I would like to ad that if you use brass guides, ream them out. When you drive them in, the brass ones hourglass and will seize valves every time

I have been building engines for 40+ years. What I have seen, when tearing down a engine with thin wall liners is, that 98% of them are crapola! Some will say that this is from improper machining or heat related or whatever. Made me think why would anyone want to run them. At one time I worked at a production cylinder head shop and I asked why we used thin wall liners. The answer was $$$! The cost of them cheap compared to others and they installed feaster and they saved money there too.

As a machinist for many years I’ve done all these techniques and I got agree with you at all points… Keep on rockin

Awesome video. I appreciate your content. I’m actually doing my first rebuild of a set of 906 vortec heads with a beehive spring upgrade was wondering if you had a recommendation or part number for valve seals?

I know the liners have critics, but I tend to suspect that they are often installed carelessly by some shops and especially in less experienced situations (shade tree) because it is economical to purchase a kit. I don't really see how they can slip until the valve stem expands and drags on the liner, too tight a fit. I think the slipping reputation comes from fitting either with worn tooling or poor finish. They advertise that you can run tighter valve clearances, which, if you know what you are doing, you probably can, but...

Wow this is very interesting, I knew knurling used to be done with pistons but had no idea it was done to valve guides I figured they were cheap enough one wouldn't need to do it.

I like bronze best for any engine and pressing them back in which is a pain but it’s my favorite way Yes I got all the tools for nurrling it but replace them is best

the late super engine builder Smokey Yunik totally agreed with you. He always preferred a solid cast iron guide. Knurling guides is just the cheapy approach. Cast iron is as brittle as peanut brittle and knurling is a waste of time

I'm only about 5 minutes in so far but just wanted to say that our high school auto mechanics shop teacher told us back in 1986 that knurling valve guides was obsolete and not recommended even before then, I can't imagine that it's even still a practice by anyone today. 🤔 We knew it was a no no 36 years ago.

I have an engine that ran with no oil for a significant amount of time (received it that way), to not get too detailed, filled it up with oil, noise cleared away after 5-10min, compression ~150psi in all cylinders, I suspect bad valve guides (not seals). lots of shavings were found in the oil filter. is it possible everything else held up but the valve guides themselves are shot? smokes on startup and I just wonder if there's an easy way to distinguish between valve guides and valve seals being bad.

Curious, on the cast guide. What's the recommended interference fit?

I used hundreds of liners without issue to date. But the preparation of the reamed hole in which it is pressed is crucial. Chamfering so the liner isnt ' eaten' by the sharp edges when pressed in. The press fit itself should also be ok. And I prefer to use only 1 broach and then hone to size . As the reamer follows the worn guide bore.... the liner is also shaped to that.... To create a straight round bore...broach 1 time ,then hone. I have 289 Ford sbc racing engines which after 40 hours of flat out racing show no measurable wear. But if you completely broach a liner to size so the valve stem fits.....Then it wears out fast as the bore has almost no area on which the valve stem can run. I experienced long ago that a broached guide had , say 0,04mm of play , but valve stem would get stuck half way the guide . Using the next broach created 0.06mm of play....and valve would go through with...hmmm...snug fit... That made me start thinking about some shops in my area stating : why replace a guide , as after 20k miles you get a head back for repair ..and guides are completely worn out??#@@???? Well.....do it THE RIGHT WAY!!!

the only bronze guide that last are the manganese bronze material, other ones are too soft or they wear out the valve stem.

What do you think of Silicon Bronz VG?

Would polishing the bore so it rides as smooth as a wrist pin be a good idea?

Whats the advantages on stroking a 5.9 and destroking a 6.7

'KNURLING' is usually done to keep costs down & is a 'USED CARS' choice.

I'm from the UK and we use them on all the b series and isb engines I've never had a problem with them they have always worked well I've only ever seen them mess up when the installation process has been messed up and it's not had enough clearance from the stem to the guide we did have a guy that was an ex pat that moved from the UK to the usa and moved back and he said that you guys always had problems with the k line guide liners he had a theory that it was because of the climate which maybe true in some states as they are extremely hot in summer months and I've probably done thousands of isb and b series heads and we don't get this problem so could be true who knows would be worth trying it out. and brass works well for petrol engines VW use brass guides In the diesel engines and they could do 30k miles and be knackered seen this before good video is that b series head a USA head or a Brazil head ? I once did a west Germany b series head

Bronze is soft carbon causes more wear especially the exhaust & diesels generate soot which is carbon

I’m about to do a head gasket on my 12v with 270k on it. At this mileage should I do the guides or run it?

