1941 Buick Limited Limousine

[Ben Bruce aka First Born]

9 hours ago, RivNut said:

My dad had a couple of these. The needed sized socket went on the long handle, the screwdriver was built into the knurled knob.  Made valve lash adjustment easy.  

It was still a two handed operation but there was no need to lay down any tools to use the feeler gauge.

 

 

 

 I have one.  Neat tool.

 

 Ben

[valk]

Whoa that is cool. Where can I get one? I always seem to have to loosen and tighten the nut several times to get the gap right due to the nut moving when I tighten the screw. With this, I’d adjust the valves with the engine running as you should. 
peter
 

[valk]

Err, “due to the SCREW moving when I tighten the NUT”....haven’t had my coffee yet.  

[Ben Bruce aka First Born]

Search?  I ran across mine in a small antique store in Harrison, Ar.

 

  Ben

[valk]

Well I’m happy for you of course but I’ve had no luck yet locating one. 

 

[valk]

...until now! FYI, it is Snap-on tool number V-21A and while no longer available through Snap-On, there are a few on Ebay. 

Peter

[Matt Harwood]

22 minutes ago, valk said:

Well I’m happy for you of course but I’ve had no luck yet locating one. 

 

 

I just bought one last night on eBay for less than $20 after I saw RivNut's photo. There are a half-dozen others available for prices ranging from $14 to $70.

 

https://www.ebay.com/itm/SNAP-ON-VINTAGE-TOOL-V22E-VALVE-ADJUSTMENT-TOOL-1-2-INCH-DRIVE-1953/133354158921?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

Drove the car this morning and it's better--not perfect, but better. I installed a generic parts store radiator cap that I bought for $8 and it seems to be sealing up well enough to end the foaming, so at least that's good.

 

Maybe 80% of the bucking is gone. I think part of it is that I can't get it warm enough. It was pretty cool this morning (50 degrees) and it slowly climbed up to about 160, but kept dropping down to 150ish as we drove, so Riley and I could see the thermostat doing its thing. After about 20 minutes it seemed to stabilize at 160 and run better, but still some stuttering at low speeds, especially off-idle when I was easing away from a stop. I'm almost thinking that I should put a 180 degree thermostat in there--the new radiator obviously has plenty of capacity and with the carburetors and intake decoupled from the exhaust, maybe they're just too cold? There were several times it backfired through the carburetors, which sounded like a cough and there was a pretty violent buck through the car, so that's new. Perhaps a little too lean?

 

The valves are also notably noisier than they were before I adjusted them. That sounds about par for the course with my projects--fix it until it gets worse. I bought the tool above to adjust them again, and may try to adjust them after a proper warm-up drive and while it's running, although I'm not sure how that tool will can on a rocker arm that's moving up and down at 400 RPM. When I adjusted it the first time, most of the valves were wider than the recommended .015" so would making them tighter make them noisy? I would think that tighter would be quieter. I can fine-tune them while it's running and decide which direction gives better results. Perhaps opening them up to .016 or .017 would be better? Any thoughts?

[JohnD1956]

I don't think solid lifters will ever be as quiet as hydraulic.  chances are you are hearing more because you are focusing on it?

[Bloo]

When I have a valve adjustment that puts up a fight, I double check with a dial indicator. On an OHV motor, I put it right out at the valvestem end of the rocker. Some engines have wear on the tips of the rockers in the shape of the valvestem end. That "fools" the feeler gauge. They could be looser than you think they are.

 

OHV engines with solids do make a bunch of noise, it is unavoidable, but if you get them all exactly the same is is more of a hash sound than a knocking lifter sound. .015 is less than many OHV engines use. It should be reasonably quiet.

 

I can't imagine how loosening them up at this point could make them quieter. I would stick with Buick's recommendation for the setting.

[valk]

I would try  locating a particularly noisy valve with a stethoscope, measure the gap and then adjust in to see if it improves. I wouldn’t go tighter than .015 though on a hot engine.

[Matt Harwood]

It's definitely louder than it was--Riley noticed it when we were out cruising today. Even at highway speeds, you can hear it ticking away up there. It was never audible before. So I know I added noise. One is especially loud--I believe it's still the intake on #1.

