[HWYSTR455]

The previous owner of the 442 had removed all the hard lines in the rear that ran from the tank to the separator, so I decided to use the vent Tanks sent. It was basically just a captured ball in a chamber, and that thing was mounted as high as possible above the rear. Fuel would slosh up the line to the ball, push the ball off the seat, and just spray past the ball thru the capture opening. Might as well have just left the vent open with no hose on it, would have been about the same effect.

I would have to go back and see how long ago that was, but I'm thinking like 4 years ago. Think I posted info in the line install thread, or in the build thread, but it's been a while since I've looked at either.

If you have a post-70 car, just use the OE setup and be done with it. I did the last 2 cars with just the one vent off the tank, but would be nice if Tanks offered one with the multiple vent tubes.

I don't use the charcoal cans, I just let it vent from the long tube in the separator into the atmosphere, and don't have any smell whatsoever. All the liquid drains back into the tank.

Here's is a cutaway of the GM 'standpipe'.


.

[78w72]

i believe you on the vent issue, just saying mine has not leakeed a drop under any conditions.

its just like the one pictured & as you described... a check ball that closes if tipped past about 90*. but where mine is installed it works great & is bone dry.

[ponjohn]

Quite a few people (om PY) run the RobbMc pumps and I bet 80% of them get replaced with an electric pump. They just don't seem to have the volume to keep up with up with sticky tires and a healthy combo.

[Formulajones]

Here's my buddy Mike's car with a RobbMC 550 pump

https://youtu.be/TWZBq9aM1bs

Mike could tell you all about it, the issues he faced etc... I believe on these passes he was only seeing 3 lbs. of fuel pressure at the end of the pass. It was still putting up good numbers, through a full exhaust and he drives it to and from the track, 100% street car. I remember he's also told me the fuel pressure would dip low when driving around on the street as well in just normal day to day traffic.

He's tried quite a few tricks, has big fuel lines etc...I think eventually he went electric with a Mallory 140 inline and didn't have any more success with that either.

[AG]

I'm surprised he had an issue with the Mallory 140. I use one deadheaded on my race car and worked fine last week running 10.09 at 134 mph. I have it set at 8 psi and it goes down to 6 psi during a run.

[johnta1]

What carb(s)?

[Formulajones]

He runs an old style 1050 dominator on it with a Warrior intake. Believe he has 1/2" lines as well.

I run a Mallory 140 on one of mine here, with stock lines even, lol. And I rigged a return line for it as well that I restrict with an orifice I made. It's a mild street car that runs 11.40's at 118 mph and it has rock solid fuel pressure I set at 7 lbs.

I remember Mike telling me he struggled with that pump and had wonky fuel pressure issues. Car ran nearly identical. He even resorted to a fuel cell setup at one point with no change in anything. The car runs extremely well for what it is, at just 9:1 compression and d-port iron heads that flow 220 on Paul's bench, and a custom solid flat tappet that Paul spec'd. Nice running little engine. He's always felt it had some more in it if he could get the fuel problems sorted, and I agree.

I'd have to get Mike in here to comment on all the details but he doesn't visit the forum much anymore.

[TAQuest]

Originally Posted by johnta1

What carb(s)?

800 q-jet

Originally Posted by RocktimusPryme

800 cfm q-jet by SMI custom for my engine.

[RocktimusPryme]

This is just a retrospect question I have been asking myself, when I was getting the pinging at part throttle on the way home. Could I have taken my vacuum advance off ported, and put it on full manifold to bandaid the issue? This is more of a curiosity thing than anything else.

I know the ported vs full manifold thing gets beat to death. Ive always run ported, but now Im thinking about experimenting the other way. See what the car likes.

Since the car is down anyway Im taking the time to do a bunch of little stuff. I ordered a DUI kit, with coil and module. Pulled the distributor to check the brass gear. I ordered a 2G starter cable to help some with the factory 4G getting heat soaked. Better secured some stuff with clamps and tech screws. Ordered a NEW Stant fuel cap. Im considering dropping the tank and adding a roll over vent, but its such a PITA.

[Formulajones]

Originally Posted by RocktimusPryme

This is just a retrospect question I have been asking myself, when I was getting the pinging at part throttle on the way home. Could I have taken my vacuum advance off ported, and put it on full manifold to bandaid the issue? This is more of a curiosity thing than anything else.

I know the ported vs full manifold thing gets beat to death. Ive always run ported, but now Im thinking about experimenting the other way. See what the car likes.

Since the car is down anyway Im taking the time to do a bunch of little stuff. I ordered a DUI kit, with coil and module. Pulled the distributor to check the brass gear. I ordered a 2G starter cable to help some with the factory 4G getting heat soaked. Better secured some stuff with clamps and tech screws.

The ported and manifold vacuum advance will work nearly identical under light throttle driving conditions.

The only big difference is that with manifold, you have vacuum advance at idle and under coast (no throttle) conditions. But worth experimenting with for sure.

[RocktimusPryme]

Originally Posted by Formulajones

The ported and manifold vacuum advance will work nearly identical under light throttle driving conditions.

The only big difference is that with manifold, you have vacuum advance at idle and under coast (no throttle) conditions. But worth experimenting with for sure.

Right, I know the main difference is idle, my general thought was that I don't know when exactly the ported provides its vacuum signal and how fast the ramp up is. It probably varies per canister and depending on how much vacuum your engine provides. So my thought was the full manifold might be providing a few more degrees earlier in the low throttle acceleration than the ported. I feel like it certainly does since its giving you the whole shabang at idle, and the ported takes at least some time/RPM requirement to kick in.

Since my problem wasn't cruise, it was pulling away from a light at idle, having that vacuum single slightly earlier might have made a difference.

[Formulajones]

Originally Posted by RocktimusPryme

Right, I know the main difference is idle, my general thought was that I don't know when exactly the ported provides its vacuum signal and how fast the ramp up is. It probably varies per canister and depending on how much vacuum your engine provides. So my thought was the full manifold might be providing a few more degrees earlier in the low throttle acceleration than the ported. I feel like it certainly does since its giving you the whole shabang at idle, and the ported takes at least some time/RPM requirement to kick in.

Since my problem wasn't cruise, it was pulling away from a light at idle, having that vacuum single slightly earlier might have made a difference.

You are pretty much on target with that thinking, and yes it does vary a bit per canister and how much vacuum the engine provides.

Sometimes can take a while to get it all dialed in and working nicely, but worth the effort.