Can I install a new 1976 fuel pump on my ZZ4 motor installation and do I need a push rod as well? I reason I said NEW fuel pump is because I ordered one once I realized the there were two tubes comming from the pump as well as the fitting to the carb. I don't know why there are two but one is smaller and connects to a line returning to the tank. Is this to provide some pressure to the tank driven off of the pump or what?. Anyway in order to connect to the two tubes I guess I have no other option than to use the original design.....correct? Will it provide enough pressure for the ZZ4 w/750 holley?

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carl

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Best to my knowledge, a standard side block fuel pump will work for you.  In my 78, the previous owner had a NO2 plate, so he had an electric Holley Blue pump under the rear bumper.. i just stayed with it, the main line went up to a regulator in the engine compartment, and the return line is blocked off, its simply a return line off the pump, guess it helps relieve some pressure when the fuel demand is not enormous(probably helps the pump last a little longer??)... as for the stock pump, it will provide enough pressure for a 750 holley.. or Q-jet... most fuel pumps are around 5 to 8 psi...  :) (dad's '76 has a standard pump with a 750 Edlebroke...seems to work just fine)...

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StingrayJim
NCM Lifetime Member #1936

Stingray's '76���������������������������� StingrayJr's '78���������������������������Lil Red '94

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The small line is a return line.  They were used to provide a certain amount of recirculation to prevent vapor lock.  The ZZ4 does have a cam to drive the fuel pump, so with a plate and push rod, you should be able to connect to your existing lines.  The important measure of a fuel pump is whether it pumps enough volume to feed the carburetor.  A ZZ4 is so much more efficient than your original engine it probably doesn't use much more gas.  In any case I have seen many Corvettes with ZZ4s and happy owners.

Larry

Thanks for the responces guys!

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carl

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HUH?
Make sure the engine you have HAS a place for a mechanical pump. Ya never know.
When Speilman's pump took a dump in Hot Springs, we replaced the fancy-shmancy polished one that came on his engine when he bought it with a plain-jane replacement pump for a '76. Worked just fine. We did have to do a little creative plumbing, but it apparently got him home safely!
Does the engine you got have the fuel-pump plate on the pass side of it? If it does NOT, then it won't have the pushrod either. If it does have the plate, it prolly does have a rod. I'm talking about a regular pump plate...not a block-off plate. Either way, you can remove the plate and look to see if there is a p-rod in there. You WILL need the p-rod if you use a mechanical pump. There's no other way for the pump to work.

hth

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Joel Adams
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My new motor came with two red plastic plugs installed in the fuel pump cavity. No Plate, just the two threaded holes for the fuel pump bolts. I will have to check with the GM Engine Depot to see if the push rod was installed or not. When I removed the red plastic plugs nothing came out or dropped that I remember.

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carl

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I got a reply from the GM rep on the ZZ4 and he stated that I will have to buy a push rod or use the one from my old motor. So I ordered the mounting plate, push rod and gasket from Corvette Central to go with the fuel pump and mounting bolts I already ordered from them. I guess I should have figured all this out but now I know.

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carl

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Be sure to put some assembly lube on the ends of the push-rod before inserting it...this will keep it from galling the cam, or the fuel pump lever. You can get a small tube of this at any parts house...it's used for building engines. Lubriplate is the most common brand. Adams' Apple2008-06-05 10:03:03

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Joel Adams
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Good Idea I will also place some heavy grease on the rod to hold it up while I install the pump but if that dosen't work I will try that method of installing a longer bolt in the engine block to hold the rod in place while I install the pump. It would have been easier if I could of done this all with the engine out of the car but I have learned that I couldn't install the motor mount bolts to the frame with the pump in the way and would have to remove it anyway.

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carl

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Mission accomplished in only two attempts! I got the fuel pump installed last weekend and found only one issue that I had to deal with besides the push rod wanting to drop down before I got the pump bolt installed.

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carl

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Congrats on a job well done!!!

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Joel Adams
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There is a bolt in the front of the block that can be removed and replaced with a longer bolt that will go in and contact the fuel pump push rod, and hold it up while installing the fuel pump.   Then remove that bolt and put the original back in. 

grease is the word..is the word..is the word...

