Any one have any experience with these?

http://www.cylinderheadshop.co.uk/K-line.html

used a bizillion of them when I worked as a cylinder head machinist. Not much reason to use them when you have removable guides tho' like you do in alum heads. Mostly used them in say a 302 Ford head with "cast in" guides. You can either bore the guide completely out and replace it with a guide insert or just open them up a bit, install the K-liner and hone to size.

Actually, the K-liner works very well in that application and many times we preferred to use a K-liner in a stock guide than to bore out the guide and drive in a replacement iron guide. You get small grooves in the K-liner from the gnurling tool that essentially expands the guide into the head to make it "stick". Those small grooves we believed held oil a bit better as we saw guides last much longer with a K-liner than they did stock.

Thank you for the reply.

I did a pair of T3 heads years ago in a 1835 with a big cam, dual springs and big valves, then I proceeded to beat the crap out of it for 10yrs. I pulled it down for a look and the guides looked and felt like the day I put them in.

I was just looking to see if there is a down side to these. I think my 1.7 daily beater is going to get them.

If you're not using Technovance guides, IMO, you're wasting your timer and money.

The Cap'n

Just the part where their page is so poorly written (taking into account the differences between imperial english and american english) scares me. It looks like this product was developed for heads without replaceable guides or heads that are irreplaceable and one would be afraid to try to press out the original guides.

We never felt there was a downside. Only issues I had heard of is some shops had them "back out" and then shit hits the fan, but we always kept the gnurling tool pretty fresh (we would replace it far more often than other shops) and that was the key. If it would even start to slightly "grab" the liner we would get a new one.


Don't let the poor writing scare you, it really is a great product and have been around for YEARS. It is pretty much the standard for replacing slightly worn guides. Now, if you F the guide up a fair amount, you need to install a replacement guide.

That said, you are correct about the intended use - they are more to repair an irreplaceable guide than a removable guide.

HOWEVER, we would K-line VW and Porsche heads often (I forgot to mention this and came back to edit but saw the responses) because the aluminum is so shitty. You would go to hammer the old guides out and the alum would be galled and yank out with the guide. Then you would have a loose hole and you would either gnurl the outside of the replacement guide (essentially rigging the setup) or have to get an oversized guide. We figured if you got a VW/Porsche head and the guides had not moved, we figured that is much better than f'ing with them so we K-lined them.

I can totally believe you had 10yrs of hard use out of K-lined guides. I had K-liners in my 302 Cleveland heads (yes, there is such a thing for you Ford guys doing this ) and I beat the living shit outta that Mustang for about the same amount of time. I pretty much shifted at 6500rpm and it was my daily driver when I was younger.

I know a certain shop that is preparing carbide guide reamers with double length blades. They will extend completely through the guide to ensure straightnessisisity.
You will croak before they will wear out.

Technovance guides rock. In a perfect world owner Bob Herman would have groupies for making such great stuff!
I've torn down T4 heads that had K-Line sleeves in them. I personally have always thought it was a half assed way of dealing with worn guides in these heads. But if it works it works.

Len, are you using Technovance guides in all the heads you rebuild?

Technovance all the way. They even make custom guides to my specs for me. Very good people. They don't deal directly with the public. I've been buying from them for many years now.
They are the best wearing guides I have ever used. Period!

I concur with Len.

I am still amazed with the way the guides in our test engines and high mileage street engines look after being given pure hell!

These guides took a once common wear component totally away from the engine IMHO.

"straightnessisisity"

I LOVE IT!!!