Engine rebuild - piston liners

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AlfaBeta
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Engine rebuild - piston liners

Post by AlfaBeta » Fri May 12, 2006 3:52 am

Hi gang,

I'm going to be doing a bottom end rebuild soon and was wondering if anyone had an opinion on the seals for the bottom of the piston liners. Is it a good idea to replace these also since everything will be apart or is it better to leave them be as long as nothing is leaking?

Thanks a lot!

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Peab
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Post by Peab » Fri May 12, 2006 4:52 am

i'd say : replace. These seals are taking a lot of punishment from the internal heat and are probably very crisp and aged by now. Good to get some fresh rubber in there.

Even if you leave them on the liner, just the dismantling / mounting of the liners may cause them to break and initiate a leak.
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Post by Jose_76 » Fri May 12, 2006 4:55 am

If you're going to replace the liners, those o-rings should be included in the kit. In my opinion, If you remove the liners, then you should replace the o-rings with new ones.
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Post by Barry » Fri May 12, 2006 6:55 am

Jose,did you get my PM??????????????
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Post by AlfaBeta » Fri May 12, 2006 7:35 am

Hi guys,

Thank you for the replies. What if I wasn't going to remove the liners? I planned on just boring them out. Actually, I guess there are 3 scenarios:
1) bore liners but never remove.
2) remove liners and replace seals, then bore out.
3) replace liners and seals with new ones

any thoughts?
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Post by TS_turbo » Fri May 12, 2006 8:20 am

best you can do is to remove liners clean them and liners's nests(!@#) put new seals and may be some high T RTV silicone for peace of mind ..reinstal liners and bore them with torque plate ...
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Post by AlfaBeta » Mon May 15, 2006 7:52 am

Hi TS-turbo,

Thanks for the reply. I think this is the path I will take. I'm hoping it's not too difficult to remove the liners??

AB
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Post by Peab » Mon May 15, 2006 1:17 pm

Liners are not pressed into the block, they are only mounted with a fine tolerance slide fit. So they normally slide right out with light hand force. But sometimes they can get warped, i guess due to overheating, causing them to get stuck. On my engine i had one such troublemaker. With a piece of wood and a hammer it came out after a while.
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Post by AlfaBeta » Tue May 16, 2006 7:49 am

Hi Peab,

Thanks for the reply. That makes me feel a lot better actually, I was hoping I didn't have to heat the block...press out the liners....etc. That would have been a huge pain!

thanks
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Post by x-rad » Tue May 23, 2006 1:52 pm

If you have your engine on a stand and the stud/liner retainers are off, be sure to put a thick blanket in a cardboard box or something similar to catch each liner when it falls out. Found that out the hard way!
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Engine rebuild-piston liners

Post by KingDom » Tue May 23, 2006 6:03 pm

A successful way of removing the liners is by fitting a top compression ring to one of the old pistons and fitting it upside down the bore all the way down till the ring expands past the bottom of the sleeve. Then you can punch it out with a block of wood and a mallett. You may want to use some penetration oil and soak the liner/block joint overnight before attempting the removal. I have used this method on the 4 cyl engines, just had to cut out a little bit of dome on 2 sides to clear the bearing webs. I am not sure about the v6 engines but its worth a look. I am sure I got this idea a long time ago from this site!
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Engine rebuild-piston liners

Post by KingDom » Tue May 23, 2006 6:06 pm

A successful way of removing the liners is by fitting a top compression ring to one of the old pistons and fitting it upside down the bore all the way down till the ring expands past the bottom of the sleeve. Then you can punch it out with a block of wood and a mallett. You may want to use some penetration oil and soak the liner/block joint overnight before attempting the removal. I have used this method on the 4 cyl engines, just had to cut out a little bit of dome on 2 sides to clear the bearing webs. I am not sure about the v6 engines but its worth a look. I am sure I got this idea a long time ago from this site!
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Post by tomp » Sun May 28, 2006 4:40 pm

TS_turbo wrote:best you can do is to remove liners clean them and liners's nests(!@#) put new seals and may be some high T RTV silicone for peace of mind ..reinstal liners and bore them with torque plate ...
Im surprised to here that they are bored in place. I was thinking they could be bored and honed like a single cylinder motorcycle.
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Post by TS_turbo » Mon May 29, 2006 9:26 am

yes i know ... but after my friend f*&ck brand new set of forged NA pistons, we measured cylinders when non torque honed ... all ok .. but when instaling head-miror torq plate and tightnen it to specs , difference was 0.04 mm :? and this is for solid cast iron block ...for turbo aplications where is plenty of clearance there is no mater .. but if u put some tight clearance NA forgies or hypereutectics , proper way is to bore liners torqued in block :?
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