LS Swap Seafari 25

[FLexpat]

I love it but don't go too crazy on that build!!!
I think the straight back Bravo 3 is limited to about 450 ft-lbs torque unless you do some upgrades. Another thing to watch is how deep you mount it - I know you can get drive extensions (0.5"-3") but I don't think you can get a shorty lower for the Bravo 3.
This might be useful: https://www.go-fast.com/Mercury-Merc...uction-Changes

[Xcomunic8d]

Thanks I’ll look into that. Most of that parts list is the heavy duty parts to handle prolonged higher rpm than car engines experience (main bearings, connecting rod bearings, heavy duty bolts, etc). I’m trying to make a how-to as there aren’t many out there and I want a simple list for the next guy who wants to do this.

The dealer was kind enough to tell me merc’s suggested mounting point of 13 9/16” up the framing sq from keel of boat. That’s the center point for the template to cut out drive hole. I’ll need to mark that and compare the centerline of flywheel and the A/V plate on foot to keel. I’ll measure it out and let you guys know how it’s going.

I was told 600hp was max. I was worried I wouldn’t have enough torque but my bravo3 has a 2.0 (we think) gear ratio. We’ll know more once we tear it apart, inspect and reseal it. It’s the older style without the swept back design. My local dealer told me it’s gonna max out around 55-60mph depending on rpm and be an absolute torque monster with dual prop and 20p blades.

The cam I’m planning on running is a tsp212/218. 437hp @6200 rpm, 418tq @ 4800rpm. I plan to high speed troll 13-20mph most of the time. Other than slightly ported heads, and maybe a bigger TB, there are no other power adders.

I’ll be mating it up to the 454 coupling on flywheel to help mitigate the chance of shearing the coupler apart. Those things are pricey.

I think I finally solved the raw water pump mounting issue to the crankshaft. Hopefully I’ll get through to guy I need to speak with tomorrow.

[Xcomunic8d]

So parts are coming in left right and center. I haven’t taken pics of each one b/c how exciting are piston rings and main bearings? I figured you see them installed.





Here’s more hand valve lapping.



Using your water pump bolts can be very helpful to install the cam. Also it’s useful to reach around behind to guid it in for the last 2 cam bearings.



Here’s my 12yo son putting in his first batch of lifters.







So the exhaust manifolds come in Monday. The majority of raw water system comes in tonight at some point.

I ended up ordering the exhaust manifolds from Hardin marine b/c they ended up being cheaper. The marine engine depot guy told me I had to pay more for O2 sensor bungs and it was not in a kit. I did however get most of the raw water system there.

[Xcomunic8d]

So I caught a mistake when I was reviewing my project. And trying to order a Holley terminator x. The timing set I ordered is compatible for a 1x sensor not a 4x sensor.

i 2 day aired a different cam sprocket in. It was a BTR.

Wrong sprocket for my gen4, 58x reluctor 4x cam sensor:



right sprocket



I tried to break my collarbone yesterday so my son is installing the second head under dads close supervision. I was helping some older friends pack and move off island. I had just repaired the bumper on their avalanche. I was up to my elbows in grease and filth due to rain and conditions. I went out back fo wash off. I went one way and mud went the other. My shoulder landed squarely on a lava rock. Boy that hurt.




torquing rocker arms









the exhaust manifolds are here and look awesome. That’s a follow-up post shortly with more research I did and info that will help the next guy.

[Xcomunic8d]

So it’s kind of bad news, good news, bad news.

bad news #1. Can’t find a Holley terminatorX 550-905 or 905t anywhere. If anyone can make a suggestion on where to find one or a different tunable system that has a harness, O2 sensors, and supports MPFI. Otherwise, I’ll be waiting until mid-late August (hopefully).

good news, as I was thinking through how the elbows and risers work along with closed cooling it occurred to me that water might be flowing over O2 sensors. That would be catastrophic. I didn’t want to change these out regularly. I see no worries fir that.



you can see the O2 bungs here.


water inlet passage:


exit:

i do have the parts to install a crank mounted raw water pump. It’s kind of cool when you think up an idea to have a machine shop build and then a little discouraging to find it’s already made. But I suppose that is reinforcement you are on the right track. I’ll post those pics and parts when the whole system is here.

Bad news #2- this is kind of painful

the bravo 3 outdrive I purchased needs a full rebuild. Gear set, cone clutch, shims, seals, bearings, everything- but case, props and shafts are done.
I’ve really considered going alpha route but I’m too far in to turn back now and Bravo is clearly better suited for my application.