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StingrayJim
NCM Lifetime Member #1936

Stingray's '76���������������������������� StingrayJr's '78���������������������������Lil Red '94

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AH, thanks guys. I'm currently biulding a motor (slowly) and haven't got there yet, so, I'll be ready for this one.

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Jimmy B.
Just can't wait to get on the road again.

 
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[QUOTE=kstyer]There is a bolt in the front of the block that can be removed and replaced with a longer bolt that will go in and contact the fuel pump push rod, and hold it up while installing the fuel pump.   Then remove that bolt and put the original back in. [/QUOTE]

Well, normally, yeah...but....the ZZ4 doesn't have the hole. Actually, the boss is there, and there is a hole drilled/tapped, but it doesn't go all the way thru the block to the pump rod. This is apparently true on several of the later "crate" engines...the holes are there, but they just don't go thu like the older engine blocks do.
I verified this in Hot Springs when we changed the fp on Spielman's car... His engine also had a unique pump rod...it wasn't steel...it was super light-weight, like titanium or something....weird. I had to remove the pump plate to get the rod pushed back up, and since it was so lightweight, it stayed up all by itself!

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Joel Adams
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This may be a dumb thought or question.

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GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.

Excellent question sarge . A billet cam (as used on the roller cam application) won't tollerate the the hard metal drive gear on the stock distributor, so, it makes sense it might need a special composition fuel pump drive rod since it's not roller ???? Where do I get one? I'm building "this" motor currently, still working on the valve train, but I'm gettin' to the fuel pump soon. What a stroke of luck that this subject came up now  . aceinthehole2008-07-03 20:24:36

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Jimmy B.
Just can't wait to get on the road again.

 
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After doing some research on the good 'ol internet, it seems the consensus is to use a bronze tipped FP pushrod on billet roller cams.

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GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.

How the heck does a roller tipped pushrod work in that position? What keeps it from spinning?
Sounds like a great idea, and should add a little HP with the drag removed from the cam, much the same as roller lifters. I'mma gonna have to do a little searchin myself, now...I'm curious!


Well, I went to Comp Cams' web-site, but...the pic is the exact same for all of the p-rods they list! Not much help there! Adams' Apple2008-07-04 07:29:02

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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Thanks for the part #s Sarge. I had to buy the dist. drive gear for Comp. cams also, very pricey, but they make the best one....AND JOEL, if you come up with any more info on these rods, I'd sure appreciate the education. ...Thanks guys

TEAM C3VR.....   

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Jimmy B.
Just can't wait to get on the road again.

 
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So now that I installed the standard FP push rod in my ZZ4 do I have to change it to a bronze tip push rod or can I leave it as is? Will the standard push rod ruin my cam for sure and if so what is the sence of urgency to replace it? Can I drive it as is for awhile? Other guys must have used the standard rod in thier ZZ4 as no mention of using the special push rod was in the installation for the GM manual.

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carl

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Sorry Carl, I don't have any more info at the moment ( and I'm at work ).  While, I was aware of the special dist. drive gear, I never considered the fuel pump rod either. This is my first time building a roller motor. A call to the Tech. guys at Comp. Cams, Summit, or Jegs could answer that quickly.

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Jimmy B.
Just can't wait to get on the road again.

 
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I contacted the tech rep at GM engine depot where I bought the ZZ4 and he said my standard steel push rod is just fine. He did mention the hardend gear for the distributer was required if I used my existing stock distrbuter. So with that info I will use the push rod that I installed. Thanks for asking the question as you got me thinking and that I needed to check.

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carl

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And thank You Carl. I haven't bought that rod yet so I guess I'll get the less pricey bronz one, just to be on the safe side. It couldn't be that much more than the stock style.

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Jimmy B.
Just can't wait to get on the road again.

 
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Well if the GM tech gave a thumbs up to using a regular steel pushrod, then leave it.

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GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.

Thanks for the info. If I get any other information to counter the use of the steel PR I will reply to this thread. Or if anyone else has any data on the ZZ4 standard cam and the use of a special alloy PR I hope they chime in. I can always replace it.

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carl

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