 

My only guess is that when I set them, I didn't heat the engine up properly. As you might recall, I put a piece of cardboard in front of the radiator and let it run for a few minutes and it immediately spiked to more than 200 degrees.. I was able to cool it off and left it idling for a while as the manual instructs, but I think that initial spike and then idling didn't warm it up properly. I have also noticed that it takes a good 20 minutes of driving before the valvetrain really quiets down, so it may take a while to get up to proper temperature. There are also 12 quarts of oil in there--that's a lot to warm up.

 

I think I will take a nice, long drive, bring it in, pull the valve cover, dial down the idle as far as it'll go, and set them while it's running and hot. It's the only way to be sure.

Edited April 2, 2020 by Matt Harwood (see edit history)

[Bloo]

Regarding idle speed and disconnecting the vacuum: On a car that uses ported vacuum, and I think this does, there SHOULD be no need to disconnect the line, because there should be no vacuum. I, and many other mechanics always disconnect it just in case (unless the manual states to set the timing with it hooked up. It is not common to see).

 

The service manual will probably tell you what RPM the centrifugal advance starts to move. Pay attention because they might specify distributor rpm, and if they do, double it.

 

With the engine idling slow, and using a timing light, slowly turn up the screw and see what RPM the advance starts at. You should be able to turn it up a little without movement, but not that much over idle spec. In normal operation, it should not be idling "on the curve", in other words a slight increase in idle speed should not make the timing move. The idle will be quite unstable if it is idling on the curve.

 

Ideally, for good throttle response, you probably want the curve to start only a few hundred RPM above normal idle. 50 or 100 RPM would be nice, but most factory jobs don't put it quite that close. Close is good, but It matters a little less when you have a manual transmission, and also matters a little less when you have vacuum advance. Comparing the distributor specs to the idle speed spec in the service manual will show you what Buick did. Whatever you do, don't idle on the curve. Never ever ever. It is the road to madness.

[Bloo]

I agree with warming it up thoroughly. That has to be done with driving. In my experience shop based methods like cardboard in the radiator, idling in the shop for long periods, etc. do not heat soak the engine in the same way as driving does, and for something like valve adjustment it could easily matter.

[valk]

Couple of things, the service bulletin makes a big deal of warming up the engine thoroughly before adjusting valves by DRIVING it. Idling in the shop won’t do. The coolant and oil warm at different rates and lash will be too TIGHT if not both thoroughly hot. Second, 12 quarts is 2 too many according to my manual. Check Your dip stick. 

[Ben Bruce aka First Born]

Matt, I have found over the years that adjusting valve lash is a hit or miss.  Sometimes.  And sometime on a worn [ as in , not just rebuilt] engine , it almost impossible to get just right. Agree with Bloo that a worn rocker may be giving a false reading.  If, when removing the feeler gauge from the rocker/valve you hear the tap noise, perhaps set that one a couple thousands tighter.

 

  Ben

[Matt Harwood]

2 minutes ago, Ben Bruce aka First Born said:

Matt, I have found over the years that adjusting valve lash is a hit or miss.  Sometimes.  And sometime on a worn [ as in , not just rebuilt] engine , it almost impossible to get just right. Agree with Bloo that a worn rocker may be giving a false reading.  If, when removing the feeler gauge from the rocker/valve you hear the tap noise, perhaps set that one a couple thousands tighter.

 

  Ben

 

Thanks, Ben. The noisy one has always been noisy, but it's considerably worse now. Interestingly, when I was setting the lash last week, sticking the feeler gauge in there while it was running silenced it. Does that mean it should be tighter? 

[Ben Bruce aka First Born]

I think so, Matt. Perhaps tighten it  "by ear" and then check for what clearance is there.  The problem is the rockers  wear to fit the valve stem, creating a concave rocker instead  of convex. The flat feeler gauge is fooled, as Bloo said. 

 

  Ben

[Dynaflash8]

Maybe your rocker arm needs to be re-rounded.  Years ago I had to have a whole set of rocker arms re-machined.  Just a thought.

