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View Full Version : how to increase range on 5.2KC



freddofrog
29-10-2008, 10:46 AM
Hi all

Contemplating increasing fuel capacity in my 5.2KC. Any one got some easy and cheap ways I may do this?

Noelm
29-10-2008, 10:51 AM
not too many cheap or easy ways, but there is certainly ways! the cheapest would be above deck tanks, but pretty messy and space eating, other than that, it is out with the floor, new or extra tanks, back together, repair floor and your done, how much extra range are you after??

evo001
29-10-2008, 11:33 AM
First off check you are getting optimum economy out of your boat, I got 1km/litre out of my KC so had a range of 225km.
I used to carry 4 x 20l jerries on long trips giving me a range of over 300km.

Where do you want to go thats over 200km trip ??

Also the economy got better as I burned fuel as the boat was lighter.

All the fuel economy figures quoted are from a Navman fuel computer and the best ever achieved was 1.3km/l ( thats both motors combined use )

finding_time
29-10-2008, 12:13 PM
Freddo frog

Mate i have looked at this from every angle using jerrys, having 1 bulk head removed putting a 200l tank in each side and the bridging the tank with support to return strength to the area but what i settled on is 2 poly fuel tanks that are 400x400x950 i'm going to have these sitting behind the seats (length ways) and run the fuel hoses to the filters via a standard quick Fuel connect. I'll run these first till there empty then connect in my normal tanks, no swaping fuel from jerry's to tanks at sea!

The tanks are 120l each so for smaller trips i'll just take one and use half on one side then half on the other but for big trips, eg 2-3 days trolling at the shelf heavy tackle i'll need both!

Once i've emptied the tanks they will just stay inside the boat for distane travel but when trolling they will be stored on the front deck via the rail and a couple of cleats that i'll install.

All up i'll have 460l on board in total which gives me 3 full days trolling plus 10 hrs travell time, i run 2x f60's and get between 1.4 to 1.6 l per hr at cruise and the added range will stop return trips to port each night to refuel

Hope that helps

Ian
ps.
Tank are sold by sam allen

evo 001

People use there boats very differant ways mate and for us between300 to 400nm over a few days is not that rare!

All the bits are here!

http://www.samallen.com.au/exhaust.pdf

blue_mako
29-10-2008, 12:24 PM
Thats a great idea Ian, the poly tanks are low maintainance and you can clean them out regularly with ease, keep an eye on the breathers but that seems to be one issue or another in exposed areas.

freddofrog
29-10-2008, 03:29 PM
The poly tanks sound like a good compromise between ripping apart the boat and just using jerry cans. How much are these costing you?

I am just looking to up my range from 160km (1.2L/km, 2st 90hp yammies, 5500rpm at WOT) to around 3-400km. On the weekend all we did was go around Rottnest Island and that was 100km. Often we do a lot more zig zagging around and this really starts to compromise the 1/3 there/back/just in case rule.

This summer we’d like to try the outer FADs which are around 70km as the crow flies, so 70km to one, 30km to another, 30km for mucking about, 70km return and 1/3 for emergency = 300km.

finding_time
29-10-2008, 03:58 PM
If your only getting 160kms for 216l of fuel your fuel your probably only getting 0.8 per km or less eg .really chewing:-[ So in that case your going to need about another 200l so poly is the way to go. Not sure what the cost of the tanks would be in Perth ( everything is expensive in Perth) maybe it would be better to swap engines?

I'll post some pics when i've got my tanks set up!


ian

Dean1
29-10-2008, 04:01 PM
Hi FF mate your'e motors seem to use excessive fuel. What speed do you sit on at cruise? I was getting roughly 1km/1 litre with the 70 yammie 2 bangers I used to have. Your motors should use similar figures if you werent on the throttles hard everywhere where obviously youd burn more fuel. Are your props in good nick and have you had your motors serviced lately? My new 60's have only done 24 hrs so their still very tight. I travelled 123 klms last weekend and used 99 litres. That was with alot of sounding around for ground/livies. With the LAN gauges im getting 1.3 klms/ litre at 23 kts and coming home from the banks sat night I sat on 25- 27kts and she still used 1 litre/ 1.3 - 1.4 klms so they must be loosening up a little ;D I used 35 litres to travel 50 klms home. Cheers.

Greg P
29-10-2008, 05:43 PM
Not sure of the prices but certainly worth a look. Being able to fold them is a bonus on space.

imho ;D;D;D;D;D;D;D;D

http://www.turtlepac.com/petroldetails.htm

Fish Guts
29-10-2008, 06:46 PM
you could also look at fitting an auto pilot to save fuel consumption.

