Twin Engine Build Need help with specs and options
08-01-2017, 05:43 PM
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Twin Engine Build Need help with specs and options
So here is my deliema and kind of plan. So I have a Formula 302 that I know everyone tells me is not a fast hull max speed is apparently 80MPH. So I am setting that as my baseline. The boats in rough shape and has no engine or driveline at all, so Ihave also another 1989 Sea Ray with tin 454's I believe they are IV 454's with a Bravo 1 that will become the donor motors and outdrives for the swap.
Now my issues is I am getting a lot of conflicting answers, one shop says it's really easy to build big power with the 454's and that I will be happy with the final outcome of the boat when I am done then Ihave another Machine shop that says they do a lot of automotive engines and rebuilding 4 502's for a boat plus doing a couple 454 stroker kits for another marina, then I have an all out boat perf racing shop that's telling me that the auto builderis out to lunch, that the motor will be unreliable and junk afterwards if I let them touch it and that I woudl be better off dumping the money into a pair of his motors he already has built for 40k plus buying his brand new bravo's for another 20k and also says that I am crazy to even think of attempting my project and I should just buy a boat complete from him or locally.
So here I am thinking I am going to discount the guy pretty much full face value. I get it that some people can build a high performance motor for a street or drag car and boats are diferent but how different is it really. It's great to want to buy a Merc Racing Motor if Ihad more money than brains yeah maybe I might go all out on a fountain boat or a custom carbon fiber hull drop in two 800 HP Big Blocks and go racing.
But the reality is 90% of the work will be done by me and my two boys. So what I am contemplating is how truthful are those two people with how the motors will be unreliable and that the bravo's wont hold together with 500-625HP.
My plan is to take the 454's get them over to the machine shop so I can have them hone, zero deck, bore and port the motor. I will install a 496 stroker kit, with new heads, pistons, intake and potentially an EFI TB System.
But what will I be have to be aware of? Is there any perfect match of parts? I get shop pricing because I have an auto dealers lic so getting 20-25% off or more is not impossible.
My only real concern is if these motors will become ticking time bombs like the one personhas claimed.
What is a good tried and tested way to build a 454 into a solid 496 stroker motor. Is there any reliable good quality EFI options? Why do I see so many people with MSD ignition systems if it's not recomended to run automotive parts.
My reason for not wanting to spend 100k for a boat is I live in Canada where I'm lucky if I get to use my boat three months out of the year so I will not spend 100k or 80k on a boat I doing get to use for more then 8 months of the year.
Anyways sorry for the rambling hopefully I can get some insight on a good way to build power out of the motors I have.
thanks again
Now my issues is I am getting a lot of conflicting answers, one shop says it's really easy to build big power with the 454's and that I will be happy with the final outcome of the boat when I am done then Ihave another Machine shop that says they do a lot of automotive engines and rebuilding 4 502's for a boat plus doing a couple 454 stroker kits for another marina, then I have an all out boat perf racing shop that's telling me that the auto builderis out to lunch, that the motor will be unreliable and junk afterwards if I let them touch it and that I woudl be better off dumping the money into a pair of his motors he already has built for 40k plus buying his brand new bravo's for another 20k and also says that I am crazy to even think of attempting my project and I should just buy a boat complete from him or locally.
So here I am thinking I am going to discount the guy pretty much full face value. I get it that some people can build a high performance motor for a street or drag car and boats are diferent but how different is it really. It's great to want to buy a Merc Racing Motor if Ihad more money than brains yeah maybe I might go all out on a fountain boat or a custom carbon fiber hull drop in two 800 HP Big Blocks and go racing.
But the reality is 90% of the work will be done by me and my two boys. So what I am contemplating is how truthful are those two people with how the motors will be unreliable and that the bravo's wont hold together with 500-625HP.
My plan is to take the 454's get them over to the machine shop so I can have them hone, zero deck, bore and port the motor. I will install a 496 stroker kit, with new heads, pistons, intake and potentially an EFI TB System.
But what will I be have to be aware of? Is there any perfect match of parts? I get shop pricing because I have an auto dealers lic so getting 20-25% off or more is not impossible.
My only real concern is if these motors will become ticking time bombs like the one personhas claimed.
What is a good tried and tested way to build a 454 into a solid 496 stroker motor. Is there any reliable good quality EFI options? Why do I see so many people with MSD ignition systems if it's not recomended to run automotive parts.