[MCHinson]

I have not typically looked in this particular forum but a conversation with another member caused me to look at his discussion here and then I happened across this one. Not that I really needed another reason to spend more time on the forum, but I have read all 16 pages of this one this evening. Two things, First thanks for the  recommendation on the LED dash light bulbs. I have them on the way for my 1938 Century project now. Second, on the valve adjustment, the dedicated valve adjustment tool is a life saver. It makes the job much easier. Simply idle the engine down nice and low after it is thoroughly warmed up and you will find it makes the job much easier than trying to use a screwdriver and a wrench. From experience, I will also say don't hesitate to try adjusting them again. It took me a couple of times to get it right on my 1937 Century. It makes no logical sense, but you can think you adjusted them and got them right but for some reason they sound worse. You probably loosened one up without noticing it while you were trying to tighten up the locknut. Try it again and you will probably get it just right and be happy with the sound. I went through the same problem but it makes you feel good when you finally get it just right! 

Edited April 4, 2020 by MCHinson (see edit history)

[Lawrence Helfand]

FYI Slightly loose is better then to tight. I learned from several race tuners over the years that hearing a little tappet noise was a good thing. Very quiet tappets were suspect of holding the valve off the seat when things got hot and higher rpm was in play as in a racing motor. Race mechanics use larger tolerances for that reason. Tight tappets will wear out your rocker shaft bushings prematurely so do not set them by sound! Also I find the cold clearance before startup will be about .017 for a .015 hot clearance.    

[Matt Harwood]

Thanks for the information, guys. I did buy the tool and have it in my hands, so this weekend I'll go at the valves again after a nice long drive to get it properly hot. I'm not entirely sure how that tool will work on a running engine, but we'll find out. 

Also, for those of you who have used the tool, is the knob for turning the set screw supposed to be stiff or easy to turn? Mine is pretty hard to turn and I don't think I could do it all one-handed. On the other hand, if it turns too easily, it might be hard to set. What is correct? Should I try to loosen it up or leave it alone?

 

Thanks!

[Ben Bruce aka First Born]

Mine turns freely. It will not spin with a thumb flip, though. Not that easy.

 

 

 

  Ben

[Matt Harwood]

Success! 

 

Took the big guy for a long drive, about 15 miles on surface streets and then another 10 miles on the highway at 65 MPH (man, this thing cruises nicely!) to get back to the shop so it was nice and hot for the valve adjustment. Dialed the idle down as far as it would go and still run--it was really struggling but it was also barely turning over. Pulled the valve cover, which came off without a fight thanks to greasing the gasket, and checked all the valves. Two were making noise and were gapped a little wider than the rest, but none was wildly out of adjustment. The spark plug cover says .015" hot, but the manual says .017" go and .018" no-go when it's hot, so I aimed for .016". 

 

 

I tried my Matco valve adjustment tool but it was too awkward so I went back to a wrench and screwdriver that worked just fine. Dialed them all in so that the .016" feeler gauge would just drag a little bit through the valve gap. The noisy valves were silenced--amazing that .018" or .019" was noisy but .016" was quiet. Once I was satisfied, I reinstalled the valve cover, turned the idle back up to a comfortable level, and took a drive. 

 

It has never run better. Pulls strong (I'm still surprised by how fast thing thing is), valves are very quiet, and the stumble at low speeds is almost entirely gone, so it must have been the timing causing that particular issue. It does occasionally hiccup ever so slightly at very low speeds and low RPM, so I'm not sure what is left to tune to eliminate it, but it's MUCH better than it was. I always get in trouble chasing that last 2% of perfection, so I think I should leave it alone. 

 

 

The idle is still kind of random but I think that'll get better with some driving and fine-tuning. Temperature remained rock solid at 160 degrees, and even while tuning it sitting still in the shop at 300 RPM it only went up to about 185 after 45 minutes or so--the cooling system is healthy. And I guess it's worth mentioning that it spent the night outside earlier this week when someone at the shop misplaced the keys (not me) and the next morning when it was 37 degrees and raining, it fired right up without issues so the carburetors are dialed-in.

 

The only thing bothering me right now is that stupid fan belt--it's easily the loudest thing on the car, followed by the faint THUMP-THUMP-THUMP of the fuel pump, which I think is on its way out. I'll get a new one shortly; that's an easy project and I'm going to rebuild the entire fuel system anyway. 

 

What next? Maybe pull the rear shocks to have them rebuilt again? Install my back-up light switch? Some weather seals? Second muffler? Turn signal indicators in the dash?

