Liners vs Guides

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mitch
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Liners vs Guides

Post by mitch » Thu Jan 29, 2015 7:07 am

What is everyone's take on liners vs guide replacement? How good are the liners? When should you replace the guide? I mostly do motorcycle heads but looking at getting into some auto stuff.If the liners are good I could do some of the motorcycle stuff with them as I think they go down to 5mm. Are the kits size pacific or will you be able to do multiple sizes. Just looking for some good input on this.
Thanks Mitch

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Re: Liners vs Guides

Post by mag2555 » Thu Jan 29, 2015 9:00 am

I use both types and if the liner types are installed right in the first place I have never had a issue with them, installing them right also means honing them to size, not reaming them which does take 4 times longer !
If I am looking for max power than once the valve stem or guide has .001" of ware, then it's time for new parts !

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Re: Liners vs Guides

Post by MotionMachine » Thu Jan 29, 2015 9:40 am

I have from 5.5mm thru 3/8" liner kits with the 9000 installation stand and hardly ever install a knock-out or integral guide anymore. I agree that honing is the only way to go also, I never never ream, it's stone age. Constant oil bath, like an HS 30 Sunnen cabinet, is a must, along with the 310 gages. Seat alignment is one of the best reason for liners given the way heads are manufactured these days. They save so much time and aggravation, no more guides galling or distorting on installation, ending up with too much clearance from bad replacement guides, no more pre-heating, just to end up with seats that don't line up worth a crap when you cut them. Liners cure all of that. It'll cost you plenty to get tooled up to do it properly, I've got probably $15K in everything when you add all the hone-all mandrels and drivers.

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Re: Liners vs Guides

Post by PackardV8 » Thu Jan 29, 2015 10:07 am

If anyone has the patience to answer, let's divide the liners vs guides into four parts:

1. Iron heads with integral guides
2. Iron heads with replaceable guides
3. Aluminum heads with iron guides
4. Aluminum heads with bronze guides

My machinist is old school and hasn't made the transition to liners. He's got his reasons, but I'm working on him to see liners may have applications.
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Re: Liners vs Guides

Post by MotionMachine » Thu Jan 29, 2015 2:34 pm

PackardV8 wrote:If anyone has the patience to answer, let's divide the liners vs guides into four parts:

1. Iron heads with integral guides
2. Iron heads with replaceable guides
3. Aluminum heads with iron guides
4. Aluminum heads with bronze guides

My machinist is old school and hasn't made the transition to liners. He's got his reasons, but I'm working on him to see liners may have applications.
My quick answer is it works better on all applications for so many reasons I can't list them all. I'm willing to bet that your old school machinist doesn't even hone valve guides. Or own a 310 gage. If not, forget about converting him, some shops just will not advance with the technology.

P.S. I should add that I type this as I bore a block on my CNC and hone another in my SV10. I can hear them but I can't see them!

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Re: Liners vs Guides

Post by twl » Thu Jan 29, 2015 3:01 pm

We used to do liners, but now we just make new bronze guides to fit.

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Re: Liners vs Guides

Post by pamotorman » Thu Jan 29, 2015 8:02 pm

replacing the guide can be a problem if the bore and the OD of the original guide are not concentric. the valve seat in the head could be way off . some guides are bored after they are installed in the heads

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Re: Liners vs Guides

Post by rfoll » Thu Jan 29, 2015 8:09 pm

I have never been happy with the results of pushing out old guides and installing new. The eccentricity of the guides has always resulted in sunken valves.
So much to do, so little time...

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Re: Liners vs Guides

Post by SMITHBERGRACING » Thu Jan 29, 2015 11:51 pm

IMO it all depends on the situation. Liners have their place and so does a new guide. If you need to maintain concentricity or don't want to risk removing a guide then a liner is the best option. If your going to a bigger valve size then it's not an issue. I recently started using liners for certain situations and was happy with the resluts. I like to be able to shrink down stem sizes with liners to be able to use a lighter valve. I prefer Rapid liners if you are going to buy, much better quality.

