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Speed Racer
12-31-2008, 12:19 PM
I have a discussion going on with my Dad, a retired offshore, circle, and drag boat builder/ racer about cooling the transmission and v-drive on the Ski Sporter.
He tells me that I cannot 'T' off of the 1" fresh water inlet in the strut, as the Jabsco water pump will starve the other side of the 'T' that feeds the Borg Warner and the V-drive. This is how the boat was set up originally, or not?
He suggests a second water pickup in the deep part of the V bottom, forward of the shaft log.
I HATE cutting holes in the newly rebuild hull... Any comments or suggestions??


Thanks and Happy New year!!

Conquistador_del_mar
12-31-2008, 12:41 PM
I have a discussion going on with my Dad, a retired offshore, circle, and drag boat builder/ racer about cooling the transmission and v-drive on the Ski Sporter.
He tells me that I cannot 'T' off of the 1" fresh water inlet in the strut, as the Jabsco water pump will starve the other side of the 'T' that feeds the Borg Warner and the V-drive. This is how the boat was set up originally, or not?
He suggests a second water pickup in the deep part of the V bottom, forward of the shaft log.
I HATE cutting holes in the newly rebuild hull... Any comments or suggestions??


Thanks and Happy New year!!

Garry,
For what it is worth, I didn't have a second water inlet to feed the transmission cooler in my 18' Corsican V drive. I would think that there would be plenty of flow since the pump will be pulling through both the main inlet hose and the other X mission/v drive cooling hoses. Under speed, there might actually be a positive pressure in the inlet lines. Mphatc or others might be able to chime in here.
How is your project coming along? Mine got held up by my upholsterer who I made the huge mistake of helping by fronting too much money - therefore I took away his incentive to get on it. Squeaky wheel approach will be getting louder - lol. Bill

Speed Racer
12-31-2008, 12:52 PM
Thanks for the Reply!!

What do you mean 'Pulling through the other hoses'???
I had a T fitting right at the strut mount, one outlet went to the water pump, the other directly to the transmission cooler, then v- drive then dumps over the port side.

I see his point that the pump will pull from both the 'lake' side and the transmission side of the T...... Can you 'splain' it to me more!?!?

The V-drive is coming along! Tank is in, Strut, shaft log, and shaft are in, V-drive goes in and gets lined up tonight, and this weekend, hopefully raw water plumbing after that.

Trailer is done, Got a carpet set from Bilt Rite for Christmas :)!

It would be awesome to get the Rudder housing, thru- hulls and engine placed in the next week or two!!

Photos soon!!
GG

Conquistador_del_mar
12-31-2008, 01:35 PM
Thanks for the Reply!!

What do you mean 'Pulling through the other hoses'???
I had a T fitting right at the strut mount, one outlet went to the water pump, the other directly to the transmission cooler, then v- drive then dumps over the port side.

I see his point that the pump will pull from both the 'lake' side and the transmission side of the T...... Can you 'splain' it to me more!?!?

The V-drive is coming along! Tank is in, Strut, shaft log, and shaft are in, V-drive goes in and gets lined up tonight, and this weekend, hopefully raw water plumbing after that.

Trailer is done, Got a carpet set from Bilt Rite for Christmas :)!

It would be awesome to get the Rudder housing, thru- hulls and engine placed in the next week or two!!

Photos soon!!
GG

The way yours is set up means there will be no flow to the transmission or V drive until you reach speed which in itself is not necessarily bad. I honestly can't remember if mine had the inlet hoses in parallel before the water pump, but my vague recollection is that I had a smaller hose after the water pump which was plumbed to the coolers and then went through an exhaust manifold (in other words a cooler hose was in line with the rest of the normal plumbing of the engine). The way you are set up, I can't see why the water pump at idle might not try to pull air through the xmission/v drive dump line. I don't know if I made sense here - let me know.
Glad to hear you are getting somewhere with your project. Pictures? Bill

Speed Racer
12-31-2008, 01:52 PM
I like the idea of routing from a manifold up to the cooler and v-drive as well!

I know! I will get some updated photos on the web soon!
Thanks again for all your enthusiastic support!
GG

gcarter
12-31-2008, 02:02 PM
I wouldn't imagine your V-drive would need much water since it may be better than 90% efficient. Maybe 5-10 HP loss. Also when you're putting no load through it, it shouldn't be generating any heat.
Your engine, OTOH, is only 15%-20% efficient, so it requires a lot of water.

zelatore
12-31-2008, 03:32 PM
Standard cooling practice on our yacht V-drive installations is to run them in series. Here's the basic layout

Cooling water comes in via a thru-hull and seacock
through a sea strainer
through the V-drive cooler
to the raw water pump on the engine
through the engine oil cooler
through the heat exachanger
and finally gets dumped out the exhaust elbows

These aren't hi-po installations, but that would be a typical small or big block gas inboard / V-drive Crusader layout. Pretty much the same on Volvos, and I believe on Mercs as well.

