Ian Hayward Posted February 2, 2007 Share Posted February 2, 2007 Before I go ahead and remove the head from my 97' 1.6 Supersport engine I just want to check that I have set the timing marks correctly. Following the description in the Haynes manual, I have rotated the engine so that the timing marks are aligned and the 'exhaust' mark on the cam sprockets are pointing to the inlet manifold side of the engine. here However this appears to put the 'knobbly' bit in the middle of the camshafts over the centre head bolts here . Is this correct? It seams a bit tight, will the bolts slip past the camshaft or do I have to rotate the cams to remove the bolts? Thanks Ian Link to comment Share on other sites More sharing options...
Kevsta Posted February 2, 2007 Share Posted February 2, 2007 Can't remember having that problem. Have you got the cam sprocket the right way around? I cannot remember whilst sitting at my chair. If you want to check if the engine is in 90 debgrees BTDC (before top dead centre) then you can either check the crank pulley position or pass a rod down the spark plug hole to the cylinder. If you compare cylinder 1 and 2 they should both be the same height from the top of the cam cover (give or take a few mm). Obviously be careful if doing this and do not drop the rod in (I use a very long crew driver). Link to comment Share on other sites More sharing options...
CageyH Posted February 2, 2007 Share Posted February 2, 2007 I think exhaust should point to exhaust, and inlet to the inlet side. So the cams have to go through another 180 degrees. Only dead fish go with the flow.... Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 2, 2007 Author Share Posted February 2, 2007 CageyH - makes sense to me but the Haynes manual quotes:- 'On the 16V engine, rotate the crankshaft until the 'EXHAUST' mark is at the rear (inlet manifold side) of each sprocket and the 'IN' mark is at the front and all timing marks are correctly aligned with the mark on the timing belt rear cover.' The crank pulley is correctly aligned and all the pistons are at the same height. Ian Link to comment Share on other sites More sharing options...
oilyhands Posted February 2, 2007 Share Posted February 2, 2007 It doenst matter which way 'exhaust' points provided that you are at 90 BTDC, it is the crank position that is important, the difference in position of the cams just indicates that you are on a different stroke of the engine. Turn the engine over one complete revolution so that 'exhaust' points diametrically opposite to what you have now and you may find that the protrusions on the cams are no longer in the way of the head bolts. When re-assembling , again it doesnt matter which way 'exhaust' points so long as the crank is at 90BTDC and both pulleys point in the same direction with the scribed lines lining up as expected. oily Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 2, 2007 Author Share Posted February 2, 2007 Thanks Oily, That makes sense, perhaps I should start thinking instead of just following the manual! I'll blame it on looking after the kid's (1 and 2 years old) while trying to fix the car. Ian Link to comment Share on other sites More sharing options...
Sheds Moderator Posted February 2, 2007 Share Posted February 2, 2007 Good luck, to be honest you have no chance with something as complex as a head removal if you are looking after the children too. Best gaffer tape them to the bench while you do the important stuff. 😬 Link to comment Share on other sites More sharing options...
Manxseven Posted February 2, 2007 Share Posted February 2, 2007 .. like this 😳 here 😬 Caterham Fireblade here Edited by - Manxseven on 2 Feb 2007 21:40:36 Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 3, 2007 Author Share Posted February 3, 2007 Well the heads off (the car not the kid's), only took three rolls of gaffer tape! It look's a bit of a mess, the inlet manifold gasket was leaking into the head, and the HG shows signs of failure in a couple of places. I think its the original gasket and was fitted with the plastic dowels. Block here Head here HG here Whats the best way to try to clean up the block and head? I think that there's some damage to the head where the gasket was going but its difficult to be sure. Ian Link to comment Share on other sites More sharing options...
John Howe Posted February 3, 2007 Share Posted February 3, 2007 Give the head to your local rebore company for a skim... costs about £20-£25. Clean the deck up with plastic type pot cleaner and re-assemble. Nothing looks serious... buy your bits from DVA and whilst your at it get some vernier pulleys. JH Deliveries by Saffron, the yellow 230bhp Sausage delivery machine Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted February 3, 2007 Leadership Team Share Posted February 3, 2007 Ian, I've found carb cleaner works best. If you carefully rotate the cams so that you close the valves one chamber at a time, you can carefully clean the head using a stiff brush and rags. DON'T USE ANY POWER TOOLS/WIRE BRUSHES ETC. I remember this done many many years ago (I must add not by myself but by someone who I thought should have known better!) and the engine was toast within a week due to an errant wire from a brush in a drill 😳 Heavy carbon deposits can be scraped of using something with a blunt edge so as not to cause any damage. Stu. Link to comment Share on other sites More sharing options...
Englishmaninwales Posted February 3, 2007 Share Posted February 3, 2007 Critical to check the liner heights. Speak to Dave Andrews (oily) for precise measurements. I think up to 0.004" proud of cylinder block deck, but I expect someone will be along with to correct me Malcolm Link to comment Share on other sites More sharing options...
