Streetstuff

My gas boils every time it shuts down. I have a 1" aluminum spacer under the carb. I have to rev the engine up for about a min. or it will die as I shift into drive. I feel like a better cooling system/making the engine run cooler is my only option. 210° before shutdown and 240° after

redneckjoe

you might try a wood or composite spacer.
what intake? you could use heat cross-over block off plates if needed.
yea, make sure your cooling system is working properly.
i have some exhaust that is near my steel fuel line. i cut up some aluminum cans into flat sheets, then wrapped them around my fuel line carefully, then put a small hose clamp on to hold it in place. homemade heat shield.

Streetstuff

Edelbrock intake and carb. Nice idea with the cans. I'll see what I can do about shielding and do some research on composite spacers.

sofakingdom

iTrader: (1)

Problem is prob not the carb...

More likely, the fuel pump.

Try putting 2 gaskets between the plate and the block, and between the pump and the plate. Or, https://www.cantonracingproducts.com...&category=8510

RedLeader289

iTrader: (2)

Sounds crazy, but I swear it works. Take wooden clothespins and put them on the fuel line in the engine bay, 2-3 spaced out should do the trick.

Damon

Motor's running too hot to begin with. Read the tech article about 3rd gen cooling system. It would be impossible NOT to pick up a few ideas from it that might help you out.

Also, as was said above, ditch the aluminum spacer and get something made out of a different material. Aluminum has excellent heat transfer properties- that's why they make performance radiators out of it.

skinny z

Now THAT is interesting!

I've got a 2 line mechanical pump and know that I have heating issues. With the pump dead-heading while I'm in the staging lines waiting to go, I imagine the fuel gets hot.

I’ve picked up a Carter 3 line pump (which one day I’ll get around to installing) however it never occurred to me that there could be heat transfer from the block. I’m less than an inch in spots along the driver’s side header (it’s a converted EFI chassis) so I know that at idle the fuel isn’t moving much and is absorbing a lot of heat there. The pump to block relationship never occurred to me.

I’ll have to investigate that Canton piece. (Or make one).

danryanm

Before you go spending money or taking things apart, check your fuel pressure. What you described about having to give it throttle is often indicative of high pressure. Even so much as half a pound over-pressure can lift the needle of the seat, causing excess fuel to enter the carb (opening the throttle allows enough air in to balance the fuel flow.) When you see fuel dripping after shut-down, it CAN be fuel percolating, but it is most likely just the result of the fuel bowl being over-filled (float adjustment is useless in this case as the pressure was sufficient to force the needle and seat open when it should've been closed by the float.)

My car exhibited the same symptoms, and I assumed it had to be heat related as I was using a factory-style pump and off-the-shelf Holley, which are supposed to run right out of the box (and did.) I put a manual pressure regulator and gauge on the fuel line, and sure enough, I had 14 pounds of pressure! The dripping stopped when I adjusted it down to 5 pounds, so I set it at 4.5 and now she is happy as a lark. No drips, no idling issues and as well-mannered as fuel injection, just not as wussy

91 camaro racer

iTrader: (2)

how do the clothespins help?

skinny z

Not to tramp on the OP's post, but in my case, I have 6 psi at idle, cruise and most WOT situations such as the occasional blast on the highway. It's when the vehicle has had a chance to sit and heat soak for a while , such as when I'm waiting in the lanes for my turn to run at the track, that I see the fuel pressure drop at the top 2nd gear or into 3rd. Pressure drops to almost 0 and my air/fuel ratio, via my wide band gauge, are off the lean deep end. The result is a reduced quarter mile ET along with popping and backfiring.
If it's not a fuel boiling issue, I'm afraid I'm back to where I was before with the fuel pump lobe cam eccentric ground down to nothing due to oiling issues. I'd been adding GM's EOS but that may not be enough.

Night rider327

iTrader: (13)

Hey Skinny... That sounds real close to what mine was doing when I did not have enough volume.

To keep a very long story short... 1st setup I used a stock replacement '70 LT1 350 pump, They are listed as a 80 gph pump.
As the fuel heated up, pressure increased at idle by .5 to 1 psi, but at WOT at top of second gear I was down to 2 psi, and top of third as I crossed the stripe, 0 psi

I installed a cheap 35 gph elec. fuel pump in the rear as a helper pump on a toggle switch... Pressure still went up at hot ides, but pressure drop at WOT prob was solved..

This worked for 4 years until I upgraded engine again... Now I was back to the same prob with low WOT pressure.

Installed this beast... http://www.speedwaymotors.com/Carter...-Pump,186.html and all troubles went away.. Even have upgraded engine again since then and no more WOT pressure drops.

Rock solid 5.5 psi from launch to shut down

skinny z

I'm pretty sure mine is a boiling issue. If I'm cruising on a country highway with everything up to temps (but still not hot to the touch) and make a pass to the top of 2nd gear, the pressure is OK and steady at around 5-6 psi. If I try the same thing after the engine has thoroughly heat soaked, to the point where the pump is hot (and I can imagine the fuel line by the header is toasty too), that's where the pressure drop shows up.

I'm presently running an Edelbrock 1721. Rated at 110 gph.
http://www.summitracing.com/int/part...make/chevrolet

I have a Carter M6626 waiting on the shelf. Ratings vary from who's website you look at but I'm thinking 120 gph.
http://dvautoparts.com/discount-stor...w-lljlpkimprrm

The think the return line may make the difference. I'll soon know. The chassis formerly had EFI so the return line is there. I just have to get it across the engine bay.

Not sure if this would help the OP or not.

RedLeader289

iTrader: (2)

It's an old trick that dates back to *****'s jeeps in WW2. I wish I could give an answer, I've tried to figure it out but truly it really doesn't make sense (since wood is an insulator, so it's not transfering any heat). All I know is that I tried in on my car and no longer have fuel boiling in and before the carb. Somehow it cools the fuel in the line.

You can see them in the pic on the bottom left.

Streetstuff

I ended up with a .5" 4-hole phenolic spacer off Ebay for $14 which has been working great.