Swapping out engine - Advice needed pls

[Iamsgf]

I have a portcraft 270 with a Merc 5.7 V8 that drinks like a fish!! I would like to swap it out for a diesel but no idea where to start looking! Can anyone suggest what size engine I should be looking at? I am after good economy and for it to also have a little bit of "grunt" when needed!

 

[[2068]]

Something like a Volvo D4-260 will give you similar performance...
BUT it is quite heavy, expensive (£20k), and might not even fit in your engine bay.
First thing to do, is measure up.

http://www.volvopenta.com/volvopent...ATIC/c_diesel_sterndrive/Pages/d4_260_DP.aspx

 

[Mexican]

When I swapped my old 5.7 in a Bayliner 2655 I went Yanmar 4LHASTZP (240hp) with Mercruiser Bravo 3x - increased fuel economy from 1mpg to over 3mpg and increased top end from 28knots to 32knots. Cruising at 2900/3000rpm at 21/22knts gave me 5/6 gph. Hope this helps - there are some out there 2nd hand I believe.

 

[Firefly625]

When I swapped my old 5.7 in a Bayliner 2655 I went Yanmar 4LHASTZP (240hp) with Mercruiser Bravo 3x - increased fuel economy from 1mpg to over 3mpg and increased top end from 28knots to 32knots. Cruising at 2900/3000rpm at 21/22knts gave me 5/6 gph. Hope this helps - there are some out there 2nd hand I believe.

great engine choice BTW.

 

[PCUK]

I may be wrong but I believe the GM 6.5 V8 is a more or less direct replacement. (Ducks behind parapet!)

 

[Mexican]

GM 6.5 V8 - looked at that one. You still have to match to a suitable drive also the engine is significantly heavier and a much older design with particular problems. Plenty in the US and used by military in many applications. One UK Supplier in UK(Devon) had major problems and also supplied an engine for Bayliner 2855 supposedly bench tested to 250hp but was infact barely 180hp - owner then went Yanmar route!!! - after considerable expense.

 

[PCUK]

Mexican, I'm glad you didn't use the 'S' word or all hell would broken out here!

 

[rhino_mac]

When I swapped my old 5.7 in a Bayliner 2655 I went Yanmar 4LHASTZP (240hp) with Mercruiser Bravo 3x - increased fuel economy from 1mpg to over 3mpg and increased top end from 28knots to 32knots. Cruising at 2900/3000rpm at 21/22knts gave me 5/6 gph. Hope this helps - there are some out there 2nd hand I believe.

I had this engine in my Monterey 250cr which was originally specced in the US with a V8. My understanding was this was designed with replacing V8's in mind. I used to get anywhere between 3 and 4 mpg out of it depending on sea state etc. Great engine and apparently, bulletproof. But expensive - i think a replacement was about £25k. You'll need a new leg etc to cope with the increase in torque as well. Think mine was a Bravo 2.

 

[Spi D]

Cost usually prevent people from going down that road.

The fuel saved will never pay the cost of repowering, but do your own budget and see.