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FE 427 valve seals = fouled plugs?

December 19 2014 at 1:44 AM

Jim  (Login 36TFisher)

I suspect my valve seals may be why my plugs fouled a few times this past season as compression was good. I hear the original material was rubber based and with 45+ years they may be past their life expectancy. Anyone know how to tell? (I just don't have the energy to tackle a full rebuild this year.)

Wondering if anyone has done a FE top end rebuild and if it was worth the effort? Details?

Once back together I will top them off with a pair of DUI units in clear of course!!

Thoughts? Advice? Getting ready to dive in!

Jim
Pacific NW Fleet Commander




 
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Paul
(no login)

FE solid lifter motor lore

December 19 2014, 10:50 AM 

The solid lifter version of the FE is known for pumping a LOT of oil up into the cylinder heads. It is one reason the rocker assembly seems to last so long, but there are many who think it is too much oil. Oil is used for lubrication and cooling. The problem is made MUCH worse if the wrong oil pump is installed, because there is NO NEED for a high volume or high pressure pump, because the stock Melling will do just fine. Perhaps if the system is worn, maybe you are pumping more oil up there than intended?

In high performance applications guys have found the oil delivery and rocker arm feed system will flood the valve covers at sustained high rpm running because the drain back system is "limited", and this not only floods valve seals on the lower end of the motor if it is tilted like a marine installation, it can also starve the main oil sump and potentially cause damage. In order to compensate for this they install a .090 or .070 Holly jet (restrictor) in the hole under the rocker arm that has the oil feed to the upper system. All that oil comes through that little hole happy.gif NOW IMPORTANT.........BE SURE THE ROCKER THAT GOES OVER THIS HOLE has a receiving hole facing down, and not up !!!!! They can be installed backwards. Also the bolts on the rockers REQUIRE flat washers, and if you just use lock washers you will have a flood up top happy.gif Just thought I would toss that into this thread.

If too much oil is getting topsides because the rocker assembly is worn, then I would not recommend reducing oil flow. Just curious about the entire oil flow conversation to this point, and a question: "which plugs are fouled"?? Just at random or perhaps the ones at the aft side of the cylinder heads, would tellme something.

Check the drain back holes they are known for being blocked if too much sealant is used for an intake gasket installation........remove the valve cover and take a look down in there. If so, this just puts too much oil up around the top of the seals, and of course if you flood them then more oil will get in.


I have some good photos of the seals. If you are careful to not let a valve drop, you can change them in the boat without pulling the heads. Certainly a LOT of work, but can be done. If it were me, I would rotate the motor each time I got to a cylinder to be sure the piston was up there as assurance to dropping a valve happy.gif

Here is a note from Randy, from our archives

The oiling issue in the CC427 or any FE is real, I installed restrictors under the rocker
shafts of my newly tweaked 427s (now 468s) to reduce the amount of oil going to the top over
3,000 RPM. If you don't, the oil level gets scarey low in the pan because all of it is up in
the top of the motor. The lower viscosity the oil, the worse the condition gets. I was watching
for it with a modified set of valve covers. The rockers still get way more than enough oil with
the 0.090" restrictors installed. Again, like you said, sustained RPM in boats versus cyclic in
cars is a huge difference. The installed angle of the engine also changes the oil level indication
on the dipstick, I am running one quart over the full line, which is 8 quarts in the pan. Any less
oil in the pan compounds the issue of too much oil on top and can cause cavitation of the oil pump.


Also.........from our archives which are available free to anyone for personal use.....is a photo of the hole below only one rocker arm that feeds the entire upper end, one per bank....
[linked image]

Here is a solution.........should the issue actually apply to your motor and boating style.
I have this issue on the 427 Lancer for sure.......... A neat little Holly jet fits right in there.
[linked image]

Here are a couple photos of my valve seals

[linked image] [linked image]
[linked image]


Plug type, brand, style, gap, and maybe even the wire to that plug, could also be a contributing factor. In addition, I would always check the PCV system as a side note, just because if you are in there, just do it.

Lastly, one more thing about the change out of valve springs and seals while in the boat. Some guys use a compressor, remove the plug, install a threaded fitting with the air hose, crank up enough pressure to hold things tight but beware, this could easily rotate the motor so keep fingers and other things clear.

Good luck with it, I'm sure there are some other guys with some tips, so let em come on!
I think I would try chaning to a different heat range plug first, because it's easiest happy.gif

Regards,

Paul











 
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Paul
(no login)

And do NOT forget to use the SPECIAL BOLT for that location.

December 19 2014, 2:32 PM 

You know, actually if anyone needed a bolt like that I don't have a clue where you would get one, and would probably have to make it.

There are two special bolts on each 427 marine motor (and all FE variants).

No matter which side of the motor you are on, if you look at the assembly it will be the second rocker stand from the left that is the oil feed, and this also takes a very special bolt that is necked down to promote oil flow. These bolts are longer and have a necked shank

Regards,

Paul


 
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Jim
(Login 36TFisher)

I will focus on other things then and leave the heads alone

December 19 2014, 8:32 PM 

I was just testing the waters to see if valve seals may be a common problem. I will focus on upgrading to DUI distributors, fresh wires, plugs, oil, disable the chokes and ensure the valves are set correctly though I set them just this past spring.

I will also replace the intakes as both developed leaks in the exhaust crossovers. I made a temporary fix with 2 part metal epoxy 5 years ago and its still holding but its time to swap them out. I was thinking of Edelbrock performers but found a pair of OEMs in good shape. I will hit the gym to bulk up before trying to swap em out.

Jim
Seatle

 
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Dave Krugler
(Login dkrugler)

Changing valve stem seals, heads on...

December 20 2014, 12:15 AM 

We used to do this all the time. We used either a home made cylinder pressure rig consisting of a gutted spark plug with a coupling to connect it to a compressor airline or you can use a flexible rubber hose adapter for a compression test gauge and connect an air lint to it. Remove both rockers from the cylinder to be serviced, then apply 80psi or better air pressure via the hose rig thru the spark plug hole. Now you should be able to use a valve spring compressor safely without worry of dropping a valve because air pressure will hold the valve closed. Remove the spring keepers, retainer and springs, change the valve seal and reassemble spring parts and rocker arm. Move on to the next cylinder and repeat. You are correct to assume 45yr old valve stem seals are suspect if plugs are fowling. Careful inspection may reveal hardened seals and some may be shattered rendering them useless. Over oiling can be a problem for sure but a good set of replacement valve seals should help.

 
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Paul
(no login)

Good tips from.....

December 20 2014, 10:39 AM 

.......The Man....who burned the knapp off his instructor's trousers at auto mechanics shop class !!

Regards

Paul

 
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Paul
(no login)

427 fouled plugs could just be bad valve seals

September 28 2017, 12:22 PM 

The rings could be fine and still getting fouled plugs. Check those seals. happy.gif

Paul

 
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