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Hi,

I just wanted to introduce myself to this forum. I have read it off and on over the last year when I purchased my 48 Aerosedan and now feel that I should be a participant in the forum. Here are the details on my car:

1948 Aerosedan with 36,xxx original miles.

Was originally two-tone green, but was painted red in 1999.

Has a visor and skirts, original interior in pretty good shape.

Underseat heater, defroster.

Vacuum shift was removed at some point in it's life, probably when it was dragged out of the barn in 98 or 99. I have some pics of the car when it was brought out. It's last registration was in 1972 in Indiana.

Original motor/trans is in the car. I received a 235 6cyl engine and some other odds and ends when I purchased the car in July of '08.

All I have done to the car is change out the fluids, minor maintenance, some cleaning/detailing on the car and driving it.

Car runs out well, but it has a minor 'skip' at idle. I've changed out the cap, wires, plugs and adjusted the carb to no avail. Seems like it may be a timing issue or something to do with the octane setting on the dizzy. Not sure how those 2 adjustments should be done. I know that the timing mark is done with a light on the steel ball on the flywheel, but at what RPM should I check that it is correctly set? Also, there are no marks or indicators on the octane setting dial on the dizzy. How do I know if I am at the correct octane setting?

One other question. My under seat heater/defroster does not blow heat. I have opened the valve on the water pump to allow the water to flow through, but no heat is generated whatsoever. Is it possible that the the hoses were incorrectly routed? Thanks for taking the time to read my long post and I hope to be a contributor and valued member to this forum.

Tony

Tony,
Welcome and hope we can share information.
Most possible cause for the "minor skip at idle" would be a burnt exhaust valve. A compression test would tell the tale. Other tan taht could be dirt in the low speed jet or a vacuum leak. It was common for these engines to require a valve job by 35,000 miles.
The timing can be set where the car runs the best. This is usually at about 8 degrees advanced. That would be first set the timing with a light - so the ball in the flywheel lines up with the pointer at a slow idle. The adjust the octane to the center "0" position. The timing is now set to run on the regular grade of gas available in 1948 which would have been about 70 octane. I find the engines run the best by then advancing the octane selector to the + 8 or +10 for todays much hiher octane gas . The fact that gas contains no lead has no effect and a lead additive is not necessary (and does not contain lead).If the timing is advanced too far the engine will turn over "hard" with the starter - worse when hot. Also may surge a little at mid speeds and a steady speed.
The octane selector is just a means of experiamenting with the timing while on the road. The timing will not cause a ship at idle unless its way off.
Even if the heater hoses are incorrectly connected they should still get hot. I would experiment by removing both hoses at the engine and placing the garden hose at the end of either heater hose. The other hose shold have water flowing out of it....possible plugged-up heater core if water does not flow.

Hello TeeZee and welcome to Chevy Chat. This is the best place to get answers to your Chevy questions .........and you started off great......Chev Nut is the very best to get advice from. If you look around and do some searches for specific questions, there's a lot of info here for your model Chevy. We all look forward to sharing information about our Aeros. Come back often.....and think about becoming a VCCA member. Lots of perks there.....a great magazine (G&D) every month, access to members only areas of this site, access to past G&D articles, great friendships.......the list goes on and on. Hey, enjoy and think about it.

I'd also do some basic checks of the spark plug wires, spark plugs. Check the contacts on the inside of the distributor cap also and the rotor contacts. Then maybe get the car good and warmed up and check the valve settings. Once warmed up good and if everything checks out do a compression test. That may point you down the right path if some of the simple stuff doesn't help. Good Luck Don

Thanks for the advice chevgene. I will check the compression and to see if there is a vacuum leak. If those check out OK, then I'll look at the carb. BTW, I did disconnect the vacuum lines last winter when I was doing some cleaning/detailing on the engine, and that's when I first noticed the car was not running like before. Might be my first stop in troubleshooting this. I'll also do a check on the timing as you suggested. I think that will check out OK as that car starts up right away when it's been sitting or has been warmed up. As for the octane setting dial on the distributor, there are no numbers or numerals anywhere that I can see on the dial itself to know what it's set at, so I'm at a loss right now. The heater issue seems to have have "self corrected". I started and ran the car for about 20 minutes yesterday and when the temp gauge was almost at it's normal operating range, I turned on the heater, and presto! I could feel some heat flowing from under the seat. Not a lot, but heat nonetheless. If I determine the heater/defroster are not pumping out enough heat, I may do what you suggest and take the hoses off the engine side and see if any water flows through them to see if the heater core is plugged up or not. Thanks again for the help, it is most appreciated.

Tony

Maybe your octane adjuster grid is just covered with crud? Mine was. Maybe you already know this stuff but here's where to look on a '50. I'm guessing most of them are similar. Adjustment is by loosening the bolt to the left and gently rotating the dizzy by holding the vacuum advance. You will hear the difference.
http://chevy.oldcarmanualproject.com/shop/1949_53/06engine/6_029.HTM

Dean50,

Thanks. That pretty much looks like my set up. The octane dial is pretty clean, but maybe I'll try cleaning it up and take another look/see. At this time, I don't think it's a timing issue, but could be a vacuum leak or carb related problem that is causing my car to 'skip' a little.

Tony

OK, here's the latest. I drove the car last week and the heater/defroster both work. No worries there. I did notice that when going down any hills while in gear and the car is on it's own power, I could hear what is best described as a 'burping' or 'belching' sound. If I step on the gas, the burping/belching sound will go away until I ease off the gas, then the noise returns. It almost seems that the car wants to backfire through the exhaust. When the car is in neutral going down any hill, it does not do this. Not sure what might be causing this. Any ideas?

Did you ever check the compression? If it has a bad valve (or an exhaust leak) it will do this.

Chev Nut,

No, I never did. If it turns out that I have a bad valve, is this an easy fix or not? Thanks for all your help.

Tony

The cylinder head would need to be removed and taken to a shop that does engine work. There is more to it than just unbolting the head. The rocker arm assembly and push rods and maniflods must be removed. For a first timer t could be a challenge.

Chev Nut (Gene),

Thanks. Not too worried about the first time doing this type of work aspect of this. I've worked on many cars over the years but have never had to remove the head off a inline six before. Anyway, I'll probably do the compression check within the next week and that should tell me more. I'll probably start a new topic/thread if necessary. Thanks again, your assistance is much appreciated.

Tony

It is a good possibilty that your carburetor is set a little on the rich side. Last year my 53 had the same symptons. A friend has an exhaust analyser hooked it up and reset the carb mixture less than a half turn lean - no problem since in over 2000 miles.