Oh Bu**er another 2/6 failure?
07-21-2007, 02:00 PM
#61
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Correction:
In my hurry to post I have made a mistake. Cylinder 4 has the scouring, only very minor, you can only just feel it with your finger nail, really only one very fine line. Not really sure what to do about that.
On the crank, it is journal 8 that has spun the bearing. NOT 4 as I originally posted.
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases. Luckily no obvious heat damage to crank or con rods. Caught it in the nick of time, lucky for me I know my car very well, and it just didn't sound happy!
The plan is as follows:
Mark, thank you for your offer of an engine, may yet take you up on that, need to check shipping costs to me here in the UK.
Get prices for following:
Down to the machine shop on Monday and price having the 4/8 journal ground by (hopefully) 1st oversize, all other big ends to stay standard. Do not see the sense in grinding the other undamaged journals. So oversize shells on 4/8 only. Paul Anderson has kindly offered to help with a couple of oversize shells.
Have crank checked for true, and polished. Fit std mains, 3 sets std big ends and one set oversize.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
Not sure whether I need to replace the piston rings, all intact but the car has done 108K miles.
Full gasket set, rebuild engine........or ship in Mark's from the states.
All done for now, roll on Monday!
John
Shopping list:
Gasket set
Std main shells
Std big ends
Pair o/s big ends
Rings?
Repair to crank
Repair to heads
Mark's engine is looking good!
In my hurry to post I have made a mistake. Cylinder 4 has the scouring, only very minor, you can only just feel it with your finger nail, really only one very fine line. Not really sure what to do about that.
On the crank, it is journal 8 that has spun the bearing. NOT 4 as I originally posted.
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases. Luckily no obvious heat damage to crank or con rods. Caught it in the nick of time, lucky for me I know my car very well, and it just didn't sound happy!
The plan is as follows:
Mark, thank you for your offer of an engine, may yet take you up on that, need to check shipping costs to me here in the UK.
Get prices for following:
Down to the machine shop on Monday and price having the 4/8 journal ground by (hopefully) 1st oversize, all other big ends to stay standard. Do not see the sense in grinding the other undamaged journals. So oversize shells on 4/8 only. Paul Anderson has kindly offered to help with a couple of oversize shells.
Have crank checked for true, and polished. Fit std mains, 3 sets std big ends and one set oversize.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
Not sure whether I need to replace the piston rings, all intact but the car has done 108K miles.
Full gasket set, rebuild engine........or ship in Mark's from the states.
All done for now, roll on Monday!
John
Shopping list:
Gasket set
Std main shells
Std big ends
Pair o/s big ends
Rings?
Repair to crank
Repair to heads
Mark's engine is looking good!
07-21-2007, 04:01 PM
#64
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Hi guys
I have owned 4 928's and I know these cars very well. Engine out only takes about 4 hours, strip down maybe another 4. Rebuilding will take me a couple of days as I will clean and check everything and double check as I go.
Parts are the only thing that will slow me down..........
Yes I do all the work myself in my drive!
John
I have owned 4 928's and I know these cars very well. Engine out only takes about 4 hours, strip down maybe another 4. Rebuilding will take me a couple of days as I will clean and check everything and double check as I go.
Parts are the only thing that will slow me down..........
Yes I do all the work myself in my drive!
John
07-21-2007, 06:00 PM
#65
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Originally Posted by johnb
Engine out only takes about 4 hours, strip down maybe another 4.
You probably need one piston. If wall is goner then so is piston skirt too. I would investicate if its possible have final lapping done on all cylinders. This would make bores like brand new again. If lapping is possible then change rings also.
07-21-2007, 11:12 PM
#68
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Originally Posted by johnb
Correction:
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
Last edited by Bill Ball; 07-23-2007 at 02:53 PM.
07-22-2007, 06:59 AM
#69
I have never heard of a crank being ground on only one journal, wouldn't it be cheaper and better to get another crank and just fit new standard bearings? I would have thought the machine shop would charge you the same to do one journal as 4 due to setup time plus balance issues you may well face also.
