Valve guides … every engine has ’em and if you’re refurbishing a cylinder head, you’re going to have to remove them. And that is what we’re talking about today.
We’ve talked a lot in the past about resizing valve guides, replacing valve guides, knurling valve guides, etc., but we’ve rarely touched on how to get the little buggers out of the head.
It’s actually pretty simple. You can ream them out; you can drill them out; you can drive them out. It all depends on what kind of head and guide you’re dealing with.
Of course, before you can remove the valve guides, you have to take out the valve seals. There are lots of tools on the market to do this job – everything from picks to pliers. Goodson offers three tools for removing valve seals. The Valve Seal Puller with Slide Hammer, Seal Puller with Adjustable Head and Universal Seal Pliers.
Each of these seal removers has its pros and cons; it really comes down to which one you’re most comfortable using.
Now that the seals have been removed, it’s time to look at the guides again. Let’s dig in …
Replaceable Guides in Aluminum or Cast Iron Heads
You have a few options when removing valve guides from aluminum and cast-iron heads. You can
- drive them out and replace them with new guides
- ream the original guides to accept oversize valve stems
- ream worn guides and insert liners
The choice is pretty much yours.
Goodson, of course, carries tools and supplies for all of your options, including the replacement guides.
Valve Guide Drivers
As the name implies, these tools are used to push (or drive) the existing guide out of the guide bore. You have the choice of powered or manual drivers in a wide range of sizes, including many diesel applications. All Goodson guide drivers feature pilots that are slightly smaller than the guide ID for easy removal and have a 1° negative angle to stop the guides from mushrooming and getting jammed in the bore. Powered guide drivers are sized to work with most standard pneumatic tools, including the Goodson Air Hammer (AH-335). For more information about Goodson valve guide drivers, including pricing and sizes, visit the Valve Guide Driver section of the online store.
Valve Guide removers are also available for diesel heads. These drivers are sold by application rather than dimension, but as with all tools, if the dimensions are right for a different application you can use it. Goodson offers several sizes for a range of applications. For more detail, check out the chart at left (click the image for a larger view).
Adjustable Powered Valve Guide Driver with Replaceable Pilots
The final Valve Guide Driver we’ll talk about today is the Adjustable Powered Guide Driver with Replaceable Pilots (that’s a mouthful!). What makes this guide driver unique is the replaceable pilot with 5/16″ – 18 threads. They are available in both SAE and metric diameters from .312″ to 9.0mm. Due to the design of this driver, you can adjust the installation sleeve to accommodate guide heights from 0″ to 1-1/4″. Once you have the correct installed height established, you can move from one guide to the next without having to reset everything.
Core Drills & Reamers
Piloted core drills and reamers have been around for ages and they still work great! Goodson recommends that you use them dry at 175 to 225 RM for best results and that you use them in matched pairs where available (see chart at right). Piloted Core Drills are designed to center accurately in the guide.
When you have cylinder heads that have integral valve guides (meaning they are part of the base casting) then you will need a core drill and a core reamer. In today’s world you can also use a Dreamer which is a core drill with the reamer built in. This newer style of tool will speed up the whole process as you will not have to change to from drilling to reaming.
Tool selection is very straight forward
Find out what the ID is for the valve guide. Find out what the OD of the new valve guide and select according.
Example: valve guide has an 11/32” .343” ID and the replacement valve has a .500” OD, then you would select and core drill with an 11/32” .343” pilot and a drill size of .468”.
You would then select a core reamer that is piloted to the .468” hole you just drilled and will now send the core reamer through the valve guide bore leaving a .500 “ ½”finished hole. When you press in the valve guide you will have achieved the “crush of .002”.
Even more simple is the “Dreamer” as you would simply select the Dreamer with the correct pilot for the ID of the valve guide and match the finish reamer size to the OD of the valve guide again and with this one tool you can do the operation in one pass.
That pretty much covers the basics. As usual, if you have additional questions, contact the Goodson Techxperts™ at 1-800-533-8010.