LML Marine swap
- Thread starter Hawk 40
- Start date
I looked through a dozen GM drawings, coolant port to EGR was best I could tell. But on the LMM's it was actually lower in that cover and on the drivers side.. Humm.
I did find where the LML's have a catch can / oil separator for crankcase vents now? It drains back into the oil pan on drivers side. The LLY could have certainly used that back when I was ventilating pistons.
:spit:
So I added a nice big can after the total rebuild. See it tucked behind the oil filter. Then she never spit up a drop in over 300 running hours. Guess it worked...
I did find where the LML's have a catch can / oil separator for crankcase vents now? It drains back into the oil pan on drivers side. The LLY could have certainly used that back when I was ventilating pistons.
:spit:
So I added a nice big can after the total rebuild. See it tucked behind the oil filter. Then she never spit up a drop in over 300 running hours. Guess it worked...
Awesome build Hawk, that boat will be a Beast on the water!
Pardon me though on interjecting a question to the group. I thought the purpose of the AF cam was to correct the harmonics that create the problem that breaks the cranks? If the harmonics are corrected with the SoCal AF Cam in each of these motors then what would the issue of strapping a supercharger on it? Just asking this for learning purposes for everyone that said hmmm during that debate. Thanks.
Pardon me though on interjecting a question to the group. I thought the purpose of the AF cam was to correct the harmonics that create the problem that breaks the cranks? If the harmonics are corrected with the SoCal AF Cam in each of these motors then what would the issue of strapping a supercharger on it? Just asking this for learning purposes for everyone that said hmmm during that debate. Thanks.
Headless, my personal opinion on a SC after considering it. Besides the crank issues, one charger won't feed it. Banks did a SC with twins, and I believe a member or two here have similar builds. While I've seen videos of both those Banks setup on a dyno, someone please show me one in a boat... PLEASE, I've search the web over.
Until I see one busting waves, it's just for show. It will def rev quicker, but any stand alone SC setup to boost quick is gonna be done quicker. I ran a Non-VGT turbo, and never had spooling problems.. Ran out of air on top end though.
So if going for 1300 hp using big twins I'd say heck yes in a boat. If looking for reliable 500hp daily use in marine, stick with stock or a slightly larger VGT.
Just my 2 ¢
Until I see one busting waves, it's just for show. It will def rev quicker, but any stand alone SC setup to boost quick is gonna be done quicker. I ran a Non-VGT turbo, and never had spooling problems.. Ran out of air on top end though.
So if going for 1300 hp using big twins I'd say heck yes in a boat. If looking for reliable 500hp daily use in marine, stick with stock or a slightly larger VGT.
Just my 2 ¢
One could always install a 2 speed transmission, and shift it into high once your going at speed. They aren't cheap, but they have them to work with some pretty big HP.
Correct prop shaft speed is the key to speed. Let Mr Smith or one of the old school Diesel racers from OSO explain this important fact better than I can. 3200 - 3600r is like the sweet spot on a Bravo setup. If you go Arneson surface drive, you can go bigger dia prop and lower that range some. But that's what the old pro's explained to me.
I spun my prop just under 3000r's with the 1.26:1 gear ratio and hit low 90's in Charlotte Harbor last year. That was just under 4k on the engine, and she was completely turbo restricted with that 4094 on it. Is my all time best with a 37P 5 bland prop and 19% slip factor on bravo.
ZF builds a 2 speed overdrive marine transmission for about $7500 that's rated at 1000ft lbs. I was speaking with them a while back. But that's actually less power than I put through the bravo XR drive. The next size up is their 320 series, which is like 12k and good to around 1300lbs. However it's bout as heave as a Duramax engine... ZF only builds these once you supply the engine specs and full payment. They will not sell you the smaller tranny if you state your making 700hp on a diesel. They rejected my build sheet that said 650hp.
Second choice is crash boxes with overdrive. Suck for docking unless you can clutch them. Lucas Oil Silverhook has a new pair in there behind big gassers. Didn't seem to help them out a bit on top speed that I can see. So who knows.
