External pickup pros & cons?
 

I tried an IMCO 2" shorty on my 26 Outlaw 600sci/xr last week.
When I get into positive trim, the water pressure drops and kicks the engine into guardian mode. Tried opening up the intake a little bit on the lower, but the same problem occurs at a slightly higher rpm.

I'm considering an external pickup and would like to know any pros/cons?
Who's using them? and what do you like/dislike about em?

Any particular brand recommendations?

anyone?

Cons have usually been from loss of a couple mph from the extra drag of the pick up.

i purchased the wp-38a

it is adjustable ,from the picture you really can't tell but it does have 4 mounting holes 2 on each side and the adjusting part is actually a piece of stainless box tube with 1 side removed to catch and direct the water. gives a little better than 1/4 of adjustment and you can mount it flush to the transom.

they have ones that can be installed in the bottom but they require trimming down to get the pressure right.

this just has to bolts and is very easy to adjust the pickup..

teauge also has 1 that's adjustable...


http://www.imcomarine.com/pages/performance.html

I use the Stainless Marine thru the hull pick-up's. It is easy to adjust the WP by how much scoop in front of the PU hole you use. It is clean install but best done with the engine removed. As mine are installed dead flat with the bottom (no scoop cut in front of the PU), I'm not sure but I don't thing it is costing me any speed.
I just dump the Bravo water back on top of the drive as a shower.

Thanks. I was thinking about the teague adjustable. Might come in handy if the smartcraft is as sensitive to too much pressure as it was too not enough.
Kinda pricey though.

I would hope it wouldn't cost any speed. Anyone experience a loss from switching to external pick-up?

the imco is a nice piece ..i would have not kept it if it wasen't.

we first ordered the hardin adjustable , sent it back...not a very good design..


heck , just order the imco and if you don't like it ,send it back..

it comes either push on or thread..

the teauge is nice looking , but too much ,the imco is a nice clean design

would never go back to nose cone pick ups.
love thru hull or adjustable pick ups.
no more motors getting pluged ect...

Mike, interesting thread!

I haven´t had my Smartcraft complaining yet, but when I look at the water pressure, I don´t know why. Trimmed level, I am still seeing 30 psi but once I trim further out (which the Baja hull needs to find speed), the pressure drops to below 20psi. But no warning buzzer or any sign of temperature increase. The pressure drops off far quicker with the shorty than the standard drive.

I would have expected opening up the intake would have done the trick.

Maybe the newer software edition (my ECU has Feb 2008 on it) is calibrated differently. Evidently Mercury is getting more and more confident about the 600 -700 motors (as shown by their 87 Ron fuel requirement downgrade) and have openend the water pressure window up a little.

I was told that transom pickups take a mile or two off, but as I haven´t made a back to back comparison, can´t confirm either way. Effectively you are running two water pickups (one for drive and one for the motor) and that has got to be extra drag.

Looking forward to hearing your impressions of the shorty, once you get this sorted.
Stephen

Imco's adjustable is very nice. Ideally, the low water nose style is the best for performance, and normally, you have gobs of water flow, in fact, many times we've had to weld the hole up a touch to lower water flow, so something is happening different in your boat, none the less, a transom pickup might slow ya down a 1-2mph, but I've also seen it do nothing to performance, so it depends on design and how much drag you need to get good water flow.

Thanks,
Dustin

I'm chasing my own tail here. Trying a Shorty to gain a few..... need an external pickup which costs a few.... WTF!!!

First of all find out what the water pressure is actually doing. Borrow (or buy - $400) a Rinda Scan Tool. Real easy to use. You can check, and erase all failure codes, and monitor all of the ECU inputs in realtime or at the dock (freezeframe).
Once you see at what point the Guardian is activated at, you know how the ECU is programmed, and may be able to drive around it , or even solve the problem with the prop.
What prop are you running?
Water pressure iincreases with speed. Too little prop, and too much slip means you are getting up to the upper end of the rev range ( and the smartcraft gets pickier the higher you go) before the water speed can shove enough water up the pickup.