Speed Racer
12-31-2008, 03:50 PM
Standard cooling practice on our yacht V-drive installations is to run them in series. Here's the basic layout

Cooling water comes in via a thru-hull and seacock
through a sea strainer
through the V-drive cooler
to the raw water pump on the engine
through the engine oil cooler
through the heat exachanger
and finally gets dumped out the exhaust elbows

These aren't hi-po installations, but that would be a typical small or big block gas inboard / V-drive Crusader layout. Pretty much the same on Volvos, and I believe on Mercs as well.

Ok, NOW we are talking.. Very interesting... So The raw water pump is actually pulling through the V-drive?
That set up would be for a FWC engine, how would it change if it were a Raw water cooled engine?

Also, I am debating putting a sea strainer on it.. The pick up is actually right in front of the prop, build into the strut..... What are your thoughts?

mattyboy
12-31-2008, 06:16 PM
my 67 had a thru hull pickup but was an I/O boat , i have seen transom pick ups as well on I/O sorry don't know bo diddley about v drives understand the feeling about putting holes in the hull, mine thru hull fitting had a shut off valve which i thought was a great Idea too bad I could not reach it if i needed it in a emergency

zelatore
12-31-2008, 06:55 PM
Ok, NOW we are talking.. Very interesting... So The raw water pump is actually pulling through the V-drive?
That set up would be for a FWC engine, how would it change if it were a Raw water cooled engine?

Also, I am debating putting a sea strainer on it.. The pick up is actually right in front of the prop, build into the strut..... What are your thoughts?

I've never seen a strut mounted intake, so I can only guess that it would supply enough water. As for a strainer, it's always a good thing to have on. You can get the cool billet bling stuff, or a simple Groco or Perko bronze unit. Any of them will do the job just fine.

The V-drive cooler is usually pretty small and mounted right on top of the unit. Yes, the raw water pump pulls through it. It should be noted that the raw water pump is usually pretty low in the boat, so although it's pulling the water a fair way through the hoses, it's not having to lift it much vertically. If you had much lift it wouldn't be able to get a prime.

I haven't messed with a raw water cooling system on a v-drive in years (we made fwc standard some time ago). But I seem to remember it pretty much being the same flow pattern.

Conquistador_del_mar
12-31-2008, 09:08 PM
Standard cooling practice on our yacht V-drive installations is to run them in series. Here's the basic layout

Cooling water comes in via a thru-hull and seacock
through a sea strainer
through the V-drive cooler
to the raw water pump on the engine
through the engine oil cooler
through the heat exachanger
and finally gets dumped out the exhaust elbows

These aren't hi-po installations, but that would be a typical small or big block gas inboard / V-drive Crusader layout. Pretty much the same on Volvos, and I believe on Mercs as well.

That system would work on the V drive Donzi except that the cooling lines are too small on the transmission and V drive to allow enough water to get to the engine in the case of my old V drive Donzi at least. My memory is that the cooling lines were only 1/2" if not 3/8" fittings. Bill

gcarter
12-31-2008, 09:55 PM
Here's a picture of another 18 V-drive boat and it uses a transom mounted pickup. It's a good setup, although I would have used a Stainless Marine pickup instead of the Merc piece.
Note that this is original also.
http://www.donzi.net/forums/attachment.php?attachmentid=41549&d=1230519111

zelatore
01-01-2009, 01:21 AM
That system would work on the V drive Donzi except that the cooling lines are too small on the transmission and V drive to allow enough water to get to the engine in the case of my old V drive Donzi at least. My memory is that the cooling lines were only 1/2" if not 3/8" fittings. Bill

1/2" ??? Yikes! That is small! The stuff I deal with is usually more like 2" even on gas motors. I'm surprised they could get away with such a small water line.

BigGrizzly
01-01-2009, 11:13 AM
OK Speed. Your Dad is correct. First no oil cooler really belongs before the pump. The only reason H&M did it was because that hull pick up that they used as in G carter's post will get over 50 psi on my boat at 80 mph and over 35 at 60mph. So the t ( which isn't necessary)comes after the pump and no other pickup is needed.

Speed Racer
01-04-2009, 12:50 PM
How is it your Dad is ALWAYS Right?!?!?! :bonk:

For those playing along at home.. Here are some updated shots of the V-drive.. Lots of distractions during the holidays, but the V-drive goes in today, if it kills me!!

Thanks for the advice, and I am now getting out .. the.... holesaw.... :eek:

Conquistador_del_mar
01-04-2009, 12:59 PM
How is it your Dad is ALWAYS Right?!?!?! :bonk:

For those playing along at home.. Here are some updated shots of the V-drive.. Lots of distractions during the holidays, but the V-drive goes in today, if it kills me!!