Third option is stick an 6spd Allison with no converter behind the engine. The other boat I'm helping out on right now has this setup with #8 Arneson 1:1 drive and about a 26p prop. If we could get it to hold 5th at WOT I think it might work out. But the boat is heavy and currently downshifting to 4th when you open it up. Joe at PPE has a small Nordic with 6spd Allison and IMCO setup. He's offered to help us work out that shifting issue. But Joe hasn''t posted up his top speeds yet. HINT HINT!! >DAN. She's gotta be topping 100 to sway my opinion about making room for a big a$$ 6spd in a boat. But I do hear they make docking very easy.. LOL
Last and my personal plans I'm leaning towards for the next build. Take a Gear Vendors overdrive unit and place it between the flywheel and a IMCO SCX drive with a 1:26:1 gear ratio. Once on plane and up in the RPM's good, switch on the overdrive (A .80 ratio if I recall) which should give ya right at a 1:1 final drive. Puts the shaft speed in the sweet spot everyone suggest. That GV unit cost less than couple grand and will hold 2000hp. Two speeds, no tranny, correct propshaft speed without adding more than 100lbs to the boat. Guarantee 100+ all day long in a 26' boat with bravo drive and a solid 700hp diesel with twins spinning under 4000 revs.
Those are all the options I've considered.. :thumb:
I spun my prop just under 3000r's with the 1.26:1 gear ratio and hit low 90's in Charlotte Harbor last year. That was just under 4k on the engine, and she was completely turbo restricted with that 4094 on it. Is my all time best with a 37P 5 bland prop and 19% slip factor on bravo.
ZF builds a 2 speed overdrive marine transmission for about $7500 that's rated at 1000ft lbs. I was speaking with them a while back. But that's actually less power than I put through the bravo XR drive. The next size up is their 320 series, which is like 12k and good to around 1300lbs. However it's bout as heave as a Duramax engine... ZF only builds these once you supply the engine specs and full payment. They will not sell you the smaller tranny if you state your making 700hp on a diesel. They rejected my build sheet that said 650hp.
Second choice is crash boxes with overdrive. Suck for docking unless you can clutch them. Lucas Oil Silverhook has a new pair in there behind big gassers. Didn't seem to help them out a bit on top speed that I can see. So who knows.
Third option is stick an 6spd Allison with no converter behind the engine. The other boat I'm helping out on right now has this setup with #8 Arneson 1:1 drive and about a 26p prop. If we could get it to hold 5th at WOT I think it might work out. But the boat is heavy and currently downshifting to 4th when you open it up. Joe at PPE has a small Nordic with 6spd Allison and IMCO setup. He's offered to help us work out that shifting issue. But Joe hasn''t posted up his top speeds yet. HINT HINT!! >DAN. She's gotta be topping 100 to sway my opinion about making room for a big a$$ 6spd in a boat. But I do hear they make docking very easy.. LOL
Last and my personal plans I'm leaning towards for the next build. Take a Gear Vendors overdrive unit and place it between the flywheel and a IMCO SCX drive with a 1:26:1 gear ratio. Once on plane and up in the RPM's good, switch on the overdrive (A .80 ratio if I recall) which should give ya right at a 1:1 final drive. Puts the shaft speed in the sweet spot everyone suggest. That GV unit cost less than couple grand and will hold 2000hp. Two speeds, no tranny, correct propshaft speed without adding more than 100lbs to the boat. Guarantee 100+ all day long in a 26' boat with bravo drive and a solid 700hp diesel with twins spinning under 4000 revs.
Those are all the options I've considered.. :thumb:
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Never thought of the gear vendors idea for a boat 2 speed. I know they have there weakness, but in a marine application the deceleration shouldn't be such a problem like it is for OTR. To bad the old US gear is out of business, them things could handle accel and decel without issue, and were as tough as the GEAR VENDOR. I know a few have used the powerglide which can be built to handle the power as well.
Yeah the old Doug Nash units off a 4+3 Vette were kinda what I was thinking of using. The next version was used on 80-90's Dodge trucks with that push button tail shaft overdrive. Those should be pretty common. All them are a simple cone clutch with a planetary gear set. Fewer moving parts the better..
Plus total case length on those OD units is like 16" or so, which in a boat can be a big deal. A bravo style "stand off" box is typically about 12-14". So you could add that and get away without a bunch of interior mods. Which you can't do with a automotive transmission.
