TOPIC:

I am installing new valve guides in my KZ1000 and I am wondering what is the correct interference fit between the outside of the guide and the guide bore in the head.

-Dave

are you using over size guides?

I will use oversize guides if that's what I need, but I need to figure out first what the desired fit is so I can select the proper guide.

-David

I have never seen the interference dimension specified. I believe the new stock guides are still available.

Got some info from a friend who does cylinder heads. Apparently the OD of the valve guide needs to be .001" to .002" larger than the hole in the head, to achieve the proper interference fit.

-Dave

I didn't know that. I recall you have to heat the head up to something like 400F to get the guides to go in....

It is about .002"

As for removing and installing guides, remember you have to remachine the seats when you change guides. If you are not equipped to do that, why not send the head to someone that can handle all of it.

As for removing and replacing. Having done this to probably over 1000 heads and the leading manufacturer of aftermarket guides, I offer these tips;

First, it is imperative that you blast the nose of the guides so there is no carbon on them. The carbon, especially on the exhaust guide is very hard and can damage the guide hole in the head if you remove the guides with it on it.

Next, to heat or not to heat. If the guides are oem steel, heat the head and drive them out. If the head has bronze guides, drive them out cold.

When installing new guides, ignore the manual. Do not heat the head or pound on the new guides.

We use special fixtures in the press and coating the guide with assembly lube, we press them in cold. This helps keeping the guide from going in crooked, and won't damage the guide.

We do make oversize guides for people who screw these heads up trying to do it another way

APE Jay wrote:

We do make oversize guides for people who screw these heads up trying to do it another way

Because of the fact that these valve guides keep going up and up in price and the addtional prices for service work like intalling guides xxx dollars, valve job xxx, shipping xxx, turn around time etc. etc. Seems to me it's getting harder and harder to afford to work on your bike and stay married, living in a house, keep your family's body fat above the legal limit. I have this to say: Ape intstalls guides for you and performs a valve job it's gonna be a biggy. No way around that. They have it set up this way by choice. That leaves one to this. I bought valve guides from a company in cal. that cost only 55.00. The guides were not undersized so no need to buy a reamer. The 180 dollar valve job on only an 8 valve head, noneed. Most machine shops would laugh. You can buy or make your own driver and drive out the guides. Using the same driver to drive in new guides. Doesnt matter if u press them or drive them they will not go in perfectly straight. If they did no one would have the seats cut afterward. Thing is you'll need to buy a reamer and a hone. Probably just the hone. Reason is the guides will contract on the way in and the hone will straighten that out. After honing all eight you can take the head to an auto machine shop, tell them it's shim over buckets and to take off a minimum of valve seat material. Probly cost you from 35 to 60 dollars and your heads are ready for shimming and installing. Make things even easier you buy the valve stem height gauge for ease of determinig proper shim choice. Like jay said make sure to remove carbon, and grease both the guide and the hole. This is very simple and quick and saves alot of money. Some of the guides may scrape off more material from the head on the way out than others. These will be the ones that that will not go in perfectly straight. There is nothing and method of removal can do about this. One exception is to heat the head to release some of the pressure. It's not mandatory and has been found to make little diff. When Driving in new guides, you can feel the pressure fit. Any guide that drives easy will need to come back out. Put on top of a vise with the jaws almost closed for a resting spot. You can take a hammer using the claw, smack the guide in four places starting on one end movng toward the other (the valve stem end facing you) turn the guide and make four more until you come to where you started from. Don't get carried away because it's easy to over do it. This makes one hell of a diff and you'll realize that after you do the first one. It's really very simple and is not any kind of rocket science. I just did this on advice from a machinest for some vw heads, it worked out fine. The heads are done and I'm not in debt. Common sense will tell you that any hammered in guide is likely to have some deformity, wether it's going to affect the lifespan of the guide is another common sense factor. Life's alot about weights and measures and it's a go figure all the way. I've personally driven a kz guide out backwards. Iv'e seen them intalled off, I've seen where someone else had done this on heads. Using the advice I gave you I truley believe your chances of zero problems is around 99%. From reading above I understood that you had have the will, I wanted add the second part here and provide a way for you to get where you want to be on your own time and with your own hands.

the proper guide drivers make all the difference,air powered drivers use vibration to slip the guides in and out without so much distortion.here is a link to guide drivers,hth.

www.goodson.com/store/template/product_d...90b4104644f4b6ebfccc

leon holmes

kibblewhite and ape both have the guides.
www.blackdiamondvalves.com/products.htm
www.kzzone.com/

leon holmes

531blackbanshee wrote:

the proper guide drivers make all the difference,air powered drivers use vibration to slip the guides in and out without so much distortion.here is a link to guide drivers,hth.

www.goodson.com/store/template/product_d...90b4104644f4b6ebfccc

leon holmes

We use an air hammer and the correct drivers as shown to take the guides out.

I have seen Kaw heads where the mechanic drove the guides in with a drift and a hammer. There were oem style guides with the wire clip. He drove the guide clear thru the hole, clip and all.

Yes, we were able to fix it. racetoolz.com/