Targa 34 fuel consumption?

[MapisM]

Is it just me, but I can't get my head around how this could possibly make a difference.

I can, because the propeller(s) thrust is NOT the same through the 360 degrees rotation.
The lower half, so to speak, "pushes" the boat more than the upper half, which works in a much more disturbed water flow.
Trouble is, my humble common sense would suggest that it makes more sense to have them aligned at 12 o'clock (hence staggered at 6 o'clock), rather than the opposite, which is what Steel Dev. suggested to Ian.
But what do I know...?

 

[Hambleite]

Great thread so far and whilst I'd agree that slightly worn turbos would seem to be an area to look at, no one has really discussed the condition of the the hull.

On our Scorpion rib we had all the old antifoul sanded off and then a very smooth new coat applied. This gained us 1.5 knots (top speed 43/44 knots) straight away. The boat had previously been anti-fouled every couple of years or so with quite a soft type anti-foul and was dry stacked. As such there were quite a few lumpy deposits and the overall surface was not particularly smooth.

I'm not too sure what significant influence hull surface friction plays on a T34 but I'd wager a bet that it plays a much bigger role as speeds increase, regardless of size/power.

Interesting thread as a T34 could be a purchase in a couple of years

 

[Dorset Dan]

Got them from dieselinjectors.co.uk. Original Borg Warner /KKK just not green and less than £800 each

Looks like you can get a replacement for just over £500 per unit with these guys with the £150 exchange for your old turbos https://turbo-diesel.co.uk/product/...ta-kad43-kad300-kamd300-k26-reman-borgwarner/

(although I am a bit dubious as it lists the same unit for KAD44 and KAD300 and 258bhp when surely they are different as the engines are 260bhp / 285bhp respectively)

 

[tico]

But they don't have any stock and don't know when they will

 

[Ian h]

I can, because the propeller(s) thrust is NOT the same through the 360 degrees rotation.
The lower half, so to speak, "pushes" the boat more than the upper half, which works in a much more disturbed water flow.
Trouble is, my humble common sense would suggest that it makes more sense to have them aligned at 12 o'clock (hence staggered at 6 o'clock), rather than the opposite, which is what Steel Dev. suggested to Ian.
But what do I know...?

I have also been advised that this set up is better for twin engine setup rather than single engine, The person working with me on my props has many many miles of trials and different set ups. he is a speed nut and always looking for more speed BUT not by throwing more horse power at the problem, For example when he took delivery of his Hunton he was at 48 knots but with tweaking was at 52 knots , its all relative as to how you wish your boat to run, For me I usually cruise between 35 - 40 knots but would like to know that when conditions allow I can have a blast at 47/48 knots as boat used to do.

You also need to see where the cavitation plate is in relation to the bottom of the hull, A lot of variables that most of us do not have the knowledge or time to play around with,

 

[Matt infinity]

Looks like you can get a replacement for just over £500 per unit with these guys with the £150 exchange for your old turbos https://turbo-diesel.co.uk/product/...ta-kad43-kad300-kamd300-k26-reman-borgwarner/

(although I am a bit dubious as it lists the same unit for KAD44 and KAD300 and 258bhp when surely they are different as the engines are 260bhp / 285bhp respectively)

The 44 and 300 both run the same turbo. As they want your old one that would suggest that they are remanufactured not new hence the price.

 

[Dorset Dan]

I have enquired and this is what they have said:

Thanks for your enquiry. The core deposit is in addition to the price and is then refunded after you send in your old turbos. But in any case, the reman turbo is not in stock, and we do not have any core to rebuild currently.

We can repair your turbochargers (cleaning/blasting, new bearings, seals, and turbine shaft and wheel assembly) for £375.00 + VAT per pc. But for this to be viable, your turbine housings will need to be in OK condition (not heavily corroded).

The new turbocharger is also out of stock, we are waiting for delivery from the BorgWarner factory, it is due some time in September. The price is £697.53 + VAT per pc.

So £450 per unit for repair (housing condition dependent) or £837 for new. As and when the time comes, my thoughts would be to get new units for peace of mind but I guess it would be worth removing existing to check of the existing condition to see it a repair is viable.

 

[petem]

Dan, some more links for you...

This is the part number apparently...

http://www.ybw.com/forums/showthrea...tioning&p=6238217&highlight=Turbo#post6238217

The housing will be knackered but Universal Turbos can apparently put a sleeve in them.

http://www.ybw.com/forums/showthrea...ous-RPM&p=6475727&highlight=Turbo#post6475727

But before doing anything I would fit your gizmo to tell you what boost your existing ones are producing and /or also carry out a visual inspection.

Where's Volvo Paul?

 

[Dorset Dan]

Currently moored in Yealm Estuary and thought I would update my fuel figures. Went from Cobbs Quay (Poole) to Brixham then nosed into Dartmouth and Salcombe, then to Plymouth.

Total mileage 120, topped up with fuel this morning and it took 354 litres. I make this 1.55 mpg.

Average speed 25 knots but did take her up to 35 knots on a few occasions.

 

[petem]

Currently moored in Yealm Estuary and thought I would update my fuel figures. Went from Cobbs Quay (Poole) to Brixham then nosed into Dartmouth and Salcombe, then to Plymouth.

Total mileage 120, topped up with fuel this morning and it took 354 litres. I make this 1.55 mpg.

Average speed 25 knots but did take her up to 35 knots on a few occasions.

Dan, is that Nautical or Statue miles?

 

[Dorset Dan]

Nautical

 

[Colin K]

Hello,
Just out of interest does anyone know what boost you should get on a Volvo. TAMD41 block. I fitted boost gauges and fuel vacuum gauges this year and got these readings at 3250rpm and the blury ones flat out port 3400 and stbd 3600. Interestingly I stripped cleaned and rebuilt the starboard one myself last Winter.

Cheers Col.

 

[petem]

Nautical

In that case I calculate that you're getting 1.8mpg (status miles) which is pretty much what was reported in post 1 of this thread and gives a theoretical planning range of 220 miles (not allowing for reserve, sea state, etc).

 

[Dorset Dan]

Currently moored in Yealm Estuary and thought I would update my fuel figures. Went from Cobbs Quay (Poole) to Brixham then nosed into Dartmouth and Salcombe, then to Plymouth.

Total mileage 120, topped up with fuel this morning and it took 354 litres. I make this 1.55 mpg.

Average speed 25 knots but did take her up to 35 knots on a few occasions.

Just got back to Poole today after our West Country trip. Some more fuel figure for comparison for you from the group that we went with:

Fairline Targa 52 with D12 715's - 810 litres = 0.67 mpg (nautical)

Fairline Targa 40 with D6 350's - 400 litres = 1.36 mpg (nautical)

Of the three boats I have to say that I am most impressed with the T40's fuel figures - it's a reasonable jump up in size and weight from our T34 and the D6 350's give it some decent shove.

In fairness to the T52, we were probably going a bit faster than what would have been it's optimal speed as far as fuel consumption goes.

I travelled back from the Yealm Estuary (Plymouth) today to Poole in one hit just us in the T34 with the T40 in convoy, averaged 30 knots and did it in less than 3 1/2 hours (to Poole entrance / chain ferry). Despite pushing on a bit more on the return, I suspect that the more direct route taken (100 miles as opposed to 120) means I've used a decent margin less fuel (as I have half a tank remaining), so will update the figures once we have topped the tanks.