Help identifying bits of my engine

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MarkTurbo

Well-Known Member
And i do mean bits :lol: My car developed a slight rattle after castle combe sprint on saturday, i thought it sounded like it was coming from the top of the engine but found nothing. So thinking it could be the start of a big end rattle i've just dropped the sump to find these in the strainer on the oil pick up. The lumps of metal look like brass but i can't think where that clip comes from?

 
campbellju

campbellju

Moderators
Staff member
I'll start the offers. Is the clip from the chain tensioner? I remember something similar looking when fitting it?
 
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takumigtir

New Member
They are the circlips that hold the bearings in place for the turbo shaft on a t28 and the other bits are a broken up thrust bearing
 
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MarkTurbo

Well-Known Member
takumigtir said:
They are the circlips that hold the bearings in place for the turbo shaft on a t28 and the other bits are a broken up thrust bearing
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Just googled T28 thrust bearings and your right. The thing is i've had a Gt series turbo on my car for ages now and the only time i've had a T28 fail on my car was at least a couple years ago now. Those bits must have been in the engine for ages :shock:
 
red reading

red reading

Active Member
I'd worry about how much of it thats not there has gone thru the oil pump! i have seen this happen on a ball bearing turbo too and that KO'd my mates engine as the broken up bearing parts were small enough to get thru the oil strainer.
 
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MarkTurbo

Well-Known Member
Yeah i think realistically the engine is going to have to come apart now just to make sure theres nothing else hiding anywhere which is a pain as Wiscombe hillclimb is only just over 3 weeks away :doh: I've just got the main part of the sump off so will pull all the big end caps off in a minute and see if theres any damage.

Not sure now whether to try and get hold of another bottom end to chuck in it for the minute to finish off the last 3 or 4 events of the year and build this one back up with forged pistons etc over the winter or try and get this one back up and running in the next few weeks :?
 
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takumigtir

New Member
I personally would do as you said and whip off the main bearing caps quickly to see how the bearings are obviousily if you find one of these with damage i would strip the main caps off as the debris will always pass through them before being fed to bigend journals, strip the oil pump off to and see if the gears are scored this will tell you first hand aswell if any bits were small enough to get through the strainer. as for the rattle have you checked if the oil sprayers are all clear and not blocked that lubricate the cams?? maybe you were hearing a big end starting to go either, did you pull off each ht lead to see if it goes away ??
 
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MarkTurbo

Well-Known Member
Yes the oil spray bars to the camshafts are all working fine as i had the rocker cover off last night to check the rocker arms were all ok. Also theres been no loss in oil pressure.

Just pulled all the big end caps off and 3&4 are damaged, the crank dosen't look too bad though apart from a slight mark on number 4 but i guess i won't know for sure until i get it off and measured.

No1





No2&3





No4







whytie said:
How long do you think they were in your engine for?
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Must be 2 years + how no damage has occured until now i don't know :lol:
 
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pulsarboby

Guest
you may be lucky mark and get away with a new set of shells seeing as theyve not spun.
oil pressure doesnt always drop with bigend probs, check the oil squirters to the pistons also as there a bitch for blocking up which can create misleading oil pressure also the retaining bolts that hold them in situ can seize up which once again causes false raised oil pressure.
just a few bits for you to keep you busy lol
 
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MarkTurbo

Well-Known Member
Thanks for the replies everyone.

So providing the crank measures ok i'm looking at new oil pump gears, and new main + big end bearings at the moment?

Can our cranks be reground without causing problems as i've heard conflicting things about it? Some people say its fine but others say the cranks are nitrided and as soon as you grind them they're scrap as it removes the surface hardening?
 
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pulsarboby

Guest
others will disagree with me but i personally will not use a ground crank especially with power your now running.
getting the main journals ground isnt a problem as they are a non thrust just rotational part but bigends are a different kettle of fish as they are under a hell of a lot of load when turbo kicks in.
you can get the shaft re-nitrided after being ground but by the time youve paid for all that you would be best off to source another good shaft.

also check the casing of oil pump not just the rotors, if the mating faces are scored then youll need a complete new oil pump and they are very difficult to get hold of at the moment.
hopefully you may get away lightly
 
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MarkTurbo

Well-Known Member
I've got another good oil pump so that won't be a problem. I've heard a few things about engine failures after crank grinds so fingers crossed I've got away with it by catching it early.

I'll get the engine out at the weekend.
 
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takumigtir

New Member
As bob said :) i personnally am going to be using cosworth but if i wasnt using them i would use the ACL race series beaings, if your measuring your crank etc might be worth you working out what theoretical oil clearance you have by measuring new bearings etc just so you know where abouts your running on the clearance side of things or you can position the beaings to suit, thats only me though.What power are you running ??
 
red reading

red reading

Active Member
anything over .25 grind will take the nitriding off, preferable is no grind at all, mark if the crank is good use acl's (white metal) as they absorb material and take more abuse than nissan ones (aluminium).............i put a thing on the tech forum ages ago about when i met the main man from vandervell bearings and what i learnt from him.
 
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