 

I guess we'll see. Regardless, it felt really good to succeed today.

 

 

Edited April 12, 2020 by Matt Harwood (see edit history)

[Ben Bruce aka First Born]

I love that car, Matt.   

 Yeah, leave it alone and drive . They were not perfect when newer.

 

  Ben

[38Buick 80C]

glad to hear!!!

[kgreen]

The engine sounds great!  Congrats for all your effort.

[EmTee]

12 hours ago, 38Buick 80C said:

glad to hear!!!

 

Or, in this particular case, not to hear! 

[old-tank]

15 hours ago, Matt Harwood said:

fan belt--it's easily the loudest thing on the car

New fan belts on worn pulleys will be noisy.  New pulleys or try a fabric wrapped belt (try at Tractor Supply).

[EmTee]

8 hours ago, old-tank said:

or try a fabric wrapped belt (try at Tractor Supply).

 

I had a bad experience with one of those 40 years ago.  I don't think they like the speeds that are common on a car engine.  OK for tractors, but I'd try de-glazing the "V" of the pulleys with an 80-grit disc first.

[Matt Harwood]

I've been searching for a suitable belt replacement. I think the problem with these current belts is that they're slotted on the pulley side rather than smooth. And since it's an inch wide and 3/4 inch thick, there aren't any alternatives. Every belt I've found that matches these specs is the same slotted Gates belt all the parts guy sell. My friend at O'Rielly's found an old one on the shelf at some store across the country that he ordered for me a few weeks ago, but it was pretty old and I wasn't interested in spending $50 for an ancient belt. I found an industrial alternative that is 7/8-inch wide so we'll see if it works. 

 

My pulley was sandblasted and powdercoated and I didn't see any notable wear or grooves on the belt surfaces. It's got to be the belt. That's why I started the whole cooling system project--my old belt sounded like a bad water pump bearing. Same slotted belt, just older. 

 

Wrrrrrzzzz, wrrrrrzzzz, wrrrrrzzzzzzzzzzzzzzzz.

[Bloo]

Im running a fabric wrapped "Bando Power King" industrial belt on the Pontiac. Mine is a B series. I am pretty sure the Buick 320 uses a wider one, probably a C series.

 

https://www.bandousa.com/power-king

[Buicknutty]

It sounds great. It took me a couple of tries on my '41 Roadmaster to get the valves to run quiet, without being too tight, as well.

Keith

Edited April 15, 2020 by Buicknutty (see edit history)

[Lawrence Helfand]

On 4/11/2020 at 6:10 PM, Matt Harwood said:

Success! 

 

Took the big guy for a long drive, about 15 miles on surface streets and then another 10 miles on the highway at 65 MPH (man, this thing cruises nicely!) to get back to the shop so it was nice and hot for the valve adjustment. Dialed the idle down as far as it would go and still run--it was really struggling but it was also barely turning over. Pulled the valve cover, which came off without a fight thanks to greasing the gasket, and checked all the valves. Two were making noise and were gapped a little wider than the rest, but none was wildly out of adjustment. The spark plug cover says .015" hot, but the manual says .017" go and .018" no-go when it's hot, so I aimed for .016". 

 

 

I tried my Matco valve adjustment tool but it was too awkward so I went back to a wrench and screwdriver that worked just fine. Dialed them all in so that the .016" feeler gauge would just drag a little bit through the valve gap. The noisy valves were silenced--amazing that .018" or .019" was noisy but .016" was quiet. Once I was satisfied, I reinstalled the valve cover, turned the idle back up to a comfortable level, and took a drive. 

 

It has never run better. Pulls strong (I'm still surprised by how fast thing thing is), valves are very quiet, and the stumble at low speeds is almost entirely gone, so it must have been the timing causing that particular issue. It does occasionally hiccup ever so slightly at very low speeds and low RPM, so I'm not sure what is left to tune to eliminate it, but it's MUCH better than it was. I always get in trouble chasing that last 2% of perfection, so I think I should leave it alone. 

 

 

The idle is still kind of random but I think that'll get better with some driving and fine-tuning. Temperature remained rock solid at 160 degrees, and even while tuning it sitting still in the shop at 300 RPM it only went up to about 185 after 45 minutes or so--the cooling system is healthy. And I guess it's worth mentioning that it spent the night outside earlier this week when someone at the shop misplaced the keys (not me) and the next morning when it was 37 degrees and raining, it fired right up without issues so the carburetors are dialed-in.

