!!PLEASE HELP!! Ford 427 engine problem

[Siavosh]

Hi All,

I have a very unusual problem and I feel like I have hit a wall with this. I would appreciate any and every help!

I have twin Chris-Craft (Ford) 427s in my 1973 Double Cabin 38. last summer 5 of my intake push-rods got bent because of stuck intake valves. When I pulled the heads I saw a dark brown glue/gum kind of material all the way from under the carburetor flaps to the valve stems and behind the valve seat.

Got the heads rebuilt and put them back together, everything ran fine, for just about AN HOUR. shut the engine after initial test and when I went back to start it again, the same gum/glue was there and 3 of my intake valves were stuck.

I poured lacquer thinner down the intake manifold and it cleans it right up and releases the valves. Here are the things I've done to eliminate the source of the problem:

- Flushed my crank case with sea foam and changed the oil. Did a compression test and I got 150-180 all around.
- Did a pressure test on my cooling system and it holds 30 pounds of pressure no problems.
- To eliminate bad fuel, I rerouted my fuel to pull from the port tank. The port engine has no problems and is running on the same fuel.

After doing all that the engine ran fine for about 50 hours of cruising until I noticed a clicking noise again, pulled the carb and saw the same buildup in my manifold.

Can someone please point me to the right direction? Where is this coming from?

Any help is much appreciated!

[miboatnutz]

You know those engines have mechanical lifters. Right? The tapping noise is the lifters out of adjustment and my guess is that's also the reason for the bent push rods. They were installed too tight and when you fired it up the push rods bottomed against the lifters and bent them.

The goo or spoo you speak of is probably charge mixture that's accumulated because the valves are not opening an closing properly, giving you blow back on those cylinders.

That would be my guess.

[doc g]

Ethanol eating up the fuel tanks.....................Pat

[UNIQUE_NAME]

Ethanol eating up the fuel tanks.....................Pat

if you put ethanol gas in your fiberglass tanks, that is your problem. the ethanol is dissolving the resin
which bypassed the filters and starts solidifying in the carb and downstream.
when you turn the engine off it turns to like a tar substance on the valves.
when you start the engines you will bend the pushrods.

why 1 tank and not the other? give it time and it will be both. its not if, but when.
the symptoms will appear. how long depends on how the inside of the tank was laid up and what kind of voids there are.
the tank is baffled, so a bladder is not the answer.
replacement with aluminum is the answer unless you can find someone to make ethanol resistant resin tanks.
this was not an option to me 14 years ago when i went thru it.
you could also try and pump the tanks and only use non ethanol fuel if its available near you.
this solution is entirely based on your comfort level of how far the tanks have dissolved.

if you will continue to use ethanol fuel you will need:
1- aluminum tanks
2- replace all rubber fuel hose with ethanol rate hose
3- pull both carbs and rebuild because you will find it in there too
4- id pull all heads again and free up the valves, carb spray or brake cleaner works for this too.
the reason i say pull the heads again, which i know you dont want to hear after wrestling with that intake manifold,
is the tops of the pistons will have it along with it starting to form a ring around the cylinder hole opening.
think of it like gorilla glue in a combustion chamber
5- as someone stated, these are solid lifter engines. when you have the heads off pull all the lifters
and make sure the pushrods didnt damage the top and the cam didnt mar the bottom.


thats about all i can remember off the top, from my ordeal.
good luck and if you have any more questions ask away

[Siavosh]

if you put ethanol gas in your fiberglass tanks, that is your problem. the ethanol is dissolving the resinwhich bypassed the filters and starts solidifying in the carb and downstream. when you turn the engine off it turns to like a tar substance on the valves. when you start the engines you will bend the pushrods.why 1 tank and not the other? give it time and it will be both. its not if, but when. the symptoms will appear. how long depends on how the inside of the tank was laid up and what kind of voids there are.the tank is baffled, so a bladder is not the answer. replacement with aluminum is the answer unless you can find someone to make ethanol resistant resin tanks. this was not an option to me 14 years ago when i went thru it. you could also try and pump the tanks and only use non ethanol fuel if its available near you.this solution is entirely based on your comfort level of how far the tanks have dissolved.if you will continue to use ethanol fuel you will need:1- aluminum tanks2- replace all rubber fuel hose with ethanol rate hose3- pull both carbs and rebuild because you will find it in there too4- id pull all heads again and free up the valves, carb spray or brake cleaner works for this too. the reason i say pull the heads again, which i know you dont want to hear after wrestling with that intake manifold, is the tops of the pistons will have it along with it starting to form a ring around the cylinder hole opening. think of it like gorilla glue in a combustion chamber5- as someone stated, these are solid lifter engines. when you have the heads off pull all the lifters and make sure the pushrods didnt damage the top and the cam didnt mar the bottom.thats about all i can remember off the top, from my ordeal.good luck and if you have any more questions ask away

Thanks this is really helpful as well as very painful! I guess the only other question is how do I replace the tanks? Do I have to cut my deck open to pull them out? Also, if I drain the fuel that’s in there now and put ethanol-free tanks, would it stop the resin from desolving any further? I’ve wrestled with all those manifolds and risers once. My lower back was done for 3 months...not really interested in doing it again...lol

[oscarvan]

No, replacing the fuel will not make the problem go away. Don't know what your tanks look like but making small pieces out of them to remove and then installing multiple smaller tanks that fit through the door is a common solution. Cutting holes in boats can have bad side effects and is $$$$.

[UNIQUE_NAME]

Thanks this is really helpful as well as very painful! I guess the only other question is how do I replace the tanks? Do I have to cut my deck open to pull them out? Also, if I drain the fuel that’s in there now and put ethanol-free tanks, would it stop the resin from desolving any further? I’ve wrestled with all those manifolds and risers once. My lower back was done for 3 months...not really interested in doing it again...lol

your profile says 1973 38 dc which is the same boat i have. laid on their sides with ALL the fitting off
the tanks will fit thru the aft cabin doorway and saloon doorway.
there is carpentry work involved with removing the aft bunks, the tanks are under them.
i cut the top platform as close to the edge as i could and removed it.
then you can unscrew/cut the bed walls from the inside and remove them without any damage to the exterior.
remove the port side first otherwise it will be in your way trying to get the stb tank up the stairs.

you will have to give the aluminum fabricator measurements for the new tanks.
the old tanks give you a ballpark starting point. i also had the exterior of the new tanks epoxy coated.
when replacing whatever rubber fuel line you have dont forget the fuel tank filler hose.

your tanks are compromised. i know i wouldnt be comfortable putting non ethanol fuel in them and going about my way.

this project sounds a lot worse that it was too. time consuming and expensive, yes, but its not rocket science and its just woodworking.
wood is easy to fix. as a gauge, it was much easier than the engine work.
have a second body with you to get the tanks up the stairs, your back will thank you.

good luck

[miboatnutz]

Other possibility is a whole bunch of bad gas causing the valves to stick, which would also explain the brown spoo.

Found this which might help

https://www.fordfe.com/bent-pushrods-in-390-t72511.html

[kelpy]

Possible tuck open /gummed up crankcase breather valve.Do you have Carter carbs?

[Eddieclemons]

Considering the small amount time that this material showed back up in the fuel path of the engine intake I would look at the quality of the fuel being delivered 1st.