I had the intake gasket failure and need some help...

[MaSnaka]

I had the well known printo gasket failure on my 390 after about 1000 miles of fun. I used the gasketsinch to glue it down to the heads prior to installing the manifold like the instructions say. I used the rightstuff at the front and back instead of the cork. No external leaks. It still split at the #6 intake port sucking in a considerable amount of oil. I have the MR-Gasket 202A to replace the Felpro now and so I think I have that problem handled.

 The plug in #6 was fouled needless to say but what I am puzzled about is the condition of all the valves when viewed through the head ports. They all have a black grimy build up, what I would call thick. These edelbrocks are fairly new (1000 miles)and I'm surprised at how much buildup there is already. The ports all look clean just the valves have deposits, there was no sign of oil deposits inside the intake plenum which leads me to believe it's not a PVC problem. Is there something else here I should be concerned about?

 Worth mentioning is the engine was running well and had been tuned by a reputable dyno guy. I also discovered my vacuum advance canister had a blown diaphragm for how long I don't know. I wonder how truly tuned it was because I have no idea when the diaphragm gave out. Thanks for any help or ideas you have.

 John

[jayb]

I wouldn't be too concerned about the buildup on the valves.  Probably once the intake gasket blew you got some oil flying around in various spots in the manifold, and it burned onto the valves because they were hot.  If you really want to take it off you could spray some solvent in there to dissolve it, BUT make sure you pull the plugs and and spin the engine over a bunch to get all that stuff out of there afterwards, then squirt some clean oil in the plug holes and spin the engine some more to make sure you have some lube on the cylinder walls.  Then change the oil to get any remaining solvent out.  It would be a lot of screwing around to do this and if it was me I wouldn't bother; some of those deposits will clean up after the leak is sealed anyway.

[machoneman]

2X to Jay's note +: pop the rocker shafts and spark plugs (or back off your adjusters as far as possible or remove them). With all the intakes closed, fill the ports with your choice of super solvent (SuperClean, lacquer thinner, acetone, paint thinner, kerosene, etc. diesel may work too but I've never tried it). Let sit for at least 24 hours or as many days as you can stand. May need to refill some ports as the valves will leak over time. Suck out the leftover with a shop vac (careful here and don't use the vac if you're using gasoline, acetone, etc.)   and crank after adding oil as Jay stated. Use very light machine oil if you can or 5w oil. Re-install with Victor Reintz or Fel-Pro street gaskets, not the Printo-O-Leaks!

[cjshaker]

I would just use any of the number of better "fuel system cleaners" designed for fuel/carbon deposits over the next few tank fills. A bottle each fuel fill-up and a little spirited driving will loosen and blow it out. I personally wouldn't try to clean any of those deposits with the engine not running. Anything you put in there with the pistons stationary will allow the gunk to run down into the cylinder and settle down into the rings and likely cause some scuffing, maybe bad, in the cylinders. If the engine is running  there is a much better chance of it blowing out the exhaust before it can get past the piston crown and down in to the rings.

[MaSnaka]

Thanks for telling me it's not much to worry about.  That is what I wanted to hear.  Rather than try and clean I will do what CJ suggested and use some fuel additives and hope I never have a another chance to see those valves.  I'm still clueless as to why the grime would affect the valves that didn't have the breached gasket.

Thanks,
John

[jayb]

I'm still clueless as to why the grime would affect the valves that didn't have the breached gasket.

Thanks,
John

Once you get something in the intake runners, it can go anywhere.  I dropped a valve on the dyno once and shut it down within 3 seconds of the event.  When I disassembled the engine pieces from the piston where the valve dropped were in several of the other cylinders.  Pressure pulses, in both directions, will shoot anything in the intake manifold to any of the cylinders.  Oil coming in at one spot will soon be everywhere...

[MaSnaka]

Thanks Jay,
Knowing that helps me understand what was going on.  It explains a lot.
I can't wait to get this repair project behind me and start enjoying my car again.
John

[Heo]

the old way to get rid of the buildup is warm up the Engine
and spray a fine mist of water in the carb  at 1500-2000

[MaSnaka]

I spoke to the mech at the BMW shop (my wife's car this time) and he said that fuel alone should clean it under normal driving but I could use a product called SeaFoam.  He mentioned another one available to him commercially.  Add to the gas tank and run it.  Really designed to dissolve carbon deposits but he thought it wouldn't hurt to use it.  Also said I could pull the carb and check the valves with a bore scope to see how clean they are after just running normal gas through while driving.  I think I will try that first then take the extraordinary measures if necessary.

John