Engine not Reving?

[G.Mac]

Ahhh, thats good to know and stay clear of!!

[Poly]

Originally Posted by Pete7

and stuff in a dishwasher to get clean

Pete is there any coincidence to you selling your Pac22 not that long after you got married and the above statement?

[doggypaddle]

Originally Posted by G.Mac

Screw the 6cyl yanmar
V8 Tigershark diesel 400HP - 948lbs torque
http://allmarinediesel.com/Tigershark%20Page.htm
Graeme

thats a girls engine
I meant a 7.1 yanmar 500hp 1100lbsft

[G.Mac]

I think we may have it sussed,
Took old exhaust hose off and found that the rubber had delaminated with the inner part dropping down and blocking the exhaust about half way along, We are 99% certain (fingers crossed) that this is the problem with regards slow turbo spool and low boost pressure but unfortunately we have not received our new hose yet so couldnt take her for a run

Graeme

[doggypaddle]

Thats good, with the bit of extra fuel you have given it it should be quite sprightly for a pac.
If there is too much smoke you may need to shut the rack stop down a bit!
let us know whan you try it.

[A.MAC]

Hope to get the new hose for the exhaust and fit within the next few days at least that should be another one of the gremlins put to rest and the performance should be restored
Fingers crossed

[G.Mac]

Well it seams the exhaust was to blame after all





thank fook for that

It sat at about 27 - 29kts without a problem, fastest we saw was 30.5 but we had a wee bit of tide helping us
She sat at 2800 rpm and pulled a bar of boost, oil pressure approx 5.5 bar, temp never got above 80*C

Graeme

[A.MAC]

Still tinkering could give it a bit more fuel ????? mm prop=savage+idle at700 rpm=4kts ish
Any ideas would be gratefull

[Pete7]

Originally Posted by A.MAC

Still tinkering could give it a bit more fuel ????? mm prop=savage+idle at700 rpm=4kts ish Any ideas would be gratefull

You are getting full revs to achieve that speed so next step would be to change the prop for a larger one or having an existing one modified with an extra inch of pitch which O/S had. Standard is 21" so you should be able to go to 22" by having one of the prop people change it. Dia should remain at 16.75"

Pete

[jackcastoff]

Its unfortunate that you will have lost the original settings by adjusting the fuel screw. Atleast it appears that it wasnt set up correctly in the first place. I have a p22 with a turbo 4 in that was 145hp as standard. I have a 103 / 113 bottom end on the leg fitted and a 19" x 20" prop. We simply opened up the fuel screw and up she went. Getting 30+ knots but I dont like doing it with a heavy boat. Engine will be giving out 200+ HP.

Temp sitting around 85 degrees C.

I would be interested to do this on a dyno and see what the engine is really pushing out !

I got alot of help from Neville through in edinburgh who lent me some props & sternpower stuff of his rental P22's. Hes worth a try if you are ever stuck.

Good luck ! JC

[doggypaddle]

if you are going to start pitching up the prop you need to be careful!
With the standard pitch youre unlikely to cook anything as the engine will run out of RPM before it runs out of power(boat unloaded), once you start to increace the pitch, this will load the engine up more, and if the fuel screw is wound out too far to achieve enough power to get the RPM the same with the coarser prop then the EGTs will be rising, you could melt your turbo.
you have two choices now you have found the problem,
1 adjust the fuel screw so the black smoke is just visible under acceleration once the boost has started to build and leave it alone.
2 fit an exhaust gas pyrometer and run at below max allowable EGT for the turbo and re pitch the prop accordingly to achieve the max speed at a sensible combination of RPM and EGT. then-when it blows up(which it will, when you least expect it and at the most inconvienent time)
fit a yanmar!

[A.MAC]

Went for a quick run before the boat was laid up for the winter for other maintainance items and she was running a treat oil pressure 5bar - gearbox 3bar and temprature 75-80 cel
could go up on the pitch but slow manovering is a total pain as it is without compounding the issue,just getting used to the boat i suppose
Still got original setting 2 turns out on fuel screw and 2 on max rpm

Many thanks for the info on all the posts regarding the Pac 22

Will keep you posted on developments and upgrades as we go

[doggypaddle]

thats the problem when you only have 1800RPM between tickover and Max rpm, i think this is why the yanmar engines are popular, they have an extra 1000RPM on tap so you can use standard srern power 101 gearing and prop.
good to hear its running as well as a Pac 22 can with that engine, you must be chuffed the engine and turbo wernt a problem!

[jackcastoff]

Doggypaddle, The yanmar setup does not utilise the same ratio in the leg. The mermaid uses a 1.32:1 and the yanmar uses 1.66:1 hence when you get a yanmar version it does not go exceptionally faster.

Ok it revs up to 3500 + but that is reduced so the input to the prop will be nearly the same.

The yanmars were mainly made 160 hp - 180 hp so for power they are very similar to the mermaid. Where they score is weight.

I have had a yamaha 240 hp put in my second P22 and retained the 1.32 ratio from the mermaid. I think its the fastest one out there !

AMAC : Try and get the tickover speed quite low for manouvering in a marina, and dont be afraid to give it a bit of grunt in and out of reverse when going alongside. Once you have the hang of it they may be better than a single O/B for manoevering.

Unfortunately the mermaids will always have a bit of black smoke. They have an ancient design of fuel pump which just pumps in as much fuel as possible to make the thing go faster. When at a standstill or going slowly, they will under cool and be more prone to smoking. When they are under load up on the plane they will be running at the correct temp and the smoke will disappear. The black smoke will be worse with no load with the fuel screw turned up.

Good luck ! JC.

[doggypaddle]

Thats what i was getting at...yanmar engine and standard mermaid transmission and prop!
yep they are smokey old ford 6000 series tractor engines, bloody good though!

[doggypaddle]

The black smoke will be worse with no load with the fuel screw turned up.


The black smoke will only be worse while under load and accelerating, once its got boost up it should be fairy smoke free.
the smoke screw makes no difference with no load, its only a rack stop on the minimec pump, the pump has no advance unit or compensator, hence they are optimised for use at near max rpm and boost, and so at low rpm and low boost it will run slightly more advanced than optimum and well overfuelled, hence the plumes of clag while the turbo plays catchup

[nik]

Originally Posted by doggypaddle

the turbo wont stop it revving to the correct governed speed off load.

Sorry, I found this thread a bit late.
But, my mercruiser diesel suffered from a stuck open wastegate valve, and it would not rev above 1500 rpm, which equated to about six knots on the water.
I agree that in theory the engine should rev, but in my case it did not.

Nick

[doggypaddle]

it wont rev if the wastegate sticks open, because the exhaust turbine is bypassed, therefore you will not get any boost, depending on whether or not the pump has a compensator you will either get low performance or low performance accompanied by loads of black smoke.
the wastegate occasionally sticks open on my landrover and i get no boost, its only a 2.0 engine and really needs the turbo, with the wastegate stuck i struggle to hold 65 on the flat

[Pete7]

Originally Posted by jackcastoff

Try and get the tickover speed quite low for manouvering in a marina, and dont be afraid to give it a bit of grunt in and out of reverse when going alongside. Once you have the hang of it they may be better than a single O/B for manoevering.

They are deffinately more manouverable compared to an outboard, can be made to go sideways with practise and turn round in just over there own length.

Thought the engine was based on the Ford 2700 series.

Pete

[doggypaddle]

Originally Posted by Pete7

Thought the engine was based on the Ford 2700 series.

Pete

I guess if you go back far enough and through enough mods the fordson thames 4D as in the trader and the major tractor? they certainly look very similar.