I have questions about the Wedge Head modifications done by Jim V. I am considering these as part of a cam upgrade. Engine is a stock gen VI 502 with a Dart single plane, Holley 800 and Lightning headers. Boat is a Baja Force 235. Running about 70 GPS with a 23 Mirage Plus and about 68 over-propped with a 25 Mirage Plus at around 44 or 45 hundred rpm. What rpm might I see with the heads and cam running the 25? I am considering a cam of around 230/236 or 236/242, something in that range.

Does anyone have any experience with the Wedge Heads? If I were to have the wedges installed I may also have the compression raised a tad, maybe 9 to 1. What performance gains could be expected with the Wedge Heads and how would those gains compare to Merlin large oval ports or an aluminum head with higher compression? Cost vs. gains comparisons?

Tim T.

Tim, I purchased a used 468 motor with JimV's heads with the wedges. While I have never dynoed the motor, it is awesome , I have run it in a 251 convinsor, 24 hydro VI
prop @ 5800 rpm. You should look for an old article in HOT BOAT on JimV's wedges. 502 running a conservative 690 HP (belongs to the Boards MRGADGETS) I love my motor and Jimv's great to work with.

Thought I'd bump this up for you, Tim, since you did not get much response...

Thanks, I think we are both curious? I have not had a chance to look for the article. Anyone know where this may be found? Jim's workmanship and reputation are well known. All I am looking for is if this is a practical application for my engine and how the results may compare to more expensive options.
Tim T.

I have stock heads that Jim put the wedges in and I have all the stuff you have except I am running HOLLEY HP950's and ULTRA DYNE solid flat tappet 251/259 @ .050 with .601/.625 lift.
I was running 23 mirage at 5100 before with the stock motors and the same props at 5800 after. I am now running labbed 26 BRAVO's at 5600rpm or unlabbed 28 bravo's at 5100 at 77 gps with my 34 SCARAB. You WILL be happy with the heads.

Tinkerboater,

What intake manifold are you running with these heads? Square port, oval port, or something that Jim developed to match up with the heads?

I am running the dart rec. port intake with the floor welded up to match the head. The boat did 65 mph stock - it now does 77 gps.

JimV knows how to make the wedges work well.

This is the kind of input I am looking for, keep it coming.
Tim T.

The head modification was the only change done that resulted in this speed increase?
Thanks,
Jerry