New to me 68 250 - Team Camaro Tech
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post #1 of 42 (permalink) Old May 16th, 20, 06:06 PM Thread Starter
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Jakob
 
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New to me 68 250

Hey guys I just inherited a 68 I6 that hasn't ran in probably 15 years. The car is in great shape, and has spent most of that time in a garage. Older cars are new to me as I cut my teeth on newer FI tech. The reason for this post is I'm trying to figure out the best way to get this thing running again. My main hang up is with the fuel system. I keep seeing things like fuel with and without ethanol, and whether or not the gas is leaded. What does ethanol have to do with anything, and does this car require leaded gas to run? There is fuel currently in the tank, not sure what kind of fuel it is, and who knows how old it is. Does the fuel tank usually get replaced in situations like this? What about the fuel lines?

Thanks for any help you can give me, and stand by for more questions I may think of!

1968 Camaro 250
1991 Z28 LT1/T56 Swap
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post #2 of 42 (permalink) Old May 16th, 20, 07:15 PM
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Pat
 
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Re: New to me 68 250

The issue with ethanol is that over time it will degrade the rubber hoses and other parts in the path from the fuel tank to the engine. You can replace these with modern parts that are compatible with ethanol.

Lead was originally added to gasoline to lubricate the valve seats. Over time, using unleaded fuel will cause the valve seats to wear more quickly than they would with leaded fuel. It's not going to wear out overnight, but if the original service expectency was 100K miles, running unleaded fuel might make you need a valve job after 70K miles. If you're using this as a daily driver, it might be a problem eventually, but if you're just driving it for pleasure, don't worry about that. Leaded fuel hasn't been sold in the US since the 80s (?) so it's a safe bet that this car has been driven on unleaded before.

If the fuel is 15y old, you probably want to siphon out what you can and replace it with fresh gasoline. While it's empty, replace any rubber fuel hose with modern stuff, and you should probably rebuild the carburetor.

Other things to replace before you head out on the road:
- Brake flex hoses (one on each front wheel, a third on the rear near the middle of the diff)
- Tires
- Brake shoes (a full brake job is probably a good idea)
- battery
- engine oil and filter


Things to check:
- coolant, radiator, and heater hoses
- radiator cap
- fan belts
- brake master cylinder, slave cylinders
- spark plugs, plug wires, points, coil, condenser.
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post #3 of 42 (permalink) Old May 16th, 20, 07:43 PM
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Al
 
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Re: New to me 68 250

No the car does not require leaded gas to run/operate. Ethanol can attack rubber and
some gasket materials. The lack of leaded gas can effect the valve seats as they're not
hardened. You can use a lead substitute if you like. Some do some don't. The 15 yr old
gas needs to be removed and tank cleaned. My suggestion is drop the tank to see what
condition it's in. There is a rubber line from the tank to the fuel hard line. Replace that
piece. While the tank is out disconnect the hard line at the fuel pump and blow compressed
air through it and maybe some brake cleaner. Remove the hard fuel line from the pump
to the carb and clean it out. I would also rebuild the carb. It's just a 1 barrel and easily
rebuilt. The new rebuild kit should have ethanol compatible of materials. The fuel sending
unit with filter sock is in the tank and and I would replace it. Keep the lock ring and o-ring.
There have been some problems with the new units being difficult to fit the new lock ring
that comes with the sender. A new gas tank is not very expensive. If you replace it get one
that is Ni-terne coated. Here's a link to one through Amazon.
https://www.amazon.com/1967-68-Camar.../dp/B01G4FUO9Q

Al

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post #4 of 42 (permalink) Old May 16th, 20, 07:48 PM
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Re: New to me 68 250

Tetraethyl lead was a development of fighter airplane use from WWII. It elevated the octane of 84 raw gas used in cars to 104 octane that could be used in a high compression blown airplane engine or a tank. It prevented icing and didn't evaporate as fast as pure ethanol. It found it's way into cars thanks to Chrysler developing the Hemi and Olds developing the rocket engine in the early sixties.

It is ideal for automotive use if you are willing to overlook the issue of lead being a heavy metal poison. Which is why it was supposed to be removed from the market in 1976 but no one wanted to give it up so it hung around until 1984 when it finally disappeared. Alcohol was put in gas by President Jimmy Carter to reduce the strangle hold OPEC had on our gasoline supply. Great theory but that didn't work out so well either.

I suggest dropping the tank and pouring everything out then cleaning it and sealing it with urethane paint inside the tank to prevent further corrosion (they sell kits for this). Replace the tank inlet rubber collar, vent hoses in addition to the recommendations made by Pat above. I would have the brake fluid pressure flushed once you have the brakes rebuilt. The Coolant also needs to be flushed as it turns acidic after sitting two years. Belts and hoses rot with time as they are made of vulcanized tree sap (aka rubber). Also check your wiring as rodents think plastic insulation is tasty, and they use silicone rubber spark plugs for bubble gum.

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post #5 of 42 (permalink) Old May 16th, 20, 09:12 PM
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Re: New to me 68 250

Lead is still around.... in aviation fuel. 100LL works great in old muscle cars.