 

The only thing bothering me right now is that stupid fan belt--it's easily the loudest thing on the car, followed by the faint THUMP-THUMP-THUMP of the fuel pump, which I think is on its way out. I'll get a new one shortly; that's an easy project and I'm going to rebuild the entire fuel system anyway. 

 

What next? Maybe pull the rear shocks to have them rebuilt again? Install my back-up light switch? Some weather seals? Second muffler? Turn signal indicators in the dash?

 

I guess we'll see. Regardless, it felt really good to succeed today.

 

 

Hi Matt, glad to hear the Limited is getting her groove back. That should improve your outlook on car life a bit. With time all ills get wrestled to the ground. My 41 was driving me nuts with its popping noise forcing me to do things that in the end were totally unnecessary but didnt hurt either. Now running better then it ever has in time for spring is very nice even if all the car shows are canceled this season.

I am trying to see what of the three holes your pump rods are attached. Looks to be the middle hole? If so I suggest you use the top hole for the least amount of throw and less fuel from the accelerator pump. The stumble should diminish even more or go away. A slightly higher idle helps as well. This low rpm stumble went away when I swapped the AV 16's for Carter 518's from the 248 motor and in general the motor is crisper in every way and less timing advance sensitive at low rpm. I am convinced the ultimate setup is with the smaller series carbs. Hope you and yours stay strong and healthy and cruising! Lawrence

[Matt Harwood]

15 hours ago, Bloo said:

Im running a fabric wrapped "Bando Power King" industrial belt on the Pontiac. Mine is a B series. I am pretty sure the Buick 320 uses a wider one, probably a C series.

 

https://www.bandousa.com/power-king

 

That's a good source to have. I just bought this one (for $7 bucks, how can I go wrong?). It's about an inch smaller in circumference than the original but I think there should be enough adjustment in the generator bracket to accommodate it.

 

https://www.vbeltsupply.com/c47-classic-belt.html

 

If that doesn't work, I'll try the Bando. Thanks for the tip!

[John_Mereness]

Maybe pull the rear shocks to have them rebuilt again?  - Try Five Points shocks https://fivepointsclassicautoshocks.com/  - I have been using for 15 years or so and turn everyone I know onto them.  I guess you could be the first person I know with a problem post rebuild, but have never heard a bad work yet, so worth the gamble in my opinion. 

[FLYER15015]

Hey Matt,

If you really want to quiet down your valve noise, you need one of these.

It shows Chevy, but they made them for Buicks too.

 

Edited April 14, 2020 by FLYER15015 (see edit history)

[Dynaflash8]

On 4/11/2020 at 7:10 PM, Matt Harwood said:

The only thing bothering me right now is that stupid fan belt--it's easily the loudest thing on the car, followed by the faint THUMP-THUMP-THUMP of the fuel pump, which I think is on its way out. I'll get a new one shortly; that's an easy project and I'm going to rebuild the entire fuel system anyway. 

Matt: It takes the guy in NJ (CARS) about three weeks to rebuild a fuel pump.  It is good if  you have a used spare to send him in advance.

I thought I had my Roadmaster fixed.  After I got it back from the shop that also rebuilt the front end and cleaned the carbs, a day or so later I took it downtown to get some non-ethanol gas.  It ran better than before, but after I got gas and was coming back home I floored it and it shut down twice.  I hardly had time to grab the electric fuel pump switch and it was back on both times.  I'm wondering if it still had some water in the gas.  It was like a vapor lock which I get with my '39 whenever I have to use ethanol, but it was quicker like turn the ignition off and then back on.  It is very hard to get non-ethanol here in Florida.....only one old gas station in town and I wonder how much $4.00 a gallon gas he actually sells.

 

[Ken_P]

Matt, following along with interest. I used your LED light source, have a quote for Remflex exhaust gaskets (I hate exhaust leaks!) and so - I'm anxiously awaiting your verdict on the new, quieter fan belt. I looked at vbeltsupply.com yesterday, and seems promising, so I'm interested in your results.

