some 2001 and 2002 F-body's have ls6 heads??
01-25-2002, 01:10 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? I have not seen a "machined" opening in the cap or the lower cylinder on an LS1 block. The LS6 block does NOT have machined windows at the bottoms of the cylinders, either. The LS6 main caps have small, machined windows on either side of the crank bearing journals. Remember, the LS1/LS6 is a deep skirt block. The crank sits well within the bottom oil pan mounting surface of the block and the caps fill that area, creating almost solid walls between bays.
The issue of GM going to the LS6 style block in all LS1/LS6 applications makes a lot of sense, as the machining is identicle for the most part(changes to the oil drain back passages, very minor, and different machining in the engine valley area to allow the LS6 style PCV system). HOWEVER, it does NOT makes sense in the case of the LS6 heads. There are several major differences in the LS1 vs LS6 head. This would not be something GM would just toss in the "mix" when parts where running short(in fact, the LS6 parts should have been the ones running short, as GM only geared up for 5000 LS6 motors in 2001).
There are many reasons why the 2001 cars are making more power. The camshaft, although specs seem more mild, is actually more aggressive due to ramp designs, the intake flows better, the cast iron manifolds flow better and the PCM tuning is nearing perfection on GMs powertrain department(look at all the PCM reflashes for earlier LS1 vehicles vs 2001 vehicles). They also adjusted the PCM to run the motor leaner(emissions) which will result in more power until the magic line is crossed and pinging becomes an issue.
Todd
The issue of GM going to the LS6 style block in all LS1/LS6 applications makes a lot of sense, as the machining is identicle for the most part(changes to the oil drain back passages, very minor, and different machining in the engine valley area to allow the LS6 style PCV system). HOWEVER, it does NOT makes sense in the case of the LS6 heads. There are several major differences in the LS1 vs LS6 head. This would not be something GM would just toss in the "mix" when parts where running short(in fact, the LS6 parts should have been the ones running short, as GM only geared up for 5000 LS6 motors in 2001).
There are many reasons why the 2001 cars are making more power. The camshaft, although specs seem more mild, is actually more aggressive due to ramp designs, the intake flows better, the cast iron manifolds flow better and the PCM tuning is nearing perfection on GMs powertrain department(look at all the PCM reflashes for earlier LS1 vehicles vs 2001 vehicles). They also adjusted the PCM to run the motor leaner(emissions) which will result in more power until the magic line is crossed and pinging becomes an issue.
Todd
01-25-2002, 01:13 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? [quote]Originally posted by BigBake:
<strong>"As the pistons move up and down, they force air in and out of the spaces (or "bays") beneath them. At high RPM, this reciprocating air flow is violent and really whips up the oil. While the LS1 block has some machined openings between bays, the LS6 block, because the engine has about 500 more usable RPM, need larger windows at the base of each cylinder to better accomodate "bay to bay breathing."
The article goes on about that this was also done for future up-grades, so that they would not have to eat costs down the road for a re-design.</strong><hr></blockquote>
Right, but doesn't this basically have the same effect as less mass. (ie....lighter valvetrain) Doesn't really ADD hp but, does make a difference?
If the pressure escapes faster, can't the car rev faster?
<strong>"As the pistons move up and down, they force air in and out of the spaces (or "bays") beneath them. At high RPM, this reciprocating air flow is violent and really whips up the oil. While the LS1 block has some machined openings between bays, the LS6 block, because the engine has about 500 more usable RPM, need larger windows at the base of each cylinder to better accomodate "bay to bay breathing."
The article goes on about that this was also done for future up-grades, so that they would not have to eat costs down the road for a re-design.</strong><hr></blockquote>
Right, but doesn't this basically have the same effect as less mass. (ie....lighter valvetrain) Doesn't really ADD hp but, does make a difference?
If the pressure escapes faster, can't the car rev faster?
01-25-2002, 01:20 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? Here's an excerpt from an article.
Aluminum Block
The aluminum block casting on the LS6 deletes machined holes in the LS1 bulkhead and adds cast-in "windows" that allow better bay-to-bay breathing. On the downstroke, the pistons push air back toward the crankcase, creating backpressure or resistance, and that translates into parasitic horsepower loss because it resists piston motion. With the overtravel windows, air is allowed to move more freely between crankcase bays, thus relieving the unwanted pressure.
Aluminum Block
The aluminum block casting on the LS6 deletes machined holes in the LS1 bulkhead and adds cast-in "windows" that allow better bay-to-bay breathing. On the downstroke, the pistons push air back toward the crankcase, creating backpressure or resistance, and that translates into parasitic horsepower loss because it resists piston motion. With the overtravel windows, air is allowed to move more freely between crankcase bays, thus relieving the unwanted pressure.
