[70oldgoat]

I am not a mechanic, so I have to keep it simple.

Couple of years ago, I had my 1970 400 ci Pontiac engine rebuilt with new cam, rings, ect.

After the engine rebuild, it used oil at highway speed at about a quart every 300 miles. No smoke, no oil leaks.

I drove this car about 4000 miles at highway speed including two out of state trips; (1) a 2000 mile Hot Rod Power Tour; and, (2) a 1200 mile RT to the coast and back.

I am currently having the engine rebuilt again. I will pick it up next week. The engine rebuilder has told me the rings did not seat after the previous rebuild.

Can you guys give me some basic advice on how to seat the rings properly in this new rebuild? The first rebuild, I first drove it on a 200 mile RT on the Interstate. Apparently, that did not work...

[Steve C.]

Just a thought.....

Used by Joe Gibbs Racing to break-in and dyno all their engines, this petroleum oil provides the highest levels of zinc and phosphorus for flat-tappet engines. The additive package promotes ring seal.

https://www.jegs.com/p/Driven-Racing...03689/10002/-1


.

[i82much]

You need a builder with a Pontiac torque plate.

[Schurkey]

IMMEDIATELY after cooling-off from "camshaft break-in", top-off any fluid levels requiring attention, grab your cellphone, head out to a lonesome highway, get the engine/trans/differential up to proper operating temp. Turn around, get into high gear, and stab the gas pedal from ~25 mph to 70 mph (but don't go over 4K rpm, speeds dependent on gearing.) Coast (in high gear) to your starting speed. Repeat until it stops being fun.

You're looking for the highest possible load without detonation or excessive RPM, followed by high-manifold-vacuum to pull oil up and wash away the wear particles. High cylinder pressure forces the rings into the cylinder wall for proper bedding.

An alternative is to do the "cam break-in" and the ring-seating on a dyno under controlled conditions. Again, high load, not high RPM.

Don't forget to verify the PCV system. Surprising amounts of oil can be pulled through the PCV into the intake manifold when the valve covers aren't properly baffled.

I also install a bypass oil filter at least during the first few hundred miles of use. Sometimes, I leave it on for the life of the engine. These filters are in addition to, not instead of the regular, full-flow filter. Such filters are available new, or used on eBay. Amsoil sells a bypass filter, and there are various versions of the Frantz toilet-paper canister. These filters will positively clean all the wear particles from the oil that a conventional, full-flow filter can't.

[mgarblik]

Originally Posted by Schurkey

IMMEDIATELY after cooling-off from "camshaft break-in", top-off any fluid levels requiring attention, grab your cellphone, head out to a lonesome highway, get the engine/trans/differential up to proper operating temp. Turn around, get into high gear, and stab the gas pedal from ~25 mph to 70 mph (but don't go over 4K rpm, speeds dependent on gearing.) Coast (in high gear) to your starting speed. Repeat until it stops being fun.

You're looking for the highest possible load without detonation or excessive RPM, followed by high-manifold-vacuum to pull oil up and wash away the wear particles. High cylinder pressure forces the rings into the cylinder wall for proper bedding.

An alternative is to do the "cam break-in" and the ring-seating on a dyno under controlled conditions. Again, high load, not high RPM.

Don't forget to verify the PCV system. Surprising amounts of oil can be pulled through the PCV into the intake manifold when the valve covers aren't properly baffled.

I also install a bypass oil filter at least during the first few hundred miles of use. Sometimes, I leave it on for the life of the engine. These filters are in addition to, not instead of the regular, full-flow filter. Such filters are available new, or used on eBay. Amsoil sells a bypass filter, and there are various versions of the Frantz toilet-paper canister. These filters will positively clean all the wear particles from the oil that a conventional, full-flow filter can't.

I think that on-the-road method should work fine. Proper cylinder wall finish matched to the type of piston rings used is also important. So that means using an engine machine machine shop familiar with the rings you are going to use . On the dyno, our newer SF-902 software has a break-in sub-program. It essentially does what you are saying to do on the road. You program in the max torque you want to run at and max RPM and it takes it from there for an hour. For a stockish Pontiac, I like 200-250 Ft. Lbs. torque and 4000 RPM Max. The dyno loads the engine to that torque setting and holds it there for about 5 minutes and then releases, letting the engine flare to the 4000 RPM setting, then gently pulls it down for another 5 minutes. It repeats through the cycle. After cool down, change oil, then make power pulls or just take if off the dyno depending on customer's wishes.

[hurryinhoosier62]

Another cause for piston rings not seating is glazing of the cylinder walls due to the use of engine oil on the rings during assrmbly. I’ve never used anything but MMO. I have never had the rings fail to seat, either. That is all we used when assembling aircraft engines as well.

[steve25]

New rings these days are pre lapped when there made unless you bought old stock rings.
On my motors running Moly faced rings unless they are going to sit and not be fired over for a month I lightly oil each ring as I place them on each piston, oil the piston skirts up and install each piston on dry cylinder walls.
This is after the very first step of brush honing each cylinder and then making triple sure the cylinder walls are clean.
With this procedure I have never had rings not bed in by 200 miles of usage if not much sooner dispite many times no using a deck plate when the block was bored, or when I brush honed the walls.

