Cometic gaskets
#1
06-17-2018, 12:02 AM
Cometic gaskets
so this started in another thread, but I believe it deserves its own place.
nodoubt believes they are the second coming, i’m not convinced.
Cometic gaskets are metal, all of us have been using composite gaskets.
if cometic is so much better, why are they not used on the regular? Is nodoubt the only smart one on this forum?
nodoubt believes they are the second coming, i’m not convinced.
Cometic gaskets are metal, all of us have been using composite gaskets.
if cometic is so much better, why are they not used on the regular? Is nodoubt the only smart one on this forum?
#2
06-17-2018, 02:18 AM
Baja
so this started in another thread, but I believe it deserves its own place.
nodoubt believes they are the second coming, i’m not convinced.
Cometic gaskets are metal, all of us have been using composite gaskets.
if cometic is so much better, why are they not used on the regular? Is nodoubt the only smart one on this forum?
nodoubt believes they are the second coming, i’m not convinced.
Cometic gaskets are metal, all of us have been using composite gaskets.
if cometic is so much better, why are they not used on the regular? Is nodoubt the only smart one on this forum?
Last edited by OffroadFrance; 06-17-2018 at 02:49 AM.
#4
06-23-2018, 06:06 AM
Pro Wrench
Depends...
What fasteners is he using?
Cometic gaskets seal at the parts that there is no pressure. Like at an oil hole, the head is bolted down and the head pushes against the block. Where there is a hole the gaskets extends just a bit, enough to create a seal, there is no pressure at the little part that extends so that part isnt crushed.
What fasteners is he using?
Cometic gaskets seal at the parts that there is no pressure. Like at an oil hole, the head is bolted down and the head pushes against the block. Where there is a hole the gaskets extends just a bit, enough to create a seal, there is no pressure at the little part that extends so that part isnt crushed.
#5
06-23-2018, 06:08 AM
Pro Wrench
#6
06-23-2018, 08:02 AM
The purpose of starting this thread was not to prove anybody wrong, but was to find out if I had missed an opportunity at a quality rebuild item.
I work with 2 accomplished rover engine builders and neither have even mentioned the possibility of using Cometic gaskets.
If anyone has followed the original thread, Paul Grant chimmed in at the end. Paul has had his finger on the rover pulse longer than most and when it comes to rover lore, I believe he is one of the more knowledgeable.
Paul’s quote:
”The last time Rover recommended the use of the Cometic style of gasket was back in the days when 14 bolts secured the heads to the block. When Rover (1995 for RRC and 1994 for DI if memory serves me) switched to composite gaskets is was to address the perpetual problem of leaks being created towards the back of the heads. There was a third row of four head bolts (with the furthest back bolt being the culprit for leaks all too many times) that were eliminated with the introduction of the composite gasket. At the time, nearly everyone involved with the Rover V8 felt that FINALLY Rover was doing something to address the issue of head gasket leaks. People bitched and moaned about the technique for tightening the new head bolts into place but for the vast majority, the change was viewed as a positive.”
I work with 2 accomplished rover engine builders and neither have even mentioned the possibility of using Cometic gaskets.
If anyone has followed the original thread, Paul Grant chimmed in at the end. Paul has had his finger on the rover pulse longer than most and when it comes to rover lore, I believe he is one of the more knowledgeable.
Paul’s quote:
”The last time Rover recommended the use of the Cometic style of gasket was back in the days when 14 bolts secured the heads to the block. When Rover (1995 for RRC and 1994 for DI if memory serves me) switched to composite gaskets is was to address the perpetual problem of leaks being created towards the back of the heads. There was a third row of four head bolts (with the furthest back bolt being the culprit for leaks all too many times) that were eliminated with the introduction of the composite gasket. At the time, nearly everyone involved with the Rover V8 felt that FINALLY Rover was doing something to address the issue of head gasket leaks. People bitched and moaned about the technique for tightening the new head bolts into place but for the vast majority, the change was viewed as a positive.”
