fangio 1 Posted May 31, 2006 I've just spent 3 hours searching on the subject and read the Haynes Manual as I'm contemplating doing my Mi re-build myself, though have serious doubts, as I've only ever done head gasket jobs before. What bothers me is this gnats c*ck of protrusion for the liners. How can it be so critical when the seals are about 2mm thick? Surely when the head goes on and the bolts are tightened down they will take up at least 1mm of error as long as you have some protrusion? I'm sorry if this sounds ridiculous to the competent and experienced engine builders here, but I can't see why it is set to such a fine tolerance and it's really putting me off doing it myself, as I don't have the money to waste. Can someone settle this for me and tell me if I should even consider doing this myself, or leave it to a professional engine builder, who has quoted me double the price; i.e. £500 for parts and £1k for total re-build. I would love the satisfaction of doing it myself and this is the only barrier in my way ( that I can think of at present) Share this post Link to post Share on other sites
Pugnut 9 1 Cars Posted May 31, 2006 because you need to gaurentee that when the head is torqued down that each liner is sealing against the head and gasket properly. they will all squash down the 'o'rings but its the all 4 liners at the top you need to worry about , all need to seal onto the head and gasket properly . I wouldn't worry too much . using all standard components and everything being clean well assembled you shouldn't have anything to worry about. if you start mixing and matching liners you should check the heights but really there is no adjustment in them anyway, its more of a check to see you havent left a spanner stuck under a liner etc. Share this post Link to post Share on other sites
huxley309 0 Posted May 31, 2006 Also the liners/block expand at different rates so it's to allow for this Share this post Link to post Share on other sites
M3Evo 0 Posted May 31, 2006 I'd spend the time getting them right if it were me, seem to recall reading that incorrect liner protrusions were partly to blame for all the K-series HG failures. Took me forever and a day to get them right on Stu's engine, untill we found out that the liners didn't actually fit properly and needed modifying to go in properly! Even then though, it took some trial and error to get them all right. Just to clarify the trial and error bit, it was a case of inserting a liner, checking the protrusion, if it was wrong, trying it rotated through 180degrees, if it still wasn't quite right, trying that liner somewhere else and so forth......yawn! Share this post Link to post Share on other sites
Alan_M 66 1 Cars Posted May 31, 2006 I remember trying to do mine, and having loads of trouble getting the last liner OK. My block was'nt square and had to have a slight skim done by MattSav. The smallest bit of crap will cause problems so have some light grade scotchbrite to hand to clean those liner seats. Share this post Link to post Share on other sites
ALEX 98 1 Cars Posted June 1, 2006 It's no hassle checking them. The proper way would be to use a DTI. (Dial test indicator) But a Steel rule and a set of feeler blades will do the same trick. Share this post Link to post Share on other sites
M3Evo 0 Posted June 1, 2006 (edited) Not quite sure how you'd use a DTI to check liner protrusions to be honest. A depth micrometer with a nice big base perhaps? Edited June 1, 2006 by M3Evo Share this post Link to post Share on other sites
Dom9 2 Posted June 1, 2006 Yep, most k series engines die 'cos the liners are too low... Think they are only meant to be 3thou proud of the block, but a lot have been found to be below the deck height - ouch! There must be some 'giv' with the Pug liners though, since there is a rubber gasket at the bottom?! Share this post Link to post Share on other sites
fangio 1 Posted June 1, 2006 Thankyou Dom. The first person to see what I'm getting at, I believe. According to the book you check that all the liners are within a gnats c*ck and have an amount of clearance above the block, w/o seals - Fair enough - but then, you bung 2mm thick seals on, which would surely take up probably 1.5 mm in any discrepancy! Share this post Link to post Share on other sites
M3Evo 0 Posted June 1, 2006 I believe the liner seals are compressed into a recess rather than being sandwiched between the liner and block. i.e. the liner will sit hard against the block with the head clamping down on it and the seal will not be in a position to raise that at all. Share this post Link to post Share on other sites
PumaRacing 1 Posted June 1, 2006 Yep, most k series engines die 'cos the liners are too low... Think they are only meant to be 3thou proud of the block, but a lot have been found to be below the deck height - ouch! There must be some 'giv' with the Pug liners though, since there is a rubber gasket at the bottom?! No. The rubber o ring is compressed between the corner of the liner and a 45 degree chamfer in the block. Once that's been squashed into place the base of the liner sits completely flush on the floor of the block. If you think about it if there was a rubber anything under the base of the liner the head gasket wouldn't work at all. Share this post Link to post Share on other sites
fangio 1 Posted June 2, 2006 Thanks Dave, you may have just made the penny drop for me. I think I understand it now. The critical height of the protrusion is so that when the base of the liner is on the deck of the block the top of the liner compresses the metal ring in the gasket? Plus I suppose also must brace the block itself - hence the gnats c*ck of protrusion? The seal then is not taking up any slack whatsoever - it gets totally squashed in the process, as the liner is pushed to the deck. Please tell me I'm there and then I can sleep tonight! Share this post Link to post Share on other sites
PumaRacing 1 Posted June 2, 2006 Yes, that's how it works. That's also why the protusion is measured without o rings in place so the liner doesn't have to be clamped down. Share this post Link to post Share on other sites
fangio 1 Posted June 2, 2006 Thanks Dave, isn't it funny when something finally becomes clear; you wonder why you made so much fuss in the first place. Share this post Link to post Share on other sites
ALEX 98 1 Cars Posted June 2, 2006 Not quite sure how you'd use a DTI to check liner protrusions to be honest. A depth micrometer with a nice big base perhaps? Useful link Share this post Link to post Share on other sites
James_m 0 Posted July 18, 2006 Looking for a bit of advice as im having a bit of a nightmare with these. Is the -.010mm as per haynes above deck height with seals in or out? as with the seals in i cant get the clearence below about 0.15, with no seals there is virtually no clearence as you would expect. Ive tried hammering with a block of wood as advised by haynes, but the seals seem to act as a spring rather than being compressed as they should. Have i got this wrong and the protrusion is with no seals anyway? Cheers James. Share this post Link to post Share on other sites
Super Josh 4 Posted July 18, 2006 Looking for a bit of advice as im having a bit of a nightmare with these. Is the -.010mm as per haynes above deck height with seals in or out? Yes, that's how it works. That's also why the protusion is measured without o rings in place so the liner doesn't have to be clamped down. Share this post Link to post Share on other sites
James_m 0 Posted July 18, 2006 Thats a releif, ive been trying to get that right for hours Typically haynes was unclear as ever Share this post Link to post Share on other sites
