Valve guide install - My take

[toms73novass]

I was installing new valve guides today so I took a few pictures of my process. In a previous thread I did make a few generalities to how I do it and misspoke on the spacers I use.

So first of all I am replacing cracked stock guides and removed them. The process I use is to cut the guide flush on the chamber side of the guide. I use a piloted counter sink (sorry no pictures). Then I put in oven and heat to 450F use "finch" tool to remove old guides hitting from inside the chamber towards the outside. I find I have had better success than going into the chamber.

Once removed I use gage pins to measure the diameter of the guide holes in the head. .5155 is what this head was. I then ordered oversize guides and on my lathe turned them down to .518.

Here are the items I used for install.

The specifications for a 140 head calls for the guide to be inserted and stop .96" from the chamber surface. (if you zoom in on the pic you will see the specifications) and the exhaust 1.05"

I made two aluminum stops one for the intake and one for the exhaust. This way when I am inserting the guides they will stop at the correct amount. I put the guides on the freezer over night and then just before I install them I put them in a cup and use air duster ,held upside down to discharge liquid refrigerant into the cup to keep the guides as cold as possible.

I could not take pictures of the actual process because you have to move fast, before the head cools. Remove 450F head from oven and put on heat proof surface. Take a guide and put on finch tool with hardened washer to act as stop. Spray guide with a bit of lube and insert till it contacts stop.

You will notice that there is a difference in height between the intake and exhaust guides they are not all the same height.

You might also notice I have an old valve on the table, I use that to sometimes drive the insertion tool out from the guide because of the interference fit of the guide causes it to pinch a bit on the tool. The old valve is place in the chamber to pop it out.

The guides still need to be reamed to final size for best fit.

If you have any comments or improvements please share.
Thanks
Tom

[Dennis66]

Interesting. Hope for success for you. There are those who say that the original valve guides were matched to the valve seats or something like that (I couldn't tell you). Once your final sizing is done, you could mark the valves (or seats?)with a permanent marker and rotate the valve and look for contact patterns. My 102 heads have replacement guides. The engine showed signs of not running well before the crankshaft broke. I disassembled everything (the heads) and ended up buying a Neway valve seat cutter and pilot and lightly finishing the seats. I will say that my first swipes showed that seats weren't even. After establishing an even pattern, I lapped the valves and finally got a good seal. Dennis

[toms73novass]

I agree seats and guides have to be done together. The seats are going to be replaced with deep seats so not an issue with alignment.

[vairmech]

I for one will not put a guide in from the stem side! I always install from the chamber side. I heat the head using 2 propane torches, very simple. I have also made different stops for the intake valves, 140 and all others. The exhaust is always flush with the chamber side and I use a grade 8 washer as a stop.
I guess I will have to get some pictures the next time I do some guides.

[toms73novass]

Thanks for the advice on installing from chamber side. Would like to see your torch method.

[toms73novass]

Since I mentioned it, honed valve guides to .343 which gives me .001+ clearance for intake and .0016 for exhaust valves. The exhaust valve stems are usually ground smaller due to the fact that the clearance spec is at least .004 more.

[chris]

I for one will not put a guide in from the stem side! I always install from the chamber side. I heat the head using 2 propane torches, very simple. I have also made different stops for the intake valves, 140 and all others. The exhaust is always flush with the chamber side and I use a grade 8 washer as a stop.
I guess I will have to get some pictures the next time I do some guides.

It's funny you mention it, I was just posting on your other post about how I enjoy that you show photos of what you do!