Myles Posted February 3, 2007 Share Posted February 3, 2007 I think up to 0.004" It's the *minimum* height that is important - and consistency between the height of each liner. My memory is hazy about the suggested range (4-8 thou?) - best search out an Oily post - or wait for the answer from the man himself. 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester Racing 7s Equipe™ 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
oilyhands Posted February 3, 2007 Share Posted February 3, 2007 4-5 thou is the correct height, any less and you could have problems, inconsistency in heights is also a problem. If the liners are too low then you will need to remove the sump, oil pickup, oil rail, rods, pistons and liners and linish the top of the block carefully to give the correct liner protrusion. Mask the block first with workshop wipes or similar and make sure you remove the metal evenly. Mark the liners with their cylinder numbers so that they go back in the correct positions and mark them radially so their radial orientation is maintained. Replace the big-end bearings and rod bolts when re-fitting. oily Link to comment Share on other sites More sharing options...
Sheds Moderator Posted February 3, 2007 Share Posted February 3, 2007 In other words if the liner heights are out then it's a bottom end rebuild. ☹️ Best hope they are right, and my grateful thanks to everything that's holy that mine were evidently OK, as at the time I did mine I didn't know to check. Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 3, 2007 Author Share Posted February 3, 2007 I've started to clean the block, it all looks OK, but there is some pitting on the top of one of the liners here I'm guessing that this will not be a problem as it is on the cylinder side of the gasket, and does not appear to be on the area where the gasket sits? Is the liner height measured relative to where the block supports the liners or the outside edge? Finally, what's the best way to clean the pistons? The Haynes manual suggests a smear of grease to seal the gap between the pistons and bore, then clean the piston (carb cleaner?) before using a brush to remove the carbon/grease from the gap. Does this work OK or is there a better way. I don't really want to fit clamps and rotate the crank. Thanks Ian Link to comment Share on other sites More sharing options...
Myles Posted February 3, 2007 Share Posted February 3, 2007 Is the liner height measured relative to where the block supports the liners or the outside edge Oily showed me (two years ago - warning!) how to check. Broadly speaking, you need a perfectly-straight edge and some feeler gauges. Everything needs to be clean - 4-thou is a teeny height to try and measure in the first place. Starting with The liner height will be (roughly) somewhere between the thickness of the last gauge combination to withdraw freely - and the first to snag... Measure the height at several positions around each liner (set the edge at 45-degree angles etc.). That was it, broadly speaking... 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester Racing 7s Equipe™ 🙆🏻 🙆🏻 🙆🏻 🙆🏻 🙆🏻 Alcester-Racing-Sevens.com Edited by - Myles on 3 Feb 2007 13:27:46 Link to comment Share on other sites More sharing options...
Tony Whitley Posted February 3, 2007 Share Posted February 3, 2007 Mine were welll short of 4 thou proud and with Oily's encouragement I linished the block with wet and dry until they were right, measured as Myles says . Despite my reservations about my abilities it's been all right for 5 or 6 thousand miles including almost 3,000 round Europe in temperatures up to 40C Fatalism means never having to wonder if it's safe to overtake Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 3, 2007 Author Share Posted February 3, 2007 I have given the head a quick clean to see exactly what state it is in, there seem to be some fairly large pitted/eroded areas These are large 3-400k images, so you can see the areas in detail:- Overall view here Pitted area where gasket had failed here General erosion of head here Will all this skim out OK? Ian Link to comment Share on other sites More sharing options...
Peter T Posted February 3, 2007 Share Posted February 3, 2007 Head looks pretty bad. It will need a skim, also worth bearing in mind that the head might have lost it's hardness, this is something worth checking prior to skimming. Dave Andrews is the man to speak with he can clarify what should be done. Worth a phone call for a chat. R500 Mango Madness Link to comment Share on other sites More sharing options...
oilyhands Posted February 3, 2007 Share Posted February 3, 2007 Mmmm, it looks pretty bad, some of the pitting will go deep. You might need to replace the head, I have a dozen or so heads here in good order. If you can get it here I can assess it better and hardness test it. Oily Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 3, 2007 Author Share Posted February 3, 2007 I've also just noticed this mark on the liner here The car has only covered 13k over the last 9 years and spent a fair bit of time sitting in the previous owners garage, I'm guessing that the inlet manifold leak has been there for quite a while, and at some point partially filled the cylinder with coolant. Obviously without the liner clamps I cannot rotate the crank to see how bad the damage is. Any ideas? Ian Link to comment Share on other sites More sharing options...
oilyhands Posted February 3, 2007 Share Posted February 3, 2007 The liner looks fubared, but you cant tell without the confirmation of 3D, can you feel the rust mark with your fingernail? To make two liner clamps, cut two lengths of domestic central heating pipe to the same length as the thickness of the head + 10mm, use two penny washers and then two of the head bolts in between cylinders 1&2 and the other between 3&4, the pipe acts as a spacer and clamps the penny washer down over two liner edges. Then you can turn the crank, makes sure that you leave it at 90BTDC with number one piston rising!! Oily Link to comment Share on other sites More sharing options...
Ian Hayward Posted February 4, 2007 Author Share Posted February 4, 2007 I've made some liner clamps up and turned the engine over to reveal the full extent of the liner damage (250k jpg) here If you run your finger over it the surface fells slightly rough, I guess this needs a new liner and piston rings? Ian Link to comment Share on other sites More sharing options...
oilyhands Posted February 4, 2007 Share Posted February 4, 2007 Yup, it might pay you to replace the one liner, glaze bust the remainder and fit a new ringset. Oily Link to comment Share on other sites More sharing options...
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