Dean confirms what Ron (at Imco) told me, that their lowers mostly produce too much, and not too little pressure. The same motor/drive settup in a 27 Cat would be running 90 mph before it hit 5000 rpm, and there would alot of water pressure.

Longer prop to drop your revs, is my first guess, buddy!

If you have smartview, monitor water psi and see what rpm/water psi it goes into guardian. If not, then borrow scan tool like wildcard said, then you can see a freeze shot when it goes into guardian. 2" might be too much for boat, might only need 1" or 1.5".

Thanks,
Dustin

Thanks Dustin,
My x is a sickening 7" w/stock xr, so 5" with -2Shorty.
The Imco intake is below the tip of the bullet, so as you start adding trim, the intake "dissappears" from the ram effect.

I do have smartview. The pressure starts at 30psi then drops into the 20's around +4 trim the pressure was down at 25 or less, and guardian kicked in. Fault said "Eng overspeed" but was only at 4800rpm or so.

I could open up the intake more but don't see the issue going away.
The boat needs a lot of trim to run, and right when you start getting there that intake falls away from the leading edge.

Thanks Stephen,
I still have the 30B1 which I had labbed at bblades.
It's a little too tall for the boat as it is, but works pretty well.
I was hoping the -2 shorty would help me gain a few hundred rpms with this prop.
Then, I want to try Dustin's mod and see if I could gain more.

After both mods, if I could not get the labbed 30 to 5400+,
I figured I would tweak the 30 again, or try other props from there.

make sense?

That makes lotta sense. However, it would be good to try a couple of different props, both four and five blade (I say that as though they are just lying around on the dock!) to see what the settup reacts to. I´m really surprised with almost every new prop I´ve tried.

Engine overspeed at 4800 doesn´t make sense, though! My fault manual is in the boat. I´ll check tomorrow.
Low water pressure is the fault you should be seeing, if anything!

I wish I wasn't seeing anything!
After reading your post I was thinking maybe something was awry with my systemview or guardian.

But I spoke to Merc today... they said systemview looks at a number of data before throwing a fault. Water pressure, temp, throttle position etc. Overspeed commonly trips first... even though the water pressure dropping below 25psi was the culprit.

First time at around 4600rpm, then after opening up the intake a bit, it gained some rpm but still happened again around +3-4 trim. I could open it up more, but the trim had a ways to go before good speed was found.
With the stock lower and a horrible 7" x, best speeds occur with the trim cranked up to a ridiculous +7 to +8.
I'm concerned that I'll continue to open it up and still have the same issue as you get into positive trim. (where I am sure I will still need to be)
With neutral trim I could spin the prop to 5150 or more and still see great pressure, but of course the speed wasn't there yet.... not even close.

So, I'm still looking at the external p/u.
Just wondering what the next obstacle will be!

I have this same exact problem, I'm also looking into external pickup. WOT with my IMCO same thing.

That the Smartcraft monitors and relates a number of parameters to each other and then throws an alarm "only" when defined boundaries are crossed sounds good. The combination of say 4800 rpm, full throttle setting and a drop in water pressure trips the alarm.
A freezeframe record of ALL the parameters at the moment that the alarm was triggered, would be good. Can the systemview give you that, or is that a speciality of the Rinda unit?

In what way have you opened up the intake? The upper edge towards the point on the bullet would make sense to me.

@ pkspx, what hull and drive settup do you have? Are you running a 600 as well?

With a problem like this (and because Imco, and Dustin W say that HIGH water pressure is more usually the issue) it is worthwhile making sure that there are no other factors contributing. Impeller, or a loose fitting (causing air to be sucked into the cooling circuit) could cause a problem. Check that the S hose that runs from the drive to the transom is not jammed up between the belows and the gimbal ring.

On my settup, lifting the drive beyond about 6 on the 10 scale of my mechanical indicator is unnecessary ( unless a roostertail is on the programme). As I said, the pressure does drop dramatically when trimming out.

