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[export001]

hi all
is it true that saab turbo rods are forged and better than the vauxhall ones? for both 3.0 engines i know that the saab engine had a low boost turbo fitted to the rear manifold but....or is that just some pish about the rods? lol

[2woody]

Yes, I think the Saab turbo rods are forged, making them indeed better than Omega rods.

it's just a shame it's a completely different engine really.

The Saab 2.8 V6 is the GM "high-feature" engine, a new 60-degree aluminium-block engine

The Omega V6 is a 54-degree iron-block unit, making it unique.

[Andy H]

2woody, I don't think you have answered the OP's question.

Just after SAAB were absorbed into the GM empire (and before GM developed the 2.8t) SAAB needed a flagship engine to go in the 9-5 turbo. It was probably the result of a marketing need rather than an engineering decision.

They fitted a small turbo (driven by only one exhaust manifold) to boost the low & midrange.

I haven't read of any conrod failures in 3.0 Omegas but there are numerous threads about noisy big end bearings, possibly caused by inadequate lubrication or maybe the bearings are just not big enough?

It would be interesting to know exactly what the differences are between the N/A 3.0 bottom end used in the Omega and the low boost turbo 3.0 used in the SAAB 9-5.

[GmasterT]

They're the same apart from the Saab rids have a small oil oil at the bottom iirc.

Afaik rods on the 3.0s are fine with torque, it's revs they don't like

[2woody]

I reckon conservatively that most Omega V6s are in some big-end trouble. It's usually caused by high oil temperature, which is a knock-on from the high "normal" coolant temperature which is standard.

[Andy H]

I reckon conservatively that most Omega V6s are in some big-end trouble. It's usually caused by high oil temperature, which is a knock-on from the high "normal" coolant temperature which is standard.

Interesting theory. I have been running my V6s on fully synthetic for years and they seem to thrive on it

[Andy H]

All modern cars have to run hot to aid emissions so that isn't really a good excuse.

V engines are shorter than the equivalent straight engine and it is a struggle to find space for the main bearings. I suspect that it is the main bearings that are under most stress. They wear first and then the big ends suffer due to the loss of oil pressure through the slack main bearings

[2woody]

have changed maybe 20 sets of big ends now for various people. Never found any worn mains yet.

It's true, emissions compliance has forced mass coolant temperatures upwards and in Omega B, this combined with strainer compromise and non-synthetic leaves hardly any headroom for oil temperatures.

With synthetic inside, this problem is a lot less likely to happen.