My reason for not wanting to spend 100k for a boat is I live in Canada where I'm lucky if I get to use my boat three months out of the year so I will not spend 100k or 80k on a boat I doing get to use for more then 8 months of the year.
Anyways sorry for the rambling hopefully I can get some insight on a good way to build power out of the motors I have.
thanks again
08-01-2017, 07:46 PM
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It all depends on what you want to do and spend. These are sea ray motors. Probably peanut port 330 motors. You will be replacing pistons at the least. You sound undecided on well ether to spend 5k and 15 to 20. What year 302? Transom good? S or bravo holes cut in transom? An early 80's 302 running and driving with good interior is hard to get 10k for. You might wanna fire up the existing 454's and put them in the back of the garage. Especially if they were raw water motors. Then start over with a pair of engines you can keep when it is time to upgrade the hull instead of watching them leave at a loss.
08-01-2017, 08:44 PM
#3
Are you capable and up to the task of taking a trs transmission boat and converting to a bravo boat? Redo do transom, set drive height, delete trannys and move engines back?
Just simply asking. On top of that based on your questions it seems you are not familiar with big blocks. The take out searay engines are likely 330s. No good for you except maybe the block and accessories. What exhaust? Etc. Etc.
as long as you know what you are getting into i hope it works out well and most on here are willing to help
Just simply asking. On top of that based on your questions it seems you are not familiar with big blocks. The take out searay engines are likely 330s. No good for you except maybe the block and accessories. What exhaust? Etc. Etc.
as long as you know what you are getting into i hope it works out well and most on here are willing to help
08-02-2017, 11:34 AM
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Are you capable and up to the task of taking a trs transmission boat and converting to a bravo boat? Redo do transom, set drive height, delete trannys and move engines back?
Just simply asking. On top of that based on your questions it seems you are not familiar with big blocks. The take out searay engines are likely 330s. No good for you except maybe the block and accessories. What exhaust? Etc. Etc.
as long as you know what you are getting into i hope it works out well and most on here are willing to help
Just simply asking. On top of that based on your questions it seems you are not familiar with big blocks. The take out searay engines are likely 330s. No good for you except maybe the block and accessories. What exhaust? Etc. Etc.
as long as you know what you are getting into i hope it works out well and most on here are willing to help
The Formula is most likely a 1980's model, which is confusing because both HIN's say 801 as the last three, and the 1 does not look added to either places. SO it should be a 2001, which matches up with the timeline from the previous owner history but the upper portion of the boat clearly looks right out of the 1980's. But to add more confusion to the whole mess Formula has no record of the boat period. At least the current response is that the HIN does not match anything they have in their records, so not a great start.
I got the hull for free, I have rebuilt 4 350's Mercruisers which the last one I still have in my Sea Ray after I got it from an owner who did not winterize it properly and let it sit for 7 years. I have rebuilt it and she's running solid now.
So from experience no I have limited in the Mercruiser world but a combustion engine still operates the same as a automotive with some differences for how fuel is introduced into the engine for gas fumes etc, as well as electronics to be shock and water resistant.
What I am trying to decide on is because the boat was free to me, I dont mind or care putting in 15-25k into the rebuilding portion of it. Especially because if i spend 8-15k on engine parts, 5-8k on driveline, and another 3-4k interior I will still have a boat that will be faster than my Sea Ray Sundeck which I have now only doing a max of 50mph on gps.... I know I could buy a formula from the 80s for 10-12k, maybe a cleanish one for 15k... but from the ones i have seen on Craigslist, Boat Trader and CoPart they are in just as bad of shape as the one I have. However IF I do actually go thru with rebuilding the boat and being able to take into account that I will then have the boat rebuilt to my desires, and trimmed out and upholstered the way I prefer I will be ahead of the race in some respects because I will have to potentially reupholster any boat from the 80-90s in the 15k range, so that there is 3-4k, plus wanting to build more power I will still be sinking in the 8-15k on that boat so I wind up in the same place basically.
My biggest fear is the stringers, and how far I have to tear into the hull to repair it not because I cant do it but I really want to get the boat on the water next summer so it will obviously take into my time and plans. The goal has been to use another twin engine 454 boat with bravo's either crashed or from cabin fire damage. Build up 496's or if I am lucky find a pair of cheapish 502's. Then by using the other boat as the donor provided I have a Gen IV 454 my options for performance parts is much greater plus from all I have been reading they are build stronger than the Gen V and VI's so they could handle the repowering better.
