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Discussion Starter · #1 ·
As my head will get some work done to it, I am looking to get the valve guides replaced with phosphor bronze items. Speaking to the guy who will be porting my head its not easy getting guides out (he has not worked on an RB head but had done many others) and when putting new guides in they may be lose and require K line inserts?

Would be interested to hear from those who have replaced the guides and how easy or hard it was an any issues.
 

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Discussion Starter · #3 ·
I am sure there must be a fair few people who have replaced guides on here open to hearing from people and their experiences.
 

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Don't know how much work it is, but Sutton Rebore replaced my valve guides with bronze ones and wasn't a lot of money.

Will dig out the invoice if you want, but may be worth your while giving it to AMT if you are having porting etc done.

Cheers,

Mark
 

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Discussion Starter · #6 ·
I have a guy to do the porting who I have had previous work done and couldn't fault his service or workmanship. As he has not done an RB head he wants to make sure that that are no issues with the valve guide as some heads he has worked on he had to get the valve guide hole line with liners.

Also when porting it is good to know wall thickness so you do not rupture a water or oil way.

As for AMT it is an option, but not dealt with them before I do not know any thing about them or their workmanship.

I am a perfectionist and expect that from people I give my car or engine to having had clowns work on my race car last year I do not need another **** up. So I need to plan things properly and do my research.
 

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Just give it to AMT to do and job done. And no, they didn't do mine but they will in future...

It pays to look at what they have done previously and Andy has churned out some of the best heads in the business. Why do you think other tuners go to him...
 

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Discussion Starter · #8 ·
Anyway that aside, I am still looking for information on the valve guides if they are an easy press out and press in or if there are issues doing so.
 

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They really aren't that hard to replace. This is how I did mine--

I changed all of mine in a small workshop, using a stove and pan to heat the head up. You have to heat the head up and then drive the old valve guides out.

Once you get them all out you have to heat the head up again and drive the new ones in(I put my new ones in the freezer before I drove them in). You can do it without a press, I did mine with a sized valve guide drift and a hammer. You have to measure the depth you drive the new guides into the head as well.


Once you get them all to the right depth, you have to ream them to get the correct size for the valve to slide properly. Once that's done, you can move onto lapping valves to see if the guides are aligned properly or if you need to have some cut.


Overall, not that hard. They aren't much different from any other modern engine that uses press in valve guides. Most important tools you will need is the correct size drifts and reaming bits.
 

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They really aren't that hard to replace. This is how I did mine--

I changed all of mine in a small workshop, using a stove and pan to heat the head up. You have to heat the head up and then drive the old valve guides out.

Once you get them all out you have to heat the head up again and drive the new ones in(I put my new ones in the freezer before I drove them in). You can do it without a press, I did mine with a sized valve guide drift and a hammer. You have to measure the depth you drive the new guides into the head as well.


Once you get them all to the right depth, you have to ream them to get the correct size for the valve to slide properly. Once that's done, you can move onto lapping valves to see if the guides are aligned properly or if you need to have some cut.


Overall, not that hard. They aren't much different from any other modern engine that uses press in valve guides. Most important tools you will need is the correct size drifts and reaming bits.
Isn't there any "stopper" which would avoid the valve guides getting pushed too far into the head? How do You do this properly?
 

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They are a normal interference fit, which means you will have to press them out/in.

I cant comment on how others do it, but I can tell you why I do it a certain way.

Removing, I would prefer to use a big arbour press or an electro hydraulic rig like I use. I dont like using manual hydraulic rigs as they can...not always.....cause galling to the guide bore with the stop/start nature of the movement. If you can press them out in one swift move, the likelihood of damage is much less.

Installing.....same as removal. I dont heat the head or chill the guide, a freezer does very little for shrinking a guide really. If you want to chill, liquid nitrogen is faster and easier. By the time you've left a guide in a freezer for an hour to chill to -4 then place it on a 120 deg heated head, it'll soon heat up as you place it in the head before you can get a press on it.....negating any shrink fit advantage you might of had.

A spacer the same thickness as the install height is used to set the install height.

If you use the correct smooth press method, you dont need to heat/chill, just a bit of lube and it'll go it true and smooth and wont gall. Just make sure there is sufficient taper on the guide nose.

I also dont install with a hammer and drift. It peens over the top of the guide and its just not worth the hassle.

You will HAVE to re cut the seats. Its not even worth the thought of checking concentricity of the existing seats because they will not be where you need them to be.

You can ream or hone the guides to final size as they will pinch when installed, usually in an hourglass manner.
 

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I know some will poo poo about me saying to check the valves by lapping them first, but in my case I didn't need to have my seats cut. I know what you're thinking and it probably sounds incredibly lucky or wacky, but none of mine needed to be cut. All of them lapped in with a good contact patch, I didn't have to "over" lap them in either. I don't have a run out number for them, but a valve seat up to .005" out will still pull full vaccum(it's not optimal, I know, but it will).


Car is together and running for 6 months, still has good compression with no valve problems. :confused: I have a whole complete extra head I'm going to be getting bigger valves in and building up, so I didn't see the need to spend the money to have all the seats cut on the current head when I'm using stock valves and seats that have a good 150k KM on them.
 
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