Rebuild advice 2.7

Overseas72 · Overseas72's Garage

I have a 1974 2.7 . It ran great . Then Hurricane Michael hit and my car sat for about 8 months. Changed the battery , drained the fuel . Started up and I'm assuming I had a ring issues as I lost all the oil threw the exhaust . So heart broken I know I need to plan my next step.
I value the advice of everyone here on pelican and know most of you have been down the same path . Should I rebuild the 2.7 or upgrade to 3.0? What is an estimated current cost for a 2.7 rebuild ? Thank you

Trackrash · Trackrash's Garage

Was the car under water? I'm not sure why the rings / cylinders would go to he!! just from sitting.

I would do a leak down test, followed by a bore scope inspection.

Henry Schmidt · Henry Schmidt's Garage

The 74 911 is one of my favorite chassis to start a project.
In California we have smog issues, so chassis' that are exempt bring a premium.
The 74 engine came without smog equipment, so most were less likely to be overheated. The death kneel for mag case engines.
I would rebuild the 2.7 with a goal to convert it to RS spec 2.7 MFI.
If so inclined, an RS conversion on the chassis and you end up with a great 911.
The cost for such a conversion can be substantial but what a fun car to drive and a reasonable investment if you ever want to sell it.

boosted79 · 05-20-2019, 09:58 AM

" I lost all the oil threw the exhaust ."

?? So the oil tank was empty? Maybe it just wet sumped from sitting. Did it smoke like hell when you started it? Was the oil on the floor, or in the sump and exhaust?? Rings don't go bad from just sitting. If it was underwater then you've got other issues.

Overseas72 · Overseas72's Garage

The car was not flooded. It just sat up for months. When it started it sounded like it was missing and would not idle or rev. It smoked a little but no more then one would expect from sitting up so long . I shut the car off and noticed oil leaking out the exhaust tip and heat exchangers at the fastening points. All the engine oil by the looks of it .

Walt Fricke · 05-20-2019, 02:26 PM

What do you mean by "I lost all the oil."? What does the dip stick show? As you may know, to check the oil level you need to run the engine until things are warm, and then, either at idle or just after shutting off, check the dip stick. Plus you want a reasonably level surface. How do you know "all the oil" is gone?

When the car sits, oil migrates from the tank into the engine until the oil levels in both are the same. It is possible for enough oil to move so the engine sump level is above the bottom of one or more cylinders. Oil on the bottom of a cylinder can leak by the rings and get into the combustion chamber. Of course it will smoke.

You might consider pulling the plugs, and turning the engine with the starter for a while, in case there is excess oil in the combustion area. Clean and dry the plugs, if they were oily or fouled. Reinstall, and start up. Expect smoke for a while. See if it clears up. With oil in the exhaust system, this may take quite a while, because while the combustion chamber gets very hot right away, it takes a long time to burn oil out of the much cooler exhaust system.

Are you saying you think you see oil coming out where the exhaust manifold gasket joins the manifold to the head? If that happens, for one thing those gaskets are toast.

Mixed76 · 05-20-2019, 03:51 PM

Probably ought to sell it cheap to someone. Too much trouble to mess with.

Dan

Trackrash · Trackrash's Garage

Quote:

Originally Posted by Overseas72

The car was not flooded. It just sat up for months. When it started it sounded like it was missing and would not idle or rev. It smoked a little but no more then one would expect from sitting up so long . I shut the car off and noticed oil leaking out the exhaust tip and heat exchangers at the fastening points. All the engine oil by the looks of it .

Listen to Walt.

So by all the engine oil? You know that these hold 3 or 4 GALLONs of oil, right?

timmy2 · timmy2's Garage

Pour a liter of oil on a concrete floor and see how much that is. Then images 8-10 times as much to empty all your oil!
Drain the sump and the oil tank and measure what comes out. You’ll be surprised.

Do as others suggest, fill it with fresh oil and run it.

bpu699 · 05-21-2019, 05:33 AM

I have had cars sit for way longer than 7 months, that shouldn't cause any issues. Living in Wisconsin, fancy cars don't get driven for long periods of time...

targa72e · 05-22-2019, 01:32 PM

I got a good deal on a car about 20 years ago that had the same issue. Had oil running out of header to muffler joint when running and smoked bad. The car had sat for a couple years while being repainted. I was planning on rebuilding the engine. When I asked around I was told it was not uncommon for engines that sat to have the rings stick to one side of the piston because of the horizontal engine design. I pulled the plugs and filled the cylinders with marvel mystery oil and let it sit. Cranked with spark plugs out to get most of oil out and then restarted, It smoked like crazy. I drained as much of the oil out of the muffler as I could. I waited until dark and jumped on the interstate near my house and drove for a couple miles at 4-5K until the smoking stopped. After that I never had the problem again. I drove the car for several years after that with no issues until a miss shift at the track bent some valves necessitated a rebuild.

john