1973 Corvette with crate engine
Thread Starter
1st Gear
Joined: Nov 2002
Posts: 1
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From: villa park ca
1973 Corvette with crate engine
Can anyone help me? My son just purchased a 1973 Corvette as a project for the both of us.
The gentlemen who sold it to us replaced the original engine with a crate engine part number 14093638 other numbers on the engine areV0916ZZ1. The engine is presently equipped with an electric fuel pump that is not running very well. We would like to go back to a mechanical fuel pump. The original owner could never get this crate engine to work with a mechanical pump. That is the reason he went to an electric fuel pump. The engine was bought new from Chevy. It came equipped with a push rod for the mechanical pump. It is still in the engine, we could not remove it to check it, it moves freely within the chamber. We tried installing a mechanical fuel pump, but we could not get any fuel pressure. My question is, does this engine take a special fuel pump and secondly how do you replace the push rod.
Any help is sincerely appreciated!
The gentlemen who sold it to us replaced the original engine with a crate engine part number 14093638 other numbers on the engine areV0916ZZ1. The engine is presently equipped with an electric fuel pump that is not running very well. We would like to go back to a mechanical fuel pump. The original owner could never get this crate engine to work with a mechanical pump. That is the reason he went to an electric fuel pump. The engine was bought new from Chevy. It came equipped with a push rod for the mechanical pump. It is still in the engine, we could not remove it to check it, it moves freely within the chamber. We tried installing a mechanical fuel pump, but we could not get any fuel pressure. My question is, does this engine take a special fuel pump and secondly how do you replace the push rod.
Any help is sincerely appreciated!
Drifting
Joined: Mar 2001
Posts: 1,514
Likes: 1
Re: 1973 Corvette with crate engine (mvelilla)
The pushrod can be removed when the fuel pump plate is removed. Just a wild guess, the fuel pump rod is driven by a lobe on the camshaft, possibly that lobe has been damaged and doesn't have enough "lift" to move the fuel pump lever enough. The other possible reason I can think of is the rod is the wrong one and is to short. I've personally never seen either of those situations, but assuming the fuel pump is operational it's the only other possibilities I can think of. This is working on the assumption the fuel line is not blocked in either direction. Hope that gives you some leads to fixing it.
Scott
Scott
Melting Slicks
Joined: Aug 2001
Posts: 3,047
Likes: 124
From: Wichita KS
Re: 1973 Corvette with crate engine (mvelilla)
When you installed the mechanical fuel pump what method did you use to (temporarily) hold the pushrod up in the engine?
Without something to hold it up against the camshaft, the fuel pump pushrod will just slide down until it stops against the fuel pump plate bolted to the side of the block. If you just bolted the mechanical fuel pump on the engine, then its likely that the pushrod will be UNDER the fuel pump lever arm. The pushrod has to push down on the TOP of the fuel pump lever arm in order to actuate the pump.
The 14093638 part number you posted indicates the block is a 350 made between the years 1986-88. It has a one piece rear main seal. You might check the web site "http://www.chevymania.com/casting/BLOCK.HTM" for additional information. I'm not sure what the original application for the engine was, however, I'll bet someone on this forum knows.
As the engine is currently running an electric pump, I would first determine if all the parts you need for the mechanical pump are in place and what the condition of the parts is. Make sure the pushrod is not scored or roughed up, it needs to slide freely.
On my older block (two piece rear main seal) - the sequence of parts from the block outward is: there is a gasket, then a plate (whose purpose is to keep the fuel pump pushrod from sliding out of the engine and dropping on the floor), then another gasket, and lastly the fuel pump.
When I installed my fuel pump I put some vaseline on the end and sides of the pushrod to help temporarily hold it up against the camshaft. Next bolt the gasket and the first plate onto the block. Note: by this time the pushrod has probably slid back down and is resting against the plate. Push the pushrod back up into the block and quickly install the fuel pump making sure that the push rod is on pressing down on the top of the fuel pump lever.
If the camshaft is in the "push down" phase, then the fuel pump will be difficult to bolt on as you are compressing the fuel pump spring. If that's the case, bump the engine around to move the lobe to a "neutral" position. It also helps if you put a little gasket sealant on the fuel pump to tack the gasket onto the fuel pump (fewer things to get out of place).
You might also have a bolt at the front of the block that allows access to the pushrod. If so, you can TEMPORILY insert a longer bolt that will press against the pushrod and hold it in place (replaces the vaseline). Be sure to remove and replace the bolt BEFORE starting the engine. Hope this helps.
Without something to hold it up against the camshaft, the fuel pump pushrod will just slide down until it stops against the fuel pump plate bolted to the side of the block. If you just bolted the mechanical fuel pump on the engine, then its likely that the pushrod will be UNDER the fuel pump lever arm. The pushrod has to push down on the TOP of the fuel pump lever arm in order to actuate the pump.
The 14093638 part number you posted indicates the block is a 350 made between the years 1986-88. It has a one piece rear main seal. You might check the web site "http://www.chevymania.com/casting/BLOCK.HTM" for additional information. I'm not sure what the original application for the engine was, however, I'll bet someone on this forum knows.
As the engine is currently running an electric pump, I would first determine if all the parts you need for the mechanical pump are in place and what the condition of the parts is. Make sure the pushrod is not scored or roughed up, it needs to slide freely.
On my older block (two piece rear main seal) - the sequence of parts from the block outward is: there is a gasket, then a plate (whose purpose is to keep the fuel pump pushrod from sliding out of the engine and dropping on the floor), then another gasket, and lastly the fuel pump.
When I installed my fuel pump I put some vaseline on the end and sides of the pushrod to help temporarily hold it up against the camshaft. Next bolt the gasket and the first plate onto the block. Note: by this time the pushrod has probably slid back down and is resting against the plate. Push the pushrod back up into the block and quickly install the fuel pump making sure that the push rod is on pressing down on the top of the fuel pump lever.
If the camshaft is in the "push down" phase, then the fuel pump will be difficult to bolt on as you are compressing the fuel pump spring. If that's the case, bump the engine around to move the lobe to a "neutral" position. It also helps if you put a little gasket sealant on the fuel pump to tack the gasket onto the fuel pump (fewer things to get out of place).
You might also have a bolt at the front of the block that allows access to the pushrod. If so, you can TEMPORILY insert a longer bolt that will press against the pushrod and hold it in place (replaces the vaseline). Be sure to remove and replace the bolt BEFORE starting the engine. Hope this helps.
Safety Car
Joined: Aug 2001
Posts: 3,683
Likes: 201
From: Waterford Mi
Re: 1973 Corvette with crate engine (mapman)
As long as you take off the plate and fuel pump than you can check the length of travel of the cam lobe by rotating the engine by hand and feeling the push rod movement. It may just be a bad fuel pump.
Le Mans Master
Joined: Jul 2001
Posts: 9,622
Likes: 16
From: absecon nj
Re: 1973 Corvette with crate engine (redwingvette)
actuallythat block was used to 94 ,this is what i would do i would take the fuel pump rod in one hand and have someone crank the motor with coil disconnected and feel if it is going up and down on the lobe,perhaps the cam doesnt have a lobe for the fuel pump rod.The motor is the beginning series of the zz motors,,,as of zz1 at the end of the engine id.If the rod isnt going up and down then its one of 2 things no lobe on it or worn off,id say no lobe on it.It couldve had a optional cam installed when it was ordered.
