vortec conversion issues

[graphicjunki]

I've got my engine back in, but I'm running into some small set backs.

First off, I got a high performance Edelbrock mechanical fuel pump. The OEM fuel pump has three ports. One large, one small/medium, and a smaller one. The new fuel pump only has two, IN and OUT. I know which one the OUT is on the OEM... But what about the other two? I thought maybe they sent me the wrong part number, so I went and I double checked. It's correct. I have the service manual, I have the service manual supplement...all that and it only shows the factory config, but only talks about the line that goes from the pump to the carb. The fuel tank section only discusses the Tank and it's connectors, but not the fuel lines.
The instructions that came with the fuel pump only talked about torque specs and trouble shooting.

So on the factory lines, is the smallest line like a breather? Not being fuel injected, I can't imagine it would be a complete return system.


another thing is that I don't even remember taking out the water temp sensor. Too much beer?! But for some reason I would swear it goes on the intake manifold. But the new manifold (Edelbrock 2116) doesn't have the same number of ports on top for 'things' to attach. I don't have a spot for my temp sensor. The engine has the type of thermostat housing that has a threaded hole. I replaced that with a new one identical and mounted it before realizing that I have no idea what the gated vacuum port on top was used for, nor was it attached to anything when I pulled the engine. So I was going to put the sensor in there. But I'm apprehensive about that for some reason. Maybe because part of me believes that the temperature there could fluctuate too much dependent on the state of the thermostat.
Thoughts?

And lastly (for now) is that when I put the carb back on (Rochester Qjet), I put the new gasket down and went to bolt it all down. The bolts are too long. I remember the old gasket feeling fatter, but chalked it up to all the crap that was soaked into it. Figured it was swollen. Is there some kind of spacer? I did see spacers on summit's site, but they were listed as performance and I didn't want to mess with height clearances. But there is also a vacuum port between the carb and the distributor that the carb won't clear now. Grrrr......

Any advice, suggestions.... would be greatly appreciated.
Thanks!

[slofut]

Originally Posted by graphicjunki

I've got my engine back in, but I'm running into some small set backs.

First off, I got a high performance Edelbrock mechanical fuel pump. The OEM fuel pump has three ports. One large, one small/medium, and a smaller one. The new fuel pump only has two, IN and OUT. I know which one the OUT is on the OEM... But what about the other two? I thought maybe they sent me the wrong part number, so I went and I double checked. It's correct. I have the service manual, I have the service manual supplement...all that and it only shows the factory config, but only talks about the line that goes from the pump to the carb. The fuel tank section only discusses the Tank and it's connectors, but not the fuel lines.
The instructions that came with the fuel pump only talked about torque specs and trouble shooting.

So on the factory lines, is the smallest line like a breather? Not being fuel injected, I can't imagine it would be a complete return system.


another thing is that I don't even remember taking out the water temp sensor. Too much beer?! But for some reason I would swear it goes on the intake manifold. But the new manifold (Edelbrock 2116) doesn't have the same number of ports on top for 'things' to attach. I don't have a spot for my temp sensor. The engine has the type of thermostat housing that has a threaded hole. I replaced that with a new one identical and mounted it before realizing that I have no idea what the gated vacuum port on top was used for, nor was it attached to anything when I pulled the engine. So I was going to put the sensor in there. But I'm apprehensive about that for some reason. Maybe because part of me believes that the temperature there could fluctuate too much dependent on the state of the thermostat.
Thoughts?

And lastly (for now) is that when I put the carb back on (Rochester Qjet), I put the new gasket down and went to bolt it all down. The bolts are too long. I remember the old gasket feeling fatter, but chalked it up to all the crap that was soaked into it. Figured it was swollen. Is there some kind of spacer? I did see spacers on summit's site, but they were listed as performance and I didn't want to mess with height clearances. But there is also a vacuum port between the carb and the distributor that the carb won't clear now. Grrrr......

Any advice, suggestions.... would be greatly appreciated.
Thanks!

The '71 I'm working on has three lines to the fuel pump, in/out/return to the tank. It's common. The tank also has a vapor line on the driver side that goes to the vapor cannister in the driver side fender.

Carb spacers are common, there's one on this car, about 3/8 thick.

Hope this helps some,
Bill

[Enginerd]

You can put the temp sensor in the cylinder head instead.
And for the carb gasket you can try using a phenolithic (spelling is probably wrong) spacer. They are designed to prevent heat transfer to the carb, which will be a bonus for you, but the main thing is that the thickness will probably be just right for you; they're usually about 1/4 - 3/8 inch.