My 427 SOHC Build..... Finally the time has come!

[cobracammer]

Hi Guys,

Got off of work early today, so I got the car back up on jack stands and rolled on under!  Oil in all the same places, so I started off by snugging up the oil pan bolts.  None of them seemed Then a quick wipe down before I started the car and rolled back under.  Was able to observe the bottom of the engine at both high oil pressure (just upon start) and lower oil pressure when the car heated up.  What I was able to observe a drip of oil that comes from somewhere and hit the lower header pipe (smoking and sizzling).  I can't see all of it from underneath or on top, but I was not able to see any dripping from what I was able to see.  I did not see it coming from the valve cover gasket, but what I could not see, it was too hot to feel around.  So mystery drip there.

Also, now that the car has had the timing adjusted a little, I have noticed that I am still getting smoke from the tailpipe.  Seemed to happen now both at warm up and now also after the car is warm and idling spot on.  Unsure.  I tried adjusting the A/F ratio when in the driveway to maybe a little leaner (13.5 to 14.0, but the smoke was still there.  I wasn't sure how lean is too lean on each setting (Idle, cruise, and WOT), so I put it back to the 13.5.

Definitely seems to run stronger now with the timing adjusted, but a few little issues to work out.  Any thoughts on what the danger zones are for each A/F ratio?  that way when I'm "fiddling" I don't go to lean and cause any damage?  Thanks Guys!

[Heo]

Color of the smoke? Black =rich.  White just the air humidity
Big engine that you send a lot of air through that contains
a lot of vapour that condense in the engine until it heats up

[cobracammer]

Hey Heo,

Blueish white smoke.  Makes the whole yard and my clothes smell like gas.  Lol 

Idle A /F ratio is 13.5.  I did notice while driving today that when I push the gas, the AF ratio goes into the 15.5 range for a moment.....  seems really lean, but dont know if the temp dip is normal ( sorry, sidd note from the smoke issue)

[cobracammer]

Another interedting tid bit.  Found some oil!  There is oil from what seems like one of the header bolts!  Not coming from above ( valve cover gasket).  Not even sure how oil can come from a header bolt.  Lol    Any thought?  Felt all the way around the valve cover gaskets.  Dry all the way around!  Also, perhaps oil is getting into the exhaust and hence the smoke?

[Heo]

Blueish sounds like oil....hold your hand behind the exhaust
pipe and see if you get an oilfilm om your hand(gues you can use a piece of
cardboard or some other sissy equipment )
Does it smoke more when you start it and when you let up the gas (decelerate)
Oil on header bolt?is there any chance the hole is drilled to deep
so you found oil that way?

[cobracammer]

Not sure.  Smells more like fuel and not oil.  I will fiddle more tomorrow.  See what I can find

[jayb]

On the smoke in the exhaust, remember that we just reinstalled the same pistons and rings that were originally in the engine.  They all looked good, and the bores looked good too, but maybe the rings aren't sealing up for some reason.  Kind of hard to say until you've got more miles on the engine, though.

As long as you are checking bolts, maybe check the front cover bolts too.  There is no path for oil to leak out of the header bolt holes, so it has to be coming from somewhere else.  My first reaction if there was oil on a header bolt would be the valve cover gasket, but if those are dry, maybe oil is coming back from a leak in the front cover area and running along the header flange to the bolt.  Just guessing...

A momentary lean condition when you accelerate means your acceleration enrichment for the EFI system isn't right yet.  Is that part self tuning, or do can you adjust that yourself?  If so, I would give the engine more fuel on throttle tip-in.

[cobracammer]

Thanks Jay,

Sorry about the above post all.  I was typing on my phone, and even I had a hard time reading/understanding it  LOL.  So last night I went in and snugged down the bolts on the headers, front cover, and oil pan bolts.

I think I figured it out....  OK, so if oil was dripping from the rear main seal, there would be a little trail of oil down the front of the scatter shield/ Backing plate and then drip off of the bell housing.  After wiping it all down, there still seems to be a drip from the bell housing, but no trail down the backing plate.  I believe this particular  drip is from the back freeze plug (the one that's not a screw in- in the center of the block).

As for the other drips, its hard.....  This engine literally takes up the entire engine bay.  Hard to reach anything at all from the top.  From the bottom, the headers take up all the rest of the space.  Can't really see anything from the bottom either  LOL.  its a case of "if I could, I would"  LOL

I will try reaching a few more of the valve cover bolts to snug down, and then I am going to take it out for a LONG drive to make sure I get proper ring seat.  I have a circular highway here in Jax (I- 295) which is a huge 61 mile loop around the city.  I figure 1 or 2 times around should do the trick.... and then an oil change!  Will post back soon!

[cobracammer]

Also, as a side note (and we all know how much I love side notes)....  The smoking at cold start has always been there...  but after warm up, that smoke started at about the same time as the PCV valve installation!  I will get the rings to seat through some mileage, but if its still smoking, I will just throw 2 really good breathers on the VC tubes and disconnect the PCV valve.

