Gonna get cylinder heads cleaned, have a question

Guys, I am working on my 71 with the 225. I am very new to engine work, but I have removed cylinder heads and am planning on getting them cleaned at a local machine shop. My question is, should I remove the valves and springs or leave them be? As far as I can tell everything looks ok, no obvious signs of damage, I am going to get the parts cleaned, replace gaskets and paint. Thanks

 

If you are planning on getting them hot tanked then they need disassembled. If just "washed" then you can probably get away without disassembly. If you disassemble them, they must go back together the same way they came apart, i.e. with the valves, springs, etc. in the same location.

 

What will you accomplish with this cleaning?

Do not take the heads apart.

 

My thinking behind this was that a couple of the cooloant passages have a little surface rust on them. i just wanted to have them cleaned up. This might not be the best way to do this, I just dont know. I would assume that they should be cleaned up somehow before being put back together.

 

IMO if you don't have a need to disassemble and clean the heads, you're just buying trouble. The water passages can be cleaned chemically once the engine is together, if you have overheating problems.

Clean the outside and paint if you want to. But I would wait to scrub everything until the engine was back together.

 

Thanks Tim, i will do just that. I know I would be getting into a can of worms if I disassembled the heads. I was just a little concerned about the surface rust. Thanks for all the advice guys.

 

Maybe it's my hotrodder older brother, maybe it's my Aircraft Mechanics training, maybe I'm just anal.....but if a set of heads is removed from an engine by MY hands, they're not going back on until they're completely rebuilt. That means stripped, tanked, blasted, all parts inspected and replaced as necessary, seats and valves ground, guide seals, the works. I'll even grind off the rough spots everywhere the best I can. And I paint them when they're back on the engine.

I do strive to keep the parts together, as in separating each valve with all its own parts, and marking the baggie with what cylinder it came from, so that all parts go back in the same hole they came out of. Same with hydraulic lifters, they must go back to the same cam lobe. Same w/pistons, rings, bearings, etc.

Like I said, I may just be anal.....but why take parts off if you're not going to recondition them back to prime operating condition?

 

Hot tanking and hot water parts washers don't remove rust. If there is surface rust on the gasket surfaces you can clean that carefully. If it's a serious concern then have them rebuilt. If not, then don't mess with them.

 

X2! If you are going to take it off you might as well rebuild. If money isn't much of a concern, you can have the machine shop disassemble and then reassemble. They will check the valve guides and clearances. Or you can disassemble and then take it to machine shop. I had the head on my F134 hot tanked and thoroughly gone over to clean out all the water ports, it came back looking like brand new.

 

Most amateur mechanics would never take heads apart. If there is a problem with the heads, fine, take them to a shop and have them checked out and rebuilt. But this will easily run into hundreds of dollars.

I guarantee, if you take them to a shop and ask them to take them apart and clean them, they will discover something more that needs to be done. Guaranteed. Just FYI.

 

Yeah, I think so. We took in hundreds of cylinder heads for repair during the time I worked at the parts store. The usual complaint was loss of compression, ie burnt valve. Hot rodders are a different group; they might take their good heads apart for an upgrade, whether it's needed or not.

My understanding is that lapping is an obsolete technique, since about the 40s. Following a 3-angle grind, no lapping is needed. Indeed, the smaller edge contact of a grind is superior to a wider lapped contact. Or so I'm told.

Certainly you can install new springs and seals (you'll need a spring compressor), but resurfacing the valves and seats is the usual objective. Be sure to put the retainers back right (not you Patrick, but anybody that's listening).

 

I remember using blue die or something similar to check the valves and valve seats with..

 

yep
that's it.

 

Yeah I remember my dad teaching me to grind the valves using this old wooden handle with a suction cup on the end (I still have it) and some gritty valve grinding compound. It was on a Dodge 440 that he was helping me overhaul.

I also remember him teaching me to use Plastigauge, which I need to re-remember when I start putting my F head back together. Funny, I think I still have some of that old Plastigauge.

 

That's not grinding, that's lapping. Done after grinding to "seat" the valve face and the seat face together. Grinding takes some very specialized equipment. A delicate procedure requiring a gentle touch, you only grind off a tiny bit, just enough to true things up. Very easy to ruin things. But, if the valve and seat faces are in good shape, you can usually get by with just lapping them.

 

http://toolmonger.com/2008/09/11/dealmonger-clover-lapping-compound/

Gotta love the clover.... I have used the high dollar diamond stuff but it seems clover is still the best

 

Why did you remove the heads?