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Re: Liners vs Guides

Post by mitch » Fri Jan 30, 2015 12:00 am

As far as just a normal rebuild an not a performance build do you have to ream or hone them or can you just use the carbide ball to size them or is that part of the sales pitch.
Thanks for all the replys.
Mitch

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Re: Liners vs Guides

Post by SMITHBERGRACING » Fri Jan 30, 2015 12:08 am

mitch wrote:As far as just a normal rebuild an not a performance build do you have to ream or hone them or can you just use the carbide ball to size them or is that part of the sales pitch.
Thanks for all the replys.
Mitch
I use the broaches that come with the kit. I believe you have to go .001 larger than your valve stem. I then use a AV&V reamer to size and hit it with a diamond hone for the last few tenths. Works out real nice that way at least from my findings so far. I also spot face/trim each end of the liner before I hone.

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Re: Liners vs Guides

Post by SMITHBERGRACING » Fri Jan 30, 2015 12:15 am

Image
This is a LT1 head where I used a liner to neck down to a 8mm so I could use LS valves. You can see some of the diamond pattern inside the Rapid liner.

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Re: Liners vs Guides

Post by Cubic_Cleveland » Fri Jan 30, 2015 5:16 am

I agree with liners being good, and I use them regularly. But replaing guides is necessary some times as you just can't put liners in some smaller metric stuff (4mm & 5mm stems) because there isn't enough parent material. Also, some powered metal guides are a real pain to cut. Using good quality replacement guides helps a lot with the concentricity issues, but there are definite problem heads where liners are all that will work.

Edit: To help with concentricity problems when replacing guides, you can always install a liner into the new guide.

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Re: Liners vs Guides

Post by MotionMachine » Fri Jan 30, 2015 7:38 am

pamotorman wrote:replacing the guide can be a problem if the bore and the OD of the original guide are not concentric. the valve seat in the head could be way off . some guides are bored after they are installed in the heads
This is what I was referring to when I said how heads are manufactured these days. Not everyone is aware of this. As a perfect example I have a 16V MBenz head in here right now that was just "fixed" by some other shop. They replaced 2 intake guides and that's all they did, no seat cutting. I put liners in the rest, cut the seats, the 2 seats with the new guides I had to sink an additional .012" each to clean. Now it needs 2 new seats in that cylinder. Using a quality guide or not has nothing to do with the alignment, the guides on a majority of heads today have non-concentric od's and id's. This started with Honda's and Mitsubishi's back in the 80's as far as I can tell by my own experience. I watched a video that showed the process of guide boring and seat cutting in one operation on a multi axis CNC with the head standing on end. I've tried to find it since on Youtube but can't. It's an eye opener.

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Re: Liners vs Guides

Post by pamotorman » Fri Jan 30, 2015 9:42 am

MotionMachine wrote:
pamotorman wrote:replacing the guide can be a problem if the bore and the OD of the original guide are not concentric. the valve seat in the head could be way off . some guides are bored after they are installed in the heads
This is what I was referring to when I said how heads are manufactured these days. Not everyone is aware of this. As a perfect example I have a 16V MBenz head in here right now that was just "fixed" by some other shop. They replaced 2 intake guides and that's all they did, no seat cutting. I put liners in the rest, cut the seats, the 2 seats with the new guides I had to sink an additional .012" each to clean. Now it needs 2 new seats in that cylinder. Using a quality guide or not has nothing to do with the alignment, the guides on a majority of heads today have non-concentric od's and id's. This started with Honda's and Mitsubishi's back in the 80's as far as I can tell by my own experience. I watched a video that showed the process of guide boring and seat cutting in one operation on a multi axis CNC with the head standing on end. I've tried to find it since on Youtube but can't. It's an eye opener.
I first ran into the off center bored guides in the 60s BBC heads

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