FNQCairns
29-10-2008, 06:57 PM
The poly tanks sound like a good compromise between ripping apart the boat and just using jerry cans. How much are these costing you?

I am just looking to up my range from 160km (1.2L/km, 2st 90hp yammies, 5500rpm at WOT) to around 3-400km. On the weekend all we did was go around Rottnest Island and that was 100km. Often we do a lot more zig zagging around and this really starts to compromise the 1/3 there/back/just in case rule.

This summer we’d like to try the outer FADs which are around 70km as the crow flies, so 70km to one, 30km to another, 30km for mucking about, 70km return and 1/3 for emergency = 300km.

FF is that on 14 or 15 pitch props?

cheers fnq

FNQCairns
29-10-2008, 06:57 PM
Hi FF mate your'e motors seem to use excessive fuel. What speed do you sit on at cruise? I was getting roughly 1km/1 litre with the 70 yammie 2 bangers I used to have. Your motors should use similar figures if you werent on the throttles hard everywhere where obviously youd burn more fuel. Are your props in good nick and have you had your motors serviced lately? My new 60's have only done 24 hrs so their still very tight. I travelled 123 klms last weekend and used 99 litres. That was with alot of sounding around for ground/livies. With the LAN gauges im getting 1.3 klms/ litre at 23 kts and coming home from the banks sat night I sat on 25- 27kts and she still used 1 litre/ 1.3 - 1.4 klms so they must be loosening up a little ;D I used 35 litres to travel 50 klms home. Cheers.

Dean what pitch are your props?

cheers fnq

Greg P
29-10-2008, 07:14 PM
Dean - are sure those numbers are right? What l/ph are you getting at 23 knots for each engine? I would have thought you would be getting heaps better than that with the F60s


Ian is that 1.4 to 1.6 l/hr or 14-16 liters an hour combined

Dean1
29-10-2008, 07:23 PM
Alloy 15k the standard alloys not the high thrust props..

finding_time
29-10-2008, 07:28 PM
Dean - are sure those numbers are right? What l/ph are you getting at 23 knots for each engine? I would have thought you would be getting heaps better than that with the F60s


Ian is that 1.4 to 1.6 l/hr or 14-16 liters an hour combined



Greg

I'm getting between 1.4 to 1.6 km's per litre and at about 22-23 knots i'm using 22l perhr combined this seems to be my sweet spot at 25-26 knots i'm about 1.3 km'per l

fnq

Both dean and i run 15's

Ian

Dean1
29-10-2008, 07:32 PM
Dean - are sure those numbers are right? What l/ph are you getting at 23 knots for each engine? I would have thought you would be getting heaps better than that with the F60s


Ian is that 1.4 to 1.6 l/hr or 14-16 liters an hour combined Greg im using about 26 litres/hr at 23kts roughly fuly loaded and about 22/hr with a light load for both motors. Ian means he's getting 1.4-1.6 klms/ litre and im about 1.3 but mine will get better. Im just starting to see 1.4 klms/ litre displaying in last few hours.

Greg P
29-10-2008, 07:45 PM
Cheers - I thought they would be getting around 2km/l. They are a sweet little engine.

Dean1
29-10-2008, 08:01 PM
Cheers - I thought they would be getting around 2km/l. They are a sweet little engine. Those numbers would be nice. One of the main benifits I like is no 2 stroke fumes and the quietness and smmooottthhhnneeessss of em ;D ;D

FNQCairns
29-10-2008, 08:11 PM
Ian an Dean are you guys over proped? waiting for it to loosen up? I just wonder because I know of a 4.5 bluefin with the yam 60 and it runs the standard 12p I think, it's tight too with few hours.

cheers fnq

finding_time
29-10-2008, 08:39 PM
Dont think so fnq?

I'm sure mine are as loose as they have 670 hrs on them

There both the high thrust models and i'm wot at around 5700-5900 depending if into or with the wind that's for the starboard motor the port one will be 200 above thisso 5900-6100

Dean had a 14 on, great take off but no top end speed

The others i know run the same prop

Ian

Dean1
29-10-2008, 08:40 PM
Ian an Dean are you guys over proped? waiting for it to loosen up? I just wonder because I know of a 4.5 bluefin with the yam 60 and it runs the standard 12p I think, it's tight too with few hours.

cheers fnq I tried a 14p and it reved too hard i spun them to 6100rpm fully loaded/fueled pretty easy and speed suffered. It only did 18kts at 4800rpm.

FNQCairns
29-10-2008, 08:49 PM
Ok thanks I didn't twig it was the high thrust model, I should have guessed being on a cat, the different gear ratio makes the difference.

cheers fnq

freddofrog
30-10-2008, 12:01 AM
Hi all

I was running 17" SS props but now run 15" allys and get around 5500 at WOT. I've also played around with the height of the motors and currently have them set so the cav plate is just skimmin the surface which I’m told is exactly where then should be. So my assumption is the motors are set up right but if anyone wants to give me any pointers more than happy to listen.