01-25-2002, 03:18 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? Someone may have mentioned it but in the April 2002 issue of High Performance Pontiac there is an article on the plant in St. Catharines, Ontario, Canada that puts the LS1 engines together. Lots of pictures. Pretty cool.
Les
Les
01-25-2002, 04:33 PM
#26
Re: some 2001 and 2002 F-body's have ls6 heads?? Guess What!!! My 01 heads say GM Overrun LS6 heads and just ignore the 241 stamp on them.. I just went out and checked since they are off the car.. I know the ls6 heads say #243... Just to let you know.. Come on guys.. Our cars already put out some great #'s.. Stop dreaming about Z06 motors..
01-26-2002, 12:00 AM
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Re: some 2001 and 2002 F-body's have ls6 heads?? BIGBAKE im with you all the way except for the breathing bay comments, if non ls6 blocks are whipping up oil, thats costing hi rpm power. So this would be worth power increase and reliability because foaming oil doesnt lubricate well! <img src="gr_images/icons/wink.gif" border="0">
01-26-2002, 12:05 AM
#31
Re: some 2001 and 2002 F-body's have ls6 heads?? I have the 241 stamped on the pass. side head. I had my FLP headers installed in early Sept. of '01, and I never even thought to sneak a peak at the exhaust ports. I might drop Nick Agostino an e-mail to see if he has flowed a set of stock '98 heads and stock '02 heads.
Here's some interesting comparisons from my '98 to my '02. My '98 T/A with a bunch of bolt-ons (with Hooker shorties, not Macs) dynoed a best of 288 RWHP. With the addition of a set of CNC "stage 1" (only "stage" available then) heads and Mac setup w/ cats, my car put down 331 RWHP and 345 RWTQ. This was with the stock '98 cam. I later went back with a TINY Crane cam (208/216, .500"/.500", 114 LSA) and gained 0 HP but 15 lb./ft. of RWTQ. This netted 331 RWHP and 360 RWTQ. The car ran a best of 12.38 @ 110 MPH w/ a 1.69 60' time with the Vig 3200 converter; that's the same converter I'm running in my SS. Raceweight was right at 3,675#, and this was on ET Streets. My SS (before the 3.73's and EW tuning) put down 332.9 RWHP and 348 RWTQ. This is with a stock engine and a bunch of bolt-ons. I've already outrun my T/A's heads/cam setup (not hard to do w/ the tiny cam I had), and I'll end up with an 11-second timeslip before too long w/ a stock-internal LS1. It took a set of CNC heads on my '98 to match my stock SS, and the #'s are VERY close to each other.
IMO, there are onle a few things that GM could change to increase the power: heads, intake, induction, camshaft, and exhaust. The intake we know about, the induction hasn't changed (although some have reported an 85mm MAF on their '02's), and we know that GM went with a smaller cam. The exhaust has changed slightly since the cars now get the dual hi-flow C5 cats instead of a hi-flow on the driver's-side and a restrictive one on the pass. side. The exhaust manifolds also changed some to supposedly net another 5 HP or so, but that isn't a factor when you compare my '98 and '02. They were both running headers. What does that leave to make up for the power difference? heads! <img src="gr_stretch.gif" border="0"> I will eventually end up with a heads/cam setup, so I'll check the heads out then. Even if we are still getting LS1 castings, I think they're flowing better than the previous castings. A flow bench will tell us.
As a sidenote, there's a local car here in DFW that's putting down some incredible #'s. It's an '01 Formula A4, and the guy has run 12.4's with a stock converter @ 110 MPH! <img src="gr_eek2.gif" border="0"> The car dynoed over 340 RWHP and 360 RWTQ with the stock manifolds in place. That's UNREAL! I'll see if I can find him in the TX section.
[ January 25, 2002: Message edited by: Trevor D ]</p>
Here's some interesting comparisons from my '98 to my '02. My '98 T/A with a bunch of bolt-ons (with Hooker shorties, not Macs) dynoed a best of 288 RWHP. With the addition of a set of CNC "stage 1" (only "stage" available then) heads and Mac setup w/ cats, my car put down 331 RWHP and 345 RWTQ. This was with the stock '98 cam. I later went back with a TINY Crane cam (208/216, .500"/.500", 114 LSA) and gained 0 HP but 15 lb./ft. of RWTQ. This netted 331 RWHP and 360 RWTQ. The car ran a best of 12.38 @ 110 MPH w/ a 1.69 60' time with the Vig 3200 converter; that's the same converter I'm running in my SS. Raceweight was right at 3,675#, and this was on ET Streets. My SS (before the 3.73's and EW tuning) put down 332.9 RWHP and 348 RWTQ. This is with a stock engine and a bunch of bolt-ons. I've already outrun my T/A's heads/cam setup (not hard to do w/ the tiny cam I had), and I'll end up with an 11-second timeslip before too long w/ a stock-internal LS1. It took a set of CNC heads on my '98 to match my stock SS, and the #'s are VERY close to each other.
