Fuel loading when hot

[Viet Nam Vett]

It's now over 8,000 miles. Actually, the problem turned up (in a severe way) twice on the Bowling Green trip.

Once, just inside Michigan, and the second time in heavy traffic going through Indy. I'll tell you about that at CruiseFest.

Tomorrow is heat shield day.

Dam...were gonna have to add another day for corvette bedtime stories....at Crusie FEET..

Gheeeezzz..:L

 

[IH2LOSE]

I had not intended to suggest that both be used. The shield protects the Holley bowls from radiant heat by deflecting it away. The spacer gives some heat relief for the carb body itself. Both can of course be used but with the clearance problem you may wish to try the shield first.

The shield is used to reflect the radiant heat and to also dissipate the conductive heat by giving the heat a place to radiate off of

so using both would be a benefit as long as the insulator was placed on top of the heat shield insulating the carburetor from from the plate it self

There is a lot of heating cooling theory / principles working with this

 

[Drjohn]

Call the guys at the tech line on the website. They'll have some suggestions. Let me know how it goes. I'm out of town at a customer this week, but can track someone down if you can't get the right person on the phone when I return.

 

[67HEAVEN]

Hi John,

I just finished installing the Holley heat shield, but without the spacer for now.

If the problem isn't cured, I'll add the spacer and cut some mesh out of the screen (as mentioned earlier) to lower the overall height for hood clearance.

HOWEVER, I did discover something that even a rank amateur shouldn't miss. I checked my intake manifold bolts part way through last summer, but not since. I should have. Several were loose. If you've got an aluminum intake folks, check the bolts. Hmmmm. I wonder.

I'm off for a drive to see what happens. I'll report back. If you don't hear from me for a few weeks, send Mac.

 

[74bigblock]

Hi John,

I just finished installing the Holley heat shield, but without the spacer for now.

If the problem isn't cured, I'll add the spacer and cut some mesh out of the screen (as mentioned earlier) to lower the overall height for hood clearance.

HOWEVER, I did discover something that even a rank amateur shouldn't miss. I checked my intake manifold bolts part way through last summer, but not since. I should have. Several were loose. If you've got an aluminum intake folks, check the bolts. Hmmmm. I wonder.

I'm off for a drive to see what happens. I'll report back. If you don't hear from me for a few weeks, send Mac.

Bob,

Enjoy the ride!

If I were me, (wait... I am me aren't I? I guess that's a different thread now isn't it???) I'd put in that spacer. I was able to put my finger and hold it on the carb after 14 runs at the strip a few weeks ago because of the spacer. If it was not there, I would have burnt my finger to a crisp instantly. It helps significantly. I also had a hard start after the aluminum intake instal when hot situation before I installed the spacer (had a cheapo cardboard gasket in there).

Dave

 

[Viet Nam Vett]

Hi John,

I just finished installing the Holley heat shield, but without the spacer for now.

If the problem isn't cured, I'll add the spacer and cut some mesh out of the screen (as mentioned earlier) to lower the overall height for hood clearance.

HOWEVER, I did discover something that even a rank amateur shouldn't miss. I checked my intake manifold bolts part way through last summer, but not since. I should have. Several were loose. If you've got an aluminum intake folks, check the bolts. Hmmmm. I wonder.

I'm off for a drive to see what happens. I'll report back. If you don't hear from me for a few weeks, send Mac.

Several were loose.

Yeah Man......Me too...On My 502..... I check mine every 100 miles or so. They have since settled in and arn't coming lose anymore. I have also cheched other bolts on the motor hear and their just to make sure nothing falls off at speed...:L

 

[67HEAVEN]

Ladies and Gentlemen....Boys and Girls....and all ships at sea.

The problem appears to be solved. Was it the addition of the heat shield? Was it the tightening of the intake manifold bolts? I think it was a combination of the two.

What I didn't do was go inside the Holley carb, nor make any external adjustments.

I drove it for over an hour, stopping three times for at least 20 minutes each time. No problems re-starting....no puffs of smoke/fuel/native-smoke-signals.....no stumbling.

