A friend of mine at work - his father passed away. He has inherited his fathers 1971 Corvette 454 (I dunno if its the original engine).

The car has not started or moved since 1987. Was kept in a heated garage and covered, but never started and has no battery.

I want to know what steps sould be taken to get this car started without causing damage.

When the car was parked, it was simply parked and the fluids were not changed. There is no visible signes of leaks, but I suspect all seals in the carb are probably dried. The car is sitting on original pollyglass redline tires, they are all flat also.

Am i looking at an overhaul to get this car started ?

There was a whole thread somewhere about a guy who found a bunch of Vettes that had been parked in a barn for about 20 years. It might help you out a lot. Maybe someone could post a link to it?

DV8R,
First I would change oil and filter. Second would be to try and turn motor by hand. If it rotates ok (will probably be a little stiff} I would pull the dist. and use a pre oilier shaft that you use with a drill, To pre oil the motor before trying to start. I would take a file to the points to clean them. Make sure to mark dist location. Timing and rotor location. The brakes seals and sleeves are most likely shot. Unless someone had SS brakes done. Look for soft hoses and rotten belts. Check all fluids. Try to drain all the gas. Refill with new gas and some dryer. Prime carb. Have fire extinguisher handy try to start. Check for spark. You can spray a little ether and WD40 together when trying to start. The WD is to lube the cylinder walls. Best of luck.

Ditto on what has been stated

MAKE SURE YOU HAVE A FIRE EXTINGUISHER CLOSE BY.

That said, might ckeck that engine out close. 71 was the only year that the LS6 was available, plus there was the very rare ZR2 option, which was an LS6 with aluminum heads. The ZR2 is worth big bucks, damn near L88 status.

Good Luck
Brent

Sorry about your friends dad.

Look in the gas tank. If it's like all the rest of the ones I've seen you are going to have to replace it. Will be full of rust. I'm sure the tank wasn't full to the neck all those years.

I passes on the advice you guys gave me, here is where its at:

I got him to tell me what the engine stamping was. This will help you guys figure out what is the next step. The deck numbers are not clearly visible, but the casting number is:
3963512 B271 BHIGHPERFPASS

the heads have the same casting numbers both are:
3994026

Motor spinns freely, but stops exactly halfway one full revolution, feels like a stop or something - something is stuck, and it wont budge even with tremendous amount of force. This is with the plugs out, cly 1 almost at TDC, exhaust stroke.

he says he can can wiggle it slightly but it refuses to go forward.

Next step ?

I don't know if you guys have ever seen this - but he says there appears to be "milk" like substance floating in the oil when he drained it.

Forgot to add, he didnt change the tank yet, he wants to establish that the engine can turn freely before he goes on.

The next step as to act horrified at the white stuff and tell him you're sorry the car is ruined. Offer him the opportunity to get out from underneath this new found headache, and take it off his hands. ;) What are friends for, right? :D Chances are that any rubber in contact with any fluid is going to be a problem. Fuel pump diaphram, accelerator pump, wheel cylinder seals, etc. They may hold for a little while, and then fail one by one. He should change all the fliuds in the thing too, from the diff and brakes to the trans, engine and coolant.

Well, the milky stuff is water/anti-freeze in the oil. Could be from rain or condensation, or could be from a blown gasket someplace. That definitely needs changed.

Finding out if it's the original motor will highly influence how much force you want to put into making it turn over. No definites, but the 1/2 way point may be where the piston/rings hit a rust ridge in the cylinder. If that's the case, keep spraying with WD40.

Just remember, most of the time these cars were parked because something went wrong ... and just sat while somebody was getting around to fixing it.

Thanks, Neal

Use marvel mystery oil in the cylinders. Pour it in all the plug and let set over night. Is the milky stuff in the oil or in the valve covers? If it is in the oil it has most likely been there since parked. It has to be churned to get milky (motor running). How thick can tell how much. It could be a head gasket or cracked head or block. Is it a coupe or a vert? Drain all antifreeze out and use water. If the antifreeze has been in there it has most likely ate into the bearings. It is worse then water on the motor as far as being in the oil. You can try and get fired but it sounds like most likely it will be going to the machine shop. He will need to have the heads and block tested for cracks.

According to Mortec.com those are 71 LS6 rectangular heads. Sounds like a keeper.
Ron

Most likely rust in the cyl as said above, I would use PB Blaster in each cylinder.

You can also take some regular motor oil and with a small funnel or a small oil squirt can. Spray a little into each spark plug hole just like the others suggested.

If you feel comfortable enough to get it started. Crank the engine without the plugs in so the oil will lubricate the cylinders and also will wetten them down to help build compression up. This is a good time to try turning the engine by hand as it will be easier to turn without the plugs in place.