I generally don’t like hydrofoils but the last trip out I put them back on just to see if it made a difference economy wise. With the additional weight of the 90hp it may make a difference but as I haven’t refilled her up again not yet sure how it went. I’d be actually surprised if it does make a difference as when you are planning there is a difference but often I am just motoring around setting up for the next drift etc so the hydrofoils are just forcing the nose down which can’t be good for fuel.

I typically cruise between 22-24knots which from memory is around the 4400rpm range. WOT is 34kn.

When I got the boat the motors has 12hrs on them. Now they have 100+ and my consumption figures have always been around 0.8-1.0km/l:'( . A service doesn’t effect it so I’ve resigned myself to the fact that this is what my boat gets.

I did look at changing for a 4st or etec and the figures don’t stack up. The change over was around $10-15k (in today’s money mind you) vs comparatively small fuels bills along the way. Maybe I should look into it again with the current fuel prices but I doubt it will be any different.

And the turtle-pac looks very interesting though very $$$. Whitworths sell the 40L one for $500

Noelm
30-10-2008, 07:01 AM
I doubt the weight of a 90 2 stroke Yamaha will come into it, probably the lightest Motor around for that HP!

FNQCairns
30-10-2008, 09:14 AM
Hi all

I was running 17" SS props but now run 15" allys and get around 5500 at WOT. I've also played around with the height of the motors and currently have them set so the cav plate is just skimmin the surface which I’m told is exactly where then should be. So my assumption is the motors are set up right but if anyone wants to give me any pointers more than happy to listen.

I generally don’t like hydrofoils but the last trip out I put them back on just to see if it made a difference economy wise. With the additional weight of the 90hp it may make a difference but as I haven’t refilled her up again not yet sure how it went. I’d be actually surprised if it does make a difference as when you are planning there is a difference but often I am just motoring around setting up for the next drift etc so the hydrofoils are just forcing the nose down which can’t be good for fuel.

I typically cruise between 22-24knots which from memory is around the 4400rpm range. WOT is 34kn.

When I got the boat the motors has 12hrs on them. Now they have 100+ and my consumption figures have always been around 0.8-1.0km/l:'( . A service doesn’t effect it so I’ve resigned myself to the fact that this is what my boat gets.

I did look at changing for a 4st or etec and the figures don’t stack up. The change over was around $10-15k (in today’s money mind you) vs comparatively small fuels bills along the way. Maybe I should look into it again with the current fuel prices but I doubt it will be any different.

And the turtle-pac looks very interesting though very $$$. Whitworths sell the 40L one for $500



I have the same engine on a fairly light 6m big tinny, the engine is a relatively low power 90hp and it returns good economy for it's type as a result.

I also run the Yamaha alum 13.5x15p but for mine I needed to modify it to pull up to 5600rpm otherwise 5400 was my WOT. So I guess my engine is working a little harder than one of yours considering you can pull a few extra rpm with the same standard prop.

My economy is more or less the same as you accounting for one engine as is my cruise but my WOT is lower at 31kn (you sure you get 34?), weight is the big killer on my boat and affects the economy greatly I just keep adding things:-[

Anyway I have nowhere to go now except for the prop, I have been waiting for one of the Yam 13.0 x 17SS to come up cheap but have been waiting for a while already.
IMO if raising another hole is worth it it will pay you back in cash/range but might cause handling problems, other than that try to find a prop that has more pitch and a less diameter to offset like the 13.0 above but 16p would be great.

I think these engines are at their best when the are fitted to a boat a 17p prop can push to 5500...just brilliant economy then, a 16p will suit both of us very well if one can be found.

If I find a prop that works on mine I will let you know because it should also work on yours and you will increaes range greatly at cruise.

In the meantime I think I too will be adding some form of extra tank.

If you want range bury those foils, for you running them is like flicking a dollar overboard every 20 minutes at cruise.

