before you remove the fuel pump crank your engine over to #1 TDC and that'll position the fuel pump cam lobe directly away from the fuel pump push rod (for small blocks AND big blocks). Very few people know this so remember it from now on.
Last edited by 71VetteLover; 10-02-2017 at 08:14 PM.
#26
Drifting
Thread Starter
Sorry, I meant PSI.
Here is the cheap FP
Fuel Type: Gasoline
Free Flow Rate: 80
Maximum Pressure: 6 psi
Inlet Size: 1/4" NPT
Outlet Size: 1/4" NPT
Inlet Attachment: Female Threads
Outlet Attachment: Female Threads
Material Type: Aluminum
The 6 psi was $25
UPC: 090127484012
Free Flow Rate: 170 gph
Maximum Pressure (psi): 8 psi
Inlet Attachment: Female threads
Inlet Size: -8 AN O-ring
Inlet Quantity: One
Outlet Attachment: Female threads
Outlet Size: -8 AN O-ring
Outlet Quantity: One
Gasket Included: Yes
Quantity: Sold individually.
This the Holley $135
Not sure how many HP 6 psi can feed.
I would think 350 hp?
Here is the cheap FP
Fuel Type: Gasoline
Free Flow Rate: 80
Maximum Pressure: 6 psi
Inlet Size: 1/4" NPT
Outlet Size: 1/4" NPT
Inlet Attachment: Female Threads
Outlet Attachment: Female Threads
Material Type: Aluminum
The 6 psi was $25
UPC: 090127484012
Free Flow Rate: 170 gph
Maximum Pressure (psi): 8 psi
Inlet Attachment: Female threads
Inlet Size: -8 AN O-ring
Inlet Quantity: One
Outlet Attachment: Female threads
Outlet Size: -8 AN O-ring
Outlet Quantity: One
Gasket Included: Yes
Quantity: Sold individually.
This the Holley $135
Not sure how many HP 6 psi can feed.
I would think 350 hp?
#27
Le Mans Master
6 psi will more than cover about anything you can throw at it. It's not to likely you'll be running 6500 RPM for more than a few seconds at a time. 80 gallons per hour is a pretty good volume. Save the $110 difference for other goodies.
#28
Drifting
Thread Starter
R
#29
Le Mans Master
Maybe, but I wouldn't count on it. The only difference is the spring(s) in the relief valves are bigger. The diaphragm is going to be pretty much the same stuff.
I replaced the original pump on my 69 in 2006 because the weep hole looked like it had some stains around it. That pump was delivered with the car, and saw service with the original 427/435 engine, an L-88, a bone stock 454 out of a Caprice, and finally an LS-7. Never once had a fuel delivery problem. The pump I put on is a basic BBC pump with an inlet and an outlet. And it's feeding a 496 now.
I replaced the original pump on my 69 in 2006 because the weep hole looked like it had some stains around it. That pump was delivered with the car, and saw service with the original 427/435 engine, an L-88, a bone stock 454 out of a Caprice, and finally an LS-7. Never once had a fuel delivery problem. The pump I put on is a basic BBC pump with an inlet and an outlet. And it's feeding a 496 now.
Last edited by TimAT; 10-03-2017 at 07:36 PM.
#30
Drifting
Thread Starter
This is something I am interested in. There has to be a reason race teams try to keep the fluids cool. I have always wondered about an engine that runs 20* cooler water, fuel and oil. I'm thinking there is some tuning to be done. Perhaps more comp and or ign lead?
I have heard of 40* for this product.
This Seals-it product originated in conjunction with Robert Yates Racing, and after months of research and design changes, and a year of actual racing, Seals-it introduced a fuel pump seal for Ford and GM applications.fuel-pump-image
The fuel pump seal designed for the Robert Yates Belt Drive system was developed to contain lubrication inside the fuel pump cavity in order to lubricate the pump arm.
Seals-it fuel pump kit is designed to keep hot engine oil in the engine and out of the fuel pump.
Centrifugal force throws the hot oil into the fuel pump housing, causing oil leaks and transfer of more heat to the fuel.
Our insulating gasket and sleeved insulated bolts, cut down on the engine heat transferred to the pump to reduce fuel temperature.
I have heard of 40* for this product.
This Seals-it product originated in conjunction with Robert Yates Racing, and after months of research and design changes, and a year of actual racing, Seals-it introduced a fuel pump seal for Ford and GM applications.fuel-pump-image
The fuel pump seal designed for the Robert Yates Belt Drive system was developed to contain lubrication inside the fuel pump cavity in order to lubricate the pump arm.
Seals-it fuel pump kit is designed to keep hot engine oil in the engine and out of the fuel pump.
