Prop/Spacer testing update:

Went down to OCM today to test the boat with the spacer completely removed.
Thank you Tim, for getting this done while it was pouring rain last week.

As Steve commented, the 4 blade Bravo's were completely useless with the prop shaft only 3.5" deep, posting slip numbers between 22% and 24%. The best 4 blade speed was with a Bravo 32 @ 87.8 mph.

Now for the good news... Raising the drive removed about 70% of the chine-walking issues, and made the Hering props come into their own.

I initially tested my 27 Hering, and went 91.6 mph @ 5900 rpm. Very slight chine walk, but controlable. Because of the raised height of the outdrive, slip was about 9.8% This is only .3 mph faster than my previous best, but the boat was now controlable.

I was very pleased, but thought RPM was a little high.

Went back to OCM and Tim suggested that I triy his slightly massaged 29 Hering. (One of the two he likes running on the Flame), to bring the RPM down a bit.

WOWSER!!

93.3 mph @ 5700 :evilb:

Four runs, all between 92.9 and 93.3 mph

I am completely stoked!!

Tim and I are now arm wrestling, for the 29 Hering.
I am pretty sure I can take him... :ernaehrung004:

Chris

What size props does he run on the flame with 525's? You mentioned there were two. One is the 29, what is the other?

Great stuff Chris...
So ho much are these Herings :party-smiley-004:

Dave

Tim runs the Hering 29's on his flame.

And I just stole one of them :ernaehrung004:

Chris

Dave,

The Hering 5 blade Bravo props are about $1600 a peice.

This price includes having the props blueprinted, balanced, and adjusted if needed after running them on your boat.
Adjustment includes cupping, diameter reduction, trim ring removal, etc. Whatever is needed.
If the prop you purchase is not the correct pitch for your application, they will exchange it for the correct pitch.

Jeff at Hering is simply awsome to work with!

The props are hubless, and come splined for an XR shaft, to insure better balance, and lighter weight.
They also come with a teflon sleeve to insure a tight fit on the prop shaft.

They are works of art!

Chris

Sweet, nice work, again

Best speed to date = 94.1mph - one run.
Could not duplicate it.

Average between 92.9 and 93.3

29 Hering 5 blade, 15" diameter, 5600 rpm

I am going to try a 28 Hering next, to get my rpm up to the target 5800 rpm.

Chris

New personal best: 94.8 mph

The new trim tabs completely eliminate any chine walk, and the Hering 28 pitch 6 blade hauls butt!

I did three runs today over 94.4.

This trim tab placement works!

Chris

That's awesome.

Your continuous tuning has dramatically paid off.


UD

Tabs look sweet.