Small block V-8 fuel pump push rod install

[Troy P.]

I know I have read how to lock the fuel pump push rod into place for fuel pump removal and installation but I can't find the details anywhere now that I need them.

The procedure is to remove a short bolt that goes into the front of the engine block and temporarily replace it with a longer bolt that contacts the push rod and holds it from sliding down. What are the lengths and thread sizes of the two bolts?

For some reason there is no bolt in the hole now. Seems to be there should be a short bolt to close the hole. Correct?

[Joe L.]

Re: Small block V-8 fuel pump push rod install

I know I have read how to lock the fuel pump push rod into place for fuel pump removal and installation but I can't find the details anywhere now that I need them.

The procedure is to remove a short bolt that goes into the front of the engine block and temporarily replace it with a longer bolt that contacts the push rod and holds it from sliding down. What are the lengths and thread sizes of the two bolts?

For some reason there is no bolt in the hole now. Seems to be there should be a short bolt to close the hole. Correct?

Troy------

1) Turn the engine over so that the pushrod is at its maximum "retracted" position;

2) Remove the short bolt; Install the longer bolt;

3) install the fuel pump;

4) Remove the longer bolt; install the short bolt with sealer on the threads.

If there is no bolt in the tapping I would expect an oil leak of one degree or another. The short bolt is 3/8-16 X about 1/2" (maybe 3/8"). For the long bolt, the length is not critical. It can be anything from about 1-1/4" long or longer. I like to use a brass or nylon bolt to ensure I don't nick the pushrod.

[Troy P.]

Re: Small block V-8 fuel pump push rod install

Joe with the fuel pump installed how would one know if the engine is in such a position that the rod is fully retracted?

Troy------

1) Turn the engine over so that the pushrod is at its maximum "retracted" position;

2) Remove the short bolt; Install the longer bolt;

3) install the fuel pump;

4) Remove the longer bolt; install the short bolt with sealer on the threads.

If there is no bolt in the tapping I would expect an oil leak of one degree or another. The short bolt is 3/8-16 X about 1/2" (maybe 3/8"). For the long bolt, the length is not critical. It can be anything from about 1-1/4" long or longer. I like to use a brass or nylon bolt to ensure I don't nick the pushrod.

[Gary C.]

Re: Small block V-8 fuel pump push rod install

Troy,

The old mechanics trick is to use a small amount of wheel bearing grease on the rod shaft to hold it up while the fuel pump is being reinstalled.

Gary
....

[Troy P.]

Re: Small block V-8 fuel pump push rod install

That's the process described in a few of the resources I've checked and I've used it myself. But I thought the bolt trick was a cleaner solution.

[Joe L.]

Re: Small block V-8 fuel pump push rod install

Joe with the fuel pump installed how would one know if the engine is in such a position that the rod is fully retracted?

Troy------


It's not done with the fuel pump installed. After you remove the old fuel pump, have someone turn the engine over by hand while you keep a finger on the fuel pump pushrod to feel for its most retracted position.

Actually, there is a way to determine it by crankshaft position but I've forgotten that.

[Joe L.]

Re: Small block V-8 fuel pump push rod install

That's the process described in a few of the resources I've checked and I've used it myself. But I thought the bolt trick was a cleaner solution.

Troy------

Grease works most of the time (but, sometimes the rod slides back anyway). The bolt trick works ALL of the time. However, you must be 100% certain to remove the long bolt and replace it with the short one after you finish installation of the pump.

[Joseph C.]

Re: Small block V-8 fuel pump push rod install

Just did this 3 months ago. IIRC set the distributor firing on #1 cylinder. I used grease to pack the rod and hold it up. I had the add fun of it being a factory AC car and got to the bolts via the front wheel well.

Joe

[Michael M.]

Re: Small block V-8 fuel pump push rod install

Troy,

The old mechanics trick is to use a small amount of wheel bearing grease on the rod shaft to hold it up while the fuel pump is being reinstalled.

Gary
....

Actually, grease is more than an old mechanics trick - it was the way it was done in the factory. At the Fremont Plant (Chevelles), the assembly process was to dip the push rod in a pan full of grease and insert it - small blocks and big blocks (which didn't have the shipping bolt). If you look at a Corvette AIM, in the '67 it's UPC 6, Sheet C1, you will see the flag 1H Grease, pointed to the rod.

I've used grease without a problem since my days on the engine line at Fremont, dating back to 1965.

[Troy P.]

Re: Small block V-8 fuel pump push rod install

Other than providing the opportunity to use a long bolt to hold the rod, what is the purpose of that threaded bolt hole in the block? Seems like one needs to put a small bolt in there to keep oil from coming out. But why is it there if even the plant used the grease approach to hold the rod?

[Joe L.]

Re: Small block V-8 fuel pump push rod install

Other than providing the opportunity to use a long bolt to hold the rod, what is the purpose of that threaded bolt hole in the block? Seems like one needs to put a small bolt in there to keep oil from coming out. But why is it there if even the plant used the grease approach to hold the rod?

Troy-----


The hole is there as an attachment point for the front engine mounts used for 55-57 Chevrolet small blocks and all 1955-1962 Corvettes. Even after the front mounts went away, the front mounting points remained on the small blocks produced for many years. The upper right side bolt is a through bolt which goes through to the fuel pump pushrod orifice in the block.

[Troy P.]

Re: Small block V-8 fuel pump push rod install

Well that explains it. You are brilliant, Joe!

Since I used to restore 55-57 Chevy passenger cars and pick up trucks you'd think I'd know that. But I switched to Corvettes many decades ago.

[Mike M.]

Re: Small block V-8 fuel pump push rod install

the 55-62 corvettes used the 4 water pump mounting bolts, not the 4 holes drilled and tapped in the blocks for 55-57 pass cars. mike

[Joe L.]

Re: Small block V-8 fuel pump push rod install

the 55-62 corvettes used the 4 water pump mounting bolts, not the 4 holes drilled and tapped in the blocks for 55-57 pass cars. mike

Mike-----


Yes, that's correct. I mis-spoke.

[Joe L.]

Re: Small block V-8 fuel pump push rod install

Well that explains it. You are brilliant, Joe!

Since I used to restore 55-57 Chevy passenger cars and pick up trucks you'd think I'd know that. But I switched to Corvettes many decades ago.

Troy------

As a matter of fact, Gen I small blocks still produced today(in Mexico) still have the bosses and tappings for the front motor mounts 60 years after their PRODUCTION use ended.