IMO, there are onle a few things that GM could change to increase the power: heads, intake, induction, camshaft, and exhaust. The intake we know about, the induction hasn't changed (although some have reported an 85mm MAF on their '02's), and we know that GM went with a smaller cam. The exhaust has changed slightly since the cars now get the dual hi-flow C5 cats instead of a hi-flow on the driver's-side and a restrictive one on the pass. side. The exhaust manifolds also changed some to supposedly net another 5 HP or so, but that isn't a factor when you compare my '98 and '02. They were both running headers. What does that leave to make up for the power difference? heads! <img src="gr_stretch.gif" border="0"> I will eventually end up with a heads/cam setup, so I'll check the heads out then. Even if we are still getting LS1 castings, I think they're flowing better than the previous castings. A flow bench will tell us.
As a sidenote, there's a local car here in DFW that's putting down some incredible #'s. It's an '01 Formula A4, and the guy has run 12.4's with a stock converter @ 110 MPH! <img src="gr_eek2.gif" border="0"> The car dynoed over 340 RWHP and 360 RWTQ with the stock manifolds in place. That's UNREAL! I'll see if I can find him in the TX section.
[ January 25, 2002: Message edited by: Trevor D ]</p>
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01-26-2002, 12:12 AM
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Re: some 2001 and 2002 F-body's have ls6 heads?? "As the pistons move up and down, they force air in and out of the spaces (or "bays") beneath them. At high RPM, this reciprocating air flow is violent and really whips up the oil. While the LS1 block has some machined openings between bays, the LS6 block, because the engine has about 500 more usable RPM, need larger windows at the base of each cylinder to better accomodate "bay to bay breathing."
The article goes on about that this was also done for future up-grades, so that they would not have to eat costs down the road for a re-design.
The article goes on about that this was also done for future up-grades, so that they would not have to eat costs down the road for a re-design.
01-26-2002, 02:32 AM
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Re: some 2001 and 2002 F-body's have ls6 heads?? FWIW:
I've looked at a few 98-99 & 00+ heads and I know that the 00+ valves are better. They're shaped better and have less overhang below the valve seat. The exaust valves are smaller around the stem (where the aftermarket valves are undercut). And I believe the valve jobs are also better in the newer heads. So I can definately see a HP increase just in the newer LS1 castings.
I've looked at a few 98-99 & 00+ heads and I know that the 00+ valves are better. They're shaped better and have less overhang below the valve seat. The exaust valves are smaller around the stem (where the aftermarket valves are undercut). And I believe the valve jobs are also better in the newer heads. So I can definately see a HP increase just in the newer LS1 castings.
01-26-2002, 02:08 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? [quote]Originally posted by BLK 98WS6:
<strong> The LS6 block does NOT have machined windows at the bottoms of the cylinders, either.
Todd</strong><hr></blockquote>
This is incorrect.
The LS6 block I'm looking at right now has windows at the bottom of each cylinder <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
I have pictures <img src="gr_grin.gif" border="0">
<img src="graemlins/z06.gif" border="0" alt="[Z06 Corvette]" />
<strong> The LS6 block does NOT have machined windows at the bottoms of the cylinders, either.
Todd</strong><hr></blockquote>
This is incorrect.
The LS6 block I'm looking at right now has windows at the bottom of each cylinder <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />
I have pictures <img src="gr_grin.gif" border="0">
<img src="graemlins/z06.gif" border="0" alt="[Z06 Corvette]" />
01-26-2002, 05:27 PM
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Re: some 2001 and 2002 F-body's have ls6 heads?? I have a set of heads here that are numbered 287?
No one has posted this number yet. These are new and I picked them up really inexpensive, but they say 287.....
<img src="gr_emb.gif" border="0"> What are they? <img src="gr_emb.gif" border="0">
No one has posted this number yet. These are new and I picked them up really inexpensive, but they say 287.....
<img src="gr_emb.gif" border="0"> What are they? <img src="gr_emb.gif" border="0">
