Car Forum / Subaru Cars / May 2004
Outback H6 Aluminum Crankshaft
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G.R. Aydelotte - 25 May 2004 23:43 GMT Well, I thought I had my wife convinced of an 05 outback, but she drove a 2001 LL Bean H6, and she likes it. I've been reading on these engines and came across a reference from a Subaru site that this engine has an aluminum crankshaft. Is this good, bad or indifferent? I did notice it had a timing chain vs belt. Engine is plenty powerful for me, and the leather interior doesn't hurt etc.
Gregg
Jim Stewart - 26 May 2004 00:03 GMT > Well, I thought I had my wife convinced of an 05 outback, but she > drove a 2001 LL Bean H6, and she likes it. I've been reading on these > engines and came across a reference from a Subaru site that this > engine has an aluminum crankshaft. Is this good, bad or indifferent? I > did notice it had a timing chain vs belt. Engine is plenty powerful > for me, and the leather interior doesn't hurt etc. In my humble opinion, the timing chain is a good thing.
I have never in my life heard of an AL crankshaft in *any* internal combustion engine. I would have to seriously doubt the veracity of this data. Find me a link.
Florian Feuser /FFF/ - 26 May 2004 03:03 GMT >> Well, I thought I had my wife convinced of an 05 outback, but she >> drove a 2001 LL Bean H6, and she likes it. I've been reading on these [quoted text clipped - 9 lines] > to seriously doubt the veracity of this data. Find > me a link. Aluminum crank pulley maybe? but then, not with a timing *chain*... Which, by the way isn't infallible either. Plus, it adds mass, sort of like a flywheel. Isn't that why they put a timing *belt* into the Lamborghini Diablo?
florian
Jim Stewart - 26 May 2004 02:59 GMT >>>Well, I thought I had my wife convinced of an 05 outback, but she >>>drove a 2001 LL Bean H6, and she likes it. I've been reading on these [quoted text clipped - 13 lines] > Which, by the way isn't infallible either. Plus, it adds mass, sort of like a > flywheel. Isn't that why they put a timing *belt* into the Lamborghini Diablo? There's really nothing wrong with either one. I'd just give a chain a slight preference over a belt because the chain does not have a changeout schedule.
As the the crankshaft, I'm guessing they meant crankcase.
oothlagre - 26 May 2004 08:53 GMT Not just that, but it adds to engine noise as well. True, chains are not indestructible. The Nissan Sentra 4cyl. models have a chain that goes out around 100k. My mechanic said labor for timing chain on that model is 13 hours. Motor swap is only 7.........
Henry
> >> Well, I thought I had my wife convinced of an 05 outback, but she > >> drove a 2001 LL Bean H6, and she likes it. I've been reading on these [quoted text clipped - 15 lines] > > florian G.R. Aydelotte - 26 May 2004 18:34 GMT > > Well, I thought I had my wife convinced of an 05 outback, but she > > drove a 2001 LL Bean H6, and she likes it. I've been reading on these [quoted text clipped - 9 lines] > to seriously doubt the veracity of this data. Find > me a link. Well, I hadn't either; I have misread the specs athttp://www.cars101.com/outback2001.html which say aluminum crankcase not crankshaft. My apologies, I'll double check next time.
Gregg
Rick Courtright - 26 May 2004 17:23 GMT > engines and came across a reference from a Subaru site that this > engine has an aluminum crankshaft. Is this good, bad or indifferent? I > did notice it had a timing chain vs belt. Engine is plenty powerful Aluminum crankshaft? Not saying it's not possible, but I've never seen or heard of one. Sounds like a recipe for short life if true. Cranks experience a lot of flex, and aluminum's not the best material for that type of app. Aluminum "crankcase" as someone suggested sounds more like it.
On timing chains--properly designed and lubricated, chains should be much longer lived than belts. Poorly designed (particularly in the lubrication department) they'll fail early like the Nissan example. BTW, 100k on a chain is absolutely criminal in my book--they should be good for double that or more. Sounds like a lube problem?
Subaru's timing belt life has always seemed a bit short to me, but my first experience with timing belts, on the first water-cooled VWs, might have spoiled me. ISTR seeing something about steel cord in the original VW belts. I only know there wasn't a recommended change interval in the book at the time, and I got 190k miles on one of mine. Even if I had to change a belt, it was only a 30 minute job, not the exercise my Subie belts are. My guess is Subie went with a chain on the H6 cuz of the longevity issue?