The other limiting factor marine is shaft rotation direction. Yes single engine setups can use an automotive style trans like a powerglide. However when you have twin engines, one of those output shafts MUST spin in the opposite direction... This is either done inside a transmission, the outdrive, or by using a jackshaft. Once again limiting your options greatly..
I tend to look at turbo diesel boats like driving a stick shift in 3rd or 4th gear only, while pulling a load up a hill... Ya gotta gear it so she will get moving and lite the turbo, but still shoot for a top speed over 30mph. It's a very fine line, further limited by only about 2 common gear ratio's available in drives. Typical Bravo outdrives have a 1.75:1 or 1.5:1 ratio. More rare is the 1.35:1 and 1.26:1 which my build had. What's needed is a 1.0:1 or a 0.85:1 for a fast diesel. Which do not exist unless you know someone who can machine and harden a set from scratch.
Ok again I've highjacked Hawks build thread.. :hug: Sorry.
Plus total case length on those OD units is like 16" or so, which in a boat can be a big deal. A bravo style "stand off" box is typically about 12-14". So you could add that and get away without a bunch of interior mods. Which you can't do with a automotive transmission.
The other limiting factor marine is shaft rotation direction. Yes single engine setups can use an automotive style trans like a powerglide. However when you have twin engines, one of those output shafts MUST spin in the opposite direction... This is either done inside a transmission, the outdrive, or by using a jackshaft. Once again limiting your options greatly..
I tend to look at turbo diesel boats like driving a stick shift in 3rd or 4th gear only, while pulling a load up a hill... Ya gotta gear it so she will get moving and lite the turbo, but still shoot for a top speed over 30mph. It's a very fine line, further limited by only about 2 common gear ratio's available in drives. Typical Bravo outdrives have a 1.75:1 or 1.5:1 ratio. More rare is the 1.35:1 and 1.26:1 which my build had. What's needed is a 1.0:1 or a 0.85:1 for a fast diesel. Which do not exist unless you know someone who can machine and harden a set from scratch.
Ok again I've highjacked Hawks build thread.. :hug: Sorry.
Yeah I'm gonna have to change the gear sets in these 6's but I want to get in the water and see how it acts first. The guy I bought them from told me they were 1.1's but they're 1.35 or maybe even 1.50's.
They did make some of the wet sumps in 1.1 and 1.15 so maybe they're around to be had.
Most of the yanmar/bravo xr set ups around here are around 1.50, I guess the thinking is that top end is useless if you can't get on plane
The best approach would be to start with a really efficient hull like Will's stretched 30 Phantom. He's getting a little over 100mph with a single 600 hp BBC.
They did make some of the wet sumps in 1.1 and 1.15 so maybe they're around to be had.
Most of the yanmar/bravo xr set ups around here are around 1.50, I guess the thinking is that top end is useless if you can't get on plane
The best approach would be to start with a really efficient hull like Will's stretched 30 Phantom. He's getting a little over 100mph with a single 600 hp BBC.
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Been following that new build for a while. I heard the Cummins powered Vee used for Bermuda run is setting out at LOTO. Where it's been for sale since last year.
Anyone else think they are shooting a little high on HP goals to expect more than a few hours wide open running on Dmax blocks?? I've seen some of Stings leftover pieces first hand. With way less than a hour running at those levels. Wagler is betting his name on em, so more power to him. But boats are a different animal.
I do like the size of those charge coolers. Should do the job well. However Tyson blew off a serous question someone brought up on another site about condensation. My charge cooler was also mounted on top the engine when I first bought the boat. Engine had less than 35hrs boating time on it over 2 previous years. But I don't know the engines history before that.
Then when we tore it down that first time to fix a spun rod, there was major water etching marks in at least 3 cylinders. Could never say for certain how the water got in there, but it definitely set long enough to etch the block 0.30 deep sometime before I bought it. After we punched out the block, you could still make out those water marks. So I moved that charge cooler off the engine to remove any chance of condensation draining into cylinders after shut down.
I recently heard Ford recalled the F150 Ecoboost due to condensation issues related to over chilling the charger air. That's just an Air to Air unit. So makes me wonder...
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Yes they did and the solution was to block part of the cooler to make it not so efficient.