[Matt Harwood]

On 4/13/2020 at 11:30 AM, Lawrence Helfand said:

Hi Matt, glad to hear the Limited is getting her groove back. That should improve your outlook on car life a bit. With time all ills get wrestled to the ground. My 41 was driving me nuts with its popping noise forcing me to do things that in the end were totally unnecessary but didnt hurt either. Now running better then it ever has in time for spring is very nice even if all the car shows are canceled this season.

I am trying to see what of the three holes your pump rods are attached. Looks to be the middle hole? If so I suggest you use the top hole for the least amount of throw and less fuel from the accelerator pump. The stumble should diminish even more or go away. A slightly higher idle helps as well. This low rpm stumble went away when I swapped the AV 16's for Carter 518's from the 248 motor and in general the motor is crisper in every way and less timing advance sensitive at low rpm. I am convinced the ultimate setup is with the smaller series carbs. Hope you and yours stay strong and healthy and cruising! Lawrence

 

Thanks, Lawrence. I'm going to take your advice there--I noticed that not only are my accelerator rods on the middle hole, but the rear carb (this car's former front carb) that it is routed to the OUTSIDE of the cam on the throttle shaft, so it's not even aligned correctly. I was looking at it after reading your post and saw that the front carb's linkage was almost perfectly vertical, but the rear carb was at an odd angle. You can kind of see it in the most recent video, above. I'll correct that and move it to the lowest setting and maybe that will help with the off-idle buck, which is still there--greatly diminished, but still there. I may try that tonight, although it's currently about 40 degrees here so any improvements will be hard to quantify.

 

On top of the cold weather, this car also runs ice cold. I'm relieved that my cooling system upgrades were positive, but maybe it's too efficient now. It never really warms up. I've been driving it for the past few days and while it was cool outside, the thing runs at about 150-155 degrees and I can watch the thermostat opening and closing fairly rapidly on the gauge--it never goes above 160. It also takes a VERY long time to get the carburetors warm so it runs right. I'm not going to change anything until the weather gets hot and I can truly evaluate what the new normal is, but I'm sort of leaning towards a 180-degree thermostat. The carburetors seem to like a bit more heat than they're getting since they're decoupled from the exhaust manifolds now. Again, no changes until hot weather, but there's so much excess cooling capacity that it should be able to maintain 180 degrees no matter the conditions. On the to-do list for warmer weather.

 

 

On 4/14/2020 at 11:49 AM, John_Mereness said:

Maybe pull the rear shocks to have them rebuilt again?  - Try Five Points shocks https://fivepointsclassicautoshocks.com/  - I have been using for 15 years or so and turn everyone I know onto them.  I guess you could be the first person I know with a problem post rebuild, but have never heard a bad work yet, so worth the gamble in my opinion. 

 

You're the second person to recommend Five Points to me. I've had good luck with Apple Hydraulics and I'm confident that Lazar will rebuild the rear shocks again and fix them without a hassle. I think one is good, but the other is pretty limp. I used thicker oil in them to firm up the rear damping, which helped quite a bit, but it still bounds over big dips to the point where it bottoms out. Apple will take care of it, I'm sure.

 

 

22 hours ago, FLYER15015 said:

Hey Matt,

If you really want to quiet down your valve noise, you need one of these.

It shows Chevy, but they made them for Buicks too.

 

 

What the deuce is that thing? I can't quite make out how it works? An insulation pad inside the valve cover or something?

 

 

18 hours ago, Dynaflash8 said:

Matt: It takes the guy in NJ (CARS) about three weeks to rebuild a fuel pump.  It is good if  you have a used spare to send him in advance.

I thought I had my Roadmaster fixed.  After I got it back from the shop that also rebuilt the front end and cleaned the carbs, a day or so later I took it downtown to get some non-ethanol gas.  It ran better than before, but after I got gas and was coming back home I floored it and it shut down twice.  I hardly had time to grab the electric fuel pump switch and it was back on both times.  I'm wondering if it still had some water in the gas.  It was like a vapor lock which I get with my '39 whenever I have to use ethanol, but it was quicker like turn the ignition off and then back on.  It is very hard to get non-ethanol here in Florida.....only one old gas station in town and I wonder how much $4.00 a gallon gas he actually sells.

