[Z06] A little info on LS7
06-28-2005, 09:24 PM
#1
Racer
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A little info on LS7
In talking with some sources, be prepaired for the engine being a little louder than your standard LS2 engine. The LS7 has shorter piston/skirts, allowing the piston to move around some and cause some extra noise. Just a pre warning, after all this is a "detuned" race engine on the street. 
06-28-2005, 09:29 PM
#3
Racer
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Unfortunatly I didnt get into that with the person. Mostly talked about even short shifting the engine at 4000 or so it was one of the most incrediable factory cars he ever drove.
06-28-2005, 09:58 PM
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Everything says cast hyperutetic with big valve reliefs cut in the top (LS2 has flat-tops).
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
Last edited by yelloz06; 06-28-2005 at 10:09 PM.
06-28-2005, 11:42 PM
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St. Jude Donor '09
Originally Posted by yelloz06
Everything says cast hyperutetic with big valve reliefs cut in the top (LS2 has flat-tops).
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
They are definately cast "Eutectic" not Hypereutectic pistons. The amount of silicon in the aluminum determines the type.
Aluminum silicon alloys used in pistons fall into three major categories: eutectic, hypoeutectic and hypereutectic.
Aluminum can only take 12% silicon before it is saturated, which is the eutectic state. Hypereutectic is usually about 4% more than saturation, or about 16% silicon, and that will precipitate out as silicon crystals. The silicon makes the pistons more heat resistant in the crown area, better resistance to seizure, and lighter weight.
My experience has been very negative with hyperutectic pistons in the LS6 under boost, and wish that GM would have gone the forged 2618T6 piston material.
The new Eutectic pistons will have no silicon crystals and will have between 11% to 12% silicon.
Jim Hall
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06-29-2005, 12:17 AM
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Originally Posted by yelloz06
The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
06-29-2005, 05:35 AM
#7
Originally Posted by dexter
No way - you'd think GM would have learned by now how determined an idiot can be. My prediction is that within 6 months of the delivery of the first Z06, you'll hear a story on this forum about a catastrophic engine failure where the causal event is the PF 44 filter blowing off the PF 48 threads, where it was mistakenly installed by some monkey who couldn't be bothered to read the instructions.
06-30-2005, 10:21 PM
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Originally Posted by Jim Hall
They are definately cast "Eutectic" not Hypereutectic pistons.
The new Eutectic pistons will have no silicon crystals and will have between 11% to 12% silicon.
Jim Hall
Halltech
The new Eutectic pistons will have no silicon crystals and will have between 11% to 12% silicon.
Jim Hall
Halltech
07-01-2005, 07:59 AM
#10
☠☣☢ Semper Ebrius ☢☣☠
Originally Posted by dexter
No way - you'd think GM would have learned by now how determined an idiot can be. My prediction is that within 6 months of the delivery of the first Z06, you'll hear a story on this forum about a catastrophic engine failure where the causal event is the PF 44 filter blowing off the PF 48 threads, where it was mistakenly installed by some monkey who couldn't be bothered to read the instructions.
07-03-2005, 12:57 AM
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Originally Posted by Z06Tech
In talking with some sources, be prepaired for the engine being a little louder than your standard LS2 engine. The LS7 has shorter piston/skirts, allowing the piston to move around some and cause some extra noise. Just a pre warning, after all this is a "detuned" race engine on the street.
Sorry - not true. I've heard a few of them in person - the damn engine is quieter than a caddy at idle and low rpms. You literally hear the accessory belt over the engine/exhaust.
07-10-2005, 12:09 AM
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Originally Posted by Dan Parker '96
If one is so mechanically inept that he/she relies on "lube jockeys" to change the oil then you deserve what you get.
Last edited by RV-7 2004; 07-10-2005 at 12:12 AM.
07-10-2005, 09:27 PM
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St. Jude Donor '07-'09
Quote:
Originally Posted by Z06Tech
In talking with some sources, be prepaired for the engine being a little louder than your standard LS2 engine. The LS7 has shorter piston/skirts, allowing the piston to move around some and cause some extra noise. Just a pre warning, after all this is a "detuned" race engine on the street.
I think he may have been referring to engine noise, not exhaust noise....
Originally Posted by Z06Tech
In talking with some sources, be prepaired for the engine being a little louder than your standard LS2 engine. The LS7 has shorter piston/skirts, allowing the piston to move around some and cause some extra noise. Just a pre warning, after all this is a "detuned" race engine on the street.
Originally Posted by 415LT5-badZR-1
Sorry - not true. I've heard a few of them in person - the damn engine is quieter than a caddy at idle and low rpms. You literally hear the accessory belt over the engine/exhaust.
07-10-2005, 09:55 PM
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Originally Posted by yelloz06
Everything says cast hyperutetic with big valve reliefs cut in the top (LS2 has flat-tops).
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
Pan has 2 drain plugs with a cast arrow that spans the two drains so lube jockys will get them both.
Also the LS7 wears a unique PF48 oil filter that incorporates an internal bypass valve. The filter is the same size as the common PF44, but it's thread pitch is different so the PF44 can't be mistakenly installed. (GM HighTech July/August 05)
I was going to buy a case of PF48 in advance of my 06Z delivery. But I can not find these Filters anywhere on the market. Is this PF48 a good number ? If so, we will not be able to change our oil without a Filter. If I can't find them then, the guy who goes to the " Oil Change Place " is in real trouble. Guys ........we may have a problem here.
Zack
Last edited by Zack; 07-10-2005 at 10:11 PM.
07-10-2005, 10:55 PM
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St. Jude Donor '07-'09
Originally Posted by Zack
I was going to buy a case of PF48 in advance of my 06Z delivery. But I can not find these Filters anywhere on the market. Is this PF48 a good number ? If so, we will not be able to change our oil without a Filter. If I can't find them then, the guy who goes to the " Oil Change Place " is in real trouble. Guys ........we may have a problem here.
Zack
Zack
