Head replacement-what else needs replaced?

[neverdone]

This is my first engine rebuild, and having to replace my 1979 2F head. My question is, while replacing the head, do I also need to replace camshaft, lifters, valves, pushrods, or anything else? Or is it OK to reuse the old camshaft, lifters, valves, push rods?
Thanks for helping me get this done the right way!

 

[charliemeyer007]

It would depend on the condition of all those things. Did you pull the engine or are you changing the head in place.

 

[neverdone]

Pulled the engine, complete disassembly, everything else looks good; cam, lifters, rods, valves. The head had multiple cracks and some of the exhaust valve seats were also cracked, so that’s why I am replacing the head.

 

[charliemeyer007]

If the parts are "good" why replace them. If the parts are almost worn out, then you are $ ahead by replacing them now. How was the oil pressure last time it was run.

 

[neverdone]

Oil pressure was good, at least according to the gauge it’s been the same for the last 17 years. I just wasn’t sure if other parts had to be replaced if the head was replaced. Figured I better get advice from you guys instead of screwing something up and having to redo it later!

 

[65swb45]

Flip it over, pop the pan, and inspect the bearings while it’s out and head-free.

 

[neverdone]

Good advice! Already flipped it over, and did complete engine disassembly. Definitely will be replacing rings and bearings, also honing.

 

[65swb45]

Good advice! Already flipped it over, and did complete engine disassembly. Definitely will be replacing rings and bearings, also honing.

From what I’ve read on the forum lately, if you have a set of rings, you should buy a lottery ticket.

 

[igotta40]

If you put it all back together with the old parts in it you will be constantly worried if and when something isn’t right and whether you should have just done the complete job. Or put it this way - why would you go to all this time trouble and expense just to put it back together with the old parts? If you outsource any machining, like getting the crankshaft turned, you probably won’t get a warranty. Buy once, cry once.

 

[73FJ40]

Since you're getting a replacement head, your machinist will let you know about valve guides, seats, and valves that may not be salvageable.

There's a plug in the head above one of the spark plugs that could be replaced with a pipe plug.

There are welch plugs on both ends of the oil galley that have a tendency to leak. Make sure to get the correct size.

There's an OEM very shallow metric freeze plug at the rear of the cam shaft that has been known to leak. Don't let them use a generic freeze plug.

I'd be replacing the thermostat and all the hoses. Boil out the radiator or buy a new one from Toyota.

When you stab the distributor into place, make certain you get it seated. If your oil pressure gauge isn't functional on startup, get a mechanical gauge, and crank the engine with the spark plugs removed. This minimizes load on the bearings if the oil isn't flowing. I got 35 psig with a fresh battery, cranking with no spark plugs.

Welch and Expansion Plugs

forum.ih8mud.com

 

[73FJ40]

Oil gallery welch plug @ 10 o'clock, cam "rear plate" at 2 o'clock:

 

[Pighead]

Are you going to be running the air rail? Now is a great time to block off those holes, I got a set of plugs from Jim C. Also may want to use new manifold studs & nuts. New studs are a little longer than my old ones

 

[neverdone]

Since you're getting a replacement head, your machinist will let you know about valve guides, seats, and valves that may not be salvageable.

There's a plug in the head above one of the spark plugs that could be replaced with a pipe plug.

There are welch plugs on both ends of the oil galley that have a tendency to leak. Make sure to get the correct size.

There's an OEM very shallow metric freeze plug at the rear of the cam shaft that has been known to leak. Don't let them use a generic freeze plug.

I'd be replacing the thermostat and all the hoses. Boil out the radiator or buy a new one from Toyota.

When you stab the distributor into place, make certain you get it seated. If your oil pressure gauge isn't functional on startup, get a mechanical gauge, and crank the engine with the spark plugs removed. This minimizes load on the bearings if the oil isn't flowing. I got 35 psig with a fresh battery, cranking with no spark plugs.

Welch and Expansion Plugs

forum.ih8mud.com

Great info! Thanks

 

[neverdone]

Are you going to be running the air rail? Now is a great time to block off those holes, I got a set of plugs from Jim C. Also may want to use new manifold studs & nuts. New studs are a little longer than my old ones

View attachment 3628276

View attachment 3628277

No air rail, already desmogged. Good to know what size and part number those are! Thanks!