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Engine Bearings Gone 20Seh


dynamytedan
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its been a while but im back again after many 1000s of miles of happy manta motoring .

just fitted all new shocks and springs ,balanced the carbs , oil change , speedo cable , got the rear shocks adjusted just right , got rid of the mushrooms coming out the carpet , washed it ,filled the tank .... went to Margate and back 220miles , even went on the woolwich ferry without breaking down or catching fire . it was going great .next day went the 800 yards to work and back ,lazy yeah i know , bearing failed as i pulled into the drive .

for some reason im not that upset about it , now it could have gone at 90mph on the motorway but it didnt , it saw me good all the way home ... gotta love the ol manta for that . and gotta fix it so it can do it again one day :-)

anyway , if the heavy knocking didnt give it away , with no4 not firing and being able to push the piston down through the plug hole with a screw driver , also having little or no compression (thumb test) its more that likely a big end bearing spun with some valve damage probably .

so its had it .

im trying to weigh up my options : fix this engine ... regrind crank all new bearings and bolts , new head set , 2 valves . am i missing anything?

or get another engine to fit shells rings and an oil pump etc to that . is there one for sale ?

i dont mind paying out for a good engine already made up , i dont want to go bottom dollar so repair may be within my budget also .

any ideas or suggestions welcome

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thanks for the suggestions , things got mooving today alot quicker than i expected . no work booked in so had all day to fathom mine out .

so , took engine out , stripped off ancilaries , once the head was off some damage was evedent .

all sorts of moovement in piston no4 , damage all over the piston and head from a foriegn body !!!

took out the piston and GOOD GRIEF ! its well buggered , huge cracks all through its skirt , never seen anything like it .

no.4 big end bearing seems good and theres no crank damage (just normal wear as you might expect)

looking closely at the head/ piston crown damage (ill post a few pics soon) its clear that a screw has fallen inside .

so remooved the air filter from the carbs and sure enough 1 of the screws was loose and 6 were tight and one missing .

(a few weeks back i payed a bike mechanic to use his syringes to balance my carbs , he took off the air filter and put it back after , looks like ive got a bone to pick there....)

took it all down to the engineers .spoke to them where i was hypnotized and dazzled by engineering jargon into parting with all my cash ...no no they are a good family run buisiness ive delt with for 10 years and they bent over backwards to help me out as much as possible .

took it all back to the garage . took out the crank , valves and everything . back to the engineers and priced it all up .

all new big end and main bearings ,all new rings , honed , crank not ground but cleaned up on a belt? ,new no4 piston ,head skim , all the gaskets bolts seals etc .

itll be ready tomorrow afternoon in pieces for me to re-assemble .

by then id like to have a new clutch ,cambelt ,water pump ,rubber sumpgasket allready to go on .

should be driving again by the end of saturday .

ive probably gone a bit too far with the repairs in the way of bearings,rings and honing , i just want it to be the best it can be so while im there...

still have one concern that the CR will still be too high and i should use a thicker head gasket , perhaps high cr wont give the rings a chance to bed in , causing the bores to become mirrored like they are now . but its all mooving so fast i cant see me being able to get a thicker gasket quick enough ?

that might have to wait till later ....

back tomorow

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CR wise you're just worrying.

Think i tend to agree. The comp ratio won't stop it bedding in, using the wrong oil will!!! The way engines are machined nowadays the rings are virtually bedded in after 20 mins of running, don't cane it for a few hundred miles and everything should be fine.

Chris

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more developments today with the engineers ....

bottom end...

turns out the bores are worn 4 thou ? they said thats more than you can get away with .

so its now getting 4 new pistons,rings a rebore , new mains and big ends , big end bolts .

engineers will assemble it aswell for free :-) , and heavyly discounted the boring and pistons .

head...

after expressing my concerns of high cr ,over skimming,heavy breathing ,slight ignition timing issues and thick headgaskets he did a bit more investigating .

as it is the guides have some slight play and 6 threads need replacing and the skimming done again .

it turned out my head has had 1.2 mm shaved off it , they tell me thats alot, and so is a thicker gasket . they dont reccomend 2 put together either .

later on they found a good second hand head to skim and put in , not polished or ported like the old one but just good and standard .

now all thats just saved me probably £400 easy and obviously taken work/money away from themselves .

so im extreemly grateful for that .

and now im feeling alot better about it all , no more worrying about CR .

