I have never had a car use oil like this 455 I have. It is a Craigs list bought 1971 455 with E heads, I paid $200 and it came with an engine stand so I'm not whinning. The guy said it was rebuilt and the engine had signs of a rebuild including minimal wear on the rods and mains, new oil pump, and a very nice chalky residue on all the exhaust ports, it seems to run strong and has pretty good power. I raced a 14 sec. flat Camaro on the street and it was very close but I lost.
1. The oil usage is unbelievable, 1 quart= 100 miles. It does have a few drips around the rear seal but no major leaks.
2. I did a compression test and found all cylinders 130-135 except for the front 2 they were just over 100. I shot some oil in the lower cylinders and it may have went up 5 pounds.
3. The exhaust pipe tips have a nice color and only a little smoke during real hard acceleration, then a let off of the gas and another hard acceleration.
4. Is it possible a valve job could cure this problem?
5. Also it seems to have the Chevy piston slap noise until it warms up.
Thanks for any opinions.
Dave

 

Wow that is alot of oil. What do the plugs look like? If you are burning that much oil they would be gummy. Also if you are burning that much oil the back bumper would be oil coated. Maybe it is pumping it out at speed through a leak. Look around the oil pump and back of the intake manifold. Try running a thicker oil like 15-50 and see if that makes a difference. The only piston slap I ever had with a Chevy engine was one with an aluminum block.

 

Sounds like a crankcase ventilation problem. THe plugs should be pretty bad if it was burning that much. I think I saw that motor listed on Craigslist. Told the boy about it.

 

If it isn't a crankcase ventilation problem as 442_Mustang suggests it would almost have to be an issue with valve stem seals and perhaps valve guides. How do the plugs look? I can't imagine an engine consuming that much oil not having serious plug fouling issues.

Those two cylinders with lower compression are an issue but not necessarily the point of the oil loss. The numbers you give on the compression check would indicate those cylinders are too far out relationship to the others to be acceptable with the lowest acceptable being no less than 80% of the highest.

Never heard of a 455 having piston slap issues are you certain it isn't lifters being slow to pump up due to oil pump related issues or improper oil viscosity for the engine?

 

i would also think the crankcase ventalation.

 

The front plugs aren't as clean as the rest but they are still firing.
Yes there was a film of residue on the rear bumper. There is a chance of at speed leakage but very minimal. I have been adding 20-50 and I don't think it has slowed any. I installed the original W30 intake that has a PCV in the front of the intake. I have one breather going up to the air cleaner, I am missing one breather. The last I checked it had no blow by.
I'm pretty sure it has piston slap. It sounds and acts just like my 99 Chevy 5.3 pick up.

 

Are you from the MPLS ST Paul area?

 

I 'll have to consider the lifter suggestion. It has good oil pressure 18-20 hot idle and 45-50 @ 3000RPM. It isn't a tic sound, its the hollow tin can sound.
After reading these responces I'm thinking of pressurizing the front cylinders with 130 lbs of air and check the carb and tail pipe for a 30 lb leak. I'm hoping the motor will last the summer and I'll need a set of over sized pistons.
Maybe I'll take a youtube video of the engine tomorrow and post it.
Thanks for all the help.

 

Kinda. I live near Princeton. I work in Roseville

 

That pretty close. It's probably a good thing your son didn't buy this 455.

 

That is ALOT of oil. I am thinking rings, but do a test.
Pull out your plugs and put a teaspoon of Bon-Ami in each hole, and then crank without plugs in.
Replace plugs, and drive.
See what your oil consumption is afterwards.
If it drops consumption by 30-40%, you will need rings, and fresh hone.
No- change, valve job ( which I seriously doubt here).
Remember, whenever an engine is run with a bad plug wire, or some kind of miss, that hole will never FULLY recover from that, because the miss causes the rings to unseat.
JMO
Jim

 

That is just a test, not ANY sort of cure.

 

Thanks Jim,
I never heard of the Bon-Ami I'll have to check into that. I did notice a pretty good puff of smoke coming out the left pipe when I fired it up yesterday that cleared out sfter running a while. Maybe there is still some hope for only needing some head work...I'm not getting my hopes up too much. Ill check it out today. The funny thing is I just remembered I have a set of .030 455 pistons in storage that I may be able to use if the cold Chevy type knock is in fact piston slap and it needs a re-bore.
Thanks for the help.
Dave

 

Bon Ami is like Ajax cleaner.

Never heard of this one.

 

Bon-Ami? Isn't that an abrasive? Why would you want to put an abrasive into your engine? Please explain if you would.

The only way your rings will "unseat" in a hole that's not firing is becasue of the raw fuel going thru it. And that will just continue to wash the walls and maybe scuff the cylinders, rings and pistons as well.

Check the valve seals. It sat for awhile right? I've even seen "engine builders" forget to install seals, or they install the wrong ones. Run it with open crankcase ventilation. Is the aircleaner oily inside from the crankcase vent! Is the PCV oily? I'd do this before I put any abrasive into the cylinders. Unless you have a big cam, 100psi in an engine that was just "rebuilt" is a bit low. If you have scoring in those cylinders they'll use more oil and it won't necessarily show up when doing a wet test.

 

The last oiler 455 I had traced back to bad seal between the intake and heads using Mr Gasket intake gaskets without the turkey tray.

Apparently the 70s-vintage Offenhauser Dual-Port I was running wasn't exactly true on the head side and allowed oil to suck out of the valley and into the intake ports.

It ran like a raped ape, but rarely got more than 300 miles out of a quart of oil no matter what viscosity I used.

BonAmi is a very very fine talc based abrasive that won't scratch like most scouring powders. The idea is that if there's any glazing on the rings or the cylinder walls, it will be abrasive enough to deglaze but not enough to screw anything up. I've heard of using it, but never have myself.

 

Wow, very good! Also Bon-Ami is supposedly non detergent (or very low in detergents). This will not hurt the engine. Old trick from an old-time mechanic.
I have used this trick on a couple of occasions, I was amazed. The last one being a 383 Mopar about 3 or 4 years ago, and it cut the oil consumption by 40%. It still was a heathen pig, but the guy got the drift.
How many miles on this "rebuild"? I am thinking, something was missed, or the rebuild was not so complete.
JMO
Jim

 

Used by many "old time mechanics". Normally poured into the carb of a running engine.

Particularly useful in seating the factory chrome rings in '55 Chevs.

Norm

 

My Old Pig Ain't Running


Or that's what one of my hardcore Mopar friends says anyway...

 

Yeah, and my Mopar friend say's...Old Lady Drives Slow. But he is the guy that brought it to me.
Go figure.
Jim

 

Bon Ami was originally in a soap bar form and used with a wet rag...the resultant foam was spread on windows and when it dried was wiped off with a dry cloth and then you could see right through the glass!!

 

If you listen close you can hear a hollow rapping sound. The rebuilt carb I first used did have some needle and seat issues so there is a chance some gas got down the cylinders but the front two were the low ones.

http://www.youtube.com/watch?v=wNbgktSLY3A

 

I had enough, and pulled it out. The cylinder walls have slight ridges, similar to a washboard, also the pistons rattle from side to side in the hole. I figured it had piston slap. Those 71 pistons are an ugly sight. They'll make good ash trays.