rebuilt engine problem

[jvoice]

I recently had my 327 350 hp engine rebuilt, $2800 parts, 35 hours labor plus re and re. The invoice says engine dyno'd and broken in. I have put 800 miles on the engine, it burns a full quart of oil every 100 miles.
The shop says it needs to be broken in ?? and after I put a couple thousand miles on it the oil consumption will go away. 2000 miles is 2 years driving. Could this be true, and if not what can I do about it?

 

[89blackvette]

Heck no, that is crap. A little oil in the first hundred miles then NO oil consumption. Is crankcase ventelation installed correctly and working? I have rebuilt a bunch of small block Chevrolet motors and have NEVER had oil consumption on that level.

 

[Hib Halverson]

A quart per 100 miles is way too much oil use, even for an engine which is freshly-rebuilt.

First, you need to start documenting the oil use in case the rebuilder is hard to convince there is a problem.

Next, you need to communicate with the engine builder and make sure he/she knows there's a problem.

You might want to attempt to find out where the oil is going, ie: is this a case of rings which didn't seat or a broken ring, is it an internal oil leak into the intake tract, is it bad valve seals?

 

[Rex S]

I've done Ford, Chevy & MOPAR and the worst one, 440 MOPAR, used 1qt/first 500 then settled down to none between 3K oil changes on Mobil1.

 

[67l36driver]

I recently had my 327 350 hp engine rebuilt, $2800 parts, 35 hours labor plus re and re. The invoice says engine dyno'd and broken in. I have put 800 miles on the engine, it burns a full quart of oil every 100 miles.
The shop says it needs to be broken in ?? and after I put a couple thousand miles on it the oil consumption will go away. 2000 miles is 2 years driving. Could this be true, and if not what can I do about it?

That is horse hockey! Moly rings usually seat in the first 15 min. of run time.

If the valve stem seals were totally absent it wouldn't use that much oil.

 

[navy2kcoupe]

Using that much oil, I would expect to see one of two things.........
1. A large puddle of oil somewhere under the car.....................
or
2. nothing but smoke following it.
Either of these present............?
What do the plugs look like right now?
Andy

 

[Oz's 59]

Rebuilt my '59 283ci 3-years ago & I never used any oil between changes.

 

[jackfit]

Where is the oil going?

I recently had my 327 350 hp engine rebuilt, $2800 parts, 35 hours labor plus re and re. The invoice says engine dyno'd and broken in. I have put 800 miles on the engine, it burns a full quart of oil every 100 miles.
The shop says it needs to be broken in ?? and after I put a couple thousand miles on it the oil consumption will go away. 2000 miles is 2 years driving. Could this be true, and if not what can I do about it?

Check plugs, re-torque the intake manifold bolts. As stated in other reply's, a pool of oil , smoke out the rear, or fouled plugs.

Tell us more and we can help. I had the same problem, it was the intake manifold bolts.

Jack

 

[jvoice]

Check plugs, re-torque the intake manifold bolts. As stated in other reply's, a pool of oil , smoke out the rear, or fouled plugs.

Tell us more and we can help. I had the same problem, it was the intake manifold bolts.

Jack

thanks for all the advice. The engine is burning oil, smoking, not leaking, it has been to several shops , none of whom can figure it out. The intake manifold bolts have been tightened, valves checked, it has been back to the shop several times, carbuerater has been redone, rejetted etc, engine tuned on a chassis dyno. Runs better temporarily until the plugs foul again. The suggesion about the pcv valve is interesting, taking it back to the shop again tommorrow to have that checked.
Are there diagnostic tests that can determine the problem?

 

[jvoice]

A quart per 100 miles is way too much oil use, even for an engine which is freshly-rebuilt.

First, you need to start documenting the oil use in case the rebuilder is hard to convince there is a problem.

Next, you need to communicate with the engine builder and make sure he/she knows there's a problem.

You might want to attempt to find out where the oil is going, ie: is this a case of rings which didn't seat or a broken ring, is it an internal oil leak into the intake tract, is it bad valve seals?

thanks, I have in constant contact with the builder, he acknowedges and is trying to fix the problem. See reply after jackfits response.

 

[jackfit]

I leak down test will help

thanks, I have in constant contact with the builder, he acknowedges and is trying to fix the problem. See reply after jackfits response.

You should do a leak down test. It will help identify ring or cylinder problems. In my case, the block was not block honed. That is when you attach a device that distorts the cylinders as they would be when the heads are on. If you bore or hone the cylinders without it, they will be right , until you put the heads on, the heads will distort the cylinders and allow blow by.

The leak down test will help tell you if oil is getting past the rings. Ask your builder if he "block honed" the block.

I had to rebuild the engine with only 400 miles on it , because the first builder did not do it.

Jack

 

[jackfit]

Here are some pictures of the engine block honed

Take a look and ask your builder if he did it. The block plate is the blue plate attached to engine just like the heads. You bore or hone with this plate in place.

Jack

 

[89blackvette]

I think the shop let someone with little or no experience rebuild your engine. Some oil control rings have a taper on one side and if installed upside down will allow some oil to pass them. Compression and leak down test will not show this as you are mostly testing the compression rings. I saw this happen years ago on 2 cylinders of an engine. I would take it back to the builder and explain the situation toi him and request that he repair the engine.
Mike

 

[navy2kcoupe]

IIRC the splits in the rings need to be at 12 o'clock, 4 o'clock and 8 o'clock when looking down at the top of the piston. maybe yours were put on with all of the splits in line. Just something else to check if the motor gets pulled apart again.........
Andy

 

[jvoice]

Take a look and ask your builder if he did it. The block plate is the blue plate attached to engine just like the heads. You bore or hone with this plate in place.