The only additional change I may have to make is the installation of the heat-shield-spacer as we move into July and August weather. We'll see.

It's good to be back in Heaven. Thanks for all the input and suggestions.

 

[paul67]

Good stuff!

 

[Viet Nam Vett]

Ladies and Gentlemen....Boys and Girls....and all ships at sea.

The problem appears to be solved. Was it the addition of the heat shield? Was it the tightening of the intake manifold bolts? I think it was a combination of the two.

What I didn't do was go inside the Holley carb, nor make any external adjustments.

I drove it for over an hour, stopping three times for at least 20 minutes each time. No problems re-starting....no puffs of smoke/fuel/native-smoke-signals.....no stumbling.

The only additional change I may have to make is the installation of the heat-shield-spacer as we move into July and August weather. We'll see.

It's good to be back in Heaven. Thanks for all the input and suggestions.

I think it was your intake manifold sheet metal screws.:L The only way to find out for sure is to remove the flying saucer form undernieth the carb.

But it is nice to hear that she's a starten up when hot.... Congrats

 

[BarryK]

now that you have solved your problem..... Happy Cruising!

 

[Drjohn]

Ladies and Gentlemen....Boys and Girls....and all ships at sea.

The problem appears to be solved. Was it the addition of the heat shield? Was it the tightening of the intake manifold bolts? I think it was a combination of the two.

What I didn't do was go inside the Holley carb, nor make any external adjustments.

I drove it for over an hour, stopping three times for at least 20 minutes each time. No problems re-starting....no puffs of smoke/fuel/native-smoke-signals.....no stumbling.

The only additional change I may have to make is the installation of the heat-shield-spacer as we move into July and August weather. We'll see.

It's good to be back in Heaven. Thanks for all the input and suggestions.

Super. I'm thinking that it was the bolts.

I'm curious to know what happens when it gets warmer.

Does it really get warmer there? I lived in WNY for half my life. I know better.

 

[67HEAVEN]

It was warmer today, and sunny, so I decided to take much of the day off to run a longer test.

I checked with the boss, and being that he's a car guy too, I got to move on down the highway.

So, after a 150-mile trip all over south-central Ontario, with the heat shield in place and the intake bolts tight, and with plenty of stops to test out the hot-start problem, I can report that all is well and ready for the trip to CruiseFest.

Near the end of the run, I decided to see if I could re-create some of the original problem. I shut the electric fans down about two miles from a coffee shop, and then shut the engine down very warm, when I got there. I didn't drain the bowls by shutting off the electric fuel pump early.

After 20 minutes, I came out and it fired just fine......BUT....just after pulling on to the road it coughed and died. It took about 30 seconds to get it going again, with lots of fuel-smell evident. The fans quickly brought it down cool again, and there were no more problems after that.

I'm convinced that high under-hood heat combined with perhaps some vacuum leakage due to the loose intake bolts contributed to the problem. During the above experiment, I saw no blue, black or any other colour of smoke. I think the fuel was just percolating in the bowls.

I think this problem has been beaten into submission.

 

[Viet Nam Vett]

It was warmer today, and sunny, so I decided to take much of the day off to run a longer test.

I checked with the boss, and being that he's a car guy too, I got to move on down the highway.

So, after a 150-mile trip all over south-central Ontario, with the heat shield in place and the intake bolts tight, and with plenty of stops to test out the hot-start problem, I can report that all is well and ready for the trip to CruiseFest.

Near the end of the run, I decided to see if I could re-create some of the original problem. I shut the electric fans down about two miles from a coffee shop, and then shut the engine down very warm, when I got there. I didn't drain the bowls by shutting off the electric fuel pump early.

After 20 minutes, I came out and it fired just fine......BUT....just after pulling on to the road it coughed and died. It took about 30 seconds to get it going again, with lots of fuel-smell evident. The fans quickly brought it down cool again, and there were no more problems after that.

I'm convinced that high under-hood heat combined with perhaps some vacuum leakage due to the loose intake bolts contributed to the problem. During the above experiment, I saw no blue, black or any other colour of smoke. I think the fuel was just percolating in the bowls.

