I was just checking something here. I had my engine replaced and found my 99 had flat head piston which means it had 9.5:1 compression ratio. The 9.7:1 compression ratio used dished pistons. But it appeared my engine had everything a 2000 up had except the pistons which would explain why my car feel better and a little stronger from what is was in the past with the exact same modifications.
For those who know for sure. There has been lots of specultation on the compression ratio of the 2.4 for the 99 engines
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
The falt top pistons are 9.7:1 compression. The dished pistons are 9.5:1.
Gilles
2.3 Ho
The information i have just seen has the 2000 motor with a dish piston
http://www.grand-am.com/ARCHIVE/grandamcup/img/tif/cavalier.pdf
URL=http://www.grand-am.com/ARCHIVE/grandamcup/img/tif_01/01cavalier.pdf]http://www.grand-am.com/ARCHIVE/grandamcup/img/tif_01/01cavalier.pdf[/URL]
here is the links of the info i found for a 2000 and 2001[
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-
#30 to register on
JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
think about it logically for a second befor you go running around telling us we're wrong, dished pistons = more CC's in the combustion chamber, the more cc's the less the air gets compressed, the less the air gets compressed, the lower the compression ratio...
so thus flattops = less CC's = higher compression ratio..
_______________________
** Flat Broke Racing Inc.**
ok someone correct me then i really want to know the correct information on this.
The links i posted above are giving different information. Someone give me some information on where to go for fact not here say.
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
shifted..... you put it backwards....
96-98 are DISHED
99-02 are FLAT TOP
I've had a 97 and 02..... and know what both had.
plus its been posted on her 1.4 million times.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
oh yea...... and they (GM) never changed the tech info about the 2.4...... there is no OFFICIAL info from GM saying they ever used Flat top pistons.......
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
and whats up with the info on that file you posted?
the cam info..... .375 lift & 217* duration...... thats more then the Secret cams.....
seems like its the specs on the Mantapart Grand-Am cup car....... which isnt stock.......
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
98 2.4 ive got in the garage looks like its got flat tops
i havent taken the head off my 97 motor , so im not sure what they look like
and both my 00 and 01 motor are running
forgot
i though the diffeence was from the design change in the head
1 head has humps between the valve closing part of the combustion chamber , the other is more open
So it looks like there was no change in the piston the compression change may have been from the head. I am not saying this is fact now. It will be interesting to find out what other 96-98 engines pistons look like.
[quote=97cavie24ls(JDM&00s/c sedans™)]98 2.4 ive got in the garage looks like its got flat tops
i havent taken the head off my 97 motor , so im not sure what they look like
and both my 00 and 01 motor are running
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
My 99 are FLAT TOP pistons.
~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ
My 99 has flat top pistons....................9.7:1 compression ratio.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
but erics 98 look like it may have had flat tops. So that may mean that all engines may have had flat tops. Need more people now with 96-98 to say what pistons they had in their engine.
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
Just found out from someone that a 96 Engine had Flat top pistons as well. SO it looks like the compression may be from the head.
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
I'll post pics tonight..... the 96-98 had a slight dish to the pistons. I've had at least a half dozen apart, and they ALL share the same dished pistons. I've also had at least 5 99+ motors apart, and they DIDNT have the dished pistons.
This is all in the 6 years I've been working on J-bodies.
So.... when I get home from work, I will take pics, and post them up (attachements, so only the PREM. members can see them
)
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
Cool i want to see this dish.
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
Mylife75 (ajose) wrote:The information i have just seen has the 2000 motor with a dish piston
http://www.grand-am.com/ARCHIVE/grandamcup/img/tif/cavalier.pdf
URL=http://www.grand-am.com/ARCHIVE/grandamcup/img/tif_01/01cavalier.pdf]http://www.grand-am.com/ARCHIVE/grandamcup/img/tif_01/01cavalier.pdf[/URL]
here is the links of the info i found for a 2000 and 2001[
Ajose... that file you're suddenly posting is very OLD news... and it is NOT stock info. It was a modified race car. None of it was stock, or at least very little.
I took a couple good pics of them, BUT I cant find where my woman put the cord for the camera (to hook it to the PC)..... so I'll have to post them in the morning....
I also have a pretty good pic of the difference in ring land thicknesses...... and shows that the wrist pins are in the same place on both pistons.
SPD RCR Z -
'02 Z24 420whp
SLO GOAT -
'04 GTO 305whp
W41 BOI -
'78 Buick Opel Isuzu W41 Swap
you should be able to tell if there is a dish vs flat top.
I was a retard, and now I'm permanently banned.
Here's 2 pic's I took from my '96 and '01 motors. Notice the difference in rod beam thickness also
.
"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
My 99 just had a 2001 2.4 put in it and it feels a whole lot better than my 99 engine and seems to have a little more pep to it.
2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time
ill clean the carbon off the piston tonight , but i cant see any kinda dish
and i know there is 2 different heads out there
