ZZ454:2 questions
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Instructor
Joined: Mar 2007
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From: Cataumet MA
ZZ454:2 questions
Getting ready to install Crate ZZ454 in my !973 coupe. Just noticed two things.
First, the oil pan on the ZZ454 is about two inches deeper than the original 454. Doesn't seem to be a problem for installation, but I'm not so sure that I'll have sufficient pan to ground clearance for the street. If anyone is running this combo, maybe you'll give me a heads up on whether to keep the ZZ pan, or use the original 454 pan. The trans is a TKO 600.
Second, the fuel pump is the original, and 35 years old, so it will be replaced with a new mechanical pump. The GM Performance Parts pump, and all the aftermarket pumps that I have looked at, only have one inlet and outlet of 3/8". The original has the 3/8" in and out PLUS the fuel vapor return line to the tank. Do I need that vapor return line for everything to operate properly, or is it strictly an emmisions item?
Thanks for any input that you might have on this!
First, the oil pan on the ZZ454 is about two inches deeper than the original 454. Doesn't seem to be a problem for installation, but I'm not so sure that I'll have sufficient pan to ground clearance for the street. If anyone is running this combo, maybe you'll give me a heads up on whether to keep the ZZ pan, or use the original 454 pan. The trans is a TKO 600.
Second, the fuel pump is the original, and 35 years old, so it will be replaced with a new mechanical pump. The GM Performance Parts pump, and all the aftermarket pumps that I have looked at, only have one inlet and outlet of 3/8". The original has the 3/8" in and out PLUS the fuel vapor return line to the tank. Do I need that vapor return line for everything to operate properly, or is it strictly an emmisions item?
Thanks for any input that you might have on this!
Melting Slicks
Joined: Feb 2004
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From: State of Confusion!!!
2018 C2 of Year Winner
You need a low pro pan. Moroso makes a 6qt pan. Just make sure to check the corners for a good fit. You may need to use some RTV goop. Ask me how I know!!!!
Ditch the return line. You will be driving this at full throttle all the time anyway!!!
Ask me how I know that, too!!!!!
You are gonna LOVE that engine. I put 3.73's in the rear, and it really woke up!!! Happy trails!!!
Ditch the return line. You will be driving this at full throttle all the time anyway!!!
Ask me how I know that, too!!!!!You are gonna LOVE that engine. I put 3.73's in the rear, and it really woke up!!! Happy trails!!!
Last edited by DIP51; Aug 6, 2007 at 09:32 PM.
Thread Starter
Instructor
Joined: Mar 2007
Posts: 103
Likes: 8
From: Cataumet MA
You need a low pro pan. Moroso makes a 6qt pan. Just make sure to check the corners for a good fit. You may need to use some RTV goop. Ask me how I know!!!!
Ditch the return line. You will be driving this at full throttle all the time anyway!!! Ask me how I know that, too!!!!!
You are gonna LOVE that engine. I put 3.73's in the rear, and it really woke up!!! Happy trails!!!
Ditch the return line. You will be driving this at full throttle all the time anyway!!!
Ask me how I know that, too!!!!!You are gonna LOVE that engine. I put 3.73's in the rear, and it really woke up!!! Happy trails!!!
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
if you have both engines in front of you, see if the new one has a one piece rear main seal, if so, the pans are different.
the fuel return line is for fuel, not vapor, and is not an emmisions item. hook it up and you will have less problems
the fuel return line is for fuel, not vapor, and is not an emmisions item. hook it up and you will have less problems
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
I put a zz4 in my vette but it is a small block. My original fuel pump had a return line for fuel. My new GM pump has an inlet & outlet but no return fuel outlet. I plugged the return line but at the vapor canister I also had a return line that needs to breathe. When I capped it the fuel gauge needle moved all over the place.
Melting Slicks
Joined: Feb 2004
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From: State of Confusion!!!
2018 C2 of Year Winner
Thread Starter
Instructor
Joined: Mar 2007
Posts: 103
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From: Cataumet MA
Thanks for the input. I'll swap mine just as you did. I thought that I might be able to do it, but I don't have both pans off yet to compare.
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Thread Starter
Instructor
Joined: Mar 2007
Posts: 103
Likes: 8
From: Cataumet MA
Thanks again!
Burning Brakes
Joined: Feb 2006
Posts: 1,024
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From: AL
Actually, it shows that line in the Service Manual as a vapor return line. It turns out that I had disconnected it when I replaced my fuel tank a number of years ago. You may be thinking of the fuel return line on fuel injected engines. I never had any problems without it.
Thanks again!
Thanks again!
Thread Starter
Instructor
Joined: Mar 2007
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From: Cataumet MA
this is what i initally thought too, but this subject was touched several times on the forum; a search may turn them up. to be clear, we are talking about the "return line" on the passenger side of the car from the factory mechanical fuel pump back to the fuel tank which runs next to the fuel supply line. someone posted a pic of a factory fuel pump cut apart. the return line starts out as an orifice (or the swaged end of a tube) inside the pump. the measured orifice or opening of the tube was about the right size to act as a by-pass or return. i had issues at first with the return discharging to the top of the tank, but the flow rate is slow enough that it isn't a problem. others indicated that they could hear the return fuel spilling into the tank with the engine running and gas cap off.
Burning Brakes
Joined: Feb 2006
Posts: 1,024
Likes: 1
From: AL
the last engine transplant resulted in no return line, and so far so good here as well. i am looking for the best way to accomplish the return line with the new elec pump in the rear.
if i could use a mechanical pump, i'd go back with the return line if possible. if yours has no issues without - keep on going; just file it for future reference in case a hard start or whatever other issue it can cause pops up . . .
if i could use a mechanical pump, i'd go back with the return line if possible. if yours has no issues without - keep on going; just file it for future reference in case a hard start or whatever other issue it can cause pops up . . .