I would stay away from the transom pickup first of all, unless there is no other solution.

I'm going to see if I can drill a new hole through the top side of the bullet on the IMCO.... If it is possible without getting into the bearing support areas, that would allow it to take in water when in positive trim mode.

My prop to pad measurement is 7" with the stock lower and 5" with the shorty, so it is still plenty deep!!!

Not sure if it is possible but will take a look this weekend.

I want to wrap this up in the next week or so, do some testing and then try the whipple upgrade....

Only problem I have is in weedy water. The transom mount plugs up easy and I need to back flush with air to clean it out.

Aside from that, it flows HUGE water ! If my striner isn't tight, it sprays out the top seal when running at top speed.

I have a 600 sci with a merc xr that had the same problems. I plugged all of the vertical holes on the xr except the bottom 3, oversized the nosecone holes by 1/16" each. Routed an external bottom pickup to feed the intercooler only through a separate strainer. Problem was solved. The 600 requires water pressure to be in the 30's at high rpms. One of my problems was that when I trimmed up I was starving the outdrive for water.

I have a 600sci in my Heat, and an IMCO extreme outdrive. I was continually having the problems you describe with water pressure. I was frustrated with this for months!

You are correct in that as you trim up that the nose of the IMCO lower is shadowing the water inlet.

My solution was to drill a 5/16 hole on the top of the nose-cone directly towards the rear of the outdrive. The hole is about 1.25 inches deep before hitting the water inlet channel from below. I determined how close to the nose to go by putting my IMCO hose fitting on the outdrive, and marking it so that the upper inlet would be covered by the blue, hose water inlet, and I could still run the boat on a hose when needed.

I had zero reduction in speed, and the over-trim/water pressure problem is gone. Water pressure stays in the 40 psi range at 81.5 mph on GPS.

My outdrive is at 4.5 inches below the keel.

Hope this helps.

Chris

P.S. Another option is to have Dustin re-program your ECM, but I have not had the coin to do that yet. Supposedly worth an additional 75hp.

I also had Dustin do the reprogram. I like the results! I have alot more torque and the motor pulls much harder. The boat is much faster now. Most of all I like the torque.

Chris,
thanks for the good info. I´m not quite following your description of where the extra intake hole is. Can you give more details.

Whipple`s reflash does sound tempting, although I´ve been pretty convinced of keeping my blue motors bulletproof stock up till now!!!

My boat is at OCM in Oregon for some warantee work, or else I would take a picture.

The stock water inlet on an IMCO lower is a slot at the lower leading edge of the pointed nose cone. When the outdrive is trimmed up , this pointed, front nose-cone, shadows the water inlet, thus reducing water flow. I drilled a 5/16 hole in aproximately the same location as the lower pickup, only on top of the point. This hole is pointed from the front of the outdrive towards the back, and connects with the lower stock water inlet about 1.25 inches into the aluminium. This way, when the outdrive is trimmed up, water is still in direct contact with my new water pickup, which is located on the top of the cone.

I determined where to place my new inlet by placing the stock, IMCO, blue, hose connector, onto the front point of the outdrive, and marking the top front of the point on the outdrive with a permanent marker. I wanted to make sure my new inlet was covered by the blue, hose connector, so that I could still run my boat on a hose if desired. I drilled my 5/16 hole aproximately half way between this mark, and the point on the outdrive.

I hope this helps.
If not, I will be getting my boat back in a couple of weeks, and I will take a picture.

Chris

Now I´m following. It makes sense and sounds like a good solution.
Although my 600 hasn´t complained about trimmed out pressure loss. the readings I see off the Smartcraft (when trimmed out) make me wonder why. I´ll try your mod. Thanks!

This mod also increases water flow to the engine... and that is a good thing. More water flow equals a cooler innercooler which in turn makes more horsepower.

Chris

Chris,

Do you have a pic of the hole you drilled yet? I think I am having a similar problem and would like to duplicate your solution over the winter.

Thanks,

Tom