fine tuning fuel system after restoration, help appreciated!
 

Hello all,
With the first nice day of the year I made my own drive your car to work day which is about a 100 miles round trip. Since the restore I've put 600 miles on it in 6 months so you can guess I was a bit nervous. The journey on the way out went rather fine, steady idle, no starvation, no hesitating.
The way back was something different. The car had been sitting in the warm spring sun all day as you can see in the picture. It didn't fire up immediately and seemed to suffer from vapor lock a bit and also noticed the idle was erratic, the car wanted to stall. While driving I noticed fuel starvation (pushing the throttle made it want to stall. On the highway it ran not too bad but still rather rough, not as during the drive in the morning). After taking the exit (hard right) I opened my window to try and enjoy the sound of the engine and had a constant fuel smell. At that point the tank was near half empty. Once parked in the garage the smell seemed to come from the driver's side wheel well (odd see further on). I opened the gas cap and the tank was highly pressurized which is something I've never had before. (Sealed cap)
On to the specification
New gas tank, new fuel pump with return, new vapor canister, new roll over check valve. Check valve to frame line connected, check valve to tank connected, frame line to vapor canister connected, pump to return line connected, return line to tank connected. All new hoses and preformed where required.
350HO 330 hp crate engine with Holley 4160 non emission 600 cfm carburetor (came with deluxe kit). So the canister purge and canister vapor line are NOT connected to the carb and PCV mostly because I'm missing a purge port on the carb. Both ports on the canister are therefore plugged...
Transmission 700R4, rear 3.36, CC true dual exhaust with hideaway mufflers, open filter element, hard line from pump to carburetor if it matters. The car was running at 200F the whole time on the temp gauge although this was never verified with a heat gun. I haven't seen lower operating temperatures during all the other drives I've done.

1) To try and eliminate the heat soak I'm thinking of trying a heat shield like this: holley heat shield or is it just a waste of money?

2) The rear fuel smell got me worried. Could this be a result of the plugged canister you smell gas near the rear tire?

3) To connect the canister I would need an emissions carburetor. To limit the amount of work to be done (fuel hard line bending, TV setup, throttle setup) the easiest solution would be to stick with a Holley with similar body but more ports. Eventually I found this one :0-80451 with looks exactly as the carb which is on the car now but more ports. While looking on the Holley web page you can also see a 0-80450, 80452 and 80453 but nowhere I can find the differences explained except this little list
http://i494.photobucket.com/albums/r...ps0f1620ed.png.
I contacted Holley but either I didn't explain myself very well or they didn't bother. The answer was 'If you need to pass emissions you need a Holley remanufactured carb that fits your vehicle’....
I've read good things about the Summit carbs on here but that would be the last step I would like to go as it involves re bending the hard line.
Is anyone on here running that specific Holley carb or has any other suggestions what to choose?

4) Lastly is the terrible drone during highway driving. Yes I've read the threads where people get flamed asking solutions to reduce the exhaust noise but I don't care, the drone is obnoxious to the point highway conversations are not possible. To try and solve this I would get a Dr Gas X pipe as the general consensus is that it tones down and reduces the drone (more than an H-pipe) right? Most people say the stock mufflers are the most quiet so that leaves me no options.

I'll have a speed shop do all the work but would like to hear from the fuel delivery experts on here.
Any help is greatly appreciated.

Nick
http://i494.photobucket.com/albums/r...psd5c95d83.jpg

Unplug that vapor can. The tank can't vent through the cap, and the plugs aren't allowing the tank to vent through the normal route, the vapor can. No real danger in not having the lines to the carb.
Carter

Agree on the venting, but I want to do it right and get rid of the fumes so the canister needs to be hooked up :)
Nick

You can hook up the large vacuum hose in line with the PCV valve, and the small vacuum line should be hooked to a ported vacuum line on the carb. I don't think you need an "emissions" carb, most carbs have both ported and maifold vacuum lines. The small ported vacuum line operates a valve in the top of the canister that controls the large manifold vacuum line to suck the vapors out during high vacuum conditions on the ported line, basically almost any throttle position above idle. I do not know at what vacuum level the valve on the canister operates at exactly. If you hook the small vacuum line to maifold vacuum on the carb, you will create a full time vacuum leak.

As a test, loosen the gas cap a little to let the tank vent, and go for a drive.

:cheers:

Thanks 7t2 but the current carb only has a timed (spark) port, 1 full vacuum, and 1 PCV port so no provision for the purge signal unfortunately as you can see in this instruction manual
I still have a vented cap around and was going to test it to see if the car runs better after a long drive but it's been raining ever since that (sunny) tuesday but it's no solution to solve the smell :)
Nick

The "timed spark vacuum" source should be ported. :thumbs:

True but is T'ing it in with the distributor vacuum advance a good idea??

I don't think it should cause any problems, but it is pretty easy to hook up and try. You could use a timing light to watch your timing before and after hooking up the canister purge valve to see if anything changes. :thumbs:

Any other suggestions on how to hook it up, different carb and the X pipe please?

I agree with the suggestion to vent the tank. I use a vented cap on mine with the return line and vapor canister hooked up with no problems.