Thanks for the advice, and I am now getting out .. the.... holesaw.... :eek:

Garry,
That is a new one on me. I have never seen a pickup built into the strut. What size are your fittings on the cooler lines? Are you going to install a clamshell pickup and dump it out the side fitting? Bill

Speed Racer
01-04-2009, 01:31 PM
Yea, I think it is a pretty strange deal, the intake in the strut.. Per the photos I posted, raw water comes up through that hole in the strut, then the top plate of the strut has a 1" outlet, which, in my case went to a 'T' fitting, then split between the water pump, and the V-drive. That was the genesis of this thread. Dad sees the V- Drive and transmission starving when the Jabsco is pulling like a #$%&@.
I think a small clamshell strainer forward and to port from the strut may be in order. That fitting would probably be 3/4" and go from the intake to the transmission cooler, then to the V- Drive, then dump over the port side.

GG

zelatore
01-04-2009, 03:15 PM
Dad's probably right. I would be very hesitant to install two draws off the same port as it's always possible that one will overpower the other and starve it.

In fact, I think it's against code to do so (except in a sea chest installation) although I don't know this for fact.

What sort of pump would you use for the new intake?

gcarter
01-04-2009, 06:31 PM
Garry, I would agree that you need another source for water.
But rather than put a hole in the bottom, IMHO, a transom pickup has some advantages.
I prefer the Stainless Marine 1" NPT (1 1/4") part # 05-8888803
http://www.stainlessmarine.com/myProducts.CFM?CFID=14578755&CFTOKEN=ff34f3b898b8be92-69E064E6-3048-2D85-1B436C6CBDD3915B&parentcategoryid=53%7CWater%20Pickups&productID=57&showDetail=1&categoryID=53|Water%20Pickups&vendoridtodisplay=0&filterFor=&collection=


If you shop around, you can find them for less than their reccomended retail price. I found my last one on eBay, or Poodle can supply one.

I installed one in Von Kamps 18 (not a V-drive). Here's a reference to it;
http://www.donzi.net/forums/showthread.php?t=49388&page=2

Ghost
01-05-2009, 05:57 AM
Yea, I think it is a pretty strange deal, the intake in the strut..

I'm curious if anyone here knows the history of this. I believe all the Nova Marine boats with v-drives used pickups on the struts, and this was in the what, '68-'73 range.

It certainly seems like a good theoretical idea from a drag perspective, so long as you weren't having to make the strut a lot bigger as a result.

But it sounds like an idea that maybe builders played with and then scrapped? If anyone knows, I'm curious.

gcarter
01-05-2009, 06:40 AM
The idea had been popular on race boats for probably 30 years or more.
Any hole in the bottom of a performance boat, regardless of era, can have a detrimental effect on handling and performance.

BigGrizzly
01-05-2009, 09:25 AM
I am going to disagree with George. Unless George is saying you need only to move the pickup. You don't need two the cooler goes after the pumpand befor the engine, and no separate dump is needed. Ghost they did use the strut intake but moved away because of air, expense and other characteristics. The strut also caused prop issues. In the case of the 16 it doesn't matter. My take on this is LISTEN to Dad. When building history go to a historian. I have tons of true stories, where the old guy kicked the new computer engineer's butt. I have cam, carb, Blower, and suspension stories up the gazue.

zelatore
01-05-2009, 09:44 AM
Any idea who made the strut? Buck Alganquin maybe? I wouldn't doubt if one supplier cast them all and sold them to the various boat builders.

It does seem like a good idea - get rid of a thru-hull. But as mentioned, there are plenty of other things to consider about intake placement.

As has already been said, I don't think you'd need two intakes and pumps. Just put everything in series. You can run it like I mentioned earlier, just put the items in a different order to have the pump right after the strainer and before any of the coolers. It should be happier that way - the pumps don't suck very well.

BigGrizzly
01-05-2009, 10:10 AM
Watch it ZEL, your experience is showing.

zelatore
01-05-2009, 10:23 AM
Watch it ZEL, your experience is showing.

Oh crap - I'd better zip that up!

Speed Racer
01-05-2009, 03:40 PM
Really good discussion!
I am still going back and forth on this one. My Howard Day cruiser had two intakes, and two dumps, and I raced it back and forth to Catalina numerous times, flat out, with no heat issues at all. It however used a neovane cam driven pump, which I loved.

I am using ( and not liking the idea) the original Jabsco belt driven pump that mounts to the HM motor mounts. Routing the output back down might end up being an issue, as will filling the original V-drive/ transmission dump hole on the port side.
Thanks for the ideal of the stern mounted unit, it is pretty big and shiny, and might get in the way of my big shiny rudder back there!

Stay tuned, still designing and figuring it out and spending money.. Good news is that the V- Drive is in, and lines up beautifully with the shaft. Whew!

GG