#7
06-23-2018, 08:29 AM
Pro Wrench
The purpose of starting this thread was not to prove anybody wrong, but was to find out if I had missed an opportunity at a quality rebuild item.
I work with 2 accomplished rover engine builders and neither have even mentioned the possibility of using Cometic gaskets.
If anyone has followed the original thread, Paul Grant chimmed in at the end. Paul has had his finger on the rover pulse longer than most and when it comes to rover lore, I believe he is one of the more knowledgeable.
Paul’s quote:
”The last time Rover recommended the use of the Cometic style of gasket was back in the days when 14 bolts secured the heads to the block. When Rover (1995 for RRC and 1994 for DI if memory serves me) switched to composite gaskets is was to address the perpetual problem of leaks being created towards the back of the heads. There was a third row of four head bolts (with the furthest back bolt being the culprit for leaks all too many times) that were eliminated with the introduction of the composite gasket. At the time, nearly everyone involved with the Rover V8 felt that FINALLY Rover was doing something to address the issue of head gasket leaks. People bitched and moaned about the technique for tightening the new head bolts into place but for the vast majority, the change was viewed as a positive.”
I work with 2 accomplished rover engine builders and neither have even mentioned the possibility of using Cometic gaskets.
If anyone has followed the original thread, Paul Grant chimmed in at the end. Paul has had his finger on the rover pulse longer than most and when it comes to rover lore, I believe he is one of the more knowledgeable.
Paul’s quote:
”The last time Rover recommended the use of the Cometic style of gasket was back in the days when 14 bolts secured the heads to the block. When Rover (1995 for RRC and 1994 for DI if memory serves me) switched to composite gaskets is was to address the perpetual problem of leaks being created towards the back of the heads. There was a third row of four head bolts (with the furthest back bolt being the culprit for leaks all too many times) that were eliminated with the introduction of the composite gasket. At the time, nearly everyone involved with the Rover V8 felt that FINALLY Rover was doing something to address the issue of head gasket leaks. People bitched and moaned about the technique for tightening the new head bolts into place but for the vast majority, the change was viewed as a positive.”
No offense to anyone...but forget what rover thinks.
It's an aluminum block with aluminum heads using a GM design. This has been done before on many types of vehicles. I haven't used them on a head gasket on anything I've built, but, if the technology is there, why not?
The more I learn about rover the more I learn that there were some serious idiots working in engineering.
#8
06-23-2018, 09:05 AM
Rover engineers might not be the brightest bulb in the chandelier, but they have more hands on experience with that specific motor than Buick did. And if Paul’s account holds water, it sounds like they had to make a change.
so, if Cometics are the best thing since sliced bread, why are we all running composites?
What other aluminum block & head engines run Cometics that are daily driver tasked, non high performance engines?
so, if Cometics are the best thing since sliced bread, why are we all running composites?
What other aluminum block & head engines run Cometics that are daily driver tasked, non high performance engines?
Last edited by abran; 06-23-2018 at 09:25 AM.
#10
06-23-2018, 06:53 PM
Pro Wrench
Rover engineers might not be the brightest bulb in the chandelier, but they have more hands on experience with that specific motor than Buick did. And if Paul’s account holds water, it sounds like they had to make a change.
so, if Cometics are the best thing since sliced bread, why are we all running composites?
What other aluminum block & head engines run Cometics that are daily driver tasked, non high performance engines?
so, if Cometics are the best thing since sliced bread, why are we all running composites?
What other aluminum block & head engines run Cometics that are daily driver tasked, non high performance engines?
When did cometic come out? Theres a business called cometic that makes gaskets that started in 1989. If that's the case the answer is simple. Cometic gaskets had just came out and were new technology then. Rover wrote its books on the materials used at the time.
Would you use stretch bolts? ARP? What are the torque settings and will the block hold up to them?
Theres also business deals that would have to be thought about. Maybe rover had a gasket deal or made the gaskets themselves, to switch could mean huge loss of money etc.
I'm building a 454 currently, I may put cometic gaskets on it since it 500+tq, 550+hp.