Replacing 2F exhaust valve

3_puppies

SILVER Star
Joined
Dec 2, 2002
Messages
15,539
Location
Helena MT
I have yet to find a reputable machine shop that will get back with me, and from what I've heard, wait times are way out there, so in the interest of getting it running again, I'm willing to try just replacing the one valve.

wait times are out there on most everything custom/hands on right now.

is Mosley Motors close by?
 

1911

chupacabra
Joined
Aug 11, 2006
Messages
6,716
Location
Parker County, Texas
I lost my #5 cylinder in my 1975 FJ 55 recently, and have discovered it was my exhaust valve. Upon pulling the head and valve, I'm wondering if I can just throw a new valve in there, lap it and drive on or if I need to do something more elaborate. Plus, any other suggestions would be appreciated

View attachment 2806492

View attachment 2806493

View attachment 2806494

The photo is not in great focus, but the valve seat does not look badly burned. If that is the case, I would not feel bad about lapping it with compound and the new valve. But I am a lazy SOB, and would be inclined to go ahead and do a complete valve job while I had the head off. New seals for sure; no reason not to now.
 

Dizzy

GOLD Star
Joined
Feb 5, 2018
Messages
2,331
Location
Santa Fe, New Mexico
What is the engine's history, compression and vacuum, etc? Also, with the head off, you can measure the cylinder diameter. My Feb. '75 2f still has the original honing crosshatch, original cylinder bore.

There is probably half of a 2F's value worth of standard practices. Magnaflux for cracks comes to mind, milling the head, replacing head bolts, those are all, in my mind, optional. Then you always have a must-do for a new headgasket, maybe manifold gasket, and valve stem seals. I just couldn't justify investing in a partly, or fully, reconditioned head, without knowing how the bearings that actually spin this thing look, personally. Even the investment of time and money in the head gasket is only good for as long as it is mated to the block, then you will need a new one. What if a simple ring job and honing is somewhat due for this engine? I say fix what is broken for as deep as you have to for the repair, and what you know is vulnerable. A friend's FJ40 had valve guides replaced on his SBC, but it wasn't long before they got loose in the head, an issue that was related to aftermarket part sources. For all we know, the damage shown could have been isolated to one cylinder. Run a straight edge on the head with a feeler gauge, do what you can if it is within reach.

IIAC, a later 2F head is the way to go, 8/80+. The flat-top piston type head would be a nice investment because it will allow you to use the OEM .020 over piston, but, that might be distant on the horizon.

Otherwise, full rebuild. Why, because that is the easy answer that is easy to stick with in a long-term sense.
 

Pighead

Stop calling it an FJ
Joined
Aug 31, 2004
Messages
8,437
Location
Camino
I don't know, sometimes I think it's a good idea to keep your bush-fix skillz up.
I found an old hand-crank valva lapper tool and was secretly planning on an old-school valve job on my bench someday.
Sure, farming it out to Professionals may be the smart thing to do, but are we not 'Cruiserheads?
 

Users who are viewing this thread

Top Bottom