It is pretty standard with the bearing failure to get that cylinder scoring, little bits of metal must get between the piston and wall. Nick is right about the scrapers reducing oil consumption, mine barely uses any, I have my second order in just now. Another engine on the way.
Greg
It is pretty standard with the bearing failure to get that cylinder scoring, little bits of metal must get between the piston and wall. Nick is right about the scrapers reducing oil consumption, mine barely uses any, I have my second order in just now. Another engine on the way.
Greg
07-22-2007, 08:54 AM
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Greg, thats a good point on the balance front, only wanted to have the damaged journal ground to preserve the others for future failure!
I will see what the machine shop say about just the one journal tomorrow.
The bore scouring is quite fine, basically just the one line which bairly catches your nail.
Would you think I would get away with it without touching it?
Regards
John
I will see what the machine shop say about just the one journal tomorrow.
The bore scouring is quite fine, basically just the one line which bairly catches your nail.
Would you think I would get away with it without touching it?
Regards
John
07-22-2007, 09:21 AM
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With thicker bearings the balance is only disturbed by the weight difference of the copper versus the steel.
I'd check with the machinists before worrying too much. They may be able to polish the crank sufficiently or weld on some fill so that the bearings stay stock sized.
BTW - there are no double-oversize bearings available. The PET and catalogs may list them but no one actually makes them. Then again, somewhere on God's green earth a set is gathering dust, I'd wager.
4 hours, eh? Air tools or fully manual?
I'd check with the machinists before worrying too much. They may be able to polish the crank sufficiently or weld on some fill so that the bearings stay stock sized.
BTW - there are no double-oversize bearings available. The PET and catalogs may list them but no one actually makes them. Then again, somewhere on God's green earth a set is gathering dust, I'd wager.
4 hours, eh? Air tools or fully manual?
07-22-2007, 10:25 AM
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I have some hand tools somewhere! 
Full auto mode where appropiate, I have an electric impact wrench, DO NOT use for assembly
Don't you hate those tyre guys who **** your wheels back on with an air gun, and then make a big song and dance about going round with a torque wrench to show your wheels are torqued to 130Nm, when infact the gun has already done them up to 300Nm! (Pet Hate)
John
Full auto mode where appropiate, I have an electric impact wrench, DO NOT use for assembly
Don't you hate those tyre guys who **** your wheels back on with an air gun, and then make a big song and dance about going round with a torque wrench to show your wheels are torqued to 130Nm, when infact the gun has already done them up to 300Nm! (Pet Hate)
John
07-22-2007, 01:20 PM
#73
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My engine is ready to go. the only expense will be shipping. trust me, as you may know if you have had 4 other 928 engines out of the car, whatever you are going to do, will exceed shipping costs to the US!!
This engine is new. all new seals, NEW rings, new bearings, and it is clean, not to mention it is just barely broken in. forget about all the labor, as you are pretty good at the assembly, but think about the costs for all the little stuff, as well as the shop labor to balance or modify the crank. those cylinder walls look toast too. I wouldnt put that engine back together with those scratches.
engine (almost) ready to go. need to wrap engine and ship it out .
take advantage of this. right now,its a perfect engine that scot or I will not ever have a use for.
Mk
This engine is new. all new seals, NEW rings, new bearings, and it is clean, not to mention it is just barely broken in. forget about all the labor, as you are pretty good at the assembly, but think about the costs for all the little stuff, as well as the shop labor to balance or modify the crank. those cylinder walls look toast too. I wouldnt put that engine back together with those scratches.
engine (almost) ready to go. need to wrap engine and ship it out .
take advantage of this. right now,its a perfect engine that scot or I will not ever have a use for.
Mk
Originally Posted by johnb
Correction:
In my hurry to post I have made a mistake. Cylinder 4 has the scouring, only very minor, you can only just feel it with your finger nail, really only one very fine line. Not really sure what to do about that.
On the crank, it is journal 8 that has spun the bearing. NOT 4 as I originally posted.