For the life of me I have trouble getting my head around the cruise and maximum speeds the blokes with the Yam 60s are getting when related to your/our engines, they must have a bucket load of torque at midrange and higher, ours are known low torque engines, if this is the reason It shows a person really shouldn't be taking notice of HP, they should be stickering outboards with their torque figure.

cheers fnq

finding_time
30-10-2008, 11:27 AM
Fnq

I think it is all about the torque mate, i know when kitty cat had his 75 honda's on his he had a bit of speed on me but not much,and was very suprised on how i was able to keep up with him. Dean also reckons his 60's have more go than his old yami 70's . I have lost count of the number of people that have said the 60 yami is probable the pick of the engines in that range and goes to show once you decide on the HP you want you should then pick the brand based on it's performance not the brand and every HP range seems to have 1 or 2 stand out performers

ian

Dean1
30-10-2008, 05:36 PM
Hi all

I was running 17" SS props but now run 15" allys and get around 5500 at WOT. I've also played around with the height of the motors and currently have them set so the cav plate is just skimmin the surface which I’m told is exactly where then should be. So my assumption is the motors are set up right but if anyone wants to give me any pointers more than happy to listen.

I generally don’t like hydrofoils but the last trip out I put them back on just to see if it made a difference economy wise. With the additional weight of the 90hp it may make a difference but as I haven’t refilled her up again not yet sure how it went. I’d be actually surprised if it does make a difference as when you are planning there is a difference but often I am just motoring around setting up for the next drift etc so the hydrofoils are just forcing the nose down which can’t be good for fuel.

I typically cruise between 22-24knots which from memory is around the 4400rpm range. WOT is 34kn.

When I got the boat the motors has 12hrs on them. Now they have 100+ and my consumption figures have always been around 0.8-1.0km/l:'( . A service doesn’t effect it so I’ve resigned myself to the fact that this is what my boat gets.

I did look at changing for a 4st or etec and the figures don’t stack up. The change over was around $10-15k (in today’s money mind you) vs comparatively small fuels bills along the way. Maybe I should look into it again with the current fuel prices but I doubt it will be any different.

And the turtle-pac looks very interesting though very $$$. Whitworths sell the 40L one for $500


Hey FF mate ive been through the whole height thing. The height you want is from the bottom of the 'hull' (where it sits on the skid) to the underside of the cav plate when in line with the hull is no less than 2 1/2 inches. I had 2 1/4 and it only did 26 kts and 5300rpm when they first fitted my 60's. They raised them to the top hole which is now 2 3/4 inches and it picked up to 29kts and 5600rpm. My old motors were too low and mine now even handles better, steers better and feels more in control. Measures yours and let us know. Cheers.

kitty_cat
30-10-2008, 07:07 PM
good post mate its something most off us with 5.2 kc (older models) are after longer range ,lets face it these are the best 17 ft boat around for offshore work and more and more off us are looking for 250klms + fuel range plain and simply because we can (safely).
i like ian have installed valves that run off the water seperator racor filters they allow 2 inlets just install on/off valves on the main tank and then on jerrys ect and you dont need to poor any fuel just use the valves.

ps suzuki 90hp 2009 models
0.8 ltrs fuel per klm
wot 6100 rpm = 42knts

dean is spot on with engine heights not sure but i have the lrg pods as well and really like the solas laser foils as i can trim out to half trim and free the props right up with no porposeing and great fuel economy

wayne

gofishin
30-10-2008, 08:30 PM
FF, do you have a fuel monitor – maybe with the Yam gauges? If not they would probably be well worth their money.

FNQ, wouldn’t it be great if the O/B manufactures provided torque curves in their brochures like you get in any 4WD brochure? So, so important for choosing the best donk with respect to cruise performance & economy (next to prop selection) – but it’s all a big secret.

Ian, very interested with the prevalent use of High Thrust O/B on performance craft such as the KC 5.2. Obviously they perform very well, but I remember years ago when theses type of models first came out that manufacturer’s recommended that they not be used on performance craft, as they were developed more for heavy ‘displacement’ type applications, like house boats etc. Obviously that statement makes a bit of sense, large gear cases (drag) & slower revving large hub/diameter props etc doesn’t normally lend itself to ideal economy/performance. Are you running std props? Would be interesting in comparing figures to equivalent KC’s with the std F60’s/, do you know if there is much difference?

Wayne, Kitty Cat looked like she handles those 90’s without too much problem coming back into Round Hill that day. Did you install the foils straight off?

FF, sorry mate, not trying to hijack your post, love cats & the KC5.2’s, they just didn’t fit the ‘needs’ the last time round.;D
Cheers Brendon

finding_time
30-10-2008, 09:11 PM
Brendon

Running std 15 yami alloy props.Trent ( Fly1) had the guys from solas try a few differant ones on his and couldn't better the performance of the standards so they'll do me

Ian

fly_1
31-10-2008, 08:27 AM
To back up Ian, we spent over half a day stuffing around with the boys from SOLAS with as many options as they could come up with re props. Some were great out of the hole, others not so good, but at the end of the day, the best overall one for what most of us do, were the alloy yamaha ones.

Trent ( fly_1)

gofishin
31-10-2008, 09:06 AM
Thanks Ian & Trent. Interesting.