smoking newbuild
 

my newly built 3.2 ss is still smoking more than I like after 1400 miles. Should I worry ?

Bored and plated Carrerra cyliners from EBS, 10.5CR CP pistons, run in with loading it properly with high loadings at moderate RPMs. Refurbished heads and everything else. I am stressed by how it smokes on startup. There is a big blue cloud, followed by a smoke trail for the first 2-4 minutes. It is embarrassing. I don't see smoke at idle after a trip when engine is hot and no, I don't overfill the oil tank. Oil is LiquiMoly 10w-40 Mo2S Leichlauf and oil pressure is 1 bar per 1000 rpm

You might want to do a leak down test just to confirm your rings are sealed properly.

FWIW, I had a T1 motor that smoked at start up not too long after a rebuild. I tore it down and found that some of the rings had re-orientated so the gaps were on the bottom of the bore.

Unfortunately the rings move - a LOT. I tore an engine down after a couple of hrs of running. And my carefully oriented ring gaps were all over the place. (I posted pics with them marked, on the 930 forum I think). I seriously doubt the placement of the gaps has any lasting effect. I still do it, as a matter of habit. But I know they will not stay that way from the first start up. The rings should have bedded in by now. As above - a leakdown would be useful. Maybe a broken ring on assembly? A broken oil ring would be hard to detect like this tho. Maybe pull the plugs and see if all same, or you have one or two suspect cylinders?
Does it smoke on trailing throttle, or just after you re apply some power (guide seals).
Alan

no smoke on trailing throttle as I have been able to observe myself from the car but it does smell. Nothing on applying power (new valve stem seals). It is only at startup and a few minutes after. Seemed to get significantly worse btw after changing from Motul 10w-40 Break-In Oil to present 10w-40 oil. I'll pull the plugs and have a look .

Do you see smoke from a warm motor on a re-start after an hour or two of sitting?

Oil draining from the tank back into the sump after sitting? Drain the sump when warm immediately after you shut it down and set it aside. Then put another container under it and see if it continues to drain over the next few days. If it does, installing a Rothsport check valve in the S hose will fix it. Not cheap but it works. Just don't install it backwards.

Hello,

It is maybe just because of the viscosity of the motor oil, 10w40 seems to me too low, I would make for your place a replacement 15w50. :)

It does sound like maybe rings not bedded in properly, and/or drain thru when sitting. As above, changing to 50 grade oil may help.
If all the plugs look same (ie no abnormal cylinders), a leakdown may tell you if the rings are properly bedded in.
What sort of oil consumption?
Alan

Thinking on, it sounds more like a valve seal issue than rings. The oil has to get into the combustion chamber, and on sitting, usually is via valves.
Pulling plugs may tell you if it is only one cylinder. Maybe a seal has come loose, or got torn?
Alan

I had a similar situation as yours. Brand new Mahle pistons and cylinders in my rebuilt 3.2, and a lot of smoke for the first couple minutes. It all went away after a couple laps at a track day....it was just what was needed for the rings to seat, hope this helps!!

Pd: i would use mineral oil for a couple miles....I used VR1 for first kms and first oil change, and will change to motul 300v afterwards

thanks for good advice. I do not notice smoke on hot restart, after 1-2 hours. It seems to be worse when parked uphill. It does not consume much oil but I should have a number after next weeks planned 2000 miles roadtrip.... I did not get around to pull plugs but plan to do so over the weekend. If all look the same then rings have not bedded in or there is a small seepage into engine from tank=rothsport valve.

Check oil level.

Funny thing, I have much the same issue here with the CP 98 mm pistons I installed this past winter. Leakdown numbers vary between 4 and 10% and the engine runs fantastic but it smokes on start up and uses about 1 liter per thousand kilometers (600 miles). My theory it's the 3 piece oil rings CP uses. The side rails are super thin at .0165 thou and have a very low radial tension. It makes for minimal HP losses but you pay the price in oil consumption. That's my two cents on the subject.

I agree that modern rings are designed more for V type engines and can contribute to increased smoke on start up. But your oil consumption is higher than average for a CP ring package.


There are a minimum of three common scenarios that can cause excessive smoke on start up.

1. oil level is above the ring gap on one or more cylinders. this would be normal and nothing to worry about.

2. damaged ring/piston/cylinder...improper gap, etc. depending on where the damage is this may contribute to smoking intermittently.

3. intake valve stem seal damaged or has unseated itself. This typically produces excessive smoke on start up and also shows up soon after the engine has been turned off and is started after 30 minutes to an hour.

Aaron, thanks for your input on the normal CP oil consumption. I'm not really happy about it and based on the regular smoke on decel, I'm leaning toward a valve guide seal issue. The seals and guides are only about 8K miles old but as you stated, one (or more) could be out of position. More to follow as I discover. It sure runs strong though and leakdown numbers help to reassure me the cylinders are OK.

Dave

VICTOR REINZ used to include a valve stem condom to prevent damage of the seal when installing. They no longer provide the tool and there is a very good chance of damage upon installation.