 

 

I haven't had a serious problem with ethanol gas in any of my cars other than after some long-term storage. However, it does percolate more easily at lower temperatures (I think it boils around 160 degrees). That can cause problems in carburetors on really hot days, but the electric fuel pumps definitely help. I think my Limited should be largely immune to that sort of thing now that the exhaust isn't cooking the intake, but I have experienced what you describe in the past, usually while sitting in traffic on a hot day or when I've been running at higher speeds for a while and have to come to a stop, like at the red light at the top of an exit ramp after being on the highway. Those conditions are ideal for modern fuels to vaporize in the pump, lines, and/or carburetors. Lots of heat and suddenly pump output drops to near zero because the engine is idling. The cooling system isn't moving much coolant or air, so the heat remains but fuel is almost sitting still, which is very much like the heat soak that you get when you shut it off hot. It just gets hotter and hotter until it boils, which doesn't take very long at all (it's only about four or five tablespoons of gas).

 

An electric pump should not be regarded as a crutch or a band-aid, but rather as a solution to a problem that didn't exist in 1941. I found that I could often eliminate any traces of vapor lock by applying the electric pump BEFORE those situations arise. When I would come off the highway, I'd switch it on before I came to a stop so that the gas would keep moving and have a little pressure on it to stave off the boiling (if you really want to cure the situation, install a return line to the tank so that gas can circulate instead of dead-heading against the float valve). By acting pre-emptively, you can often eliminate the situation altogether. It's probably a non-issue for me now with the new exhaust manifolds (as I said above, this car almost runs too cool now), although I still use the electric pump for priming purposes. In fact, I ran out of gas in the shop yesterday--I literally drove it to work, then apparently had just enough to pull it inside and idle for 30 seconds, and then it sputtered to a stop. The electric pump ensured that it fired up instantly after a refill.

 

Note to self: fix the gas gauge and add a sending unit to the list of things to buy once we're back on solid footing again.

 

I also have a fuel pump rebuild kit from Then-And-Now Automotive on its way. Several restorers I trust recommended their kits over others. Jim Capaldi said that the one thing that often causes problems and the step most rebuilds skip is to slightly clean and lap the valve seat in the pump. The kits usually supply new valves, but the seats get pitted and if they aren't cleaned then they don't seal properly. There are also a variety of different springs, which can affect how much pressure the pump puts out so it's important to make sure you get the right spring. I'll give it a try--how hard can it be?

 

 

I think the next projects I'll tackle will be to pull the shocks, get my dash indicators working for the turn signals, and perhaps even to install my back-up light switch, which I've had for like 5 years and just never got around to it. It's a cool little trick that I'll show you when I tackle the job.

[Dynaflash8]

49 minutes ago, Matt Harwood said:

 

Thanks, Lawrence. I'm going to take your advice there--I noticed that not only are my accelerator rods on the middle hole, but the rear carb (this car's former front carb) that it is routed to the OUTSIDE of the cam on the throttle shaft, so it's not even aligned correctly. I was looking at it after reading your post and saw that the front carb's linkage was almost perfectly vertical, but the rear carb was at an odd angle. You can kind of see it in the most recent video, above. I'll correct that and move it to the lowest setting and maybe that will help with the off-idle buck, which is still there--greatly diminished, but still there. I may try that tonight, although it's currently about 40 degrees here so any improvements will be hard to quantify.

 

On top of the cold weather, this car also runs ice cold. I'm relieved that my cooling system upgrades were positive, but maybe it's too efficient now. It never really warms up. I've been driving it for the past few days and while it was cool outside, the thing runs at about 150-155 degrees and I can watch the thermostat opening and closing fairly rapidly on the gauge--it never goes above 160. It also takes a VERY long time to get the carburetors warm so it runs right. I'm not going to change anything until the weather gets hot and I can truly evaluate what the new normal is, but I'm sort of leaning towards a 180-degree thermostat. The carburetors seem to like a bit more heat than they're getting since they're decoupled from the exhaust manifolds now. Again, no changes until hot weather, but there's so much excess cooling capacity that it should be able to maintain 180 degrees no matter the conditions. On the to-do list for warmer weather.

