LS1 MLS gasket on standard head?
05-30-2017, 09:17 AM
#1
LS1 MLS gasket on standard head? Assuming I goofed here since I blew the HG the first night out right at the head notch. I installed the felpro LS1 gasket with the head recess notch on a 799 head with no notch. Anyone done this with any success?
05-30-2017, 12:22 PM
#2
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It'll be fine. Its only a problem when you have an un-notched gasket and a notched head
05-30-2017, 12:26 PM
#3
Really? It looks like it caused the problem here? Like it deformed the gasket a ton maybe when it was clamped down?
This was 10.8AFR 13* of timing at 25lbs of boost. Heat mark on the plug was about half way down the strap. 100* IAT. Tune seems spot on. Can't figure why it lifted otherwise. (e85 fuel with IC and water/meth)
Run the same tune and motor combo before without issue on LS9 gaskets. Seemed to hold alright on the street on low boost and let go after about 5 passes at the track.
This was 10.8AFR 13* of timing at 25lbs of boost. Heat mark on the plug was about half way down the strap. 100* IAT. Tune seems spot on. Can't figure why it lifted otherwise. (e85 fuel with IC and water/meth)
Run the same tune and motor combo before without issue on LS9 gaskets. Seemed to hold alright on the street on low boost and let go after about 5 passes at the track.
05-30-2017, 01:24 PM
#7
Thanks for the input! NA guys mostly? It was ok until I leaned on it good. I just flowed the injectors after the failure. All checked good. Plugs looked good, heat about half way down the strap. Timing overly conservative IMO and 10.8 AFR.
I have been pushing these motors for quite a few years now time now with big boost. This is the first gasket failure I’ve had. Also the first time I’ve used anything but an LS9 gasket. Really don’t think the tune was off and can’t imagine what else would have caused it at this point.
Looks like it let go centrally right over the pocket area. Usually gaskets blow outward but this one is like a deformed "S". Are most pushing the engine as hard? I’m not aware of any boosted guys running it. This is also my first build using bolts instead of studs. After seeing guys make over 1200whp on stock head bolts the studs seemed like an unnecessary expense. I might be wrong there too… You can also see where it clearly looks like it was biting into the head and sealing somewhat.
I have been pushing these motors for quite a few years now time now with big boost. This is the first gasket failure I’ve had. Also the first time I’ve used anything but an LS9 gasket. Really don’t think the tune was off and can’t imagine what else would have caused it at this point.
Looks like it let go centrally right over the pocket area. Usually gaskets blow outward but this one is like a deformed "S". Are most pushing the engine as hard? I’m not aware of any boosted guys running it. This is also my first build using bolts instead of studs. After seeing guys make over 1200whp on stock head bolts the studs seemed like an unnecessary expense. I might be wrong there too… You can also see where it clearly looks like it was biting into the head and sealing somewhat.
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05-30-2017, 01:31 PM
#8
Until we released our gasket set for notched heads, that was the only other option besides cometic for mls. Otherwise they ran the composite or reg felpro. There have been many boosted guys use em all due to the amount of time all the parts have been out. I cannot give you any names as its been too long between then and now, but the felpro mls gaskets were pretty big in 2010-2012 when people were scrutinizing the cometics. After that they kinda fell on the back burner. Cometic has released a newer line of hd gaskets that seem to work well, but are more $$$ With what you are doing, possibly O rings would be more reliable and less costly overall.
I know your 799s arent notched of course.
I know your 799s arent notched of course.
05-30-2017, 01:35 PM
#9
Thanks. It could have been a tune issue or a fluke. I’ve had great luck with the LS9’s (even on the small bore stuff) Blown the ring lands and bottom end out before lifting the head. Just wanted the bump in compression with the .041 gasket this go around so I tried something different. I’ll most likely pull the other side and run an LS9 to keep things symmetrical. I've already installed the LS9 on the passenger side. Cars driving again with slightly mismatched compression per bank.