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Bellamachinna
Alfa 33
Joined: 12 May 2003
Posts: 352
Location: Lisbon-Portugal
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 Posted: Sat Mar 03, 2012 2:06 am Post subject: Crankshaft problems (1.7 16v) |
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Hi all...
It´s been a while since my last post... 
Well my car crankshaft was heavily scratched after being chewed by the connecting rod shell of cylinder #4.
Have not yet took the engine out but already removed the oil sump to check the damage.
My first option was to find a "new engine". The problem is, that i can`t find none.
Here in Portugal, the 33`s are a rare sight, and all car`s vanished even from
dismantlers.
Is the crank reusable???
I`ve read on the manual, that the crank is subjected to a special treatment and can not be reground.
Is this true?
Or can it be reused and used with oversize shell`s?
Thanks in advance
P.Camilo
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Brit01
Gold Cloverleaf
Joined: 24 May 2010
Posts: 665
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| Posted: Sun Mar 04, 2012 3:51 pm Post subject: |
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The crank can be re-ground but MUST be re-nitrided after. This is expensive and not recommended as hair-line cranks and warping is a risk when re-heating to treat it.
Can you not find a good used one?
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Brit01
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Bellamachinna
Alfa 33
Joined: 12 May 2003
Posts: 352
Location: Lisbon-Portugal
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| Posted: Sun Mar 04, 2012 10:17 pm Post subject: |
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Thanks for your reply...
| Quote: |
| Can you not find a good used one? |
Unfortunately no. I`ve even searched for engines from S2 1.7Q.V.`s , 1.7IE`s, and 145/6 1.6, that share the same crankshaft.(this were the only cars that were sold here as well as the 145/6 & 33 16v)
Can`t find none.
Seems that this type of car is ancient history to dismantlers... 
The only one that i found, was in worse state than mine.
So my last port of call, will be regrind the existing crank. However seems that
if i will have to re-nitrided her again, there will be no one to do it
What make of shell bearings, should i opt for? Seems to me that original ones are very weak, as i`ve seen so many engines let go, by them...
Thanks
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Brit01
Gold Cloverleaf
Joined: 24 May 2010
Posts: 665
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| Posted: Mon Mar 05, 2012 2:05 pm Post subject: |
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Shell bearings are very good from Glyco/Federal Mogul.
But original ones IMO are not weak (where did you hear this?). They are available from various sources.
If you have good crank journals and good oil with the correct pressure either original shells or aftermarket ones are equally as good.
By the way after a re-grind the crank MUST be re-treated otherwise it will erode and destroy the new bearings in no time (and other parts).
The hardened surface is only about 0.008 inches thick. The smallest undersize is 0.010 inches.
I guess buying from another country is not an option due to the weight.
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Bellamachinna
Alfa 33
Joined: 12 May 2003
Posts: 352
Location: Lisbon-Portugal
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| Posted: Mon Mar 05, 2012 10:43 pm Post subject: |
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| But original ones IMO are not weak (where did you hear this?). |
I didnt just heard... I know from several engines (not only 1.7 but also 1.5 and one 1.3), that "died" from shell bearings failure.
Can be motivated by poor maintenance, but they seem to be the weak link.
| Quote: |
| I guess buying from another country is not an option due to the weight. |
Maybe! Buying fom outside EU is out of the question due to weight and customs taxes, but from inside EU i can consider it.
Seems a better option than regrind and re-coat. Anyway, i cant find any place were to re-coat, so it will always be a "bad job"
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Brit01
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Joined: 24 May 2010
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| Posted: Mon Mar 05, 2012 10:59 pm Post subject: |
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I know from several engines (not only 1.7 but also 1.5 and one 1.3), that "died" from shell bearings failure |
Shell bearing damage/wear is generally, if not always, due to bad maintenance/wrong oil/low pressure/worn pump/debris in the engine from a broken tappet or something like that.
Or cold start ups and revving hard before the oil has warmed up and lubricated the journals well.
Yes they wear down over time but not fail.
If you have good lubrication there should be no metal to metal contact and always a good layer of oil between the surfaces.
Oil accumulators are good for start ups to prevent that initial dry period.
80% of wear occurs on start ups.
non-return valves on the oil filters help with the boxer engines.
I just replaced my shells, all rod shells and 1 main shell. It had the originals after 24 years and were scratched due to a broken tappet and it's debris. They didn't fail but I had low oil pressure.
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S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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