Looking for suggestions: need time for pre-buy

[mhorowit]

Re: Looking for suggestions: need time for pre-buy

If $14K is a baseline for a 500-hour-engine on an airplane with "good" fabric (Crispy now says that's a bargain--I agree), then some amount should be factored in for engine overhaul and recover. For example, if $4.00 per hour is the cost of an overhaul at TBO, then a 0 SMOH airplane would be worth $2K more. If twenty years is a reasonable time between recover jobs on average, and it costs $15K to do the recover and associated repairs, and assuming your basic airplane has ten years on its cover, then a brand new cover job would add another $7.5K to the value. Now a rebuilt, 0 time airplane in this example would be worth $23.5K. Just a way to look at it. Obviously, TCrafts are not going that high, and there's a lot of other factors to consider, but if you're buying a plane to hold on to, as most of us seem to do, it makes a lot of sense to buy a good plane to begin with and it's going to cost more.

Hmm. hadn't thought of amortization, but now that you mention it that makes good sense. What did the group decide a recently O/H'd A-65 was worth? - Mike

[alwaysoar]

Re: Looking for suggestions: need time for pre-buy

I don't know what the group thinks, but my overhaul less labor cost $6,000 not including mags (just bought new Slicks--add in $1100 or Carb overhaul add in $350.00). Round that out, $7500.00. There was discussion earlier about recover jobs and I mentioned the guy around here does them for $10K. That's low, and does not include tube/wood work and other repairs )e.g. gas tanks, etc., that need work after twenty years. Taylorcrafts are going too cheap, though there are a lot of them out there that are beautiful that aren't for sale, and I don't know what $ the owners figure they're worth.

You can no longer buy land in Vermont for $100 an acre (I did once), and you can't find a decent TCraft for $12,500.

[lawheelock]

Re: Looking for suggestions: need time for pre-buy

Mike, on the subject of auto fuel:
The author of the reply to you that seems to have an un-scientifically based aversion to auto fuel (with the proper STC in place) gave good advice on all the other issues.
I do have to firmly disagree with him on the auto fuel issue. True, some of the old Stromberg carbs have a rubber type float needle that does not do well, however the solvents in 100LL cause exactly the same problems as they are mostly the same as in the New auto fuel. Those with the metal to metal float valve seats won't be affected other than the normal wear from vibration that made them a problem years ago.
I cannot say that I have ever seen any damage to an aircraft engine that was caused by auto fuel usage. I have seen extensive damage to aircraft engines that were designed for 80 octane and have been run consistantly on 100LL (which has 4 times as much lead as the old 80/87). The damage is usually to the valves. The old low compression engines never run high enough combustion temperatures to vaporize the lead and it ends up depositing on the valve seats. As it builds up on the seats, the lead thermally insulates the valve face from the seat. Valves are cooled during the time they are on the seats and if they are insulated from the seats they will develop hot spots and you end up with a burned valve. Air cooled engines have a difficult time in properly cooling the exhaust valves and if anything interfers with the thermal cooling path, damage results.
The bottom line is that if auto fuel was so bad, we would see thousands of cars strewn along the roadways. Most of these auto engines have parts and fuel systems that are much more suceptable to attack by the bad stuff that the author says is in the auto fuel than the simple systems and engines in a T-Craft or most any of the other old airplanes.
Larry Wheelock, A&P, IA, Professional Engineer

[VictorBravo]

Re: Looking for suggestions: need time for pre-buy

OK, but what about all thew additives they put in car gas today that were not put in way back when? I'm absolutely not an expert on it, but I have heard from others who are that there is lots of crap in there now that was not there before. All the ethanols and "clean burning" stuff. Here in California we probably have more stuff in the gas, but maybe not anymore.

One fellow just posted that a carburetor overhaul was $750 I recall. If the car gas caused even the slightest problem with the carb, a conservative owner would have the carb done. So knock that off the price of the plane, IMHO.

One point I was trying to make is that somebody __ineptly__ fooling around with a good carburetor, to modify it for car gas, made my plane unsafe to fly which I didn't know when I bought it. When it quit on me, I was lucky to be over a runway...so knock off one pair of underwear and 5 years worth of gray hair from the price.

I don't know whether there is 80/87 octane gas available in most parts of the country now, anyway. If it was, I can't imagine the cost. The carbs were designed to run on 80, and using 100LL causes it's own problems as you said.

I actually hope that somebody develops a modification that allows today's car gas to be used safely in older airplanes. But I sincerely think that the old EAA STC is not as valid today because of new car gas issues... I understand that the EAA STC involves testing the gas, and if it has the stuff in it that most car gas has today, you can't pour it into your airplane. Is this correct?