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases. Luckily no obvious heat damage to crank or con rods. Caught it in the nick of time, lucky for me I know my car very well, and it just didn't sound happy!
The plan is as follows:
Mark, thank you for your offer of an engine, may yet take you up on that, need to check shipping costs to me here in the UK.
Get prices for following:
Down to the machine shop on Monday and price having the 4/8 journal ground by (hopefully) 1st oversize, all other big ends to stay standard. Do not see the sense in grinding the other undamaged journals. So oversize shells on 4/8 only. Paul Anderson has kindly offered to help with a couple of oversize shells.
Have crank checked for true, and polished. Fit std mains, 3 sets std big ends and one set oversize.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
Not sure whether I need to replace the piston rings, all intact but the car has done 108K miles.
Full gasket set, rebuild engine........or ship in Mark's from the states.
All done for now, roll on Monday!
John
Shopping list:
Gasket set
Std main shells
Std big ends
Pair o/s big ends
Rings?
Repair to crank
Repair to heads
Mark's engine is looking good!
In my hurry to post I have made a mistake. Cylinder 4 has the scouring, only very minor, you can only just feel it with your finger nail, really only one very fine line. Not really sure what to do about that.
On the crank, it is journal 8 that has spun the bearing. NOT 4 as I originally posted.
I have just finnished flushing the entire oil way system out to remove all signs of any metal, jus rad left to do. Absolutely no sign of metal in heads or cam cases. Luckily no obvious heat damage to crank or con rods. Caught it in the nick of time, lucky for me I know my car very well, and it just didn't sound happy!
The plan is as follows:
Mark, thank you for your offer of an engine, may yet take you up on that, need to check shipping costs to me here in the UK.
Get prices for following:
Down to the machine shop on Monday and price having the 4/8 journal ground by (hopefully) 1st oversize, all other big ends to stay standard. Do not see the sense in grinding the other undamaged journals. So oversize shells on 4/8 only. Paul Anderson has kindly offered to help with a couple of oversize shells.
Have crank checked for true, and polished. Fit std mains, 3 sets std big ends and one set oversize.
Heads are a bit sad around the water ways, so need to investigate having them repaired WITHOUT having them being overall skimmed.
valves are all clean and tidy.will strip heads to replace valve stem seals, and lap valves as required.
Not sure whether I need to replace the piston rings, all intact but the car has done 108K miles.
Full gasket set, rebuild engine........or ship in Mark's from the states.
All done for now, roll on Monday!
John
Shopping list:
Gasket set
Std main shells
Std big ends
Pair o/s big ends
Rings?
Repair to crank
Repair to heads
Mark's engine is looking good!
07-22-2007, 01:26 PM
#74
Rennlist Member
do you have pictures of the pistons for us??? I dont think anyone has posted a picture of an actual M28-21 piston. Is it the deep cuts, like the earlier S euros, or the shallow cuts?
thanks,
Mk
thanks,
Mk
07-22-2007, 01:28 PM
#75
Rennlist Member
scot and I got his "engines" out in 3.5 hours, with hand tools (metwrench) however, it was both of us going at it, and it was on an engine stand at the end. going in was quite a bit longer!
MK
MK
Originally Posted by glork98
With thicker bearings the balance is only disturbed by the weight difference of the copper versus the steel.
I'd check with the machinists before worrying too much. They may be able to polish the crank sufficiently or weld on some fill so that the bearings stay stock sized.
BTW - there are no double-oversize bearings available. The PET and catalogs may list them but no one actually makes them. Then again, somewhere on God's green earth a set is gathering dust, I'd wager.
4 hours, eh? Air tools or fully manual?
I'd check with the machinists before worrying too much. They may be able to polish the crank sufficiently or weld on some fill so that the bearings stay stock sized.
BTW - there are no double-oversize bearings available. The PET and catalogs may list them but no one actually makes them. Then again, somewhere on God's green earth a set is gathering dust, I'd wager.
4 hours, eh? Air tools or fully manual?