I am currently putting in 8.2 New GM marine carb engines. The boat had mismatch 7.4 mpi Engines . 1997 Blue water and a 1999mpi. The 1999 failed and I ended up with the boat as is . The boat is fresh water cooled and still has two log style mufflers with 3” risers on the exhaust manifolds. Could not find the mpi parts to build up matching motors so I went carbs. Do I need to replace the exhaust manifolds with a new style or will old ones work. Not sure what happened to the bad motor . Took the intake apart and and there was rust .It had been setting for two years with no spark plugs in it.
Repower 1998 370 Sundance
- Thread starter Maxdog
- Start date
Stee6043
Well-Known Member
Do some googling for "water reversion". Your original motors could have been victims to a known issue with the log style mufflers. I don't know for sure the years/models that were most susceptible but you're definitely in the age range.
It sounds like it's too late but I personally wouldn't have put carbed motors in a '98 boat. You're at the age range where people are going to expect EFI. Though nice, new, fresh motors might offset the perceived downside to carbs. Cold be a toss up.
It sounds like it's too late but I personally wouldn't have put carbed motors in a '98 boat. You're at the age range where people are going to expect EFI. Though nice, new, fresh motors might offset the perceived downside to carbs. Cold be a toss up.
PlayDate
Well-Known Member
502s are beasts. I don't see a problem going with carbs other than you will have to change out the fuel system and deal with the wiring differences. The good news is you won't have an ECU that will stop working and make your life miserable.
I use Holley Marine 800s on mine which are easy to work on. Holley now makes a Holley Sniper EFI for marine applications which I find interesting. It basically is throttle body injection which you can tune and manage with very little effort.
I would sort out the exhaust manifold issue. The last thing you want is water in those engines.
I use Holley Marine 800s on mine which are easy to work on. Holley now makes a Holley Sniper EFI for marine applications which I find interesting. It basically is throttle body injection which you can tune and manage with very little effort.
I would sort out the exhaust manifold issue. The last thing you want is water in those engines.
Thank you for your feedback. I wanted to go with mpi but the cost of the new motors only at 40k to 50k would not work. I did come across a complete Cummins packages 5.9T with all the drive out of a 95 44DA with 1100hrs . This is still available if someone is looking for a major change and It’s all there including exhaust. I do have pictures .
RollerCoastr
Well-Known Member
- Nov 15, 2007
- 3,884
- Boat Info
- 1997 400DA
340HP 7.4 Mercruiser Bluewaters
Garmin 741, 742, 8212, 24HD, Intellian I2
- Engines
- 1999 280BR
Twin 250HP Merc 350 Alpha Ones
Wait, what?! I'm in perpetual Mercarb hell. The 2 barrel version of the Sniper is only $849! If I paid myself minimum wage for all the messing I've done with gunked-up or ethanol-attacked carbs I'd have enough to buy a set of these. This sounds too good to be true...
Have you heard any reviews?
yobub
Well-Known Member
*This*
This generation Sea Ray had issues with water ingestion that are well documented. I believe it was more prevalant on the 330s than the 370s, but it may have been the reason for the engine replacement you have. If you search sea ray water ingestion you will find a ton of information. If you are a boat us member you can call them and they have a lot of info on it as well.
I was told (by a salesman) that it didnt happen to the 370s, but I have read elsewhere that it did. It will be important to understand what you are working with before you replace the engines, so you dont replace twice.
Different people have different feelings on carb vs fuel injection, but I am 100% with @Stee6043 , when I was looking at 98 370s, I was only looking for fuel injected engines. I've owned both over the years, and personally would never go back to a carbed engine.
Also, you may be aware of this, but the 98 was the only year the 370 had the higher radar arch. It makes it a more desirable 370 for many people because you can stand when driving. That may give you more resale value that will be compounded by putting the right engines in the boat.
Stee6043
Well-Known Member
That cost seems really high? I may be way off but I would imagine a reman big block Merc should be available in the $5k range? $50k for motors sounds like diesel levels of expensive....
PlayDate
Well-Known Member
Tell me about it! I have been looking at these things for years and Holley just got the USCG rating for them. I looked today and couldn't find a lot of installs to read. The only hitch is the wideband o2 sensor but even that isn't a big deal. They do require a return fuel line but that isn't a big deal either.
If I had the time, I would swap out my Holleys for a couple of these just to see what the difference would be. It makes a lot more sense to have a fuel curve that fits the boat. It has always been a guess with carbs because you need to dyno them off the boat to jet them properly. I like the design of the Sniper because the ECU is built in and controls the distributor as well as the fuel.
It would be a good article for Boating magazine........I have all the fuel numbers for the Holleys..........if I didn't have so many projects......I would offer to make the change and write it up.
Saverio
Well-Known Member
- Aug 31, 2010
- 1,503
- Boat Info
- 1995 450 DA
- Engines
- Cat 3126 420hp
900 hours Westerbeek Generator
PlayDate
Well-Known Member
Interesting.....my only concern is that they are recycling rebuilt GM TBI Throttle Bodies in their kits which raises a question if they have USCG certification. Maybe they do and I haven't found it. Still, I like the Holley design a bit better since the ECU is built into the unit so there are far fewer wires.
https://www.affordable-fuel-injection.com/product/chevrolet-marine-complete-tbi-system/
midexp
Active Member
- Oct 5, 2016
- 423
- Boat Info
- 1999 40' Sundancer
- Engines
- 454 merc
I agree 100%!!!!
Can someone tell me where I can find info on the up grade water lift mufflers. Who sells them for a sea ray 370?
Also the boat has 3” riser blocks on the exhaust and I am thinking about going with 6” for a little more lift since I have the room. Any thoughts? Also this boat has lost two starboard motors in 725hrs and it looks like water damage on the bad motor coming out.
Also the boat has 3” riser blocks on the exhaust and I am thinking about going with 6” for a little more lift since I have the room. Any thoughts? Also this boat has lost two starboard motors in 725hrs and it looks like water damage on the bad motor coming out.
PlayDate
Well-Known Member
Give Perfprotech.com a call.....they will help you sort out what pieces you need to ensure it won't happen again. They can also help you with the engines.
WV 320 Dancer
Well-Known Member
- Oct 28, 2018
- 971
- Boat Info
- 2003 Sea Ray Sundancer 320
- Engines
- Twin 350 MAG - V Drive
While I do not have any experience on the marine application of the Sniper we put this system on my friends 1972 Cuda 340 and all I can say is WOW! No more carb waiting for the car to fire while you are cranking it. Just hit the key and it hits on the first lick. The wiring was super easy to retro fit. If it were me I would definitely add EFI your ability to resell the boat will be much better.