Jack

thanks for the info, yesterday the shop plugged off the crankcase ventilation so that the hose from the oil filler to the carbuerater is no longer connected. That didnt stop the smoking. They then poured a mild mixture of water and bon ami into the engine to create an instant ring seating, that didnt work either. When it was tuned on the chassiz dyno last week, the mechanic, an independent, not the builder, said the carb jets were way oversized and pouring a lot of gas into the cylinders, he said that might have prevented the rings from seating right from the start. The engine was built with moly rings, forged pistons, bronze valve guides, apparently all the best stuff. However I have now put about 300 hard miles on the car since the carb was jetted properly but it still burns a quart per 100 miles. Apparently a leak down test has been done and all cylinders were within 5 pounds of each other. Any other ideas or suggestions?

 

[jvoice]

IIRC the splits in the rings need to be at 12 o'clock, 4 o'clock and 8 o'clock when looking down at the top of the piston. maybe yours were put on with all of the splits in line. Just something else to check if the motor gets pulled apart again.........
Andy

thanks, would it be advisable to pull the heads and look at the splits??

 

[89blackvette]

I hate to say it but you need someone that knows what they are doing working on your engine. Bon Ami and water in an engine!! Give me a break, why don't just gey some of that liquid glass thay put in the clunker cars if you want it damaged further. Get someone to remove and take the engine apart and see what the heck some idiot did wrong. You now also probably have some damaged bearings from the Bon Ami stunt. With that much oil consumption there is a problem that will not be fixed by testing and pouring S%$t in the motor. Did you get any type of warranty from the builder, if so tell him to fix it in a timely manner or you will sue for the rebuild price plus whatever it takes to get it fixed. Time to play hard ball with them. Sounds like you got screwed and did not even get a kiss.

 

[jackfit]

That is not a leak down test

thanks for the info, yesterday the shop plugged off the crankcase ventilation so that the hose from the oil filler to the carbuerater is no longer connected. That didnt stop the smoking. They then poured a mild mixture of water and bon ami into the engine to create an instant ring seating, that didnt work either. When it was tuned on the chassiz dyno last week, the mechanic, an independent, not the builder, said the carb jets were way oversized and pouring a lot of gas into the cylinders, he said that might have prevented the rings from seating right from the start. The engine was built with moly rings, forged pistons, bronze valve guides, apparently all the best stuff. However I have now put about 300 hard miles on the car since the carb was jetted properly but it still burns a quart per 100 miles. Apparently a leak down test has been done and all cylinders were within 5 pounds of each other. Any other ideas or suggestions?

It sounds like they did a compression test which you measure in pounds. 160 or 170 etc, per cylinder.

A leak down test is done by putting each cylinder at top dead center, engine off , to close both intake and exhaust valves.
The cylinder is then pressurized with air by the a testing device that has two gauges. The cylinder is pressurized, and you watch how fast the air escapes from the cylinder. The rate is measured in % . 8% is normal for a new rebuild. It sounds like yours would be over 20 to 40% .

If your builder does not know how to do one, find someone who can. It is called a leak down test, because it measures the amount of air passing the rings, or leaking down.

You should have this test done first before putting anything in the engine.

A compression test is done with a gauge attached to the cylinder and then you crank the engine over. It will not show an out of round cylinder, which is what it sounds like you have because of not block honing the cylinders.

Did your engine re builder use a block like I showed in the picture? If not , stop wasting you time trying to seat the rings, that is not the problem.

Find some one who knows about a leak down test and do it.

Jack

 

[89blackvette]

He said they blocked off the crankcase vent hose also, this would create crankcase pressure and multiply the problem. A leak down test and compression test only tests from the top of the cyllinder and does nothing to tell you about pressure in the crankcase that could push oil past valve stem seals and ring from the bottom end, or incorrectly installed rings etc. I still hold that the engine should be taken down by some ones that knows what they are doing and find the problem. You can spend a fourtune and infinite time poking, proding, testing and guessing, just go ahead and have a GOOD mechanic look at it and then decide what to do. You are just pissing away time and money now. You klnow the saying you can put a monkey in a suit and it is still a monkey. If it was mine I would have the engine apart in my garage and be shoving bad or incorrectly installed parts up someone's butt by now. Again just my 2 cents.
Mike

 

[1963SS]

I've built many high HP engines and a few fairly stock ones. There just arent't that many things to cause your problems. Bon-Ami, give me a break! It's only purpose on a vehicle is cleaning the windshield to stop that awful wiper chatter. Nope, won't scratch the glass at all. If it won't scratch glass I seriously doubt it'll seat a ring.

I fully agree with the other posts that you NEED to have someone go inside and find the problem. Occam's Razor suggests that all things being equal, the simplest solution is probably the correct one. The simplest solution here is to pull your mechanic away from his Ouija board, slap him a few times and tear the engine down. Your rings are apparently blowing by (an assumption) and he has just introduced a mild abrasive and water into your oil. Call me silly but that just doesn't seem like a good idea.

Good luck with your choices and sorry about your misfortune.