I think this problem has been beaten into submission.

beaten into submission

Well glad to here that Heaven is running ok. And it's nice to have Boss to let you take off to test your car.

I can just see me asking my boss to take off cause I want-a check for heat soak and perculation...:L ..Yeah... How about checking for work done...

I gonna be putting the RedRat on the lift and go over all chassie nuts and bolts as well as drive line bolts..IE..Drive shaft yoke bolts and "U" joint bolts.
Also check all front end steering component nuts and bolts for tightness.

Don't wanta be making a deposite on the highway..

 

[gmjunkie]

I think the fuel was just percolating in the bowls.

I think this problem has been beaten into submission.

Could be!! I sometimes Procrastinate in a Bowl on Hot Days!!:L Glad you got it Rumble'n!!

 

[67HEAVEN]

Never one to miss a photo opportunity. One of my test stops was at Mosport International Raceway, the 2.5 mile road course northeast of Toronto.

After blowing the Formulas into the weeds, I took time for a few photos.

 

[bossvette]

Glad to see you have it sorted out, when are you going to ditch that ancient carb for EFI?

 

[67HEAVEN]

Glad to see you have it sorted out, when are you going to ditch that ancient carb for EFI?

Never.

 

[Gerry]

Glad to see the problem is solved. My bet is on the bolts. I have also noticed the loosening of bolts due to the vibrations of my engine. I now use locktite on everything I find loose and probably should just redo every bolt but that would take a lot of time. I actually lost a bellhousing bolt about a month ago so I learned the hard way. Good luck.

Best regards,
Gerry

 

[Kid_Again]

Some random thoughts. Good to see that you fixed the problem. I've been busting Mark's chops to get rid of that CHOKE TOWER to increase airflow so I'm gald to see that you didn't seriously consider shortening the housing.

I made symmetrical cutouts in the back of my '67 hood and you're welcome to the template but, looking at your work, you should be able to do a nice job just free-handing it. Let me know if pictures would help. On a 65* day, the top of the air cleaner is cool to the touch after driving the car around town...but it's a small block. And I use Mark's FAVORITE accessory...the K&N filter top.

 

[Viet Nam Vett]

Some random thoughts. Good to see that you fixed the problem. I've been busting Mark's chops to get rid of that CHOKE TOWER to increase airflow so I'm gald to see that you didn't seriously consider shortening the housing.

I made symmetrical cutouts in the back of my '67 hood and you're welcome to the template but, looking at your work, you should be able to do a nice job just free-handing it. Let me know if pictures would help. On a 65* day, the top of the air cleaner is cool to the touch after driving the car around town...but it's a small block. And I use Mark's FAVORITE accessory...the K&N filter top.

And I use Mark's FAVORITE accessory...the K&N filter top.

What a piece of over priced Junk ......$80.00 ...I could get 4 Ladies of the Evening right outside the Casino on Pacific Ave for that. And they flow a hell of a lot more air then that K&N piece of junk.:L

Plus...That's what was causing my problems.... Those of you who don't own one (K&N Filter Top's)...here's the deal.. It looks like the top is open to just that oily gack material doesn't it..EEEEEHHHHHH.!!! Wrong.. :ugh Turn it over and you'll see a metal plate with a 100 or so 1/8' holes drilled all around. This plate drops down about 1" from the lip of the cleaner.

From the outside the top comes to a peak in the center where the hold down nut goes. But undernieth it's lower inside where the plate is and is flat across.
This is what hits the choke horn and air tube. It also crushed the backfire arrestor screen in the drop base down about 3/8". If anything it limited the flow because it was closer to the drop base internally.

So.. I got me a good old stock chrome Air Cleaner Lid that rises in the center and clears the internal Carb parts like the stock one does. End Of Story


So... Does the K&N Top Air Cleaner Lid Flow more Air...Ahhhh Yeah ..a little bit more considering it flows thru a plate with a bunch of holes drilled in it.

Will it always flow that ammount of air??... Yes until that oily gack filter material starts to clog up...which is how Long??? Not very long..

My advice....Stick With The Paper Unit..