What I am learning is what parts work best for marine use. Heck this is a project, I dont expect to make a living rebuilding these old boats... I am doing this to teach my kids how to work with their hands, how motors work, and for some father son bonding much like my father had done with me before he passed. So this is pretty much why I am looking for the short cut ways of do's and don'ts for the motors. I haven't built a 500hp Marine motor before, but this is my plan for the Formula.
But to answer your question yes the Sea Ray has 330hp 454's with Bravo 1s. I am not to sure if my transom has/had TRS drives or Bravo's or an Alpha installed. Can you tell me what was installed there previously? To me it looks like an Alpha One drive but again I have limited experience in this area. I will be converting it to a Bravo 1 regardless. My thinking with the engines was to use them as starter points so I could get the required marine parts and exhaust from them and keep buying derelict boats that I can scavenge parts from and make my franken boat LOL.
08-02-2017, 01:06 PM
#5
That is a trs boat so the transom will need to be redone. The boat was designed for transmissions and the engines forward 18 inches to accomodate them.
The change may affect the balance of the boat, not sure.
The 330s will put the boat to about 60ish. They are good engines in stock form but not a good foundation for performance build with cast crank, cast pistons, low compression and small peanut port heads.
The change may affect the balance of the boat, not sure.
The 330s will put the boat to about 60ish. They are good engines in stock form but not a good foundation for performance build with cast crank, cast pistons, low compression and small peanut port heads.
08-02-2017, 02:21 PM
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That is a trs boat so the transom will need to be redone. The boat was designed for transmissions and the engines forward 18 inches to accomodate them.
The change may affect the balance of the boat, not sure.
The 330s will put the boat to about 60ish. They are good engines in stock form but not a good foundation for performance build with cast crank, cast pistons, low compression and small peanut port heads.
The change may affect the balance of the boat, not sure.
The 330s will put the boat to about 60ish. They are good engines in stock form but not a good foundation for performance build with cast crank, cast pistons, low compression and small peanut port heads.
Ok so with the 330's some of the parts I am looking to replace the setup with are these.
MSD Pro-Billet Marine Distributors 8560
Ignition MSD 6M-2L --- But finding a lot of bad reviews about reliability with them now that makes me concerned
Holley M-Series 850CFM Marine Carb
Edelbrock Performer Intake Manifolds 2561
Edelbrock Marine-Duty Performer RPM 454 Cylinder Heads 61459
Scorpion Endurance Marine Series Rocker Arms 4016
Eagle Competition Rotating Assemblies 11012030
Thats some of the parts I am looking at right now for the build. What I am disappointed with is that there is no Marine Aftermarket Rectangle Port Intakes that I have found, plus I am still trying to research what type of Cam and if the Heads I selected will wind up helping get me to the 500-600 HP Range.
But I am also wondering if the Bravo 1's will hold up to the power of a build, basically with the Eagle rotating kit it will not bring the motor to a 496 but to a 489. Which might not be all that bad I guess. So I am still wondering if I am on the right path or am I on a path to not making a lot of power or torque. My goal is 80 MPH out of twin motors/bravos.
08-02-2017, 03:12 PM
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As much as I like talking engines and such- that's really all I talk about, I would really sit down, remove your excited / infatuated feeling you have right now, remove all thoughts about power, and really, really look at and think what it will take to get the boat ready before installing the engines.
This is the OP's newly acquired boat, if one hasn't seen it, which i almost missed myself. I'm not being an azz, I'm presenting reality.
http://www.offshoreonly.com/forums/f...n-project.html
This is the OP's newly acquired boat, if one hasn't seen it, which i almost missed myself. I'm not being an azz, I'm presenting reality.
http://www.offshoreonly.com/forums/f...n-project.html
08-02-2017, 05:27 PM
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Wow. Definately a late 70's early 80's 302. And it is too heavy to do 80. And I feel you are in over your head with this beastie. Sick stinger has a 24 pantera hull-drive-int-trailer for 4k. Boston area. That is a fast fun boat. These 302's are more of a cruiser than performance boat. Ride good, but so does my hatteras. I understand your feelings and point of view, but this boat is not a good starting point. Old engineer's axiom: If it can be made, it can be fixed. But that doesn't mean it is a good idea.
08-02-2017, 08:20 PM
#9
do yourself a favor and find a more complete,less trashed father son project ..I think that boat will bum your kids on boats and could instead be a lesson in what not to do ..it cost 45 per ton here to get rid of a boat like that ...just a reality check
