Valve guide problems

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Brad77 · #1 Post by **Brad77** » Sat Dec 03, 2005 10:24 pm

I think I may have a problem. I was trying to install my kibblewhite valves into the stock valve guides. The exhaust valves slid right in. The intake valves didn't work out so good. When the valve is about halfway into the guide it stops. Now I can slowly turn the valve while applying light pressure and the valve will go all the way in, but once it is in place I can feel resistance when I push on the stem side of the valve.

I read the other post about valve guide sizing. So I went and borrowed a 5.5 mm valve guide reamer from my friend at the Honda shop. When I inserted the reamer into the guide I can push it all the way though and can even turn it with my fingers with little effort. Before I even inserted the reamer into the guide I looked inside both of them and did not see anything that looked like it was causing blockage.

Well after using the reamer I tried inserting the valve again, same results. So then I started troubleshooting procedures. To make sure it was not the valve causing the problem I stuck the intake valves into the exhaust ports, the valves slid right in. Next I tried inserting the exhaust valves into the intake ports they stuck just like the intake valves.

Now when I was taking the head apart I did notice that the valves were a little harder to get out than normal. Just to see what would happen I also took one of the stock valves and tried putting it back into head. It stuck also. In fact I think that it stuck harder than the kibblewhite valve did.

I looked again into the guide with a brighter light and I noticed that there were horizontal and diagonal lines in the intake valve guides. The exhaust guides were smooth like they should be. Also in the ring at the top of the stem on the intake valves there was gold gunk that I figure is valve guide.

So I am guessing that the reason the valve is getting stuck is because of the lines causing resistance.

My question is why did it do this? Why was it just the intake side? How hard is it to replace the guides?

I tried to get some pics but my camera would not focus up that close.

Happyboy · #2 Post by **Happyboy** » Sun Dec 04, 2005 10:05 pm

I hate to see a thread just sit here not getting replies....I am sure someone else will reply tonight or tommorrow.

If your valve guide reamer slides through ok then I would think your valves would too. Measure your valve's shaft diameter and measure your reamer. Be sure the reamer is the 5.5 that it is supposed to be.

haydug · #3 Post by **haydug** » Sun Dec 04, 2005 10:19 pm

Well, just taking a guess here without putting my fingers on it, but I would say that the stock guides are scarred from something, maybe inhaling dirt at one point.
If the reamer indeed does slide right through, and every valve hangs, than that only leaves the guide to be damaged. I have also see dirt hang a valve open, and it kiss the piston. I know that Timbo is good at changing them, and that is who I would use.

cannondale27 · #4 Post by **cannondale27** » Mon Dec 05, 2005 12:42 am

Roll the valve on flat suface to check if it is bent.

Brad77 · #5 Post by **Brad77** » Mon Dec 05, 2005 4:07 am

I think the reason the reamer goes on through is because of the vertical notches in it. I measured it when I picked it up, but I do need to remeasure it just to be safe.

Rolling the valve is a good idea. Although I did try that.

Yeah I am thinking that the light scarring that I see in the guide is causing the hangups. I always thought that changing valve guides looked like something that I did not want to try.

Thanks for the replies

cannondale27 · #6 Post by **cannondale27** » Mon Dec 05, 2005 12:55 pm

That scarring could also have been caused when you removed the stockers.Sometimes there will be a little knick on valve from the keepers or smooshed on top from the shim.Need to get rid of that before pulling valve out.

cdsracer · #7 Post by **cdsracer** » Mon Dec 05, 2005 5:53 pm

I would really check the valve carefully for being bent.

440EX4ME · #8 Post by **440EX4ME** » Mon Dec 05, 2005 8:43 pm

QUOTE

Originally posted by cdsracer
I would really check the valve carefully for being bent.

I was thinking the same thing until he stated that the exhaust valves and original ones did the same thing.

Chances are not good that all the valves both old and new are bent, and its looking like there is a problem with the guides.

One thing I didnt see mentioned was that there is a chance the guide itself isnt the problem but that the fit into the head is too tight and therefore causing the clearence inside the guide to be too tight.

Its not a popular thing, but working with improper clearences can cause problems when fitting etc, and just be aware of it if none of the other potential causes pan out.

One thing thats confusing is that if the reamer is of the correct size and you have reemed it out then the id of the guide should be clean and ready to go, but your still having trouble so maybe its the wrong size reamer.

Brad77 · #9 Post by **Brad77** » Tue Dec 06, 2005 4:45 am

Yeah, I am almost certain that the intake guides are causing the problems. Cause when I insert the intake or exhaust valves into the intake guuides they hang, but when I insert the intake or exhaust valves into the exhaust guides they slide right through like they are supposed to. Plus when either set of valves are inserted in the exhaust guides I can slide the valve in and out with one finger on each end of the valve without feeling hardly any resistance.

I would think that if the valve was bent that it would hang in either set of guides.

I wish I could get a pic of the scarring lines that I see in the intake guides. You would think that with the valve going up and down in the guide that there would be vertical lines in the guide but there are many of the lines that are horizontal inside of the guide. Although I suppose that if there was something that got into the guide and it hung in one spot it could still work its way around the valve making its way around the inside of the guide.