My further amateur understanding is that the car gas eats up or swells the rubber seals that are in the fuel system, fuel valves, seals, etc.

Does anyone know the real story about what the additives, ethanol, and other stuff are? Is there a real expert who can de-cipher this in terms of TODAY's auto gas being used in yesterday's engines?

If there was a safe, reliable way that didn't cause any engine problems and was just as reliable, then I'd be glad to use car gas and save the money just like everyone else.

[lfries]

Re: Looking for suggestions: need time for pre-buy

Car gas is one of those issues that we do or we don't. I have the STC used it and had to have the push rod tubes re seated twice. I don't know why. I do know that when I stayed with 100ll and an infrequent use of 80/87 the tubes have not needed to be re seated. Were talking years here vs months on the autogas. I know that I haven't had 100ll problems and attribute that to running around at 2250 rpms. Someone once told me to just run the engine a little harder to keep the build up off the valves. I know what has worked for me and what hasn't so I'll stay with what has. I do know people who only use car gas and are happy. Naturally they burn a few more gallons per hour so it probably makes a major $ difference for them.

[M Towsley]

Re: Looking for suggestions: need time for pre-buy

VB,

That "stuff" you are talking about is ethanol, (corn alcohol). The original 1980's EAA STC for my plane stated to not use gasoline with alcohol. Being from a corn state ethanol is big around here and is in just about every fuel at every gas station. Very few have regular grade gas without it. Ethanol is one of those ingredients that swells the neoprene tip on the needle and causes other crap to loosen up from gas tanks, swell fuel lines, etc. This was a major problem with Japanese motorcycles in the '70's when they had fuel system problems when gasahol was first introduced. A simple test with a graduated test tube and water can tell you in a couple of minutes if there is ethanol in the gas. As I have stated before, all the majors, BP, Shell, etc., supposedly don't have ethanol in their high grade (octane) gas. But test just in case. I have been burning regular grade ethanol free gas with no problems and run a little 100LL when I am usually away from home base. The change to your carburetor probably should only have been a stainless steel or delrin tipped needle, with an added weight to the float, with the mogas STC. Not sure if anything else should have been done. Hope this helps........

[flyguy]

Re: Looking for suggestions: need time for pre-buy

Maybe we should change this thread name to Auto Gas Usage In Aircraft. Lol.
Anyway, I'm waiting for Fedex delivery of my subframe mounts for my 74 Z28 camaro, so here is my two cents worth on the subject.
First, if you have a 65 with a stock (certified ) coating (shellac) on the fuel quantity float, you do not want to use car gas with alcohol in it, and don't ask me how I know. Mine is now coated with marine epoxy and I don't care if it is certified or not.
Fact: in or around 2003 there was a law passed by CONGRESS that MANDATED the use of ethyl alcohol (horray for the farming lobby) in ALL car gas in the U.S.
California managed to hold off until 2005 because there apparently wasn't enough alcohol to go around and we were having so much trouble just getting the poision MTBE (that the state government had mandated) out of our gas.
Now every california gas that I have tested has alcohol in it. Shell. Exxon, Arco, Joe's Rotgut Stuff, ect.
Marty, and anyone else, are you saying there is gas available in the lower 48 that doesn't have alcohol in it? I keep hearing that on this forum, but I wonder how the states involved are getting around the federal law.
Anyone know anything about that?
I personally suspect that the use of car gas, even with say 5% alcohol, like we have here, is a lot less likely to get you in trouble than hundreds of other dangerous things that happen to an airplane over the course of it's life.
Darryl

[mhorowit]

Re: Looking for suggestions: need time for pre-buy

Marty, and anyone else, are you saying there is gas available in the lower 48 that doesn't have alcohol in it? I keep hearing that on this forum, but I wonder how the states involved are getting around the federal law.
Anyone know anything about that?
Darryl

Oh Yeah!. Here in Virginia, I'm very careful to test the autogas for alcohol, 'cause of the damage it can cause. So far, no alcohol at the CITCO station next to the airport. - Mike

[lktiller]

Re: Looking for suggestions: need time for pre-buy

Please, no one be insulted here!!!! Just trying to stop some misinformation.

-there is no CURRENT federal law requiring the addition of ethanol to auto fuel across the U.S.A.
-Calif. maybe but not in the u.s.of a. (watching for flames)
-Vibration and A&Ps are the most likely causes of oil leaks in the pushrod tubes.
-no carb mod or adjustments to the Cont 65-75 is allowed under the autofuel STC. Only mod is to place that sticker near the fuel filler cap.
- I agree alcohol will disolve shellac, then so will gasoline. Or mineral spirits.
-Alcohol will make short work of older rubber fuel tubing but I hope no one has any of that left since the '80s.

