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green96v4 V4 Mad
Canada 737 Posts | |
melle V4 Guru
United Kingdom 3830 Posts | Posted - 05 Aug 2019 : 17:05:52
| Listed are a cam and crankshaft gear, so with that kit you're missing the balance shaft gear (which is different from the camshaft gear). Not sure if Burton or anyone else sells that separately. Someone posted earlier on here that the V6 gears are an imperial pitch, whereas the V4 ones are metric (or the other way around); no idea if that's correct. Sounds strange to me, I would think the V6s are all-metric too. 25.4mm = 1" though.
Personally, I don't think metal timing gears are an upgrade for an otherwise standard V4.
www.saabv4.com | |
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green96v4 V4 Mad
Canada 737 Posts | Posted - 06 Aug 2019 : 13:06:41
| Thanks Melle - I've always worried the fibre gears are going to let go one day, (having seen many posts about them) most recently a guy 85kms away form the SAAB museum!!! never sure of the circumstances (are these engine tuned up, going too fast, etc, etc)
Maybe a quiet fan bearing will settle me back down ;) | |
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melle V4 Guru
United Kingdom 3830 Posts | Posted - 06 Aug 2019 : 13:38:54
| Although some balance shaft gears fail unexpectedly indeed, I think in general fibre timing gears are extremely reliable for normal road use. They definitely have a service life (so do all engine parts), but I suppose the majority that fail prior to their life expectancy, do so because of worn balance shaft bearings (which may be a result of poor lubrication or an over-tightened fan belt). On a standard engine that's been taken reasonable care of, I would expect a set to last about 80–100,000 miles, which coincides with a full engine overhaul interval.
You could fit an oil pressure light and periodically whip the fan belt off and have a wiggle on the balance shaft pulley to keep an eye on things. Otherwise, don't worry and enjoy driving your 96!
www.saabv4.com | |
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green96v4 V4 Mad
Canada 737 Posts | Posted - 08 Aug 2019 : 12:19:06
| Thanks for the (always) great advice - I'll take a look at the balance shaft pulley and see where's it's at - we did rebuild the engine when doing the restoration, but I'm not sure which bearings were replaced (I remember my father telling me the main bearings were fine, despite my "replace all serviceable parts" attitude!!) car had done 160K miles when I pulled it off the road
And, whilst you've convinced me to not bother with the steel gears, I saw a YouTube video somewhere of a V4 with steel gears being revved up and it (whilst noisier) sounded like it had a supercharger on it, was a cool noise!!! | |
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melle V4 Guru
United Kingdom 3830 Posts | Posted - 08 Aug 2019 : 13:09:30
| Link? I bet that wasn't an otherwise standard engine; I guess if you rev those up to 6-7k you'll at least bend a push rod or a valve stem. It would surprise me if your engine has managed to get to 160k miles on its first set of balance shaft bearings.
www.saabv4.com | |
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green96v4 V4 Mad
Canada 737 Posts | Posted - 08 Aug 2019 : 20:45:05
| https://www.facebook.com/stephen.broadhead.16/videos/1589613494390500/
hoping this works with Facebooks ever changing privacy policies!!
and yes, not sure on my engine's balance shaft bearings, I got the car in 1989 with around 80K miles on it, we didn't ever replace them when I was driving the car as a daily driver and I should trawl through the service bills to see if they were replaced before I owned it | |
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GeoffC V4 Mad
United Kingdom 507 Posts | Posted - 09 Aug 2019 : 19:41:49
| As Melle says if the balance shaft bearings are good and the fibre gears aren't damaged (ie.no chipped teeth) you shouldn't have a problem. I rallied my rebuilt engine, new bearings, big valve heads,high lift cam, uprated oil pump and 40 dfi weber with fibre gears for several years. It regularly saw 7000 rpm and occasionally more and was still going strong when it was sold. If you are going to 1815cc then maybe you need steel gears but otherwise I really wouldn't bother. Plus as mentioned they are really noisy. | |
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