Basic Questions, 1986 454 Class A

[QRTRHRS]

I borrowed a friend's South Wind Class A for a three day trip to upper New York state over xmas. She had bought this rig for herself and her gentleman friend, planning on doing some travelling. Neither of them are(were) to able to maintain this thing and he passed away five weeks ago. In addition to making sure it will be road worthy, I am going over it for her.



Gas: this one still calls for leaded. She was using regular and I don't hear any knocking. Any suggestions on octane? How about a lead additive once in awhile?



Oil: 10-30 or 5-30?



GVWR is 11,800. It has air bags inside the front coils but just a static system. Assuming it holds air, I need a ballpark value on air pressure? It will just be two people and two dogs, no water, minimal luggage.



Gas furnace. It has a Suburban furnace. Can I operate it while moving or is it best to shut it down? TIA

 

[drees1]

Gas, Should run on anything 87 octane or higher. Most engines requiring leaded will do ok on the latest unleaded gas. But it never hurts to add some, especially if the engine is working hard. The lead was to help the exhaust seats from burning, but the newer gasolines do not seem so bad.



Oil. Whatever the manual says for temp, conditions, and type of operation. Personally, in NY, I would run 10-30 in the winter and straight 30 in the summer.



Suburban furnace. Tough call. Depends on the installation and exhaust ducting to the outside. If it is in good order try it and keep your eye on it. It will certainly run ok while it is on and making heat, as it has forced combustion air and exhaust to the outside of the coach. But when it reaches temp and shuts off, outside disturbances, like passing a semi, on comming, could blow out the pilot. If that happens, the gas will shut off and you will just get cold and have to relight it. I have owned several and had some work ok and others blow out. Just try it. Of course, to be safe, you should travel with the propane tank shut. Your call.



Air bags. Only someone with your exact make and model would know the correct pressure. Try the southwind dealer.



Good luck



Doug Rees

 

[DPelletier]

Don't know about the rest of the stuff, but as far as gasoline goes;

Doug is correct, but to be clear, lead was removed from gasoline as it plugged up the pellet type catylitic converters that were the first type that came out in 1973. Lead was originally used to prevent wear of the valve seats. Engines built after 1973 (approximately - some manufactures varied by a year or two) typically have hardened valve seats that don't require lead. In an application such as your motorhome, it would have been exempt from the requirement to have a converter, but I believe that long before 1986 - all engines were produced with hardened valve seats. If you want to be sure you would have to get the casting numbers off of the heads themselves and do some research. A good engine rebuild shop should be able to tell you for sure, but my guess is that your fine with unleaded.

The octane issue is based primarily on compression ratios (an oversimplification as timing and camshaft profiles also have a part to play), simply stated, most engines built prior to 1971 ran between 9 1/2:1 and 11 3/4:1, after 1971 compression ratios were reduced with most V-8's running at 8 1/2:1 compression.

87 octane should be OK, but if it knocks, move up a grade.



Oh, and I also agree with Doug on the oil. A 454 will run on the hot side in this application (usually) and you want to make sure you have a thick enough viscosity oil in the summer



Dave

 

[QRTRHRS]

Thanks guys, I will only be putting maybe a thousand miles on this thing. So far, I only drove it home from my friend's house, about 30 miles, and it seems to run okay. No knocks and plenty of power.



I already picked up a case of Valvoline 10-30 for it.



The manuals are all there. The GM manual says to use leaded but it is okay to use unleaded on occasion, ha!



I guess I will put maybe 15lbs in the airbags and if they don't leak, see what that feels like. I just kind of wanted some general feedback on someone who uses them.



Like I said, my friend is not to capable. I just want to help her out for letting me use it.



My dogs already gave it their approval. I figure the rottie will park her butt on the engine cover so she can "ambush" trucks.

 

[B.G. Smith]

Beside the point but

The lead in gasoline was anti-knock compound to control the combustion of gasoline, (spark knock, valve clatter). There werer additives in the compound for the valves but the reason it was added to gasoline was not to protect the valves. There was great concern when switching to unleaded fuel that the valves would suffer however that has not been the case and valve problems have all but dissapeared. I spent 22 years in a tetra ethyl lead manufacturing plant. Also, the Suburban heater has an auto ignition system, no pilot light and you can run it while on the road( if it's freezing outside you will have to run it to keep the tanks from freezing). bg

 

[nball]

To low air pressure in the airbags will cause them to rub against the coil springs and it won't be long until replacement is required. It been a lot of years but it seems 40-60 psi it what the dealer told me... I drove from Ohio to Texas a few years ago in my 31ft Winne with the furnace on with no problems... ... norm

 

[Underdog]

If it pings,go to a higher octane.

As for the furnace,for safety you might consider turning it

and the refrigerator ( if gas ) off ,while you are at a

refueling station. A gasoline explosion can ruin your day.

 

[QRTRHRS]

Thanks for the replies.

I spent all day Sunday doing as much as I could. The Suburban heater is automatic and it fired up and shut down correctly. It does stay lit while in motion, no problem. For only a three day trip, I won't bother with the wet system or the fridge.



40lbs in the coil spring airbags seems to be working.



Now if the weather cooperates, all systems are go. I was planning on taking 81 north but I heard the lake effect has it shut down north of Syracuse, New York.