Engine Cylinder Head Valve Guide Replacement

[Kenskip1]

I have been wondering about how a machine shop removes and replaces valve guides. I have watched several videos on the tube and in all honesty, it appears to be a relatively simple procedure. Can anyone point me in a proper direction with the tools required to do these jobs. I am not going to make a commitment however, I would like to know what tools are required along with the financial resources required. I am not talking about a valve job but rather simply removing and installing new valve guides. BTW, I have compressed air, air hammer, grinder, drills, plus all the other general tools. Thanks, Ken

 

[Stephenw]

It depends on the specific engine. I have done some where a special punch and a hammer is used to to drive out the old and then drive in the new. On some, a reamer is used to cut the old guide oversize and then a sleeve is pressed into the hole. Knurling the guide with a knurling tool and then reaming to the correct size is another option.

 

[theoldwizard1]

I am not talking about a valve job but rather simply removing and installing new valve guides.

If you are going to do new valve guide, you should also do valve seals and lap the the valves. Not much additional cost and well worth the time and effort.

 

[toolchaser]

On cast iron heads they usually drive them out with an air hammer.Like Wizard 1 says at the very least, lap the valves, you'll probably find your valves don't seat correctly after guide replacement

 

[metlmunchr]

If the guides are worn enough to warrant replacement, then its pretty much a sure thing that the valves and seats will need to be ground.

When the head is off, cleaned up, and disassembled, you're already at 90% of the labor for a complete valve job. No need to skip the last 10%.

 

[BlakeTheCarGuy]

If you are going to do the guides definitely need the seals too and probably to have them lapped.


Sent from my iPhone using Garage Journal

 

[Packard V8]

Driving out the old guides and driving in the new only requires an air hammer and the proper driver. That's the blacksmith part of the job.

What requires skill and tooling is reaming the new guides to the proper ID and then cutting new seats and regrinding the valves. (Most shops won't reuse old valves as the stems usually have too much wear.)

Lapping is last century, unnecessary and not seen in today's production machine shops.

jack vines

 

[vssjim]

You must re-seat valves by grinding or cutting after guide replacement and reaming or honing to size, valves need to be faced or replaced. You are not really saving any money by changing guides your self as it is only one step of many.

 

[txvwnut]

When I do them I core drill the old guide half way then press them out. For install I freeze the new guides and heat the head and back to the press. But just changing guides out doesn’t stop there you have to team them to size then valve job after that to everything concentric. If you’ve never done this type of work I suggest letting a professional do it.