Final reductions!!!

[BarryH]

Just come back from a great day out of poole. Only down side was the roadworks on the M27 and the nice co...er policeman that let me get away with 95 on the M3.
Still i digress, what i need to know is the final drive ratio on the volvo 280 leg that i have. Apparently volvo produced them with 3 different ratios. I need to know for ordering a prop for the boat, first time ive been asked mind you.

Theres no indication on the VIN type plate on the drive itself, but the engine is a AQ145A if that makes any difference. The prop change is due to the engine being turbo'd snd injected, doing away with the twin solex's. It now reaches and passes its rev limit very quickly, and from information gleened by the prop suppliers it down to the prop being spun too quickly! They say that the final drive ratio may need to be changed along with the prop (i presume turn it slower at a higher pitch so it grips the water better).

Well you wanted a boaty post, get your grey matter round that and lets see what golden nuggets of info turn up. Oh and by the way if it helps the engine is now pushing close to 195hp with all the mods, dont know if that makes any difference

 

[hlb]

There all a bit thick on here IMHO. I only asked what props on my P35 and got no inteligable answer. There all prity thick. Err well. Answer to "kwestion". Y nead bigger props. So do I. I'm going to bed!!

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[DepSol]

Let me know what the red line is and also estimated top speed correctly propped and top speed now

so AQ145 on 298- leg ever thought of going duo now?

Give us a shout if you want new props but I'll come up with a recommendation tomorrow once I have been to Herm for lunch.

Dom

 

[mtb]

Chalk marks , put a mark on the front crankshaft pully , then the prop while some mug turns the engine by hand you count the number of times the prop turns
Mick

http://homepage.ntlworld.com/boats
I want a big steel ex trawler / tug v / cheap or swap for tug

 

[scottie]

2.15:1


the problem with any outdrive is the limited diameter that you can fit due to the cavitation plate

a lot of what you do will be trial and error unless who ever did your uprating has done it before.
do you hav e any real figures on hp and at what revs?

you may have to go to steeper pitch and greater blade area but it will depend on how much torque you have low down to get the boat up on the plane.

lancing marine may be of help to you

<P ID="edit"><FONT SIZE=-1>Edited by scottie on Sun Apr 21 16:24:47 2002 (server time).</FONT></P>

 

[BarryH]

Umm, 2.15:1 was one of the figures mentioned, but then so was1.89:1 and 1.61:1. The problem being they were all ratios that the 280 drive were available in. Nowhere on the drive does it give the final ratio.

The mods to the engine were carried out by myself. The print out from the dyno gave a peak power of 194hp at 4950 with max torque at 3210. The engine has loads more grunt over the standard 138hp. The camshaft was changed to give a smoother power curve to make the engine deliver the power smoothly rather than all or nothing, as most tuned engines do. Also the valves were enlarged to take into account of the longer duration. The compression ratio dropped for the turbo with is only running at aroud 3 psi of boost at the mo.

The prop people I've been talking to say they need the reduction ratios to compute the blade size, and if it is possible to re hub a stainless four blade prop to fit the 280.

 

[BarryH]

I thought of that too, but trying to get SHMBO to decide whether the crank has turned 2.15 times or about 2.5 times...or mabe it was 1.5....no I'm sure it was only three and a quater turns.....no i was wrong its only gone round once. Oh that one I was'nt looking at that one I was lookin' at this one!

So i just get fed up with her indecision and go down the pub!

 

[scottie]

the 280 used with the aq145 should be 2.15:1

give your engine number to a volvo dealer whi should be able to confirm the original drive fitted

 

[BarryH]

To be honest, the volvo dealers i know are about as helpful as a rubber spanner. I had a good look at the drive this afternoon while i was waiting for the oil to drain. I have to remove the bathing platform to do this. I found another plate with a few numbers on it a lo and behold a little box saying ratio. Only problem it says D. now all i got to do is find out what "D" means.

I think I'll go with your 2.15:1 ratio as this sounds about right, and to be honest theres not much in it with rgards to the others for this drive. Will it make that much difference to the prop people. There program will only probably work it on a standard set of figures for the engine/drive anyway. The only variables will be boat wight/length/hull type, surely. Did'nt I read somewhere that each extra inch of pitch drops the rpm bt 350 revs or something

 

[tcm]

Re: tell us about the cops

Getting away with 95 is very well done indeed. Or was it 95 grade petrol, haha.

If not, what sort of car did he have? And what sort of car were you driving? Techniques of escaping dreaded plod (other than not doing 95 of course...) are most welcome hereabouts.

 

[BarryH]

Re: tell us about the cops

His car volvo V70 or something like that, estateish/caravan towing type car. My car Porker 944 turbo S2. He only pulled me cos i went past him. He was doing 85 in the middle lane. I came up behind him indicated in plenty of time changed lane and hoofed it past. indicated to go back into the middle and the blue lights in the grill came on. Must say my car came out well on his video. No smoke from the exhaust or anything. Mind you i did,nt pick up the pearl paint very well. Any way I digress. It turns out he has one. got talking about the car etc and would i like to take it to a track day his club are organizing and can he have ago cos hes only got a series 1 non turbo jobby. How did i get away with it! Pure grovelling plain and simple!

 

[scottie]

TRY 16 X 23 LH VP854991 FOR 3 TON BOAT
AT LEAST IT IS SOMEWHERE TO START