 

 

 

You're the second person to recommend Five Points to me. I've had good luck with Apple Hydraulics and I'm confident that Lazar will rebuild the rear shocks again and fix them without a hassle. I think one is good, but the other is pretty limp. I used thicker oil in them to firm up the rear damping, which helped quite a bit, but it still bounds over big dips to the point where it bottoms out. Apple will take care of it, I'm sure.

 

 

 

What the deuce is that thing? I can't quite make out how it works? An insulation pad inside the valve cover or something?

 

 

 

I haven't had a serious problem with ethanol gas in any of my cars other than after some long-term storage. However, it does percolate more easily at lower temperatures (I think it boils around 160 degrees). That can cause problems in carburetors on really hot days, but the electric fuel pumps definitely help. I think my Limited should be largely immune to that sort of thing now that the exhaust isn't cooking the intake, but I have experienced what you describe in the past, usually while sitting in traffic on a hot day or when I've been running at higher speeds for a while and have to come to a stop, like at the red light at the top of an exit ramp after being on the highway. Those conditions are ideal for modern fuels to vaporize in the pump, lines, and/or carburetors. Lots of heat and suddenly pump output drops to near zero because the engine is idling. The cooling system isn't moving much coolant or air, so the heat remains but fuel is almost sitting still, which is very much like the heat soak that you get when you shut it off hot. It just gets hotter and hotter until it boils, which doesn't take very long at all (it's only about four or five tablespoons of gas).

 

An electric pump should not be regarded as a crutch or a band-aid, but rather as a solution to a problem that didn't exist in 1941. I found that I could often eliminate any traces of vapor lock by applying the electric pump BEFORE those situations arise. When I would come off the highway, I'd switch it on before I came to a stop so that the gas would keep moving and have a little pressure on it to stave off the boiling (if you really want to cure the situation, install a return line to the tank so that gas can circulate instead of dead-heading against the float valve). By acting pre-emptively, you can often eliminate the situation altogether. It's probably a non-issue for me now with the new exhaust manifolds (as I said above, this car almost runs too cool now), although I still use the electric pump for priming purposes. In fact, I ran out of gas in the shop yesterday--I literally drove it to work, then apparently had just enough to pull it inside and idle for 30 seconds, and then it sputtered to a stop. The electric pump ensured that it fired up instantly after a refill.

 

Note to self: fix the gas gauge and add a sending unit to the list of things to buy once we're back on solid footing again.

 

I also have a fuel pump rebuild kit from Then-And-Now Automotive on its way. Several restorers I trust recommended their kits over others. Jim Capaldi said that the one thing that often causes problems and the step most rebuilds skip is to slightly clean and lap the valve seat in the pump. The kits usually supply new valves, but the seats get pitted and if they aren't cleaned then they don't seal properly. There are also a variety of different springs, which can affect how much pressure the pump puts out so it's important to make sure you get the right spring. I'll give it a try--how hard can it be?

 

 

I think the next projects I'll tackle will be to pull the shocks, get my dash indicators working for the turn signals, and perhaps even to install my back-up light switch, which I've had for like 5 years and just never got around to it. It's a cool little trick that I'll show you when I tackle the job.

Matt:  Up until most recently all of my trouble with ethanol gas has been with my '39 Buick.  It gets really hot here in south central Florida.  I'm not sure what is going on with the '41.  I haven't been able to get out of the house for nearly a month now.  Anyway, with the '39  I can be running along 55-60 on the highway on a day in the high 80s or 90s and it will simply run out of gas.  I turn on the electric fuel pump and it starts up right away and goes on.  Also, if I stop for gas or at a store, the old '39 will start right  up and go about 100 feet and run out of gas.  I have to restart it with the electric fuel pump.  One problem I can see is that the steel gas line runs from the fuel pump on the right side of the engine across in front of the engine to the carburetor on the left side of the engine.  Where it crosses over it is clamped into a metal clip that is bolted to the cylinder head right at the thermostat housing.  I improved the car somewhat with the use of a foam sandwich from Home Depot that is designed to use on home water heater pipes to keep them from freezing in winter.  I have found a 1941 Limited 90F in driver condition.  It's probably too late for me now since I'm 81.  And, my Roadmaster is finished.  I got the Limited declared Full Classics back in 1974 or 1975 by myself.  The Roadmaster took until 2018, with help from Doug Seybod, Terry Boyce and I guess others, but in any case now it is a Full Classic too.