I was going to do all of this Sunday, but there was some torrential downpours and Jax was once again Flooded all around town.

:0)

[machoneman]

W/O some kind of material in the VC underneath the PCV's opening, the oil will get sucked out of the engine, past the PCV valve and into the intake, hence the smoke.
SS steel wool, that Choreboy SS kitchen sink material, etc. goes a long way to prevent oil from being sucked out.

I'd not wait. Take off the PCV now and just run breathers for your long drive. Why? Excess oil can coat the inside of your entire exhaust system and this can take some driving time and exhaust heat to burn it off.

[My427stang]

Out of town so sorry for not responding earlier

I agree that if the PCV is improperly designed, without adequate baffling if front of the PCV, then it needs to be fixed, either with a better baffle or a oil trp.  However I do not think breather vents are the right answer long term, especially if it has marginal ring seal.  If you think your valve covers or breather basket (depending what you use) is not adequate, fix it.

Experiment?  OK, that makes sense to find the source of smoke, but my hunch is there is something not right causing oil burning and leakage, not the PCVm a fresh motor shouldn't be making a mess

Regardless, pick a course of action and before you go add 2 to your accel fuel and get some miles on it.  Not just highway, accel and decel too. 

Oil leaks generally do not solve themselves though, my guess is you'll be pulling it out one more time

[cobracammer]

OK...  Took today to get a few additional things buttoned up.  I don't know if I mentioned it or not, but the coolant overflow tank hose touched the header on the drivers side.  It wasn't leaking, but there was a divot melted into it.  Rather than take a chance on a longer trip, I just purchased a new hose and replaced it (Shorter this time so it cannot touch the headers).

In other news, I pulled the PCV valve/ cap, and there was a little puddle of oil in the top of the baffle tube.  I am pretty sure it was sucking oil vapors and burning them....  hence more smoke.  The K&N crank case breather filters came today, so I swapped them out and re-capped the vacuum port on the side of the throttle body.

Lastly, I wanted to get to all of the bolts on the valve covers. Given the size of this engine, and the tiny little engine bay I stuffed it in....  Getting to almost anything is a challenge to say the least.  Using a combination of hand wrench, rachet and socket, and vavious extensions and swivel elbows, I was able to get them all.  It also required that I pull the battery and battery tray, as well as to put the end on jackstands to reach some from the bottom.  While down there, I noticed more oil.  This time on the passenger side headers.  I agree (as Jay has stated) that there is/ was a definite leak in the valve cover gaskets.  Hopefully tightening them all down will help.

With that being said, I started the car and let the oil warm before setting out for another 5 mile drive (I know I need to put like 60-70 miles, but I will get there).

I can say that (as Ross just stated, up-ing the accel fuel to +2 now allows the car to accelerate without choking.  The cruise issue seems to have fixed itself with the adjustment to timing we did last.  The car did smoke a little, but I am sure this will get better with 100+ miles or so and a fresh oil change, giving the car time to burn off what is still in the exhaust system, and also giving the computer time to learn.  Much Much better though just with todays changes.

This was the last mini drive today.  I will go out for a long (50+ mile) drive tomorrow.

Thanks to you guys again and keep you posted

[My427stang]

Sounds good, just for giggles, can you pull the valve covers off in the car?

[jayb]

It sucks that you've got to pull the battery and tray to get the valve covers off; you need to be able to access those occasionally to check valve lash, check the rockers, etc.  Also, at the time I put the engine together the thick cork gaskets were all that were available for the SOHC, but recently SCE gaskets has come out with a combination cork/composite gasket that holds up much better than the straight cork ones.  I tried one of them on Drag Week and never had to re-tighten the valve cover bolts all week.  The problem with the cork gaskets is that they shrink with heat cycles, so it seems like you are always re-tightening them.  Also, they tend to get cut by the head castings when they get thin, which will cause a leak no matter how much you tighten them, and you just have to replace them at that point.

As far as I know SCE has not provided a part number for the new gaskets yet.  I got the first two copies, and I was the guinea pig for them, so they are not really in production yet, as far as I know.  I am trying to order at least four sets for myself, and may pick up 10 sets, just so I can have them available for others when they are in production.  I will post information on the valve cover gaskets as soon as I have more info.

[cobracammer]

Thanks Jay.  I had some time today to do a little snooping.  I found 2 leak spots.  The dipstick tube is leaking, so I will reseal it and retighten it.  Another I found was a little worse.  There is a little "well" right next to the distributor behind the front cover.  The oil is leaking from maybe under the intake ( china wall) and fills up the little "well" and then flows down between the front cover and drivers side head to pool up ontop of the oil adapter.  Seems like at anytime, there is a tablespoon of oil sitting in the "well".

This doesnt explain the rear oil drip (bell housing) but getting them found a little at a time.  Not sure if this picture is that clear, but its the beat I could get with my phone;