V6 to V8 Swap in a Tritoon

[Flow9181]

Hope everyone is doing well. Was curious how hard is to do a V8 swap if I go with the another volvo motor

I have a 26' premier tritoon with a 4.3gxi V6 (225hp). I average 37-38 mph gps and I was curious on swapping to a V8 if I can find one at a decent price.
How much speed could I gain with a V8 ?? Volvo has the 5.7 or the 6.0 (380hp)
My DPS-A outdrive should handle a V8 and bolt right up right ?
Would I have to change the gear ratio or just props ?
if I buy a complete motor what all else would i need to change ?

Gear Ratio
Motor Mounts
What about computer ?

 

[Scott Danforth]

first, you need to have about 4-5 inches in front of your existing V6

you buy a complete bobtail, you may get away with just a prop change

motor mounts will be in a different place

computer comes with the motor, you will need to get the correct ECM for the new motor.

you may get to 42-44mph, then again, you may tear the engine pod from the 'toon

 

[Flow9181]

first, you need to have about 4-5 inches in front of your existing V6

you buy a complete bobtail, you may get away with just a prop change

motor mounts will be in a different place

computer comes with the motor, you will need to get the correct ECM for the new motor.

you may get to 42-44mph, then again, you may tear the engine pod from the 'toon

Yea i have plenty of room in front of the engine,
I really thought a V8 swap would net more mph. Would like to see 50
maybe I'll just leave it be and buy something else way down the line. I figured a engine swap is cheaper than a new boat

 

[Scott Danforth]

if you are only getting 37-38mph with your V6, you will gain about 5-6mph with the 5.7 you will gain a bit more with the 6.2, however doubt you would hit 50mph. the increase in HP needed is exponential to the increase in speed.

adding lifting strakes will help

 

[Bondo]

however doubt you would hit 50mph. the increase in HP needed is exponential to the increase in speed.

Ayuh,..... That, ^^^, would probably take a well built BBC,.....

 

[Flow9181]

It has lifting strakes on it from factory. boatmag did a article on the same boat with the 5.0 and it hit 39 with a single prop and no adjustments.



Our test of the 235 Escapade took place on the St. Croix River just outside of Stillwater, Minnesota. The current was enough to cause us to take numbers upstream and downstream to get an accurate average. We had two people aboard for the test and a half tank of fuel (26 gallons — about 163 pounds). For power we had a 270 hp 5.0 GXi Volvo Penta spinning a three-blade aluminum prop.

Acceleration was commendable at just under seven seconds from 0 to 30 mph — this is good considering we're used to seeing between nine and 10 seconds for smaller fiberglass runabouts and deckboats. Spooling up for top speed got us to 39.7 mph at 4,500 rpm. The 5.0 GXi Volvo is rated for a top rpm of 5,000, so there's plenty of room here to experiment with some propellers with a little less pitch to get the rpm closer to where it needs to be, which should give the craft a nice little bump in speed as well.



Wonder if it would handle a mercruiser 454 lol

 

[Scott Danforth]

So a 5 liter gets you 39mph......

Your 4.3 MPI has a WOT RPM of 5200. Why are you limiting it to 4500 RPM. The ECM will keep it from over reving

Change your prop and let the 4.3 spin where its happy

 

[GA_Boater]

Scott Danforth The OP did a copy and paste of a review from somewhere to justify tossing the 4.3 and putting in a V8.

 

[Flow9181]

Yes Sir that was a copy and paste from the boatmag test they did.

I'm working on some prop play now. When I bought it, it had F6's on there and it would only hit 4k rpms. The guy I bought it from said he bought it with those and that's all it ever did was 4k and best was 39 mph... I changed the fuel screen, had the injectors cleaned and flow tested and changed the fuel pump assembly cause of the volvo paint and then I bought a set of used F4's to try. took the boat out and it did 4400 but when I backed off and got back in it back to 4k it went... sent the props to my local prop shop for him to work on but he still has them. waiting on him to finish them so i can retry them.

I'd love to have a V8 in it though but only if I can find one for the right price. Keeping an eye out for one

Will a Mercruiser Bolt up to a DPS-A drive ?

IF I every do this I would like to put in a Mercrusier instead as just for the ease of local mechanics and parts.
Nobody wants to work on these volvo's around here

 

[Scott Danforth]

it would be cheaper to sell what you have and buy the boat you want.

 

[Flow9181]

it would be cheaper to sell what you have and buy the boat you want.

I figured the cost would be cheaper, say 20k or less.. I only paid 24k for the boat

I'll probably end up getting my use out of it then sell it and buy another unless i find a steal on a motor

 

[WorkingFromHome]

I figured the cost would be cheaper, say 20k or less.. I only paid 24k for the boat

This fits your criteria... https://www.michiganmotorz.com/volvo-penta-complete-engine-package-380hp-p-11476.html

 

[Flow9181]

This fits your criteria... https://www.michiganmotorz.com/volvo-penta-complete-engine-package-380hp-p-11476.html

I looked at that one since it would bolt right up, even seen one on ebay for 3k but needed to be gone through.

Curious how much faster it would actually make my boat go though