mfg Posted November 10, 2018 Report Posted November 10, 2018 Owners of Chevrolet V8 powered Avantis.......please take time to read the "Fueled Avanti" trivia question elsewhere on this forum........It pertains to poor engine lubrication of the stock mechanical fuel pump used with these engines.
WayneC Posted November 12, 2018 Report Posted November 12, 2018 (edited) While I agree it is good practice to inspect and lube the pump pushrod when installing a fuel pump, the Chevy small block V8 has been produced in the many, many millions and fuel pump pushrod failures have not been an issue so far as I know. The pump is driven by a lobe of the camshaft, which is throwing oil in all directions inside a crankcase full of oil mist. Prolonged periods of not driving the car would probably be a more common reason for failure. Or an internal coolant water leak, or a very, very high mileage engine, or use of vice grips on the pushrod when installing a fuel pump. Also, there is a bolt on the front of the engine that aligns with the pushrod and some folks use a long bolt in that bolt hole snugged against the pushrod to hold it in place while they install a fuel pump, then replace the original bolt; I've always used a dab of heavy grease on the rod to hold it in place while installing the pump. Not an issue that would keep me up nights. Edited November 12, 2018 by WayneC added info
mfg Posted November 12, 2018 Author Report Posted November 12, 2018 7 hours ago, WayneC said: While I agree it is good practice to inspect and lube the pump pushrod when installing a fuel pump, the Chevy small block V8 has been produced in the many, many millions and fuel pump pushrod failures have not been an issue so far as I know. The pump is driven by a lobe of the camshaft, which is throwing oil in all directions inside a crankcase full of oil mist. Prolonged periods of not driving the car would probably be a more common reason for failure. Or an internal coolant water leak, or a very, very high mileage engine, or use of vice grips on the pushrod when installing a fuel pump. Also, there is a bolt on the front of the engine that aligns with the pushrod and some folks use a long bolt in that bolt hole snugged against the pushrod to hold it in place while they install a fuel pump, then replace the original bolt; I've always used a dab of heavy grease on the rod to hold it in place while installing the pump. Not an issue that would keep me up nights. Hello Wayne, and thanks for your reply!.......please understand, the fuel pump push rod is not what's lacking lubrication in small block Chevrolet engines....it's the fuel pump arm and pin, which ride on that push rod, that get very little engine oil lubrication....possibly the only lube they get is the small amount of oil that seeps off of the bottom of the fuel pump push rod! Once again, fuel pump manufacturers have seen failures due to the pump arm and pin not receiving lubrication from inside the engine, hence they recommend packing the replacement fuel pump operating arm 'cavity' with grease prior to install!
Avanti83 Posted November 12, 2018 Report Posted November 12, 2018 I've found this an interesting discussion. It's been a number of years since I installed a mechanical fuel pump on an SBC engine but I've done a fair number and I can't remember either finding instructions or advice that said to pack the pump body with grease. Greasing the push rod prior to installation is the old trick to keep it in-place. As I'm currently in a position to surf the net. I've Googled any number of word combinations on packing the pump prior to installation but I've come up with nada. Airtex has a video that covers installation 68-88 Sbc's, no mention and Holley, Edelbrock and the others I've found don't mention it either. Here's what TSP says on their copy. https://www.topstreetperformance.com/media/pdf/Mechanical_Fuel_Pump_Installation_Instructions.pdf The internet mentions it occasionally but generally as opinion not published fact. A good idea, I guess but 10's of millions ran without lube for years. I guess opening a box from Cardone with a pump in it could be educational but now way to do that currently.
mfg Posted November 12, 2018 Author Report Posted November 12, 2018 The fuel pump I installed on my '83 Avanti in June of this year is a Federal-Mogul (Carter ) pump. This manufacturer recommends packing the fuel pump 'arm' cavity with heavy (wheel bearing) grease prior to installation.....The grease helps keep the arm and pin lubricated during operation. Hope this information helps!
Avanti83 Posted November 13, 2018 Report Posted November 13, 2018 Good data, now does Carter say that for just SBC or all mechanical pumps? Can't find anything on the Carter Website.
mfg Posted November 13, 2018 Author Report Posted November 13, 2018 (edited) On 11/12/2018 at 7:47 PM, Avanti83 said: Good data, now does Carter say that for just SBC or all mechanical pumps? Can't find anything on the Carter Website. At work today, my computer savvy (and smart phone equipped!) technician friends 'googled' for information concerning this issue of "packing the pump"! As it turns out, on the "GM Motors Forum" (.com?) and the "Team Camaro" (Camaros.net) there were two inquiries which mentioned the owners had purchased ( ACDelco) replacement mechanical fuel pumps...one for a Corvette the other for a Camaro, they both came with instructions to fill the fuel pump's operating arm cavity with thick grease before installation. There really is no question that engine lubrication to this rather critical area is poor (at best). PLAY IT SAFE!!....Next time you replace a mechanical fuel pump OF ANY BRAND on a small block Chevrolet V8.........."PACK THE NEW PUMP"......Ed Edited November 14, 2018 by mfg
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