Volvo Penta MD6B reboring

[Ifylios72]

Hi all,

I am building a 29ft sailboat attempting some controversial lines on the shape of the hull before I start working on the sail plan. I have bought for this boat a VOLVO PENTA MD7B 17 hp engine only to realise soon after that in fact it is the MD6B 10 hp engine cheated on paper but thankfully in sound condition.
I got to like this good old simplicity and robustness in design and engineering quality of this engine comparing to popular here Japanese makes so I decided to keep it.
The MD6B is the minimum option for my boat and I am considering the possibilities to improve on power if this is possible.
Doing my research and comparing the two engines according to Volvo parts lists I see that differencies between the two engine types (MD6B and MD7B)are only in the piston bore, intake/exchaust valves and injectors (ie cylinder head).
Am I right to believe that I may be able to obtain those extra 7 hp by attempting reboring and replacement of the cylinder head?
Has anyone else attempted a conversion like this?
Any ideas or help will be much appreciated.

[tommays]

Volvo parts are rather costly and not always that easy to get

[Ifylios72]

Very nicely put Tommays. I have done my research on the parts and except from the pistons it is possible to replace the valves and injectors on the old head and work out the modification not depending upon finding the original parts and surely cheaper. First however I would like to know if that can work. Can she rev up to 3000 rpm's without problems as the 6B has a spec of max 2400, (identical components throughout). I can also make a thicker gasket in order to increase the volume of the combustion chamber and decrease the compression from 19:1 to 17:1 of the spec of the 7b. I began to love the character of this engine and the brick like cast iron body with minimal vibration that allows it to be fitted rigidly and reminds the good old days of engineering. This project is for next year so there is plenty of time to think about.
Thanks again