Post Reply
AlfaBeta
Silver
Silver
Posts: 41
Joined: Fri Jan 06, 2006 10:22 am

Engine rebuild - piston liners

Post by AlfaBeta »

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!

AlfaBeta
Peab
Silver
Silver
Posts: 45
Joined: Sun Feb 06, 2005 9:07 am
Location: Oslo, Norway
Contact:

Post by Peab »

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.
User avatar
Jose_76
Gold
Gold
Posts: 193
Joined: Thu Mar 10, 2005 5:56 am
Location: Murcia - Spain

Post by Jose_76 »

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.
'84 Red GTV6 3.0
User avatar
Barry
Verde
Verde
Posts: 1995
Joined: Sat Nov 27, 2004 1:21 am

Post by Barry »

Jose,did you get my PM??????????????
AlfaBeta
Silver
Silver
Posts: 41
Joined: Fri Jan 06, 2006 10:22 am

Post by AlfaBeta »

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?
User avatar
TS_turbo
Gold
Gold
Posts: 185
Joined: Fri Dec 24, 2004 10:06 am
Location: Bulgaria
Contact:

Post by TS_turbo »

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 ...
AlfaBeta
Silver
Silver
Posts: 41
Joined: Fri Jan 06, 2006 10:22 am

Post by AlfaBeta »

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
Peab
Silver
Silver
Posts: 45
Joined: Sun Feb 06, 2005 9:07 am
Location: Oslo, Norway
Contact:

Post by Peab »

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.
AlfaBeta
Silver
Silver
Posts: 41
Joined: Fri Jan 06, 2006 10:22 am

Post by AlfaBeta »

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
AlfaBeta
User avatar
x-rad
Verde
Verde
Posts: 1223
Joined: Sat Mar 05, 2005 1:21 pm
Location: Canton, Ohio, USA

Post by x-rad »

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!
KingDom
Silver
Silver
Posts: 25
Joined: Mon Jul 18, 2005 5:08 am
Location: Sydney, Australia

Engine rebuild-piston liners

Post by KingDom »

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!
KingDom
Silver
Silver
Posts: 25
Joined: Mon Jul 18, 2005 5:08 am
Location: Sydney, Australia

Engine rebuild-piston liners

Post by KingDom »

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!
tomp
Gold
Gold
Posts: 97
Joined: Thu Jun 30, 2005 3:22 pm
Location: central texas
Contact:

Post by tomp »

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.
-Tom P.
User avatar
TS_turbo
Gold
Gold
Posts: 185
Joined: Fri Dec 24, 2004 10:06 am
Location: Bulgaria
Contact:

Post by TS_turbo »

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 :?
Post Reply