DRoger5739

I have a 1967 Olds 442 with original 400 engine. Pistons were stuck so I had the whole engine rebuilt at a machine shop with moly rings, .020 bore. I now have about 700 miles on it, but it uses a quart of oil every 100 miles and will blow blue smoke out both exhaust pipes. It does not smoke at freeway speeds but will smoke at lower speeds or when you rev it up. It does have plenty of power
The machinist says it might be running a little rich with Edelbrock rebuilt carb so I put a Quadrajet carb on it. Still using oil at 70 miles
Should I just keep driving it in hopes the rings will seat or just tear it down and install iron rings?

redoldsman

A rich carb will not make it use oil. The rings make take a little time to seat but a quart of oil every 100 miles seems excessive to me. Sounds like the machinist is trying to dodge a bullet.

joe_padavano

Moly rings require more careful cylinder wall prep than do straight cast iron rings.

Sugar Bear

Try seating the rings by getting up to temp then accelerate at full throttle from 20 up to 50 MPH, then no throttle/coast from 50 -20 MPH. Repeat this cycle 10 times.

Had severe oil consumption after a rebuild on a SBC, the problem was umbrella type valve seals that did not secure to the cylinder head. The tailpipes were wet with oil on this one. Look closely at the seals before re-ringing.

Good luck!!!

joe_padavano

Umbrella seals aren't supposed to secure to the head. They ride up and down on the valve, deflecting the oil like, er, an umbrella. If you want seals that secure to the head, you need to have the heads machined for teflon seals.

Sugar Bear

Umbrella seals aren't supposed to secure to the head. They ride up and down on the valve, deflecting the oil like, er, an umbrella. If you want seals that secure to the head, you need to have the heads machined for teflon seals.

Yes you are correct that umbrella seals are not supposed to secure to the head; nor, was it stated that they should. Was trying to point the OP toward an area that could be a source of the problem. Seals were used that did not require machining which retained themselves on the head and solved the problem but this was on a SBC. I do not know if anything like this is available for an Olds.

11971four4two

Valve stem seals are likely NOT this cats problem. Leaky will smoke all the time...... and not that much oil consumption

The SEALS will move on the valve while in travel
Unless positive style which often involves machining of the valve guide




If the cylinders were not trued and then honed for MOLY there will be a problem with those rings


All the BEST

joe_padavano

All factory Olds seals were umbrella. I am not aware of a seal retained on the valve guide that does not require machining. I realize that they exist, but not for Olds.

11971four4two

ALL

No they are not "all" umbrella seals on EVERY oldsmobile...

















AND



some of the oldsmobiles had chevrolet engines in them

cherokeepeople

yup try this.we did this with every rebuild.

Oldsmaniac

I have used positive seals many times on Olds heads. No machining required. One set I got from NAPA made by Perfect Circle. Other sets were found on Ebay.

https://www.ebay.com/itm/Engine-Valv...0AAOSwjzJbGrEi

joe_padavano

That's good info, thanks.



The point I was trying to make was that Olds did not use positive retention valve seals from the factory, and thus factory style umbrella seals should not be the cause of excessive oil consumption if installed properly and in good shape. Unlike the Chevy example above, there are no Oldsmobile heads that REQUIRE positive retention seals. Olds built tens of millions of V8s with umbrella seals that did not consume oil.

My442

Disagree.

Too much fuel washes the cylinder walls down, and prevents the rings from seating.

edzolz

Seems to me that a dry cylinder wall would cause the rings to seat faster because of the friction between the ring and the cylinder wall would cause the ring material to wear away faster. Maybe my thinking is off.

DRoger5739

It was suggested that I put in a quart of Marvel Mystery Oil or Rislone additive to help seat the rings. Anyone had experience with this?

Sugar Bear

An additive would likely have the opposite desired effect. Scuffing is needed, not more lubrication to seat the rings.

Try the ring seating procedure listed in posts 4 and 10 instead of an additive.

DRoger5739

I did try this today, then drove the car about 50 miles going 50 to 80 mph on the freeway. Maybe a little improvement in smoke. Would you suggest I do the 20 to 50mph thing several times in several days?

Sugar Bear

Yes, try it again and keep an eye on the oil level. Even if the rings do seat it will take quite a bit of driving to burn the residual oil out of the exhaust system to stop the smoking.

Good luck!!!

70Post

What motor oil are you using?

Sugar Bear

What motor oil are you using?

X2, Are you using synthetic?

DRoger5739

I am using regular Oreilly 10/30 motor oil which the machinist recomended for break in. He said I could use synthetic after 500 miles which I have not yet done

Sugar Bear

Good...may want to delay a switch to synthetic until the problem is resolved which is hopefully soon.
Still do an early oil and filter change though.
Good luck!!!

DRoger5739

I actually did change the oil at about 150 miles because it was looking dirty (clean now). I am running a 180 degree thermostat, but stock is 195, so I was thinking of going to the 195

My442

The last 5 engines I had rebuilt are all run in and tuned on an engine dyno.

