Aq151b sohc head for a aq171 dohc head ?

[dearborndeuce]

Can I install a DOHC head from a AQ171 to my AQ151B eng ( if I can find one ) ?
Reason; looking for more performance on my 18' on a VP290D drive with a 2.15 ratio.
If this is possible, how much more perf might I expect ? dearborndeuce in BC thks

 

[captmello]

Re: Aq151b sohc head for a aq171 dohc head ?

Welcome to iboats!

Looking for more power?

after a quick look at the manual, It looks like the conversion could be done, however, there are more differences besides the heads.

these differences stuck out.

Different exhaust manifold.
Similar carb but all different jet sizes.
Different ignition system.
and of course the DOHC head.

For the 20 more hp, I wouldn't try it. there is bound to be more differences besides the ones I mentioned and the cost could be quite high.

What type of performance are you looking to improve? speed? hole shot? What RPM's are you reaching with your motor currently at WOT (wide open throttle)

 

[dearborndeuce]

Re: Aq151b sohc head for a aq171 dohc head ?

Many thks for your advice Captmello, I agree there is most likely more changes and for only 20HP is it worth it ? My boat is a open 18' fishing rig ( 17.5' centerline ). I just got it from a guy who had a big stainless ( heavy ) fin attached to the drive for a quicker holeshot. Once its up, he said it performed well as long as it wasn't too heavy ( normal I guess ). Many thks, I wait & see if anyone else has any ideas.cheers