Why recondition the cylinder head?

[DGG]

I'm rebuilding my Series II 109 SW with a new galvanized frame, and am currently taking apart the engine. I removed the cylinder head and took it to an engine guy and got a quote to rebuild the cylinder head. New valves, seats etc...It got me thinking...I don't really know why I'm having my cylinder head rebuilt other than I thought everybody did, and it was just expected. What is the purpose of having the cylinder head rebuilt, or under what circumstances should the head be rebuilt. Would I be fine if I just replaced the head gaket and put the cylinder head back in as is?

[greenmeanie]

Main reason for rebuilding a head is loss of compression or excessive oil smoke on start up. Inspect the valve seats and valves for recession and then slop in the valve guide (With the springs removed.) If these are good and there are no cracks elsewhere then you are good to go. Clean all the carbon off at the very least.

[LaneRover]

Putting in stellite exhaust valves is also a good idea.

[Jeff Aronson]

Brent is right. If the head has never been rebuilt, then the valves are not those designed for unleaded gas. The head will stay sealed a lot longer if you make the change now.

Jeff

[Terrys]

Your old head is probably a 7:1 compression ratio head, so If you replace the valves and seats with hardened ones, and I was always under the impression it was the seats that were stellite overlayed, then you can well afford to have the head planed to get your compression ratio up to 8:1
Old valve guides were grey Iron, and they generally no longer knurl them, but there are now bronze guides as well as steel guides. Over time they wear oval as do the valve stems, so, even with steam seals, oil leaks down and gives a pretty smokey start-up.

[gudjeon]

My machine shop installed hardened seats that are normally used for propane conversions. I purchased all the other parts: stellite valves, guides, seals, etc. so the shop can rebuild it with genuine L/R stuff. Magnaflux for checking cracks and having it planed/ground is a good check as well. This way, you know what has gone into it.

Skimming a head too much can cause the thermostat housing to foul with the top of the water pump - just be aware before going too gung-ho on this.

[scott]

i had my block shaved, forgot how much but the clearence between thermostat housing and head is bearly enough to get waxed dental floss through

[DGG]

All good info. Thanks. Unfortunately I never had a chance to run the engine before I started the breakdown. I will probably go ahead with the rebuild. I was quoted $750. Is this reasonable?

[yorker]

Doug-
I thought the early heads couldn't be safely skimmed to 8:1, the casting # info was on TW's page IIRC? $750 seems high to me... Is that Steere's quote?

[DGG]

Hey Matt, I was wondering when you would chime in. Yes that is Steer's quote. Well he quoted me $614, but I have to buy the valves, and guides. He can't find them. He's not skimming to 8:1, I think he is just cleaning the surface. He's milling it, but said he was taking very little off. I haven't given him the green light yet.

[superstator]

Can't one just about get a brand new Turner 9:1 head for $750?

[xsbowes]

Our host list the 8:1 at $775. The cheapest I could find for Turner 9:1 online was over $1100.

[sven]

Last year I paid 175 in labor to a local machine shop. I spent roughly 250-300 in parts. This included installing unleaded seats, valves, guides. This machine shop never saw a rover head before but they are quite familiar with tractors and motorcycles.

[DGG]

So if I were to go to another machine shop, what would I tell them I need. New valves and guides installed, and stellite valve seats installed, and they would know what to do? Because my cylinder head is an early series II, I can't have it converted to a 8:1 ratio. What would they do with the head faces?

[yorker]

yeah I bought a new head for $500 a couple years ago- all new with new valves, hardened valve seats etc. 750 is a lot, heck he just redid a Chevy 283 for Chad for $1500( I think that was what it cost anyway). I wonder what he thinks he has to do to it for that kind of $$$...

Hot tank it- new valve guides- hardened seats, umbrella type seals for the valves, maybe resurface the head. There isn't a lot of work to it.