The dyno shop I use has been in business for over 40 years, and they know how to "Get It Right".

The engine is started and brought up to 2000-2500 RPM immediately for about 20 minutes.

Then, the throttle is "goosed" to higher then lower RPMs.

The added vacuum of the throttle goosing raises vacuum and helps seat the rings.

They actually beat on it to achieve the results.

The added $$$ is cheap compared with having to pull the engine and fix it.

70Post

X2!...get the oil problem resolved before considering any switch to synthetic.

cherokeepeople

also do not hold a steady rpm,if you have a 4 spd this will be no problem.

D. Yaros

The ring setting procedure I was trained on "back-in-the-day" was to not drive at a constant speed for the first 50 miles or so. In fact, it was recommended to 'lug' the engine. With a manual tranny that involved having the car in 1st or low gear, goosing the engine to 40-50 MPH and letting off the accelerator while still in gear. One did this more than quite a few times during the break-in period using both 1st & 2nd gear.

BillK

A quart of oil every 70 miles is a serious problem. I doubt seriously that is has anything to do with rings "seating" properly. Modern piston rings are pretty much sealed up on the engine stand if the cylinders are finished properly. I did my Wife's 307 over the winter and it has just about 2000 miles on it and has not used a drop. I did not do anything special as far as break in. Started it up on Saturday morning, drove it a few miles and double checked the fluids. She drove it to work on Monday and has been ever since.



I wonder if the engine builder got the second rings on the piston upside down ? That will make it suck a ton of oil.


Other possibility is the intake manifold valley pan not sealed properly. That will also suck a bunch of oil. Take the pcv valve and breather out of the valve covers and block off the pcv valve. Tape over the hole in one valve cover and see if you have a suction on the other side. If so there is a good chance the intake is leaking. You can also spray some Gumout carb cleaner in the valve cover hole. If the idle changes a few seconds later the intake gasket is not sealed.



Look in the pcv hose. There should not be any oil in it. If there is there might be something wrong with the baffle in the valve cover.



Valve seals mostly cause smoke at start up. The first small block Chevy engines had no seals to speak of and they did not use much oil at all.



Also, plain iron rings without the moly coating would be a step backwards.




I hate to say it but there is a good chance it will have to come apart to find the problem

OLDSter Ralph

ANY engine should never use that much oil ! Driving the car expecting something "magical" to happen is not good reasoning. There is something WRONG. Time to get that shop to figure out whats wrong, or take it to another shop. Good luck.

jensenracing77

I agree. I have rebuilt many engines and none of them ever used that kind of oil seating the rings. Even some of the off road race engines I built would get hammered on the second they were fired up with new rings and never used much if any oil.

edzolz

Sounds to me like there are broken rings involved here. That is a lot of oil to blow by piston rings unless there are other factors to look at. What clearance do the pistons have? They might be too loose also.

BillK

Who assembled the engine ? If the machine shop assembled it you should be talking with them before doing anything else.

DRoger5739

The machinist assembled the whole engine and yes, I did drive the car over and showed it to the machinist. He kept saying he didn't know, but suggested I get the air fuel ratio checked as he could smell some gas coming out the tailpipes. Then if that was the case to correct it and drive another 200 miles to see I the rings will seat. Instead I put another carb on it to see if it makes a difference. Can't tell yet

OLDSter Ralph

What difference are you expecting ? Will you drive it back the machinist to have him "sniff test" the air/fuel ratio ?

D. Yaros

Seems to me that in addition to your engine, the engine rebuilder is also "blowing smoke?"

You need to get tough with him!

RandyS

Yep, these guys always find someone/something else to blame. Make him fix it right. If the rings haven't seated by now, they probably aren't going to.......
just my .02

DRoger5739

Last resort I am going to pull the intake manifold to see if there are any vacuum leaks sucking oil into the cylinders. I did a compression test hot and the results are 175-180 in all cylinders except #5 and #6 which were 200 and 210. The spark plugs in 5 & 6 were a little more dirty than the rest. Don't know why the compression could be so high if the rings were not seated and maybe oil is making 5 & 6 have more compression

oddball

You can get a cheapy borescope for your phone and run that down the intake runners. Oil will be very apparent. I've had several small blocks pull oil between the head and the intake valley. It can take some work to get a good intake seal.

OLDSter Ralph

It would appear the rings have seated sufficiently. You have added close to TWO GALLONS of oil (1 quart in 100 miles) during the break in. I would think that much oil should show up where its going.
Are the tail pipes wet with oil ? Do you see smoke from the exhaust ? #5 & 6 plugs are not fouled with oil ?

DRoger5739

I pulled the intake manifold and found fresh oil inside the manifold and oil pooling on the intake valves. I reinstalled the intake manifold and it still uses oil.
I pulled the engine out and took it back to the machinist who says he will guarantee the rebuild. I have heard of 2 olds 400 cu 442's using oil after a complete rebuild. I also saw one at an auction last week with only 200 miles on rebuild blowing blue smoke out the exhaust.
I assume they all had moly rings. Can anyone tell me what kind of rings were put in these engines by the factory?