Here are the details. 351W stock block 0.040 over, sized and honed by a reputable machine shop to fit new DSS pro-lite pistons. 0.005" piston to wall clearance per piston mfg specs. Rings are speed pro plasma moly, file fit by me to 0.019" on top and 0.023" on second. Standard tension oil rings. Heads were just rebuilt with new bronze valve guides and I very thoroughly prepared the valvetrain to have optimum geometry to best avoid side loading the valve guides (lots of test fitting of different rocker arm combos). Teflon valve guide seals were used.

Pistons were installed (by me) with Childs and Albert piston assembly lube, and the rings gap positions were aligned properly. Engine was broken in using non-synthetic 10W-30, with a filter change after the first 20 minutes and a full oil change (still 10W-30) after the first 10 miles.

This is the third engine I have put together myself and I have never had this problem. I pulled a few plugs (the accessible ones) and they did not look too bad...semi clean and grayish on the insulator and electrode, and little black soot near the threads. I have had minor carb issues with my new 750 double-pumper so it has been running a bit rich if that means anything to the rings.

Any suggestions? Any way to rectify the situation short of pulling the engine again and trying new rings? Any hope to surpress my blues?

Have you done compression and leak down tests to see if it's an actual ring seal problem?

Is it just a little hazing, or are you killing mosquitos county wide?

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'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip

You can cover the PCV System and use a unlit propane torch. Allow the propane into one of the valve covers. If the engine picks up or misses then ya found your problem. This may also be contributing to your carb problem as well?

Sorry to hear your having trouble with your new engine. Personaly I'm a Steel Ring fan.

Les

Intake gasket pulling oil from the valley side is another possibility but I would think that would show up on a vacuum gauge as a flutter. Just add this to the list of maybe's.

1) I have spent time hoping it was the PCV, so I temporarily disconnected it and drove around a bit. No change to the amount of smoke.

2) I cannot prove that it is not sucking in oil from a bad intake gasket, but it smokes under wide open throttle too, when there is no vacuum in the intake manifold. That is why I keep thinking it is rings.

3) The valve guides are those tight fitting white teflon style. The heads are newly rebuilt so they "should" be okay, but they are unproven. I think the only way to check this would be to pull the intake and check the valves for oil on their topside?

Next: I do own a leakdown tester and a compression tester, so I will try those tests, and the propane check too. A 351W in a '66 is no fun task to pull the plugs, but it is just a little easier than pulling the engine.

Results were that all cylinders were between 188 and 193 psi cranking pressure (cold engine). Sounds about right to me. Engine has a 10.3 to 1 CR and a 236/242 deg. at 0.050" solid roller cam.

I am not sure what to think about the plugs. They were all pretty consistent: clean insulator and ground strap, but shiny black at the thread area.

Last idea then,

Moly rings have a different wall finish. I've read pros and cons on this.

I use to coat the pistons with 30w oil for assembly but found out that if oil gets trapped behind the rings it can burn a ring tight to the piston. I was told to use WD-40 oil in the future and just coat the wall. I'm not trying to change the post here just offering ideas to think about.

Since you've built engines befor it's kind of hard to find fault such as rings installed upside down and such!

Um, what about this... leaky fuel pump or overly rich carb duluting the engine oil to the point it is thin? Or a leaky needle and seat so when the engine is shut off over night the fuel will puddle and dulute the oil? How is the oil pressure?

What engine temp are you running? High temp can break down engine oil as well.

See ya!

Les

I do have a capacitive discharge ignition, so it is probably just cleaning the plugs for me. That explains the plugs.

As far as having to add oil, I do not have enough consistent miles to be able to measure that. I have added a little, but I have also pulled the valve covers a few times and dripped a little out, etc.

Engine has good oil pressure: 60 psi hot at 2300 RPM and above, 24 psi idle hot, 80 psi when cold. Standard volume oil pump. Engine has a 180 deg thermostat and the engine has never been past about 185 degrees.

I did thoroughly coat the pistons and rings with some Childs and Alberts assembly lube designed for pistons rings (seemed like just heavy weight oil). Maybe I used too much lube? I don't think the rings are in upside down, I was pretty anal putting this engine together.

