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FE Power Forums => FE Technical Forum => Topic started by: amdscooter on May 10, 2015, 01:31:58 PM

Title: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 10, 2015, 01:31:58 PM
(http://i234.photobucket.com/albums/ee6/amdscooter/IMG_5363_zpsw3ghmc6d.jpg) (http://s234.photobucket.com/user/amdscooter/media/IMG_5363_zpsw3ghmc6d.jpg.html)

I'm almost afraid to ask... but #8 is having issues. All 3 plugs in the photo were pulled in the last month o so. The plug on the top in the photo only I pulled on Tuesday after coming back from a local show and shine and has about 40 miles on it. All the other plugs look fine and I had the heads refreshed (hardened seats, viton seals, etc.) maybe 2500 miles ago. What are the chances I'm looking at a valve seal gone rogue vs. rings or something worse? It'll be coming apart as this is obviously not going to fix itself, I'm fishin' for advise on what I should/could be looking for when I get into it.

Thought I'd also share this photo of a nice 64 Galaxy 445FE that showed up...

(http://i234.photobucket.com/albums/ee6/amdscooter/20150505_170957_zpsr6gu1rwo.jpg) (http://s234.photobucket.com/user/amdscooter/media/20150505_170957_zpsr6gu1rwo.jpg.html)

 ;)
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: ScotiaFE on May 10, 2015, 02:56:11 PM
Intake gasket leaking?
It's sucking in oil.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: shady on May 10, 2015, 04:04:45 PM
a compression check is where I would start.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: WConley on May 10, 2015, 04:54:05 PM
+1 on the intake gasket.  Print-o-Leaks?

That's a lot of oil.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 10, 2015, 06:30:57 PM
Well just had the valve cover off and removed the rocker assembly. The valve seals are where they should be and everything looks normal otherwise. I'm going to borrow my buddy's leak down tester next. At this point I'm praying for a sucked intake gasket.  :-\
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: machoneman on May 10, 2015, 06:47:29 PM
What make are the intake gaskets? Hopefully they are Print-o-Leaks and new gaskets will fix her up.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 10, 2015, 07:02:30 PM
I used a Fel-Pro gasket set, here is a photo just prior to installing the intake...

(http://i234.photobucket.com/albums/ee6/amdscooter/IMG_2898_zpstkg8hjoq.jpg) (http://s234.photobucket.com/user/amdscooter/media/IMG_2898_zpstkg8hjoq.jpg.html)

What are the chances that one got sucked in at #8??
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: ScotiaFE on May 10, 2015, 07:18:21 PM
It didn't really get sucked so to speak. The angle cut at the back just above
the oil drain back is probably weeping and that is the source of the oil entry
into #8. If it was an aluminum intake then the rear bolt may have been a tad loose.
Over the years I have found that it is like a spring get the car ready thing. Put small box end on each intake bolt and give them
a snug. That is a pretty big chunk of alum, that does a lot of heating and cooling.
A small smear of goo on it will help also.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 10, 2015, 08:52:24 PM
^^^ I'm really hoping you are right.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: machoneman on May 11, 2015, 07:52:57 AM
Those don't appear to be the 'bad' Fel-Pros. As noted, perhaps a re-torque will help. I've noticed as well that sometimes the head gasket tabs aren't your friend! The intakes can slip a tad when plopping on that heavy FE intake and hang up the gasket.

Btw, if you do pull the intake, save the old gaskets. One can 'mike' the edges around a few good ports and compare same to the #8 port. Intake twist, misalignment, etc. could be a cause and the gaskets telegraph just how much crush, or not, they have. 
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: NIsaacs on May 11, 2015, 08:13:51 AM
When I see plugs like that, my experience has been a cylinder problem as the cause. Rings, piston or piston pin loosing a snap ring and gouging the cylinder wall.

Nick
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: ScotiaFE on May 11, 2015, 08:43:39 AM
All Nick's gloom and doom aside. ::)
As Bob said, put a wrench on the intake bolts and snug them down and give it another try.
If it works great, if not it needed fixing anyways. ;)
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 11, 2015, 12:48:36 PM
^^^ To be fair, the same thoughts Nick voiced have been running through my head as well  ::). There has not been any metal on the plugs I have pulled from #8 and when I pop a new plug in it runs great.... until the plug fouls. I'm hoping that if I lost a ring, landing, etc. it would run a lot worse regardless of whether there was a fresh plug in it or not. That's what I'm hoping for anyway. I'm going to put the rockers back in tonight and snug up the intake to see of any of the hardware is loose. Leakdown as soon as I have my hands on the equipment to do it.

Thanks for all your replies. 
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: MustangGT on May 11, 2015, 03:35:18 PM
Those plugs look exactly like the #8 plug on my old 390. Replaced the intake gaskets even though they looked decent and problem was gone
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 11, 2015, 05:07:41 PM
Those plugs look exactly like the #8 plug on my old 390. Replaced the intake gaskets even though they looked decent and problem was gone

^^^ That is damn encouraging news, thanks for the morale support!  ;)
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: spork1o1 on May 12, 2015, 08:04:41 AM
If you have a PCV valve is it plumbed in to the intake runner for #8 cylinder?
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 12, 2015, 11:02:26 PM
If you have a PCV valve is it plumbed in to the intake runner for #8 cylinder?

