LS Build: In Progress
01-29-2019 | 06:07 AM
#51
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Joined: Nov 2005
Posts: 4,554
Likes: 3
From: Fredericksburg, Va
Yes, and no need for a $$$$ front drive setup, no water pump, p/s, etc needed, just a alt mount..simple, thinking about twin turbo deal, as can get most of those parts for the cost of the marine exhaust.
01-29-2019 | 08:08 AM
#52
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Joined: Sep 2003
Posts: 213
Likes: 1
From: Bradenton, Fl
01-29-2019 | 11:58 AM
#53
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Joined: Oct 2011
Posts: 273
Likes: 4
From: Dayton, OH/Burnside KY
This will be my 4th season running a 408ci LS in my Checkmate and I love it. The sound is amazing and what surprised me the most was how much the handling of the boat improved over the big block, especially in rough water. To me, this is how the boat should have come from the factory. I'm still playing with my set up prop wise, but so far I have seen a best of 75.9mph. That's only turning 5700rpms. I have a few props to play with this year to try to get those revs up. I will say this, after 3 years I'm getting bored, so the next thing is going to be some kind of boost.
One thing I haven't heard anyone mention on here yet, especially with your cam choices, is reversion. The LS is a water sucking M.F.er!!!! I fought it for months with mine. I'm running lightning headers and started out with just extended collectors. That sucked so much water that it milkshaked the oil in less than 5 minutes of idle time, on the hose. So then I had the headers made dry to the tip. The water came into the exhaust stream in the last 1/4" of the tailpipe and it still sucked it in like crazy. I ended up having to make the exhaust completely dry (still jacketed, just no water in the exhaust stream). While it sounds awesome, the noise can get annoying (98dB at idle in the cockpit) through long no wake zones. So when you guys do your initial fire ups, keep a close eye on the tips.
One thing I haven't heard anyone mention on here yet, especially with your cam choices, is reversion. The LS is a water sucking M.F.er!!!! I fought it for months with mine. I'm running lightning headers and started out with just extended collectors. That sucked so much water that it milkshaked the oil in less than 5 minutes of idle time, on the hose. So then I had the headers made dry to the tip. The water came into the exhaust stream in the last 1/4" of the tailpipe and it still sucked it in like crazy. I ended up having to make the exhaust completely dry (still jacketed, just no water in the exhaust stream). While it sounds awesome, the noise can get annoying (98dB at idle in the cockpit) through long no wake zones. So when you guys do your initial fire ups, keep a close eye on the tips.
01-29-2019 | 12:17 PM
#54
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Joined: Jan 2016
Posts: 493
Likes: 17
From: San Tan Valley AZ
This will be my 4th season running a 408ci LS in my Checkmate and I love it. The sound is amazing and what surprised me the most was how much the handling of the boat improved over the big block, especially in rough water. To me, this is how the boat should have come from the factory. I'm still playing with my set up prop wise, but so far I have seen a best of 75.9mph. That's only turning 5700rpms. I have a few props to play with this year to try to get those revs up. I will say this, after 3 years I'm getting bored, so the next thing is going to be some kind of boost.
One thing I haven't heard anyone mention on here yet, especially with your cam choices, is reversion. The LS is a water sucking M.F.er!!!! I fought it for months with mine. I'm running lightning headers and started out with just extended collectors. That sucked so much water that it milkshaked the oil in less than 5 minutes of idle time, on the hose. So then I had the headers made dry to the tip. The water came into the exhaust stream in the last 1/4" of the tailpipe and it still sucked it in like crazy. I ended up having to make the exhaust completely dry (still jacketed, just no water in the exhaust stream). While it sounds awesome, the noise can get annoying (98dB at idle in the cockpit) through long no wake zones. So when you guys do your initial fire ups, keep a close eye on the tips.
One thing I haven't heard anyone mention on here yet, especially with your cam choices, is reversion. The LS is a water sucking M.F.er!!!! I fought it for months with mine. I'm running lightning headers and started out with just extended collectors. That sucked so much water that it milkshaked the oil in less than 5 minutes of idle time, on the hose. So then I had the headers made dry to the tip. The water came into the exhaust stream in the last 1/4" of the tailpipe and it still sucked it in like crazy. I ended up having to make the exhaust completely dry (still jacketed, just no water in the exhaust stream). While it sounds awesome, the noise can get annoying (98dB at idle in the cockpit) through long no wake zones. So when you guys do your initial fire ups, keep a close eye on the tips.
01-29-2019 | 12:36 PM
#55
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Joined: Jun 2009
Posts: 952
Likes: 83
From: East Greenwich, RI
This will be my 4th season running a 408ci LS in my Checkmate and I love it. The sound is amazing and what surprised me the most was how much the handling of the boat improved over the big block, especially in rough water. To me, this is how the boat should have come from the factory. I'm still playing with my set up prop wise, but so far I have seen a best of 75.9mph. That's only turning 5700rpms. I have a few props to play with this year to try to get those revs up. I will say this, after 3 years I'm getting bored, so the next thing is going to be some kind of boost.
One thing I haven't heard anyone mention on here yet, especially with your cam choices, is reversion. The LS is a water sucking M.F.er!!!! I fought it for months with mine. I'm running lightning headers and started out with just extended collectors. That sucked so much water that it milkshaked the oil in less than 5 minutes of idle time, on the hose. So then I had the headers made dry to the tip. The water came into the exhaust stream in the last 1/4" of the tailpipe and it still sucked it in like crazy. I ended up having to make the exhaust completely dry (still jacketed, just no water in the exhaust stream). While it sounds awesome, the noise can get annoying (98dB at idle in the cockpit) through long no wake zones. So when you guys do your initial fire ups, keep a close eye on the tips.
Mine haven't made it into the boat yet, but the builder put 40 hours on them with full dry exhaust. Does anyone make anything to muffle dry exhaust? Inserts?
01-29-2019 | 01:02 PM
#56
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Joined: Jan 2016
Posts: 493
Likes: 17
From: San Tan Valley AZ
I onow dennis said he did have some reversion initially with those but corrected it. I have ran ggb mufflers on gil dry exhaust. Helped alot. I ran 5 rings. Idle before mufflers was 119db after 107db. You can buy tgem with more as well. He also makes an external clampon that works well too. Hope this helps.
01-29-2019 | 01:04 PM
#57
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Joined: Oct 2011
Posts: 273
Likes: 4
From: Dayton, OH/Burnside KY
What are your cam specs? You will notice I setup my cam with antireversion in mind. I do have 8 degrees of overlap at .050 and [email protected] but to combat reversion I have the evc at -.5 which does not allow the down stroke to draw back on the exhaust. Also going to be running the tall hp500 tails modified with 60 degree downturn where water dumps over the edge of a cliff. Post your specs. Info for future guys to build upon. Thanks for the post
01-29-2019 | 01:07 PM
#58
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Joined: Oct 2011
Posts: 273
Likes: 4
From: Dayton, OH/Burnside KY
I built a set of clamp on mufflers for mine using GGB mufflers. I used the 3 ring sport mufflers and it made a heckuva difference. I can post videos of the differences later when I'm not at work (government computer). I always use the mufflers when I have my 6 year old twin girls on the boat with me, but pull them when it's just the wife and I.
01-29-2019 | 01:15 PM
#60
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Joined: Jan 2016
Posts: 493
Likes: 17
From: San Tan Valley AZ
Good power cam. See how the int/ex split forces the exhaust closing past 0 (8in your case). I can see why you had to go dry. Good for scavenging. Bad for reversion. I opted the other way to keep the db down and headers are not in the budget. Yet........... lol. Any dyno numbers??