One other note, if I pull the PCV hose with the engine running at normal operating temp, I can see a small mist of oil(?) trickling out of the valve cover hole. I do not know if this is normal or not.

Is there any way to check valve guides and seals without pulling the heads?

Thanks again for all the replies so far.

Maybe it's time to pull the intake - leakdown is beautiful!

quote:

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Originally posted by matt d:
One other note, if I pull the PCV hose with the engine running at normal operating temp, I can see a small mist of oil(?) trickling out of the valve cover hole. I do not know if this is normal or not.

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Can you plug the pcv hose and put a breather in the valve cover? Then take it for another test drive. If the smoke goes away you'll need a baffle under the pcv port in the valve cover.

It could be the intake gasket too, but this is an easy test.

I guess I need to pull the intake. One last question though, does "rich" smoke ever look blue/white? I am grasping here.

I appreciate all the advice from everybody.

With your test results the last thing I'd do is pull the motor out. Run it and see what happens. Pull the intake if you want, but I've had that happen before and it oil fouled some plugs more than others. Just my .02

As far as coolant goes, it appears to have zero loss. The tranny is a manual so no tranny fluid possibilities.

So the possibilities that I see are:
1) Intake gasket issue allowing oil to be sucked into intake ports.
2) Valve guide/seal issue allowing oil to be sucked into intake ports.
3) Rings that hold combustion pressure okay but do not control oil well.
4) PCV pulling too much oil (maybe I didn't drive around long enough with it disconnected or the extra blowby with it disconnected cause a second oil burning problem)
5) rings need more time to seat.
6) engine runs rich and magically changes its smoke from black to white.

I am going to retry my PCV disconnect test and rig a baffle and or oil separator setup. I will also change the oil again in case it got too contaminated when it was running rich and breaking in. Then I will probably pull the intake after a few more miles.

This is right from Federal Mogul's website (must be true).

We use Speed Pro plasma moloy rings in our motor - we consider break in done after completion of the first pass on the rings!

With your leak down numbers, I don't believe you have a problem with rings - and if it has new guides / positive seals.....

So doing nothing but drive it is definitely the easy plan. I will change the oil and be patient for now. I also put a baffle in the valve cover at the PCV pickup last night just in case that helps. If the fuel wash on the cylinders hurt the break-in process I hope it can be rectified with miles.

Block off the pcv for the time being, but be sure to ventilate the crankcase (install a filter in each valve cover).

I pulled the intake and one head, and there is oil throughout the top end...in the intake manifold and intake ports, more heavily in one "plane" of the manifold than the other. The intake gasket looks fine, was in the proper place and appears to have been evenly compressed. It is not the PCV, since the oiling occurs even with the PCV passage baffled, filtered, and plugged.

So that leaves VALVE GUIDES in my opinion. The heads were just rebuilt by a reputable shop in another state who put in new Ferrea heavy duty valves and bronze valve guides. So after 600 miles, it seems something is very wrong. All of the intake ports in the heads are oily and two have walls which are colored brownish-gold. All of the valves have a thick layer of black crust on the top of their heads. A couple of the exhaust ports have shiny oil surrounding the valve guides, some are fine. I pulled the springs off a couple of the valves and I can wiggle the valves. A dial indicator on the valve head shows about 0.012" to 0.015" total wiggle. My guess is that the majority of the oil in the intake is from a couple of bad guides (the ones with the gold/brown ports) and the oil is being shared with the other ports from intake reversion, etc.

So my question is: Do these clues have to add up to bad valve guides or could I be missing something? I want to know so I have more confidence when I discuss this with the machine shop. Any other opinions?

The roller tips need to be centered side to side... and front to back. They also need to have no more than 0.080" sweep as the cam goes through its lift cycle.

Good Luck!

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Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220

Did you assemble the heads yourself? Do you know what the guide clearance was before?
Some shops will clearance the bronze guides with a ball hone, works great but needs extreme attention to cleaning or the granules of grit will continue to do their job. What kind of valves? Have seen some cheapies (I learned a hard lesson on this one) lose their chrome plating in small flakes, causing massive damage to the guides.
What manufacture of guides? K-line is excellent when properly installed.