Nope, be nice and easy if it were though.  ;)
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: NIsaacs on May 14, 2015, 06:43:29 AM
All Nick's gloom and doom aside. ::)
As Bob said, put a wrench on the intake bolts and snug them down and give it another try.
If it works great, if not it needed fixing anyways. ;)


The OP asked what "might" cause his plug issue, his issue "might" be what I said.....The "I hope it's not serious stuff was already covered"

Nick
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 17, 2015, 04:43:39 PM
So I put the rocker assembly back in, tossed the valve cover back on. Re-tightened all the intake bolts and tossed a spare plug from a previous tune up in #8. The plug on the left is what I used to get after 40 miles. The one on the right is what I pulled after 40 miles just minutes ago.

(http://i234.photobucket.com/albums/ee6/amdscooter/IMG_5368_zps4inxxbbk.jpg) (http://s234.photobucket.com/user/amdscooter/media/IMG_5368_zps4inxxbbk.jpg.html)

What can I say, you guys nailed it!  ;D Thank you everyone for your input!

 8)

Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: cammerfe on May 30, 2015, 05:24:42 PM
FWIW, my then-new '64 427 was always harder on #8 plug than any of the others. And, when racing, we used-up plugs like peanuts. In the Thunderbolt, we only got one run on Champs. Luckily, they gave them to us by the case. But we'd get most of a day of runs if we used Autolites. We had to knock the porcelains out of the steel shells and give them back to get another case of the Autolites. But they worked enough better that the extra work was worth doing.

KS
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: My427stang on May 30, 2015, 07:41:56 PM
Are you running flat and lock washers on your intake?

Ford didn't, but I have found that a high quality flat and lock for each bolt, especially on alum intakes, holds their torque a lot better. 

Also, the better the bolt, the better it seems to do, but be careful not to have too long or too short, easy to push or pull the threads out with the wrong length bolt
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: amdscooter on May 30, 2015, 08:46:53 PM
^^^ I'm using just flat washers with stainless bolts. I checked the lengths several times before choosing the final set, took me a few trips to the hardware store to ensure I had enough thread engagement w/o bottoming out in the bore. I think your lock washer idea is a winner, probably pick up a handful of splits this week. Driving her out to the Goodguys tomorrow.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: Barry_R on May 31, 2015, 05:47:23 AM
I rarely disagree with Ross.  But this is one of those times.  The lock washer will not likely help.  Its not the bolt loosening up (assuming that that was the root cause) - its the gasket compressing and causing the bolt to lose it's crush/preload.  Same result - bolt gets loose - just a different cause.  Putting a wrench on those fasteners every so often is a perfectly good "cure" and you'll get a good results - especially if it has not been done for a long time since assembly.  But keep in mind that its not a forever cure.

Assuming a certain amount of torque or tightness applied to the intake bolts upon assembly, every time that intake expands and contracts from heat cycles it is going to try and move/bend.  The only part in the assembly that can accommodate this is the gasket face - so the gasket gets subjected to a fair amount of movement stress over time.  The standard Fel-Pro gasket like you have incorporates an embossed steel lined layer and can handle a great deal of movement and will still retorque nicely when it gets compressed as those embossments lose their shape.

Compare that to the paper with silicone bead Fel-Pro race gaskets, which initially seal well but are very unforgiving in terms of movement, tightness, and oil soaking.  On those, the silicone bead is less compressible than the paper base, so it embeds into the substrate acting like a "cutter" with each tightening or temperature cycle compression.  Couple that tendency with the FE oil soaked design that compromises the paper, and you have a recipe for the oft shown failures - and a gasket that can actually get worse with additional tightening.

If you are looking to the "right" way to design intake gasket interfaces you can check out how they do it on newer engines.  They'll use a sealing bead or o-ring inserted into a plastic or metal carrier.  The carrier will have hard stops for the fasteners to torque firmly against insuring that they stay tight and that compression of the sealing surface is as specified and is allowed to be separated from the tightening pressures.  Completely different sealing strategy.  I'll stick to my old stuff, but its good to see that they recognize and resolve the same problems at the OE level that we see in the driveway.
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: bartlett on May 31, 2015, 06:46:05 AM
I do the intake and Header bolts every spring 8) ...just snug them up ...
Title: Re: #8 Cylinder on my 390 is boogin' plugs
Post by: machoneman on May 31, 2015, 07:12:03 AM
If you are looking to the "right" way to design intake gasket interfaces you can check out how they do it on newer engines.  They'll use a sealing bead or o-ring inserted into a plastic or metal carrier.  The carrier will have hard stops for the fasteners to torque firmly against insuring that they stay tight and that compression of the sealing surface is as specified and is allowed to be separated from the tightening pressures.  Completely different sealing strategy.  I'll stick to my old stuff, but its good to see that they recognize and resolve the same problems at the OE level that we see in the driveway. 

Barry raises a good and often not mentioned point. Many of today's engines, and engines for some years now, never leak oil due to the attention engineers have made to gaskets & sealing surfaces. Remember that many engines of the 50's, 60's and 70's leaked oil like a sieve and coated many a driveway!