Fairline Targa 33 prop pitch

[Piers]

A new to boating friend of mine is buying a 1992 Fairline Targa 33 with twin KAD42/DP. It appears to be in good order (surveyor's report etc) but the props show the effects of cavitation.

Prop pitch is unknown, Anyone know the correct pitch props (or model No) for this boat, and whether stainless steel props be better?

 

[tico]

F'line Targa 31 with KAD43s...... B6

 

[Piers]

F'line Targa 31 with KAD43s...... B6

Thank you!

 

[QBhoy]

I’d think the usual set up would be to have A series props. Likely A6’s or A5’s at a guess. If the outdrives and diesels are original to boat. B series are usually for Petrol set ups. Mostly at least, I’d think. These props aren’t sold new in OEM form at least, these days. I think it would be J series these days or similar.
ignore the above if she has a stainless prop option.

 

[Greg2]

We had a Targa 35 (a later iteration of the 33) with KAD 42s and the props were B6 - QBhoy is right about the B series being for petrol set ups but as I understand it the lower revs oomph provided by the supercharger led to the use of B6’s.

Shifting to the J series is whole other story in terms of trying to match the old with the new!

 

[QBhoy]

We had a Targa 35 (a later iteration if the 33) with KAD 42s and the props were B6 - QBhoy is right about the B series being for petrol set ups but as I understand it the lower revs oomph provided by the supercharger led to the use of B6’s.

Shifting to the J series is whole other story in terms of trying to match the old with the new!

That’s a fair point. May well be the case with these larger SC kads. Not something I’m overly and particularly familiar with in that set up. I know the smaller kad 32’s and similar…and older just TC would mostly be A’s. Complex carry on as far as VP props go, these days. J’s and F’s etc etc.

 

[tico]

If you contact Fairline , they may be able to provide a copy of the original invoice (or is it in the paperwork)... That has the prop details

 

[Greg2]

That’s a fair point. May well be the case with these larger SC kads. Not something I’m overly and particularly familiar with in that set up. I know the smaller kad 32’s and similar…and older just TC would mostly be A’s. Complex carry on as far as VP props go, these days. J’s and F’s etc etc.

Yes, our S34 with KAD32’s had A4 props. It used to raise a few eyebrows when I said that the Targa had B6’s but they seemed to do the job, although she wasn’t happy until we got over 22-23 knots.
.

 

[QBhoy]

Yes, our S34 with KAD32’s had A4 props. It used to raise a few eyebrows when I said that the Targa had B6’s but they seemed to do the job, although she wasn’t happy until we got over 22-23 knots.
.

Fair play. Every day is a school day. Great to learn more that I didn’t know previously. You think they were on her since new ? If they work, they work though !

 

[Greg2]

You think they were on her since new ? If they work, they work though !

That’s a good question - I always thought that they were and there was never anything that caused me to think otherwise but I can’t be 100% sure. I guess Fairline would have realised early doors if the model wasn’t performing as expected with a different set of props.
.

 

[Mr Googler]

I think the KAD 4* series all came with B6. Maybe the power curve is closer to petrol with supercharges etc.

I ran J7 on a 38ft sunseeker with KAD42 (B6 original) Bit under propped but the hole shot was excellent.

 

[BruceK]

Volvo actually gave a propeller guide. You can also write to them to get a form to fill with your boat stats and they will punch that through the computer.

The guide is here: https://seastriper.com/Propeller_guide_2006.pdf

the way to use it because it's not intuitive is to know what speed your boat was designed to go with your engines and then cross reference your engine against the speed bar.

So a KAD44 1: 1.'68 gear ratio in a boat designed to do 30 knts with this 44 in it would be a B3.

So for 42's you have if your boat was designed for 30 - 35knts then B5 to B6 would be your best options. However always choose the lower number to cater for mid season fouling and or carrying load.

In saying that, I have dropped from B5 to B3 because I seldom want to do more that 25 knts and the engines just work so much more effortlessly across the entire throttle and speed range and gives me the greatest flexibility. For you that may well be B4's