smoking 390 ?
Thread Starter
|
Senior User
Joined: Jan 2003
Posts: 113
Likes: 0
smoking 390 ?
My truck is a 1973 F250 with a 390, 901 cam, "S" Code intake, 600 vac sec. holley, dynomax headers, dual 2 1/4 exhaust into 2 glasspacks, it started smoking wuite abit out of the driver side pipe wuite a bit it always did it alittle more but now it is a considerable amount someone told me i had a bad valve stem seal, I was considering replacing them what do u pro's think?
Junior User
Joined: Apr 2003
Posts: 92
Likes: 0
smoking 390 ?
I pray that it is only that. I had the exact same problem. Turned out to be the C clip that holds the wrist pin in place broke and it scored the cyl. wall really bad. If you start shooting oil out the tail pipe, start praying.
Just smoke? Probably vavle stem seals.
Just smoke? Probably vavle stem seals.
Elder User
Joined: Dec 2002
Posts: 925
Likes: 0
From: Quaker Hill ,CT U.S.A.
smoking 390 ?
Are you loosing coolent?
White some is usually coolent/oil .
If the engine has not had the stem seals replaced then I would say go for it but I think you may have more problems then just the valve stem seals .
Look at the condition of your spark plugs white looking plugs mean coolent - black with oily depsites is valve guides/rings/ stem seals .
Do a compression test and be sure to post your results here!
White some is usually coolent/oil .
If the engine has not had the stem seals replaced then I would say go for it but I think you may have more problems then just the valve stem seals .
Look at the condition of your spark plugs white looking plugs mean coolent - black with oily depsites is valve guides/rings/ stem seals .
Do a compression test and be sure to post your results here!
Senior User
Joined: Dec 2002
Posts: 168
Likes: 0
From: Omaha USA
smoking 390 ?
Make sure you get a fitting to fit the spark plug hole that you can hook up an air line to. Air up each cylinder with about 60 psi +/- so your valves dont drop down and do each cylinder that way while you are taking off your valve springs. Good Luck !!!!
Trending Topics
Senior User
Joined: Jun 2003
Posts: 107
Likes: 0
From: Allentown, PA
smoking 390 ?
Hi Guys,
Just a little trick that I have used sucessfully on a few motors when changing valve stem seals or anything else that requires removing the keepers. Instead of pressuring the cylinder with air I just remove the all the plugs crank the engine over by hand until the piston of the cylinder I'm ready to work on is at or near the bottom. I then insert about 1 foot of soft Nylon rope through the spark plug hole and gently turn the engine over by hand until the piston pushes the rope up against the bottom of the valve, holding it in place. Works great, doesn't require any special fittings and is less likely to fail then the air method.
Good luck
Just a little trick that I have used sucessfully on a few motors when changing valve stem seals or anything else that requires removing the keepers. Instead of pressuring the cylinder with air I just remove the all the plugs crank the engine over by hand until the piston of the cylinder I'm ready to work on is at or near the bottom. I then insert about 1 foot of soft Nylon rope through the spark plug hole and gently turn the engine over by hand until the piston pushes the rope up against the bottom of the valve, holding it in place. Works great, doesn't require any special fittings and is less likely to fail then the air method.
Good luck
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Senior User
Joined: Nov 2001
Posts: 261
Likes: 0
From: Western NC
smoking 390 ?
That's what I've done as well and you're right...works great and the chances of failure are exactly zero. I'd hate to see that valve stem disappear into the abyss because someone inadvertantly turned off the power to the garage. That'd be a bummer. Our method is low tech, but it works! 
Thread
Thread Starter
Forum
Replies
Last Post
LSAtexan4x4
1999 - 2016 Super Duty
42
Oct 12, 2011 09:16 PM
tastyklair
1973 - 1979 F-100 & Larger F-Series Trucks
7
Dec 20, 2005 01:34 PM
Michael Sizemore
Audio & Video Systems, Navigation, Satellite Radio & Mobile Electronics
5
Nov 24, 2003 02:08 PM
saleen92
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
5
Feb 15, 2002 08:59 AM