VP B20 heads

[wests]

Hello

Does anyone here have knowledge about the B20 heads? Are they basically the same? I have a AQ115 that has a head with pretty much corrosion and I have a head from a mb20b that I could use for replacement. Can I just change the heads without any problems/effects on power?

Thank you

 

[PiratePast40]

Re: VP B20 heads

There are several versions of those heads but information is rather scarce. Do a google search an you'll come up with some information on the differences. I believe that the cooling water opening below the thermostat housing may be different on the automotive version but not sure. Any of the marine versions will work though.

E-bay or a local marine bone yard will be your best bet for a replacement. The older heads had smaller valves and replaceable valve seats. I've seen are cracks from one valve seat to the other. Have also seen some pretty poor valve seat replacement work. Be very careful about shaving this head. Lowering the head volume, and thus increasing compression, is a bad idea on these engines. It took me awhile to find an acceptable replacement head for my rebuild but they are out there. They tend to last a long, long time and the boats tend to rot out from around the engine and outdrive before they actually wear out.

 

[wests]

Re: VP B20 heads

There are several versions of those heads but information is rather scarce. Do a google search an you'll come up with some information on the differences. I believe that the cooling water opening below the thermostat housing may be different on the automotive version but not sure. Any of the marine versions will work though.

E-bay or a local marine bone yard will be your best bet for a replacement. The older heads had smaller valves and replaceable valve seats. I've seen are cracks from one valve seat to the other. Have also seen some pretty poor valve seat replacement work. Be very careful about shaving this head. Lowering the head volume, and thus increasing compression, is a bad idea on these engines. It took me awhile to find an acceptable replacement head for my rebuild but they are out there. They tend to last a long, long time and the boats tend to rot out from around the engine and outdrive before they actually wear out.

Thanks for the answer. The thing is, the other head is from a marine engine. The mb20b just produces less power(40-50hp ?) and I was wondering about the compression/head volume. Ill have to keep googling