👍👍

I had a cylinder head for my Dodge rebuilt and I told the guy distinctly please do not use those steel key liners because of those are very hard and they’re very hard on valves what’s the jag off to use steel steel key liners and probably eight months later my engine smoking real bad again on start up and now he did a real nice job on the other stuff beautiful valve job and he and when I took the head to him he said he would have a ton on a certain day it was done and it was right what he said it would be pricewise but it ruined all my new valves and basically I had to have another Val job done so I just bought a Hamilton cam stage to head instead but anyway That one valve you were showing I’m familiar with the cast guide and with the little worm groove going down they were very good valve guides of factors to my stage to Hamilton Kim’s head I wish it had them in right from when it was new anyway yeah yeah don’t use those key liners stay away from them no good

I use all three and have seen all three have issues. The bronze liners work just fine, it's the install of them that the errors mostly occur. Guys stuff them in there to fast and finish sizing by broach. No trimming, sharp burrs on the ends and just plain rushing through the job. Then stick a worn valve back in. Hundreds or mabye even thousands of heads with them already in have come through my hands and only a small amount had any real issues. Thing I like the most about them is you can size them to your desired fit whereas the cast guides with sizing material never seem to be in stock. So your stuck with the pre set diameter of the guide which is pretty well always on the high limit. I still use hundreds of theme yearly, just a personal complaint. I find some engines prefere one over the other and do quite a bit of engine hobby for myself with some r&d in there. Not long ago I had a 302 I done for mysel on the bench for inspetion and had cast guides and liners mixed in. The cast guids worn more then the liners in that example. Years before I had torn apart a 350 I been running. It had liners and a couple were worn through the liner and into the remaining guide material. The rest were mint though, so no explination there. Maybe my install was the culprit. I prefer cast guides in diesels even though I no longer work on them. I use liners in most everything else. After thousands of heads, no one has returned with a complaint(and I'm in Lower B.C. now, complaining seems to be a social expectation here lol). With my own experimenting though personal builds including daily assult, bracket racing and many years of circle track, I have found no reason to not use a liner. As for knurling, that is hack lol. Proud to say I have never sent out a knurled guide, or piston as a repair. Replaced many though, so I know it was a common thing through small time engine shops and garages/hobby guys.

I have worked in 6 reco shops here in Australia and used all 3 types of guide. You failed to mention that most cyl heads actually have guides that can be removed and replaced with genuine parts or aftermarket. As for that thin guide liner most likely a k line guide i have found them to be highly succesful and a workmate of mine that used to rebuild the engine of a funny car with a keithblack discovered that if he fitted cast guides he could get one meeting out of them but the klines would last around 4 meetings. Also we had a car come in that had a squeek in the top end and we discovered that the mechanic that put it together had messed up something and the squeek was coming from the guides as there was no oil getting to the top end. The old volkswagen bugs used to use bronze guides. Some of the kline kits i have used came with a knurling tool to run through the guide to give it a line for lubrication, some use a reamer to take it out to size while some have a broach which i prefer as it gets knocked through the guide but does not remove any material so theoretically it should make the liner a tighter fit.

VW Diesels use brass guides

Great for Honda civics not 30k diesels

Ya those valve guide liners are a hunk of crap even on a small block Chevy I’ve seen problems with them Good guides aren’t tht much more money and the head (s) are already on the bench might as well use good parts

Some machine shops set you up with guide liners, and if the head overheats, the liners come out. And then it is your fault because the head overheated. I had one set of Ford 460 heads rebuilt by the same shop, and they put on a heat indicator to see if they had to warranty their work or not. Apparently they can make up a system where they set rules of quality standards. No part of a cylinder head should never fail because it ran a little low on antifreeze..... guide liners are a guaranteed failure if you ever have a problem with a heater or radiator hose later on, especially in a performance application. If you respect your own wallet, or your engine investment, run away from anyone who tells you guide liners are just fine. If you use your car outside the likes of Grandma's driving, liners will only gain you wreckage.

Geez get to the point

I wouldn't do it, I wouldn't watch this video, it's my oppinion, I wouldn't like doing that, I wouldn't watch this, I wouldn't do this, I wouldn't see my self doing this...christ why didn't you just show the thing you would do. Would have been a shorter video