Is this the best that GM can do?
05-23-2003, 07:06 AM
#17
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Join Date: Aug 2001
Location: Michigan's left coast
Posts: 2,405
Originally posted by guionM
Would there be any disapointment?
Would there be any disapointment?
I'd love to see this engine in front of a stronger tranmission and driving the correct set of wheels. It'd be a worthy successor to the old turbo Regals, IMO.
05-25-2003, 01:25 AM
#18
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Join Date: Nov 2002
Posts: 42
Originally posted by R377
I knew I'd get a reply like this.
I don't really want to sit here and debate the merits of OHV vs. OHC because they each have their attributes and their place in the market. There's two main problems with OHV: 1) they're perceived as being yester-tech; and 2) despite their good numbers, there's no way you can compare the refinement of the two architectures (think Cav's 2.2 OHV vs. Ecotec; 3800 vs Honda V6; LS1 vs. Northstar). In a time where pretty much every new car will go 200,000 miles and start on the first twist of the key, consumers are placing more emphasis on their wants instead of their needs, and not many people want to drive an engine that reminds them of a Massey-Ferguson.
I knew I'd get a reply like this.
I don't really want to sit here and debate the merits of OHV vs. OHC because they each have their attributes and their place in the market. There's two main problems with OHV: 1) they're perceived as being yester-tech; and 2) despite their good numbers, there's no way you can compare the refinement of the two architectures (think Cav's 2.2 OHV vs. Ecotec; 3800 vs Honda V6; LS1 vs. Northstar). In a time where pretty much every new car will go 200,000 miles and start on the first twist of the key, consumers are placing more emphasis on their wants instead of their needs, and not many people want to drive an engine that reminds them of a Massey-Ferguson.
Come again? High compression is virtually almost always more efficient than low compression. This is the primarly reason that diesels have better fuel economy. The reason that we're not all running around with 14:1 compression is fuel quality, and emissions (higher combustion temps = more NOx emissions, also a characteristic of diesels).
Last edited by fyrhwk1; 05-25-2003 at 01:30 AM.
05-25-2003, 07:38 AM
#19
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Location: Ontario
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Originally posted by fyrhwk1
I don't suppose anyone has the dynamic comp ratios of both the 3800 NA and SC motor?
I don't suppose anyone has the dynamic comp ratios of both the 3800 NA and SC motor?
05-25-2003, 08:30 PM
#20
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Join Date: Nov 2002
Posts: 42
Originally posted by R377
IIRC, the 3800 SC uses a version of the Miller cycle where the intake valve stays open partway through the compression stroke to reduce cylinder filling. That would mean the effective compression ratio is less than the n/a engine while maintaining the same expansion ratio (important for power and efficiency).
IIRC, the 3800 SC uses a version of the Miller cycle where the intake valve stays open partway through the compression stroke to reduce cylinder filling. That would mean the effective compression ratio is less than the n/a engine while maintaining the same expansion ratio (important for power and efficiency).
05-26-2003, 01:26 AM
#21
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Join Date: Jun 1999
Location: OR
Posts: 2,368
I read whats limiting the power is the transaxle.. For some reason they didn't want to use the stronger ones from Cadillac..
Anyways, these cars are more or less placeholders till the next models...
Personally, depenidng on the economy and how things pan out, I can see myself, $-wise, buying a new car around 2005-2007.. Hopefully by then I won't be saying "Is this the best that GM can do?"
Anyways, these cars are more or less placeholders till the next models...
Personally, depenidng on the economy and how things pan out, I can see myself, $-wise, buying a new car around 2005-2007.. Hopefully by then I won't be saying "Is this the best that GM can do?"
05-26-2003, 05:37 AM
#22
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Location: Ontario
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Originally posted by fyrhwk1
Are you sure? not that i'm saying you're wrong, but I can't picture them purposely allowing fuel to blow back out of the intake valve, plus with the blower the engine would be working against itself, wouldn't simply holding the exhaust valve open longer do the same result? although they'd probably have issues with emissions if they do that...
Are you sure? not that i'm saying you're wrong, but I can't picture them purposely allowing fuel to blow back out of the intake valve, plus with the blower the engine would be working against itself, wouldn't simply holding the exhaust valve open longer do the same result? although they'd probably have issues with emissions if they do that...
The idea of holding the intake valve open longer is to reduce cylinder filling and therefore effectively reduce the compression ratio. But since the rest of the valve timing is the same, the expansion ratio is still the same, and that's what's important to power and efficiency.
The Miller cylce has been used on other s/c engines such as the Mazda Milenia.
Last edited by R377; 10-30-2004 at 07:03 AM.