Pushing coolant under boost- best remedy?
05-26-2007, 11:24 PM
#1
TECH Apprentice
Thread Starter
Join Date: Sep 2005
Location: Port Charlotte, FL
Posts: 370
Likes: 0
Received 0 Likes
on
0 Posts
Pushing coolant under boost- best remedy? Ok, I have an 05 GTO with a 9.4:1 bottom end and an APS TT kit. I am running ~17-18 psi with 19 degrees of timing (alky kit too) and if I drive it hard, it will push coolant. I am using stock GM MLS head gaskets with ARP bolts. I am curious if anyone has any ideas here. My thoughts are-
1) I am only running a 2.5" cat back- too much back pressure?
2) just the typical LS1/2 sealing issues at these levels and I should try a different gasket
3) I had a couple "oopsies" when getting the tune dialed in, wonder if it could have burned a gasket? Though it does not appear to have symptoms of a blown gasket, if I drive at lower psi levels, it is fine.
4) any/all of the above combined.
The car runs great, does not over heat, etc. I can drive it 3000 miles without even thinking of checking the coolant, but if I drive it hard, it will push out of the over flow. It will also hold quite a bit of pressure over night- if I pull the cap off the day after running it hard, there is quite a bit of pressure there, further proving that it is certainly leaking compression into the cooling system.
What gasket recommendations do you guys have for a setup like this? O-ring isn't really an option since I am not pulling the block. Anyone have any experience with the Cometic Phuzion gaskets? From what I read of Phuzions claims, they seem like they should fit the bill nicely, but would like to hear from others before spending ~$500 on a set- ouch!!
1) I am only running a 2.5" cat back- too much back pressure?
2) just the typical LS1/2 sealing issues at these levels and I should try a different gasket
3) I had a couple "oopsies" when getting the tune dialed in, wonder if it could have burned a gasket? Though it does not appear to have symptoms of a blown gasket, if I drive at lower psi levels, it is fine.
4) any/all of the above combined.
The car runs great, does not over heat, etc. I can drive it 3000 miles without even thinking of checking the coolant, but if I drive it hard, it will push out of the over flow. It will also hold quite a bit of pressure over night- if I pull the cap off the day after running it hard, there is quite a bit of pressure there, further proving that it is certainly leaking compression into the cooling system.
What gasket recommendations do you guys have for a setup like this? O-ring isn't really an option since I am not pulling the block. Anyone have any experience with the Cometic Phuzion gaskets? From what I read of Phuzions claims, they seem like they should fit the bill nicely, but would like to hear from others before spending ~$500 on a set- ouch!!
05-30-2007, 08:16 AM
#7
Originally Posted by cablebandit
back the timing off to 15 deg and see what it does at that boost level
Keith
Trending Topics
05-30-2007, 06:17 PM
#10
6 Second Club Moderator
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
$500 cometic gaskets are NOT the answer, they don't work! Back off the timing and the boost a couple lbs if your going to drive it hard all the time.
05-30-2007, 06:21 PM
#11
Teching In
Join Date: May 2007
Location: J-actionville
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by LASTLS1
$500 cometic gaskets are NOT the answer, they don't work! Back off the timing and the boost a couple lbs if your going to drive it hard all the time.
05-30-2007, 09:32 PM
#12
LS1Tech Co-Founder
iTrader: (34)
9.4:1 bottom end and an APS TT kit. I am running ~17-18 psi with 19 degrees of timing (alky kit too)
When I was making 18psi with the blower, I ran 20 degrees with C16 and ran 144mph.
05-30-2007, 10:37 PM
#13
6 Second Club Moderator
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by ss53mech
Not trying to argue here, but I haven't had any problems with cometic stuff. Anything I have studded and put them on has held just fine. What was the setup that failed for you?
The 500.00 gaskets lasted three dyno pulls! Also when they blow, the special rings blow into the cylinder and beat up the piston and the head. I put gm mls in it and made it for two dyno sessions and a couple trips to the track. GM gaskets are much cheaper!
05-31-2007, 05:08 PM
#15
Teching In
Join Date: May 2007
Location: J-actionville
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by LASTLS1
The 500.00 gaskets lasted three dyno pulls! Also when they blow, the special rings blow into the cylinder and beat up the piston and the head. I put gm mls in it and made it for two dyno sessions and a couple trips to the track. GM gaskets are much cheaper!
05-31-2007, 08:30 PM
#17
6 Second Club Moderator
iTrader: (7)
Join Date: Sep 2002
Location: Lombard .IL
Posts: 3,682
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by ss53mech
Noted, did the gm gaskets give up on you also?
Yes, but I had a small problem and my boost went up to 24 lbs! I made 910 rwhp on 17 lbs so I'm sure it was making some power. The bottom line when you get close to 1000 rwhp your in trouble with head gaskets. I oringed the block and receiver grooved the heads this year, we'll see how it holds up.