there was some talk of a running in oil that you cant get easyly and the way in which you drive it during that period . im still very hazey about that ?

has anyone got more details of what oil and how to run in properly?

i did try to get a recon engine this morning starting with vauxhalls ,almost everything that age is NLS no surprise . they gave me the number of a company that had new old stock , HS solutions ?? they didnt have anything either .

then the engineer called and explained about the bores ,so im going down that road (all the above)

totally lost track of how much all this is going to cost, its gone up down, left a bit and round in a circle .

safe to say its going to be alot .

got myself a new LUK calibra turbo(c20let) clutch 14 splines and the cover holes line up ,need to try the bearing tomorrow but looks very similar to the manta one .

anyone know the vauxhall part number of the rubber sump gasket ?

Edited by dynamytedan
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more developments today with the engineers ....

bottom end...

turns out the bores are worn 4 thou ? they said thats more than you can get away with .

so its now getting 4 new pistons,rings a rebore , new mains and big ends , big end bolts .

engineers will assemble it aswell for free :-) , and heavyly discounted the boring and pistons .

head...

after expressing my concerns of high cr ,over skimming,heavy breathing ,slight ignition timing issues and thick headgaskets he did a bit more investigating .

as it is the guides have some slight play and 6 threads need replacing and the skimming done again .

it turned out my head has had 1.2 mm shaved off it , they tell me thats alot, and so is a thicker gasket . they dont reccomend 2 put together either .

later on they found a good second hand head to skim and put in , not polished or ported like the old one but just good and standard .

now all thats just saved me probably £400 easy and obviously taken work/money away from themselves .

so im extreemly grateful for that .

and now im feeling alot better about it all , no more worrying about CR .

there was some talk of a running in oil that you cant get easyly and the way in which you drive it during that period . im still very hazey about that ?

has anyone got more details of what oil and how to run in properly?

i did try to get a recon engine this morning starting with vauxhalls ,almost everything that age is NLS no surprise . they gave me the number of a company that had new old stock , HS solutions ?? they didnt have anything either .

then the engineer called and explained about the bores ,so im going down that road (all the above)

totally lost track of how much all this is going to cost, its gone up down, left a bit and round in a circle .

safe to say its going to be alot .

got myself a new LUK calibra turbo(c20let) clutch 14 splines and the cover holes line up ,need to try the bearing tomorrow but looks very similar to the manta one .

anyone know the vauxhall part number of the rubber sump gasket ?

Just use cheap 20/50 to run in nothing fancy and definately no synthetic oil. Change oil and filter after 400 miles (ish)

Cheers

Chris

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when i mentioned using two head gaskets you use a 2mm piece of stainless between them that has been cut out same as gasket.

use the cork gasket with the steel inserts so you cannot over tighten it. rubber ones squeeze out if you tighten them down uneven.

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block came back yesterday .

rebored , 4 pistons , rings , bearings , polished crank , threads made good . replacement head , gaskets bearings headbolts . everything i need .... except engine assembly lube , flywheel bolts , big end bolts ,running in oil , which should all arrive tomorrow .

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the guy responsible for the screw has not yet appeared at teh garage , hes bound to turn up sooner or later . but honestly i dont hold out much hope of getting a penny out of him .

i know he has a tool box with snap on tools , so some of that would be alright insted of £ .

ill persue it once ive got it all back together again .

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  • 2 weeks later...

so its all back in now and running in has begun , started up very easyly which must be a good sign , one or two other immidiate problems to overcome still...

developed a starting problem when hot . might be down to a bad connection or the big red wire no good anymore . worst case i need a new starter .

tackled the clutch cable and pivot adjustments today , not a 100% success . new cable , adjsuted pivot and needed to put a thick washer on the cable .... seems to work , new clutch feels great . really smooth to engage and much stronger than the last one .

so i guess thats that sorted ....almost...

done only 20 miles so far and it really motors along well , , sounds and pulls smoother easyer . so far so good . kept up with my mates yamaha dt125 and even left him behind up a hill into a strong headwind lol.

need to get the ol 1800 distributor re-curved , ill try and send that off this week to H&H ignition solutions .

need 2 new flexi brake hoses and a good bleed .

throttle cable needs .?? somthing different/tidy done to it .

breather pipes ? dont know what to do with those , might buy a fancy chrome jobbie for them to go into .

will eventually need a rolling road once all the running in is over with .

and im sure it wont end there ....

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Edited by dynamytedan
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