Your 250 does not require lead, and certainly 100LL would be overkill.

If you can fine ethanol free, that is great. If not, it is not that big a deal. I doubt it will cause issue with your carb. It MAY however cause issues with the fuel lines. Replace the rubber fuel lines with modern FI lines (even though you do not need the high pressure) empty out the old gas. Put some fresh gas in.

I would also remove all the spark plugs, and squirt some oil into the cylinders. Change the oil. Crank it over until the oil pressure light goes out. Put in clean spark plugs (the old ones are fine if they are good and clean) and fire that thing up.

Lynn
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post #6 of 42 (permalink) Old May 17th, 20, 03:34 AM
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Re: New to me 68 250

You are going to need the manual. Someone can point you to the download. If the car has decent brake pedal feel pump them hard a number of times before you change the hoses at the corners. Take the drums off and see if the wheel cylinders are weeping. Everything rubber on the car is suspect. Fuel, brake, vacuum, window & trunk seals. You can see it all.

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post #7 of 42 (permalink) Old May 17th, 20, 04:14 AM
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Re: New to me 68 250

Yes, you can go over to Camaro Research Group, join, and download the manuals, AIM, Service , and Chassis manuals.

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post #8 of 42 (permalink) Old May 17th, 20, 04:56 AM Thread Starter
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Re: New to me 68 250

Wow quite a to do list.
Probably a stupid question but Is replacing the rubber fuel lines as easy as buying a roll of the appropriate size at the store and clamping them on?

Iíve been told that fuel sludge could be a problem?

The tires on the vehicle are pre radial, what is the comparable size?

Thanks for the manual info I will definitely be looking at those

1968 Camaro 250
1991 Z28 LT1/T56 Swap
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post #9 of 42 (permalink) Old May 17th, 20, 08:01 AM
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Re: New to me 68 250

Q. Probably a stupid question but Is replacing the rubber fuel lines as easy as buying a roll of the appropriate size at the store and clamping them on?

A. Yes.

Q. Iíve been told that fuel sludge could be a problem?

A. Don't know about "sludge". If it has been sitting long enough, the gas will mostly evaporate and what is left is normally referred to as varnish. We are probably just playing semantics here. Doesn't matter what you call it. If the gas is only 15 years old, and if it were nearly a full tank when parked, then it may be as simple as emptying the tank and putting fresh gas in. Here is my recent experience with two very different vehicles.

Vehicle 1. 1999 American Cruiser Class C camper van built on a 1 ton Dodge chassis. Obviously a FI motor. Had been sitting 8 years and the gas smelled awful. Also, the in tank pump did not work. I pumped it as empty as I could, then dropped the tank. Removed all of the fuel, and replaced the pump. Pulled the line at the manifold and pumped out all of the old fuel left in the lines. Changed the oil. It started up and ran fine.


Vehicle 2. 1969 Opel GT sitting since 1974. This one was a bit more challenging. Tank had no liquid fuel in it. It probably had half a tank or more when it was parked. There was a half inch thick layer of very dark brown varnish on the bottom of the tank. With the sending unit out, and the inlet tube removed, I could poke a screw driver down there and scrape a bit. It was very hard, just like half dried varnish; hence the term. Other than the thick layer of varnish on the bottom, this tank looked perfect inside. Using flashlight and inspection mirrors I could see there was not a spec of rust. All shiny and new looking. I bought a few gallons of acetone. I put a gallon in the tank and let is sit on the work bench a few days. It softened it up, but did not dissolve it completely. I scraped loose what I could; emptied that acetone and poured in another gallon. This time, I added a couple hundred 1/4 inch washers. Let it sit. Every day I would go down and slosh the washers and acetone around, and ever day it loosened up more of the varnish. Repeated that process until all was clean as could be. Pulled the washers out with a magnet. After getting it back together, I put in some 100ll for good measure. It took about two weeks before my gas gauge started working, as there had apparently been some varnish build up inside the sending unit. Still runs good today.



The tires on the vehicle are pre radial, what is the comparable size?
What size is on it now? Do you like the look of the size you have now?
Guessing the rims are 14 x 6?

Lynn
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post #10 of 42 (permalink) Old May 17th, 20, 12:26 PM Thread Starter
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Re: New to me 68 250

Quote:
Originally Posted by bilodeaulynn View Post
Q. Probably a stupid question but Is replacing the rubber fuel lines as easy as buying a roll of the appropriate size at the store and clamping them on?

A. Yes.
Haha Ok. Im starting to understand why I've always heard people complain how cars used to be so easy to work on.

Quote:
Originally Posted by bilodeaulynn View Post
The tires on the vehicle are pre radial, what is the comparable size?
What size is on it now? Do you like the look of the size you have now?
Guessing the rims are 14 x 6?
D78-14. Which i didn't realize was a tire size until you asked that question. Obviously that realization led to my being able to answer my own question. I think it looks good the way it sits. I'm not looking to modify the stance of the car, at least not right now. I am always a fan of bigger tires. The rims are 14x6

Quote:
Originally Posted by bilodeaulynn View Post
Pulled the line at the manifold and pumped out all of the old fuel left in the lines.
Is this an acceptable way to empty the gas tank?