The other potential issue is it can take a good amount of force to install Viton seals on the guide....especially the Victor Reinz example. Viton seals are delicate and tear easily...sometimes its hard to see.

I use the elring seals as the are much easier to install.


You can R/R the seals without removing the heads. you would require a leakdown tester and the P7-I spring compressor from Sir tools....I also recommend that you drop the motor so that you can inspect your work and it's just easier on your constitution.

Trond, I hope this chatter about my car is helping your cause.
Thanks Aaron I just happen to have some of those condoms "in stock". They work so well, why do they discontinue the good stuff? This issue will be investigated at the end of the season, winters are long up here.

I am currently on a roadtrip around Scandinavia and 2000 miles of 3000 done in 3 days. I did not do any more investigation as I ran out of time before departure. I did notice there are no embarrassing blue puffs of smoke in the rear mirrors on lift off. Only on start up, and more in the morning than after having been parked for an hour. Last night it was parked nose down and no smoke at all, and it appears to be less of an issue with less oil in the tank. In 2000 miles I did not add any oil but I guess it would take a quart to bring level back up on level gauge to where it was 2000 miles ago and in conclusion I am no longer too worried
http://www.facebook.com/messages/t/thoregil.olsen.12

http://www.facebook.com/messages/t/thoregil.olsen.12


was trying to post picture but no go

Oil leak down thru the pump into the sump. You are putting on some serious miles in a short time.

??
Alan

The oil in the tank is draining through the S hose That's why it's smoking on start up, it smokes more the longer it sits. The Rothsport valve will fix it, had the same thing in my 930.

with lower level in oil tank, barely registering on level gauge when at fully warmed up idle, it no longer smokes on startup or otherwise. No need for one-way valve and engine is sound. 1,5 quart used in 3000 miles, inluding one smallish leak. Runs well too, 3.2 SS with stock cams works great for smaller roads with good torque from early on

Good deal, that's a cheap fix.

did you check oil with the dipstick
 

hello
i am may be misreading but you say the oil level gauge when determing how much oil to put into the tank.
if you are not using the dipstick when the engine is at 180 or above then you may be over-filling it.
the gauge good for ascertaining if you have oil in the tank but I would not use it as a guide to how much oil to put into the engine.

Most of the CP Pistons come with 2.0 or 2.8 oil controls, all of which are a low tension which usually is about 7-10#. It's common to see oil consumption is the 1 quart per 1000 miles, however surface finish of the bores, crosshatch angles, etc. all have a direct correlation to oil consumption. We did a study of different manufacturers honing specs for nikasil a few years back and found you can drive a school bus through the wide ranges of honing specs.

To oversimplify things, the higher the RpK, the faster the rings will seat, but the higher the Rvk, the more oil the valleys will hold and more oil the engine will consume. Problem is it's damn near impossible to eyeball a bore. You have to test it with a profilometer. The crosshatch angle will also affect ring rotation speed. That's something we do with every bore/block to make sure it's in our specifications, which is different than OE or what others use for reconditioning.

Well said. A lot of old historic ideas are still considered today. Most came out of the Iron block days and still in current use due to uncoated Iron liners.

Nikasil is getting old tech now too. It doesn't need the surface finish as rough as iron as it wont wear down like iron does. The cross hatch can be less steep as well as the oil retention is not required as much as iron due to a lower friction CF. The rings will rotate but in these engines its not as critical as in Iron blocks. Its about controlling this movement in these engines and one way is to use a non common angle.


Piston design and the ring selection play as much if not greater part in the oil consumption. Ring land designs, Gas ports, Napier style rings, tension numbers all help here.

In difference to my respected colleague here, I do not subscribe to the fact that rings seat the same way in a Nikasil liner as they do in a iron block or liner. I don't agree that they will seat quicker with a higher surface finish number. Nikasil is extremely hard compared to iron. Wear out quicker? I guess the ring may seat better on its way to wearing out.


Charles know his stuff, so I'm open to other ideas and opinions.

Thanks for your reply Neil.

I should have been more specific on honing finishes. In my evaluation of various brands and platers, I found Ra finishes as low as 3 and some over 20 with Rvk, RpK, and Rk values all over the board.

Without getting into specifics for the component values that go into calculating surface finishes, an Ra over 10 is IMHO will result in shorter ring life. Anything over 14 and for sure it's going to burn oil and smoke. On the flip side, a finish of 3-4 will have very little oil consumption, but if the engine over-rich during break-in, the bores will glaze over. Over the years I've seen incorrectly finished cylinders wear rings out in no time like Neil mentioned above.

Running rings that are higher tension on Nikasil, even with proper finishes, will result in elevated oil consumption and smoking in no time as well, again because the rings wear out prematurely. There really isn't any reason for running tensions over 10# as long as everything is set up properly.