[selje]

Re: Looking for suggestions: need time for pre-buy

I have used the EAA autogas STC on several aircraft without a problem. I test for alcohol on each batch from the local Chevron station and have never had any alcohol. Regular gas works just fine on the A-65 which was designed with minimun octane of 73.

[Guest]

Re: Looking for suggestions: need time for pre-buy

Mike, on the subject of auto fuel:
The author of the reply to you that seems to have an un-scientifically based aversion to auto fuel (with the proper STC in place) gave good advice on all the other issues.
I do have to firmly disagree with him on the auto fuel issue. True, some of the old Stromberg carbs have a rubber type float needle that does not do well, however the solvents in 100LL cause exactly the same problems as they are mostly the same as in the New auto fuel. Those with the metal to metal float valve seats won't be affected other than the normal wear from vibration that made them a problem years ago.
I cannot say that I have ever seen any damage to an aircraft engine that was caused by auto fuel usage. I have seen extensive damage to aircraft engines that were designed for 80 octane and have been run consistantly on 100LL (which has 4 times as much lead as the old 80/87). The damage is usually to the valves. The old low compression engines never run high enough combustion temperatures to vaporize the lead and it ends up depositing on the valve seats. As it builds up on the seats, the lead thermally insulates the valve face from the seat. Valves are cooled during the time they are on the seats and if they are insulated from the seats they will develop hot spots and you end up with a burned valve. Air cooled engines have a difficult time in properly cooling the exhaust valves and if anything interfers with the thermal cooling path, damage results.
The bottom line is that if auto fuel was so bad, we would see thousands of cars strewn along the roadways. Most of these auto engines have parts and fuel systems that are much more suceptable to attack by the bad stuff that the author says is in the auto fuel than the simple systems and engines in a T-Craft or most any of the other old airplanes.
Larry Wheelock, A&P, IA, Professional Engineer

Hey Larry, I was reading the post's on auto fuel, read yours and decided to quote it because of your closing, more on that in a minute.

I have seen "damage" to an engine from using auto fuel with ethanol when the ethanol acted as solvent on the sloshing compound and shellac on the cork and resulted in a wad of soft gooey shellac that cloaged up the carb & fuel lines, Had to take it all apart and clean it all out, I loosely call that "damage".

That was a result of my error in using fuel with ethanol.

Anyhow, I smiled when I saw your closing, glad to see that there are more mechaneers out there.

Dave A&P, IA, PE

[hangarb7]

Re: Looking for suggestions: need time for pre-buy

Mike,

I would like to add my 2 cents because I would certainly do it differently if I ever buy another airplane.

I would buy one locally (did buy N44057 from about 65 airmiles away from a longtime "friend") so that MY mechanic can do the pre-buy. Had I done this originally, I would have saved a lot of aggrevation. I thought I purchased a cream puff that would eventually need the TLC of a sixty year old bird, but instead I got a ship that needed lots of stuff.

But with a different mechanic, it might have needed LESS or MORE. Many of the annual condition inspection decisions are very subjective and some mechanics seeing an old bird for the first time tend to go overboard.

There are lots of Taylorcrafts in our part of the country, Mike. Be patient and you will get one that fits.

Again, my 2 cents.

Jack
'46 BC12D

[d.grimm]

Re: Looking for suggestions: need time for pre-buy

I just came from the other side. Sold my PA22/20 and the guy had the dealers mechanic do a pre-buy. I had maintained and up-graded this aircraft quite a bit in the last couple years. (A&P IA)
This pre-buy turned into the pre-buy from **ll when mechanic started making all these demands. They were all his opinion and judgement.
The only unairworthy item was taillight bulb was out. He tried to charge me $1500 to make my 50 year old airplane brand new.
I still feel my Pacer was one of the very best out there, and now I feel like I have been (you fill in the blank).
Experience and judgement are the two most important things to look for in a mechanic, in my opinion.

[crispy critter]

Re: Looking for suggestions: need time for pre-buy

Did you av-gas guys know that the A-65 has an octane limit of 73-90 octane.How often do you av-gas guys have to pull a cylinder from your A-65 or 75??

[Robert Lees]

Re: Looking for suggestions: need time for pre-buy

Kevin: On our 65-powered BC12D we have done 850 hours in five years, all on 100LL. Not needed to pull a jug yet (touch wood!)