1968 Camaro 250
1991 Z28 LT1/T56 Swap
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post #11 of 42 (permalink) Old May 17th, 20, 01:14 PM
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Re: New to me 68 250

Quote:
D78-14. Which i didn't realize was a tire size until you asked that question. Obviously that realization led to my being able to answer my own question. I think it looks good the way it sits. I'm not looking to modify the stance of the car, at least not right now. I am always a fan of bigger tires. The rims are 14x6
Years ago took the stock wheels and tires off my 77 Z28 and put them on my Dad's 67. 15" x 8" Looked nice and drove much better. Don't remember the tire size. What ever was stock on a 77 Z.



Quote:
Pulled the line at the manifold and pumped out all of the old fuel left in the lines.
Is this an acceptable way to empty the gas tank?
I bought a small electric fuel pump at the auto parts and pumped into a 5 gallon can. Poured into my 3/4 full 2008 Silverado. Truck did not like it but recovered without service. Old gasoline is not real easy to get rid of unless you burn it. Dangerous and the fire department frowns upon it.

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The older I get the faster I was.
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post #12 of 42 (permalink) Old May 17th, 20, 06:39 PM
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Re: New to me 68 250

Quote:
Originally Posted by scblucam View Post
Years ago took the stock wheels and tires off my 77 Z28 and put them on my Dad's 67. 15" x 8" Looked nice and drove much better. Don't remember the tire size. What ever was stock on a 77 Z.







I bought a small electric fuel pump at the auto parts and pumped into a 5 gallon can. Poured into my 3/4 full 2008 Silverado. Truck did not like it but recovered without service. Old gasoline is not real easy to get rid of unless you burn it. Dangerous and the fire department frowns upon it.
Stock tires and wheels on a 77 z28 were 15x7 5 spokes with 225/70/15 tires

Scott from NJ. Stay thirsty, my friends


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post #13 of 42 (permalink) Old May 17th, 20, 07:58 PM
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Re: New to me 68 250

Quote:
Stock tires and wheels on a 77 z28 were 15x7 5 spokes with 225/70/15 tires
Been a while, thought they were 8". Either way back then they were magic on the 67.

68 302 M20 3:73 - 85 IROC Z - 82 Honda CB900C
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post #14 of 42 (permalink) Old May 17th, 20, 08:16 PM
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Re: New to me 68 250

I was able to pump out the fuel in the lines because the vehicle had an electric pump in the tank. After replacing the tank pump, and reinstalling the tank, it was as easy as turning on the key with the lines disconnected and pointing into a jug.

You your car, it depends on how much is in the tank. It will take a LOT of cranking the engine over to get all the fuel out if you have much in there, because you only have a mechanical pump on the engine. There is no pump in the tank. I only used that method on that vehicle because it had the electric pump in the tank.

I have a hand crank pump hooked up to a 20 gallon barrell. As stated, hard to get rid of. Most larger cities have drop off for hazardous waste. In OKC there is no charge for residents of the City.

I have also used a small electric pump. Either way, be careful. This stuff is volitile.

If you want something close to the original tire size, a 205 75 R14 will work. Kind of skinny by today's standards. That tire would be 26.1 inches (in theory.... in practice, they are close, but never spot on as the first and second numbers are "approximations" and not dead on). They also vary by manufacturer. Still, 26.1 is very close to what a 205 75 R14 will be.

Even with 14 x 6 wheels, you could run a 70 series tire and not be in danger of rubbing. You have two choices: 215 70 R 14 is 25.85 inches tall, so 1/4 inch shorter than your current tires, but wider by 10 mm (between 3.8 and 7/16 of an inch). If you go one size larger, to 225 70 R 14, the tires are 26.4 inches tall, so about 3/10 of an inch taller. I am pretty sure you can find guys running that size tire without issue.

Good luck and have fun. I always wanted to build a 250 six with FI and a turbo.

BTW, your profile isn't filled out. In what part of the Country (or world) are you?

Also, on tire sizes, it is very easy to calculate the approximate height. I memorized the formula about 30 years ago, and refer to it often.

That first number is section width in mm, NOT inches (not necessarily tread width, but the width of the tire at its widest spot). The second number is the aspect ratio. The smaller the number the shorter the tire is in relation to section width. The R just stands for radial. The last number is wheel size.


Formula is (S x A x 2) divided by 25.4 plus W.

S = Section Width
A = aspect ratio (and remember 70 = 70%, so you use .70 for 70 series tires, and .60 for 60 series, etc.
2 = well, 2

you divide by 25.4 because there are 25.4 mm to one inch. The section width is expressed in mm, so you must convert.

Lynn
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post #15 of 42 (permalink) Old May 18th, 20, 05:40 AM Thread Starter
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Re: New to me 68 250

Iím in Ohio. I should have known better but I just assumed it has an in tank electric fuel pump. I have yet to look very closely at this car and plan on getting into it today. Should be a great learning experience. Thank you everyone for your input so far I will let you know what I find.

1968 Camaro 250
1991 Z28 LT1/T56 Swap
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