So many things go into setting things up properly. Only thing I can say for certain is that you have to check 100% of everything, regardless of manufacturer. In this day and age, you can't assume things are right, even from trusted sources, unless you have measured and quantified it yourself. We check 100% of everything.

Thanks for your continuing inputs guys. I continue to learn. Here is an article I found that deals with ring rotation. Humorous writing style, especially for an engineer. For example: "Staggering ring gaps when installing pistons is every bit as daft as having four tyres fitted and placing all the valves at "twelve o'clock". One trip to Tesco and they end up all over the place".

Ring rotation explains why some days I have zero smoke on startup, others, lots. Still, overall, unacceptable oil consumption so apart it will be once the season is over. Updates to follow.

Institution Of Diagnostic Engineers

I recently replaced ONE that was completely torn (Viton) from the previous build, as i think they used too mucho force (and think there are others torn as I still smell burning oil). Anyhow, when placing the new seal, I taped the top of the valve with any old tape and then inserted the seal, which worked great. When pressing the seal, I used (IICR) a 10mm socket and then tapped on it which worked great.

Excess oil consumption update
 

In preparation for the teardown of said oil burning engine, I had ordered 6 std rings sets for the 98 mm Carrillo pistons. And then, come time to fit them, a surprise. The oil rings were too wide for the land. I contacted Carrillo and Jerry said my 98 mm Carrillo pistons must have been a custom order with 2 mm oil control rings (their off the shelf 98 mm pistons sets are sized for 2.8 mm oil rings). I asked him if they had 2 mm rings sets and no was the answer. He referred me to two possibilities, Perfect Circle and a machine shop in Wichita KS. I called Perfect Circle and they were very helpful. Yes, they could supply a 2 mm oil ring but the pistons would need the ring land depth deepened to accommodate their ring. Keep in mind I already had 2.8 mm oil rings so now it was machining the pistons and buying Perfect Circle 2 mm oil rings. Plus, after some research, I wanted to use the 2.8 mm rings as apparently they would offer better oil control than the very delicate 2 mm rings.
On to Rebco Machine in Witchita. I explained the situation to Eric and he said no problem, he could cut the ring lands to the Carrillo spec and have them back to me in a week or so. So the pistons were shipped to him and they were ready in the specified time. I've got to say, Eric does amazing quality work at a very reasonable price. Each land measures exactly as per the Carrillo supplied spec. Based on my experience, I can highly recommend Rebco for any piston work you may need. His site is here:

https://www.rebco-machine.com

Attached, a rather poor hand held comparison of the 2 and 2.8 mm rings as well as a piston with the widened ring land.

/http://forums.pelicanparts.com/uploa...1550363605.jpg


http://forums.pelicanparts.com/uploa...1550363712.jpg

Did the wider expander solve the problem?

Good question Neil. As we have at least 6 more weeks of winter here (more like 8), I have lots of time to assemble carefully and double/triple check everything. Cylinder bores were re-conditioned as per US Chrome plus the input of the well informed people on this thread. Valve guides checked and new seals to be in place. I hope to be providing a positive report once our spring arrives.

Change the 2nd ring to a Napier style if you haven't already.

Yes, the new second rings are indeed Napier cut. And Neil, you piqued my interest on the 2.8 mm oil rings being just a wider expander so I checked the rails. The 2 mm sets have rails .012" thick, the 2.8 mm ones are .015" thick. So percentage wise, about 20% thicker but significant, I don't know.

Good.

The 2nd ring does a lot in controlling the oil too. Its probably a cast ring so be careful installing them.

I'm a big fan of 3 piece rings in these engines. I believe the separate oil rails work independently of each other somewhat and help control the oil when the pistons tip.

I am very pleased to report that my oil consumption for the first 500 miles has been negligible. Proper bore finish, new rings and valve guide seals seem to have done the trick.
I really appreciate the sound advice from everyone. Nice to have a completely dry and smoke free engine. I've been fine tuning the Megasquirt system to make sure A/F mixtures are staying out of the rich zone. I also added a knock sensor so timing can be quickly pulled back in the event of knock. And while you are in there was also in the form of an aluminum pressure plate, a new disc and a resurfaced flywheel.
Also, thanks to Craig (Cgarr) for the great job on reconditioning my rockers.
Now to get out and enjoy the driving part, winter was just too long.

http://forums.pelicanparts.com/uploa...1556237437.JPG

tell more about surface condition of the cylinders ? My engine still smells of burnt oil, even if it consumes little. 98 mm nickasil cylinders from EBS and CP pistons. No other issues

I wouldn't worry about it. I'd be annoyed but to fix it would be a big pain in the butt.

I 2nd the leak down just to make sure the valves are seating. You really should do a leak down after you get the heads on during the assembly. I did this on my 914 a long time ago to find the machine shop who installed the guides didn't cut the seats enough on the burned exhaust valve that caused me to do the rebuild in the first place.

Maybe you should have kept dino oil in the engine until you change the oil again (3000 or 5000?) Something like Castrol 4T motorcycle oil.