I was told it’s pushimg $7k for that job before I buy the gimbal housing another 3k. I got the parts list and found a way to trim some costs down. I expect it will be 4.5k-6k. And then the gimbal housing at 3k. A new alpha is under 3k for whole thing and while that appeals to my wallet. I don’t think that is a wise long term choice. But oh this one hurts, ouch really bad…

we decided to go with 1.81 gear ratio. Originally it was a 2.0 gear ratio. We considered a 1.65 but we’re concerned somethings gonna give as that was not designed for these shafts as well as the load on the engine. Given it’s primary role of fishing we decided to play it safe. I have the parts lists if anybody wants them. Partsvu.com says it’s $3k out the door.

[FLexpat]

Originally Posted by Xcomunic8d

Bad news #2- this is kind of painful

the bravo 3 outdrive I purchased needs a full rebuild. Gear set, cone clutch, shims, seals, bearings, everything- but case, props and shafts are done.
I’ve really considered going alpha route but I’m too far in to turn back now and Bravo is clearly better suited for my application.

I was told it’s pushimg $7k for that job before I buy the gimbal housing another 3k. I got the parts list and found a way to trim some costs down. I expect it will be 4.5k-6k. And then the gimbal housing at 3k. A new alpha is under 3k for whole thing and while that appeals to my wallet. I don’t think that is a wise long term choice. But oh this one hurts, ouch really bad…

we decided to go with 1.81 gear ratio. Originally it was a 2.0 gear ratio. We considered a 1.65 but we’re concerned somethings gonna give as that was not designed for these shafts as well as the load on the engine. Given it’s primary role of fishing we decided to play it safe. I have the parts lists if anybody wants them. Partsvu.com says it’s $3k out the door.

Smart move in avoiding Alpha - While it is a good drive up to ~300HP, your motor would destroy it pretty quickly. You might check out the swap shop on OffShoreOnly - I have seen decent looking Bravos there periodically. Think Bravo X if you go that route.

[Xcomunic8d]

I have given up on getting a terminator x from Holley. They have moved shipping dates to end of October for the unit I need.

I did find the lingenfelter trg-002 that allows a 58x/4x to run on a 24x/1x. Holley only had ev1 injectors and I have ev6 and I thought adding $300 to the 1k price to do something even ling was a little like “I don’t know man…it should work?” Add it about 1400 for this one engine I figured I depin and tune for much less.

I ordered a harness and ecm for $275 shipped. I’ll depin the harness and program the ecm. I plan on HPTuners ($600) unless there is better advice. I’ll just need a pair of O2’s and I’ll be in business.

I made a run stand and here pics as of now. I’m waiting on the new bell housing for the flywheel and starter. Getting a little closer everyday.

The run stand is a 4x4, some casters, a 2x4, some pocketholes and lag bolts. I figure I will get it running and tuned on stand before lifting it up with gantry crane and in.







Should be picking up bell housing tomorrow. I’ll be adding a plywood control plate for gauges and ignition switch to make sure it’s all good. I’ve been trying to figure out the cooling. It’s been kind of pain finding the fittings and hose locally (without getting destroyed on money).

[Xcomunic8d]

So here it is with exhaust manifolds on.



Problem with coils…


I’ll have to relocate the coils using ict billet stuff. #’s 551115-01, 551532- don’t forget custom length plug wires not sure which ones yet I’ll use.



I’m working on the cooling system. I’m trying to get a drawing of what I envision but I’m artistically challenged. It’s not going to be cheap… I have a friend that runs a local plumbing shop.

The harness and ecm should be here Tuesday.
I’m working on ordering the HP tuning supplies and fuel system as we speak.

[FLexpat]

Make sure you put a remote oil filter kit and remote drain valve kit on that - it will save you a ton of time and frustration. Does it have an aluminum oil pan? Oil pan rust-through is a giant problem with deep bilges.

[Xcomunic8d]

Has an aluminum oil pan that I have seriously coated in paint and primer. Everything’s been or getting painted… Definitely putting on a remote drain kit (flip lever with hose out the drain plug style). I’ve been arguing about an oil cooler (requiring remote oil filter). It’s probably worth it.

EDIT: this cooling plan is bust see new post about this.






This is what I’m going for but above shows fitting sizes. I was toying with doing a pipe manifold with 4 inputs on bottom of manifold (already has threaded holes) but think dual in and out will give more flow.




Input, suggestions, etc, please.