hydro tec heads how much improvement?

[gotmy5]

how much improvement will a set of hydro tec heads will it make with an 07 hpdi 250 the motor is on a 21I

[TomM]

I don't think heads alone will give you much at all. Just like a car, when you increase compression or flow, you have to compensate with more fuel and air. Hydro Tec sells their parts in kits for a reason.

Tom

[GE Blazer]

Depends on the boat. A performance hull, about 2-3 mph on top. Where it helps all boats is holeshot and midrange.

[reelman]

Heads give you the biggest solo mph boost (or does for most engines), been there.

My 2002 rig did 74 with them...200hp basic V-Max.

Now I have the reeds and the ECU upgrade in my 2006 Yam HDPI and do the same 74 but the HDPI has good upside potential w/o needing the heads so I stopped at reeds/ECU for now...
I would smell 77-78 with new heads on this HDPI as I understand (Matt or Wayne Worthy can verify this issue)...requires 89 or more octane for any new hi-perf heads...may get some myself this year, we shall see.
Call HT and they will answer any questions the same day.

[STROKEDYAMAHA]

pretty good bang for the buck......I really liked the flywheel too!