kameari valve guide installation?

[TA22 GT]

Hi,
Wondering if anyone has advice or tips for installing valve guides in a 3TGTE? Im thinking of heating the head to around 100c and freezing the guides. Hoping this will create a push fit so I dont need to hammer them in.

Anyine done it this way and if so was it a push fit?

[dnegative]

Done them with liquid nitrogen but it depends on the clearance in the head, some are more interference than others.
Are they bronze or cast iron? Be careful with cast lol

[TA22 GT]

They are bronze, hoping to get them in without too much force. They say the kameari guides dont need to be honed if installed properly...

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With liquid nitrogen did they push in or were they still a press fit?

[dnegative]

Press fit;

[petergoudie]

Dear TA22, I've done a set on another car and I can say that it was a heck of a lot of work and I would not recommend it. A set of guides was very cheap but not worth the effort as there are better solutions.

I found the head got cold too quickly and I had to reheat and reheat, but to no avail. Even so, I just could not get the guides out. I tried to knock them out with a brass drift but their exposed ends began to mushroom in the head but wouldn't budge.

I read a U.S. written Volkswagon manual about replacing valve guides and it said to tap a thread in the guide (I think an 8mm tap fitted the guide bore without drilling a new hole for the tap). You then screw in an 8mm stud or bolt and press out the guide with a mandrell pushing on the stud face. Using this method, the guide is pushed from inside the bore rather than from the outside. For other valve stem sizes select the best imperial or metric bolt size.

However, the replacement guides did not press back in, in exactly the same orientation and there was a lot of valve seat cutting required to seat the valves properly.

During this process I came across two better and very smart solutions I wish I had used:

The first is a product made by K-line, as I recall. The process is to fit a brass sleeve inside the existing valve guide. The sleeve is say, about 10 thou thick. A drill like a milling cutter is used to bore out the old guide. This drill has a long plain nose or guide on the front the same diameter as the valve stem. When it is put through it uses the existing hole as a guide which means minimal valve reseating as it is closely aligned with the original machined valve bore.

The sleeve (which expands slightly) is knocked in with an internal guide a bit smaller than the valve stem to stop it being crushed. The exposed ends are trimmed off with another cutter similar to, but larger than the one that bored out the guide.

The ultra smart part of the design is how the guide is sized to the correct finished bore. If you have say an 8mm valve stem, an 8mm diameter ball bearing is driven through the new guide sleeve with a pneumatic hammer gun (the type Bunnings sell).

It is fantastic as it takes about 20 0r 30 seconds per guide for an experienced operator. Also, if you ever want to do it again, the sleeve can just be peeled out and a new one fitted even quicker because it has already been bored out previously.

The second system is just as smart.

Think of a standard helicoil thread insert. The cross-section of a helicoil insert is a diamond shape.

Now think of an insert with a cross-section that is triangular such that the pointy bit is on the outside.

Also, the triangular coiled insert is made from special brass.

Using a tap with a long plain nose that uses the valve guide bore to align it, the guide is tapped with a thread.

The triangular coil insert is wound in and there you have it, a properly aligned reconditioned guide. I think it too is sized with a ball bearing.

However, even better, if you want to replace the brass coil insert, it can be pulled out (uncoiled) with a pair of long nose pliers and a new one wound in.

The manufacturer of the coil claims that oil stays between the coil tips reducing valve stem wear. Also, the coil edges are very close together - there is little or no gap, as such.

Taking all this into account, I wouldn't replace a valve guide nowadays when there are these much better repair methods available. If you are prepared to spend the money on the taps & cutters, it is DIY.

[TA22 GT]

Thanks for the info. I did get three of them in but will now leave this to the machine shop. The kameari guides are very nice, but as you say they are very difficult to fit.
By far the hardest part of the rebuild. With the right gear i think its quite easy. I just dont want to mess with it anymore as without the right tools its just a pain...
The original guides were all good except one of them appeared to be cracked. So i decided to replace all of them.

[73GTV]

Did some one say Kameari!

https://www.google.com/maps/uv?hl=en...Fcg3iAodMFgNaw

[TA22 GT]

Yep, thats the place i got them from. Very cool inside there, ill have to find some pics i have of that shop...

[JadeEstevez]

It's just a bummer they don't make as much awesome stuff for the 18RG as they do the 2TG

[TA22 GT]

Yeah, they are very focused on the 2TG. Many parts interchange with a 3TGTE and i think there are also some common parts with 18RG. Eg these guides fit 2TG, 3TGTE and 18RG.

[JadeEstevez]

Well I'd love if they made the guide replacements for RG's too...

[TA22 GT]

The valve guides from a 2TG are identical to the 18RG...

[JadeEstevez]

Oh sorry. I meant chain guides! You can't get replacements for 18RG's.