You may also need to clean the carb up fairly well also. Its likely all gummed up with old gas.

Chris.

"feels like a stop or something - something is stuck, and it wont budge even with tremendous amount of force."

dv,
If this is the case, its time to stop and do some looking before you completely ruin it. It sounds like a valve is stuck open to me. You should be able to take off the valve covers and take a look. Turn the engine over as far as you can by hand and see if any of the rocker arms are real loose. If so, that valve is probably stuck open. You could try some penetrating oil around the valve spring area and tap on the valve with a plastic hammer, but it is probably stuck solid.
I personally would not try to start it at this point. If something is stopping it from turning over by hand, then something is going to break if you hook up the starter. You are probably looking at at least pulling the heads off. Might as well do it while you are taking the gas tank out to get cleaned.

Is the milky stuff in the oil or in the valve covers?

the milky stuff was in the drained oil.

If it is in the oil it has most likely been there since parked. It has to be churned to get milky (motor running). How thick can tell how much. It could be a head gasket or cracked head or block.

I would say about 15-20% of the drained oil had this milky substance in it.


Is it a coupe or a vert?

The car is a coupe.


The car was not touched over the weekend, he wanted to see what advice was given first.

You will find it a lot easier to rotate the engine if you remove the spark plugs to try it by hand.

Remember you are also cranking the engine on the compression stroke and that makes the engine harder to turn also. Sometimes it can be possible to strip the crank pully bolt if it turns hard enough also. Having the velve covers off will let you see if any of them are moving when you turn the engine too.

Try removing the plugs and see if it turns and stops still.

Chris.

What is the suffix code on the front of the block? As stated, if this checks out to be a true LS-6, you guys have a bit of Corvette legend on your hands. You don't want to take a chance futher damaging the motor!

Dick

Originally posted by midshark:
What is the suffix code on the front of the block? As stated, if this checks out to be a true LS-6, you guys have a bit of Corvette legend on your hands. You don't want to take a chance futher damaging the motor!

Dick It appears that the bock deck has been machined once, as the deck numbers even cleaned cannot be read. The block appears to have been worked on. If there is a way to pick up the numbers let me know !

Some update though, there was a bend push-rod, it is completly twisted. The heads are currently off, the block has domed pistons, but I do not know what type - the engine is not taken down far enough. The both heads are on their way to the local machine shop to get cleaned off, checked and a new valve train installed. My friend is willing to dump alot of money into this car for something he beleives is real - I personally have not seen anything to tell me that is it though - to each their own. I'll keep you guys posted.

DV8R,
Here is a list of things to look for.
The 71 LS6 was a 454 c.i with.a 6500 red line tach. It had a 9.0:1 compression ratio, it was rated at 425hp and it featured aluminum cylinder heads, aluminum intake, 4 bolt mains, forged pistons, 7/16 rods, mechanical lifters, T. I. ignition and a Holley carb. It will have a interior engine plate on the console stating the 425HP. Hope this helps & here is a pic of an LS6.
Nelson


http://www.photohost.org/gallery/data/500/9582003BJCCA2_761_eng.jpg

Redman

It has been a few years since I was into Vettes but I think standard issue LS6 optioned vettes had iron heads, the ZR2 LS6 cars are the ones with the Aluminum heads.

Again I may be wrong but I am curiuos...

By the way either is rare and if this Vette is truly an LS6 it is a find and worth the investment of repair as it will bring some $$$ at some point.

This is a case of if there is any chance that the motor is real you should exhaust every avenue of proving it. Big blocks have been know to have a second set of VIN #'s or maybe the acid method will work, check it out and let us know.

Good luck to your friend
Brent

I think you are correct Brent, I have a true LS7 in a jet boat-unmolested as was bought in 1970 and it has iron heads.

I believe they had aluminum heads. Years back I remember that I ordered one over the counter and it came with aluminum heads. A few years later the same part # came with cast heads. GM no longer included them with the LS6. But you could order the aluminum heads separate. The ZR2 option could not be ordered with an auto and it had a aluminum radiator. I found this info below.

THE ZR2 SPECIFICATION PACKAGE INCLUDED THE DUAL PLATE CLUTCH, M22 (ROCK-CRUSHER) 4-SPEED GEARBOX, DUAL-PIN HEAVY DUTY POWER BRAKES, HEAVY DUTY SUSPENSION AND ALUMINUM HEAVY DUTY RADIATOR (WITHOUT SHROUD). OPTIONS NOT PERMITTED WERE POWER STEERING, RADIO OR AIR-CONDITIONING