[Richie Hoffman]

also make sure carburetor not running rich with today’s gas with ethanol boils fuel faster

[ta man]

I wonder how many guys mess up new engine builds by starting them , idling them over a few months or even years before actually driving their car?

[cdrookie]

Your oil consumption could be from valve guides worn out or the seals dried out. It will burn a lot of oil. Just something to have checked out during the rebuild.

[92GTA]

I honestly have the same issue with my 69 XH 400 block. It was built and engine dyno'd by Houston Engine & Balancing in 2015 using a Butler 461 kit. I bought my car from the previous owner in Oct 2016 with about 100 miles on the engine in the chassis. The receipts from the engine builder show that it was fully blueprinted/balanced, 0.030" over, square decked, and bored & honed with a torque plate.

The drive home was about 2K miles and honestly, during the engine dyno and certainly during that first 100 miles, the rings should have sealed properly. During the drive home, the car was burning a lot of oil. The seller had already changed the oil over to Valvoline VR1 and supplied me with a couple gallons. Boy did I need it! Plus upon checking at my 2nd fuel fill up, there was a TON of crankcase moisture. turns out the guy only had a 160 thermostat in it.

I now have about 23K miles on it, a 180 thermostat, and it still uses at most a quart every 400 miles depending on how I drive it. The whole time I've owned it I have run Redline 10w40 that I just buy by the gallon from Summit. When I get on it, oil just mists from the breathers like crazy. I have added an oil/air separator to the PCV and a remote vented breather for the valve cover. The spark plugs never look oily tho thankfully and compression is within 5% all the way around.

When I do my new heads and cam this coming summer I plan on having a local engine builder (who knows Pontiacs) go through and refresh the entire engine since I need new pistons anyway for the different heads. I'll also have them break it in on the engine dyno for me. On all my new engines, I'm also a big fan of running it up in a gear and letting it decelerate in that gear as much as I can in the first couple dozen miles.

[coonhunter70]

Hilly curvy backroads are where you want to break-in your engine.

[Will]

Proper hone and ring selection and the rings should break in almost instantly. Moly rings in a cylinder that's been torque plate and plateau honed will break in immediately, during the engine run-in.

Once the initial run-in is done (cam break-in if you have a flat-tappet) take the car out and drive it like you stole it. if the rings aren't seating it's probably that the wrong finish was put in the cylinders for the type of rings used. Moly rings like a real smooth finish. Old school iron rings need a more aggressive crosshatch.

[Cliff R]

Correct, it all boils down to cylinder preparation, surface finish and correct ring selection. All that other stuff isn't going to make any difference at all IF the correct things weren't done by the machine shop and engine builder.......FWIW.......Cliff

[dataway]

When I talked to Langcourt Advanced Cylinder Technology that did all my boring work for race bikes they said rings should seat in the first minute ... and if they didn't, they weren't ever going to.

[steve25]

Also please note that a few years ago ( maybe 4 to 8 I can't recall) there was a ring manufacturer that had there second ring ( yes the oil scraper) marked up the wrong way for proper install.

Yes, it was acting to push oil up into the chamber , not downi into the oil pan!

Is has also happened that builder have just plain installed these rings the wrong way on a customers Pistons ending up with the same result.

If you see oil usage in just 1 or 2 cylinders I have seen conditions more then a few times where the home builder put some pretty good scratches into the cylinder walls on piston install due to on dressed oil rail rings or just plain having one of those pop out on install and the guy just drove the piston home with a big ball peen hammer!

[455rebel]

I'm still a fan of cast iron rings, for me they always seat. Had bad experience with moly, and no tq plate. The cast may not last as long, but few of us go 50k without a rebuild. My junkyard Bonnie 73 455, never saw a machine shop. Ridge reamer, dingel berry hone, cast rings, still going after 10 years, and 20k miles, uses 1/2 qt between changes.
Ps-read once bout using borax or comet, in spark plug hole to seat rings, never tried it though. A mechanic I knew when I was a young boy, told about a service bulliten in the 50s, at a Ford dealer about new cars excessive oil usage, it said to use borax in plug hole, he said 9 out of 10 worked?

[steve25]

Well factory rings are double Moly from 68 or earlier on up ( yes , both top and second rings) and the factory does not use a torque plate so something else is your issue if you have had failed rings!

I have seen more then a few motors with issues where the cylinders where honed chrome rings, but then the motor was built with Moly rings and the Moly ring faces where taken off each compression ring within 3 minutes of the new motor firing up, and I have also seen Moly breakin lube used on the Cam keep Moly rings from breaking in at all since there was so much of in in the oil!

[gtofreek]

If you baby the new engine, the rings will not seat properly. You need to put the pedal to the metal and create cylinder pressure to seat the rings. Once the cylinders are glazed up, good luck seating the rings.

[geeteeohguy]

Originally Posted by coonhunter70

Hilly curvy backroads are where you want to break-in your engine.

THIS^^^. The actual, old time procedure is many varied acceleration and deceleration runs, letting the engine pull vacuum on de-cel, and making the engine produce power on accel. Varied throttle at all times. The WORST thing you can do is get on the highway and cruise at a steady RPM. New engines with new rings HATE that, and the rings will have a hard time seating. The trick is driving around town or on the back roads with greatly varying speeds and engine loads. I have always used this method and have never had a ring seat issue.