3ltr twincam engine, coming together
02-11-2013, 06:11 AM
#196
Drifting
Thread Starter
Hi Duke,
Actually it is cylinder 2 and 3 that have the wear on the Cometic gasket. cylinders 1 and 4 are still intact. The car is almost back together, just need to plug in the ECU's and the exhaust. May be going to the drags soon, Also Patrick has his Drift box at our work. I presume i can use that for some acceleration readings.
Actually it is cylinder 2 and 3 that have the wear on the Cometic gasket. cylinders 1 and 4 are still intact. The car is almost back together, just need to plug in the ECU's and the exhaust. May be going to the drags soon, Also Patrick has his Drift box at our work. I presume i can use that for some acceleration readings.
02-11-2013, 06:42 AM
#197
Rennlist Member
You dont have faith in my wiring skills Patrick? Im glad we got around to doing this, all of the injector harness wires were frayed, the knock sensor plug was barely holding on. It was just crumbling to bits.
I think its head movement and cylinder movement. In the past with the 2.5ltr engines we could run almost double the events on 1.1 bar compared to 1.5 bar. The more boost we run the faster the Cometic gaskets would wear on that sealing ring. I think we are getting slight cylinder lift with the boost, not enough to break the seal, but enough so that the vibrations caused by the moving pistons cause this "rubbing" effect on the Cometics.
Even if the cometic does not last any longer then a stock gasket, they are still worth it in our opinion. Even when they do breach they seal up when not on boost. meaning we can drive the car home or back to the shop for replacement.
Sean
I think its head movement and cylinder movement. In the past with the 2.5ltr engines we could run almost double the events on 1.1 bar compared to 1.5 bar. The more boost we run the faster the Cometic gaskets would wear on that sealing ring. I think we are getting slight cylinder lift with the boost, not enough to break the seal, but enough so that the vibrations caused by the moving pistons cause this "rubbing" effect on the Cometics.
Even if the cometic does not last any longer then a stock gasket, they are still worth it in our opinion. Even when they do breach they seal up when not on boost. meaning we can drive the car home or back to the shop for replacement.
Sean
Have to assume that the siamesed bores have played a part in the cometic lasting longer.
02-11-2013, 05:55 PM
#198
Race Car
That gasket certainly looks like a small amount of movement going on.
I hope I read that right that you're going to do some drag racing soon? I'm really looking forward to seeing your trap speeds.
This build is quite a success story. Congrats!!!
I hope I read that right that you're going to do some drag racing soon? I'm really looking forward to seeing your trap speeds.
This build is quite a success story. Congrats!!!
02-13-2013, 09:37 AM
#199
Thanks for posting this useful info! My build will be very similar, and seeing how well it performs eased some of my concerns about reliability.
What do you think about the HMR stronger head studs and main stud kits? They are supposed to have a tensile strength of 240,000 PSI and 280,000PSI. This is as far as I understand a huge improvement over the original bolts, and might be worth it in the long run, even if they are very expensive.
What do you think about the HMR stronger head studs and main stud kits? They are supposed to have a tensile strength of 240,000 PSI and 280,000PSI. This is as far as I understand a huge improvement over the original bolts, and might be worth it in the long run, even if they are very expensive.
02-13-2013, 05:57 PM
#200
Drifting
Thread Starter
Thanks for posting this useful info! My build will be very similar, and seeing how well it performs eased some of my concerns about reliability.
What do you think about the HMR stronger head studs and main stud kits? They are supposed to have a tensile strength of 240,000 PSI and 280,000PSI. This is as far as I understand a huge improvement over the original bolts, and might be worth it in the long run, even if they are very expensive.
What do you think about the HMR stronger head studs and main stud kits? They are supposed to have a tensile strength of 240,000 PSI and 280,000PSI. This is as far as I understand a huge improvement over the original bolts, and might be worth it in the long run, even if they are very expensive.
Sean
02-13-2013, 06:44 PM
#201
Rennlist Member
From memory I thought we got an extended period with those larger headstuds?
02-13-2013, 08:04 PM
#203
Drifting
Thread Starter
Sean
02-13-2013, 08:39 PM
#204
Rennlist Member
For some reason my recollection was that the new headstuds were an improvement in terms of track days vs headgasket replacement. I certainly agree that the Cometics are the way to go if you drive to and from the track...especially if the track is miles away. Being towed from Wakefield Park is noooo fun!
02-14-2013, 04:56 AM
#206
We ran the ARP's on your car Patrick, they are standard in size but can hold more pressure, your big engine has the larger studs but not too much testing has been put on them yet. Even with more torque on the ARP's we still had the same wear rates on the gasket. maybe its the threads in the block that flex?
Depends on the turbo and compression ratio. Turbo's have different efficiency ranges and work better(produce less heat) at certain boost pressures
Sean
I have a 1.5 hour drive to the closest track and being towed home is not realy an option...
02-14-2013, 09:29 AM
#208
Interesting reference about head studs
http://www.heritagemotorcar.com/research/index.htm
http://www.heritagemotorcar.com/research/index.htm
http://www.heritagemotorcar.com/research/index.htm
http://www.heritagemotorcar.com/research/index.htm
02-14-2013, 03:09 PM
#209
Rennlist Member
Have you been using stock head studs in the 3-liter engine, Sean?
Have you been using stock head studs in the 3-liter engine, Sean?
02-14-2013, 03:58 PM
#210
Rennlist Member
What pistons are you using Muddy?