Follow up to Oil on threads of 7-8 plugs. Intake removed. Valve issue? Help

[stotzbotz]

So I am following up on a recent post where I have been breaking in a recent rebuild of an FE 390 engine that has been smoking just out of the driver's side exhaust after about 300 miles. No. 7 and 8 spark plugs were showing oil on their threads but the compression is pretty equal while testing 5-8. Tonight I removed the aluminum intake and was hoping that the gasket failed but it looks like it was working properly. When I look into the ports for 7 and 8 they are not oily. Just dry carbon in them like all of the others. I'm sadly thinking that the head now needs to be removed and taken back to the shop that was supposed to have replaced the valve seals. Is this problem something that they should have taken care of when they were in for a general clean up re surfacing and the seals replaced or would they have not known of this problem? The placement of the headers on this 68 Fairlane make taking the head back off most annoying. I just wanted to ask you good folks if from what I'm telling you does it sound like a problem with the valves or am I not looking at this properly and could it still be the intake gasket. I'm not a professional mechanic so your help would be greatly appreciated before I go to the trouble of taking this engine further apart.

[techinspector1]

If the gasket was compressed all the way around the ports and all the ports look the same, then you have no choice but to look at the guide seals as the culprits. I don't know what you discussed with the fellow(s) who put the heads together, but if you told them to check the valve to guide clearance, replace as necessary and install positive seals, then they dropped the ball in my opinion. If you did not tell them what to do to the heads, then it's probably all on you. They cannot be expected to do work that you did not authorize.

Now, if you did authorize checking the valves and valve guides and replacing as necessary and installing positive seals and they did that work, then somebody at the shop either installed the seals incorrectly or damaged the seals on installation or screwed the pooch by leaving excessive clearance between the valves and guides and you have a legitimate beef with the shop. Did you have this work done in writing and signed off on it?

I think what I would do is to pull the head and call the shop, making an appointment to take the head down there and have one of the guys take it apart while you stand there and watch, then inspect the whole mess and talk to the owner before you go any farther.

.

[34_40]

I mostly agree with Techinspector, definitaley talk with the shop and ask them for guidance and help.
You asked for an opinion and there's mine. It's hard if not impossible to know what was said when you were there last, but be honest with them and be honest in your expectations of what you expect from them.

If they are a reputable shop they'll be willing to step up and help you fix the problem(s).

[stotzbotz]

Would it be safe to say at this point in the break in that if the other plugs are not showing any signs of oil on their threads that I should just take off the head in question and have the issue addressed that is currently happening on 7 and 8 valves? I guess this is my fault as I gave the shop the heads and told them to check them out, fix any problems and so $350.00 later I thought that they would have taken care of what needed to be done. When they had them and called me they stated that 2 exhaust valves needed to be replaced but everything else looked fine. I am new to this level of work on an engine so I might have not been specific enough.

[rspears]

Would it be safe to say at this point in the break in that if the other plugs are not showing any signs of oil on their threads that I should just take off the head in question and have the issue addressed that is currently happening on 7 and 8 valves?

Based on what you've said about your instructions, and the fact that you now have a problem on one head if it were mine I'd pull both heads and take them back to the shop, have them concentrate on the known problem first, and then decide if they maybe need to go through the other one, too. It would be sad to put it all back together after having had one head done, only to have the other side start smoking....

[firebird77clone]

Please let us know what the shop says

[jerry clayton]

Soooo, As usual I got a couple questions for you that are out of the box as for the pther posters---------What oil do you have in the engine? What assy lube did you use and where? Rings, cylinder walls, bearings, camshaft components?


Since you have said that the ports looked same as others-------probably not a intake gasket-----

Now-as a matter of reality--------your heads need a complete set of new guides and valves, common on engines of the FE era ( 60,70s ers all brands) and there isn't a shop anywhere on this planet that will do that for $350-------

If you are running syn oil and/or used some dopie new stuff on the rings, you have glased the walls and will never get it broken in-------

If you still had it together , you could rev the engine while dusting Bonami powder over the carb and it possible would have helped.

Too many internet mechs these days will pussy around with a new build (most improperly done) and not create enough internal positive pressure sealing across the ring pack to put enough ring pressure on the wall to properly lap the ring edge to create the seal.

A breakin drive around where the engine is put under full throttle pressure ( but not into the top levels of rpm) will assist in a good breakin.

When asked how I breakin in my stuff I usually with a smile say that I adjust the valves, make sure it'll start and go to the starting line and set another track record------its worked for me for 70 years(considering starting at 5 years old)

[jerry clayton]

As a side note-----------do you have the oil splash /drainback shields on the cylinder heads??????

[jerry clayton]

thanks for posting the pic DennyW

You certainly have a library full of data

[stotzbotz]

Yes sir I have these in place. Took the head off last night and it is obvious that #7 exhaust valve is leaking oil pretty badly into the exhaust port. Not sure why #8 was showing no signs of leakage though as it had oil on its plug threads too, just not as much. Going out now to take the other head off and shoot them on back to the shop. I will tell them to check all valve guide clearances and hopefully they will do a reasonable follow repair on these puppies. I am on a budget with this car and have a wife with a lot of medical problems so even though a complete valve guide and valve replacement would be the right thing to do, I'm going to see what they have to say after getting them back a second time and hopefully for now address the problems at hand and get a little more life out of the existing parts. Thanks again everyone for taking the time to help me and I'll let you know the outcome hopefully soon.

[jerry clayton]

Since 7 and 8 fire consquet?? it could be getting in on overlap

[stotzbotz]

Looks like #2 cylinder also had some oil coming out of the exhaust port so it's a good thing I pulled both heads. Dropped them off and the owner stated I probably need valve guides as all he replaced in the previous repair were the seals. I'm not getting why this wasn't done the first time but I have to be nice until I get them back, hopefully at a discount. It's the only shop in Tallahassee and they've been doing it for 35 years so I guess I expected more.

[jerry clayton]

while the heads are off look at the condition of the cross hatch in the honing of the cylinders-post some pics if you can-

Those spark plugs in #7 & 8 are hard to get out-----------
( I had 68 Torrino 428cj)