P18 peformance - Page 3

CB1 · 23-03-2005, 12:17 PM

The minimum centres on that type of twin engine set up and have usable steering is 19" so you can see where Cycos comming from. Also the fuel tank would have had to be enormous.

stevie wonder · 23-03-2005, 12:29 PM

The figure 200-220 was only ever a rough estimate, and judging by the way it leaps out of the water and blows away most 200's and 225's I kind of figured its in that area.

As stated with my earlier posts the transom and stern have been very heavily reinforced, this IS due to the fact that when I bought it their HAD been TWO mariner v6's on the back, the marks where the stand-off plate had been were still visable, the wiring inside was for 2 tachometers, 2 trim gauges, 2 remote boxes...you get the picture......

This pic shows the two engine start and cut off switches that I couldn't be arsed to take out when I re-wired the boat.

Oh the bow fuel tank takes 160 litres if I brim it.

First for everything I suppose

Dan · 23-03-2005, 12:38 PM

[QUOTE]Originally posted by stevie wonder
As stated with my earlier posts the transom and stern have been very heavily reinforced, this IS due to the fact that when I bought it their HAD been TWO mariner v6's on the back"

Ah ha, I`ve got it. It may have had 2 mariner V6`s on just not at the same time

Cyco · 23-03-2005, 01:41 PM

Got any pics of it rigged previously???

stevie wonder · 23-03-2005, 02:23 PM

Unfortunately not, I bought it via an agent, as the owner had moved abroad, and therefore I couldn't source any photo's of it in its twin engine state...shame really

sinkunit0 · 23-03-2005, 09:46 PM

ive.2.5 200 my 18 and thats kinda heavy. if it had twin 150 on the back that would just be to heavy.back to your question i,m getting abot 73 running a lazer3 23p.at about 6250

Jon Fuller · 23-03-2005, 09:58 PM

That works out at zero slip

Captain Chaos · 23-03-2005, 10:25 PM

its a fkin good prop.......................Manos Industries 23P Special!

sinkunit0 · 23-03-2005, 10:31 PM

as you know jonny the revs could be any where.the speed was on the gps .even when you knock the speed down to allow for error the slip does not increase that much 69mph 4%

Jon Fuller · 23-03-2005, 10:36 PM

Quote:

Originally posted by sinkunit0
4%

I'll have a pair of them props! where'd ya get em?

seriously tho' you say you GPS's it, where did you do this? lake, sea? ie, was there any tide/current?

sinkunit0 · 23-03-2005, 10:46 PM

i,m right in thinking 10-15% is more realistic. it was on the river here in the speed zone honest. the flow would not be more than a knot or two .around high tide is really the only time theres plenty of water to aviod the water lice.

Jon Fuller · 23-03-2005, 10:52 PM

Yeah, IRO 10-12% is realistic

sinkunit0 · 23-03-2005, 10:59 PM

so what speeds that then roughly

Jon Fuller · 24-03-2005, 10:13 AM

Well if your GPS speed was rock steady (ie, continuous indication, and repeatable) and the water flow there is low, you shouldn't be too far out with your speed, but if you tacho is to be believed, using 10% as your slip puts you at about 65/66mph.

But as you rightly point out, tachos are not that trustworthy and prop pitch can vary from what's stated, so the GPS is probably the most accurate of your factors, as long as the sea aint moving too quick under you, in which case you need to do a two way run, and work the average out.

I have to say, I would have thought a P18 with a decent 200 would run well into the 70's if everythings set up right, but I would have thought you'd be running a 25" prop.

JF

Silversurfer · 24-03-2005, 02:04 PM

Interesting stuff about the XR2 I was told mine was 200HP when I brought it I also did a scream and fly on XR2 and was gutted to see 150HP listings. Mine was built by Ocean Racing took it back there for a service and a new trim pump. The guy who built the engine said it was a strong one and DYNO'ed @ 210HP (the force is strong in this one OB1!). I have no proof of this but the engine has been really reliable and an extra 10HP for nothing makes me feel good!

Thanks for filling in the gaps regarding the infamous XR2!.

Regarding two V6 engines on a P18 I have to say unlikey. The sheers weight would mean that the lack of freeboard in the engine well would cause to sink unless it was powered by hot air!. I worry about the ammount of freeboard mine has!

Matt · 24-03-2005, 02:55 PM

Yeh, my old (1985) motah was a 150xr2, basically a slightly hopped up normal 150, completely different engine to the later xr2 'race' engines.

JamesM · 24-03-2005, 04:56 PM

Mat was the block on your '85 XR2 painted or just bare metal?

Jon Fuller · 24-03-2005, 04:58 PM

Quote:

Originally posted by Matt
Yeh, my old (1985) motah was a 150xr2, basically a slightly hopped up normal 150

I think it was banded about that the original 150 XR2 was 162hp (propshaft)

Matt · 24-03-2005, 05:04 PM

Yep, exactly the figure I've been quoted. I wasn't sure whether it was prop or crank rated though, but yeh, 10 or 12 hp over a standard 150.
It was a painted block.
I'll check to be sure tonight, but I think the only difference to a standard 150 was the the tuner, carbs and decals. And it did say 150 XR2 all over it, so it never claimed to be one of the later 200hp race xr2's. And they all had the old clamshell cowling on.

JamesM · 24-03-2005, 05:23 PM

I've seen older 2.4 block XR2's that were unpainted. Mercury dont paint there race motor blocks. Also I've seen the older 80's style drop on cowl (pictured) with XR2 written on the back.

So I thought there was a race (forged pistons) XR2 around in the 80's with I thought 150hp.

Mat you must have had the fishing motor that hydrostreme was talking about earlier in this thread. There are more modern XR4's and XR6's these are fishing motors too.