Centrifugal force throws the hot oil into the fuel pump housing, causing oil leaks and transfer of more heat to the fuel.
Our insulating gasket and sleeved insulated bolts, cut down on the engine heat transferred to the pump to reduce fuel temperature.
#31
Drifting
Thread Starter
Finally got the bolts out. I had to find a 12 pt wrench and got 1/16 turn at a time. Now that the FP is out, I'm thinking about some proper fuel line.
What else can be done "While I'm in there?"
I am going to try the FP insulator, it can't hurt to have cooler fuel.
I will resist the higher pressure pumps and stick w/stock! lol
What else can be done "While I'm in there?"
I am going to try the FP insulator, it can't hurt to have cooler fuel.
I will resist the higher pressure pumps and stick w/stock! lol
#32
Pro
Member Since: Sep 2017
Location: Modesto California
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Maybe, but I wouldn't count on it. The only difference is the spring(s) in the relief valves are bigger. The diaphragm is going to be pretty much the same stuff.
I replaced the original pump on my 69 in 2006 because the weep hole looked like it had some stains around it. That pump was delivered with the car, and saw service with the original 427/435 engine, an L-88, a bone stock 454 out of a Caprice, and finally an LS-7. Never once had a fuel delivery problem. The pump I put on is a basic BBC pump with an inlet and an outlet. And it's feeding a 496 now.
I replaced the original pump on my 69 in 2006 because the weep hole looked like it had some stains around it. That pump was delivered with the car, and saw service with the original 427/435 engine, an L-88, a bone stock 454 out of a Caprice, and finally an LS-7. Never once had a fuel delivery problem. The pump I put on is a basic BBC pump with an inlet and an outlet. And it's feeding a 496 now.
After I installed my Carter 100 gph electric fuel pump for my beefed 454" I ran some tests to see how much fuel it would consume at 5500 rpm at wide open throttle and to see if the new pump would maintain 6 psi all the way up. Here's what my test results were:
1. The pump free flowed 52 gph at the carburetor which was too much for my OEM 1/4" return line to handle. As such it was producing 9 psi with that 1/4" line. I installed a 5/16" return line and increased the size of the nipple in the tank to 5/16" and that dropped the pressure to 5.5 psi.
2. At 5500 rpm under a full throttle my 454" consumed 53 gph and the pressure dropped to 5 psi so it was slightly out-running my fuel pump. I increased the inlet line to a 1/2" hydraulic hose and that produced a free flow of 55 gph which was 2 gph more than my engine needed (but just barely more).
3. To increase the pressure to an even 6 psi I sweat soldered a 1/2" long piece of 1/4" steel tubing into my 5/16" return line where it left the carburetor (a #3310 Holley converted to a model 4150).
4. With the 1/2" inlet hose and the 5/16" return hose my fuel pump will maintain 6 psi all the way to 6000 rpm under a full throttle. If I had a larger 502" built to the same level of performance it's clear the 100 gph pump wouldn't be quite big enough to feed it.
#33
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As you saw, Taijutsu, hot oil does not really go into the fuel pump housing as stated in post #30. Insulated bolts? After months of research? GM had decades of research! Sounds like a info commercial at three in the morning. Take all that info with a grain of salt.
Anyway if you are that concerned about "cooled fuel" that's what in-the-tank-pumps are for. However, because of the unusual high temps in a C3 engine bay, anything that will reduce fuel temps is a bonus. Summit has some insulated fuel lines. Or insulated sleeves to fit your exsisting lines. Stick with the stock pressure pump. Don't worry about the heat at the pump, just the heat on the way to the carb.
While I'm at it? Change the "S" hose. Only Vette vendors seem to sell them.
ps. When I removed my fuel pump plate, all of three maybe four drops of oil came out. Stop the madness.
Anyway if you are that concerned about "cooled fuel" that's what in-the-tank-pumps are for. However, because of the unusual high temps in a C3 engine bay, anything that will reduce fuel temps is a bonus. Summit has some insulated fuel lines. Or insulated sleeves to fit your exsisting lines. Stick with the stock pressure pump. Don't worry about the heat at the pump, just the heat on the way to the carb.
While I'm at it? Change the "S" hose. Only Vette vendors seem to sell them.
ps. When I removed my fuel pump plate, all of three maybe four drops of oil came out. Stop the madness.
Last edited by HeadsU.P.; 10-08-2017 at 06:22 PM.
#35
Drifting
Thread Starter
#38
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The "S" hose as it is labeled is only sold by Vette venders. You are not likely to find it at a local parts store. Its pre-bent and the correct size. If you try to bend a store bought hose into an "S" it will kink, don't do it. Try Willcox, Corvette Central, Corvette America or maybe Ecklers? Its called C3 fuel pump "S" hose.