Rick
Jim Stewart - 26 May 2004 18:42 GMT > VW belts. I only know there wasn't a recommended change interval in the > book at the time, and I got 190k miles on one of mine. Even if I had to > change a belt, it was only a 30 minute job, not the exercise my Subie > belts are. My guess is Subie went with a chain on the H6 cuz of the > longevity issue? I'm just speculating here.
If you look at the front of the H6, you can see that they were able to shave at least an inch, maybe 2 off of the overall length of the engine by going to a chain. I suspect that this was a *big deal* to get the engine to fit. They would have probably had to use a wider belt to handle the load of 2 extra cylinders. I suspect that when they looked at the big picture of shortening the engine, removing the scheduled replacement and loosing 4 potentially leaky camshaft seals the chain started to look pretty good.
oothlagre - 26 May 2004 21:07 GMT Well, in defense of Subaru there are models with shall we say whimpier timing belts. My brother has a '96 Hyundai and the change interval on those is 60,000 miles mandatory. They can break within 10,000 or so of that limit and bend the valves from here to never. I looked at one once that needed and engine because of that very issue. I called a dealer service department to see what was involved and he gave me the rundown on it.
So, 105k on a Subie looks better to me. In fact, my dad just got a '95 Impreza with 150k and no belt change yet. I plan on doing that one this weekend.
Henry
> > engines and came across a reference from a Subaru site that this > > engine has an aluminum crankshaft. Is this good, bad or indifferent? I [quoted text clipped - 22 lines] > > Rick Skweezieweezie - 26 May 2004 23:02 GMT The H-6 uses TWO chains, slightly offset. Passenger side driven directly by the crank, Driver's side from an idler pulley driven from the passenger side chain.
John M. - 27 May 2004 00:29 GMT > Well, I thought I had my wife convinced of an 05 outback, but she > drove a 2001 LL Bean H6, and she likes it. I've been reading on these > engines and came across a reference from a Subaru site that this > engine has an aluminum crankshaft. Is this good, bad or indifferent? I > did notice it had a timing chain vs belt. Engine is plenty powerful > for me, and the leather interior doesn't hurt etc. To some of the other posts I'll add this: 1 - The chain definitely was a factor in reducing the length of the engine. 2 - The chains are designed to last the life of the engine, given that proper engine oil maintenance happens. 3 - Their are 59 (!) bolts of four different lengths that attach the front chain cover to the rear. It indeed would be a big job to replace the chains. Of more concern would be any water pump/oil pump maintenance that might need to occur. Though it looks as if only the RH chain would need to be loosened (?) to get the pump out, I would dread removing all of those bolts and getting them back in the right spots. 4 - There are oil ports that spray engine oil directly on each chain to ensure it receives the proper lubrication. 5 - The LH chain has 148 links, the RH 134. 6 - The oil pump is driven from the RH chain, as is the water pump 7 - I don't know how the noise will work out in the long run, but I know the cases were designed to minimize chain noise. I haven't notices any difference from the belt driving cams. 8 - Overall, I would not feel very comfortable doing a chain replacement... I've had no problems doing belt replacements. I'm counting on the long life, and believe that will be the case as with all-things-Subaru. John
oothlagre - 27 May 2004 18:37 GMT I hope the water pump doesn't leak into the oil if it fails. That's an awful lot of labor should one of the pumps fail. Has anyone actually had a water pump fail on a Subaru? I am going to replace mine when I do my timing belt.
Henry
> > Well, I thought I had my wife convinced of an 05 outback, but she > > drove a 2001 LL Bean H6, and she likes it. I've been reading on these [quoted text clipped - 24 lines] > and believe that will be the case as with all-things-Subaru. > John John M. - 28 May 2004 02:55 GMT > I hope the water pump doesn't leak into the oil if it fails. That's an awful > lot of labor should one of the pumps fail. Has anyone actually had a water > pump fail on a Subaru? I am going to replace mine when I do my timing belt. Henry, You are right; I guess it would be possible to get water into the oil... not good. I have never had a water pump go out (a PS pump, but not water pump). However, I did replace one when I had the opportunity during a timing belt change. John
Rick Courtright - 28 May 2004 04:47 GMT > lot of labor should one of the pumps fail. Has anyone actually had a water > pump fail on a Subaru? I am going to replace mine when I do my timing belt. Develop a slight leak? Yes. Outright fail (bearing seizure, impeller lets go with fan digging into radiator type stuff)? No.
Rick
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