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MERPerformance
07-11-2009, 10:43 PM
548 cid N/A Gen VI blocks, Proflier Heads, proper head gaskets, water cross over w by-pass, 142 degree thermostats, 20-30 psi water pressure, starts bouncing about 5 psi at 5500 rpms up till 6000 rpms, temp at 150 @ WOT, transom mount water pick-ups 8" up from center, have also installed Mercs 30 psi water relief dumps before sea strainers. What happens is above 5000 rpms cylinders 1-7 start getting hot and if you hold it, the paint will burn on cylinders 5&7 around the exhaust port and cause the gasket to lose qwench on the gasket at the water ports coming from the block to the head, the water ports by the front dowels are blocked as suppost to be and the rear dowel water port exits at the lower small one,these are the same gaskets used on the 525 efi they allow more water to flow around the the exhaust port. Ran these engines on the dyno with no problems I mean ran them hard! 165 degrees of water temp with extended run time. I can't understand why, the 1-7 cylinders are having this issue, the bouncing pressure is it coming from the affect of the water pressure relief dumps? I used these dumps only one time before on a 41 Apache with 1100. ANY THOUGHTS

Sean Stinson
07-11-2009, 11:37 PM
Is it a step bottom boat?????

Sean Stinson
07-11-2009, 11:40 PM
From the sounds of it that probably isn't the problem!!!! Are these the same relief dumps on GR????

MERPerformance
07-12-2009, 08:10 AM
Sean, non-step. The water pressure is not steady,even in flat water, it floats and the dumps are not open at 4000 rpms. The pick-ups are adjustable and I lowered them again 1/8" Can you get a air pocket even with 30# water pressure? Why, would it only burn the paint above 5500rpms. No obstructions in blocks or heads, have never had anything like this before in any other boat. pick-ups on other set-ups have not been as of aggressive as these, do I switch back to the drives as a water source they have side and a pick-up in the nose,but the volume will be decreased

MERPerformance
07-12-2009, 08:14 AM
Haven't talked with Greg, yet. I'll try again today.

Ratickle
07-12-2009, 08:18 AM
My opinion, Start with the simple stuff first.

If you've never set the pickups this high before, or never used this style before, go to what you know has worked in the past and see if that's it.


Have you used this exact same crossover setup before?


And you have used this same pressure relief system before?

MERPerformance
07-12-2009, 08:50 AM
Plenty of times. The pick-ups are not high, they are pretty low. and you are right on going back to the original set-up. The bad thing is this thing came in pretty messed up, engines to rigging, I really hate to remove pick-ups in place to use drives being the engine are 775hp have rigged plenty of boats and built alot of engines over the last 20 yrs,nothing really different except this problem with the 1-7 bank. I know people have problems with cross-overs and thermostats, crap in the blocks which block the water flow,but, this is not the issue I have check those items before getting on here and asking. never had to run bleed lines on the back of engines, gaskets come the same man that makes all of Mercs. HP stuff I know those patrs are correct, Ihave never burned the paint on an alum.head around the exhaust ports and the temps on the dyno were higher and with regular headers.

Chris
07-12-2009, 09:04 AM
Can you walk through each piece in the system, from the transom pickup through where the water exits? Also, pics might help.

I'm thinking there's a restriction somewhere causing pump cavitation. Since you ran it on a dyno, clearly you have rigging issues.

BUIZILLA
07-12-2009, 09:27 AM
EFI or carb?

if it's carbed, dual plane or single plane intake?

Ratickle
07-12-2009, 09:58 AM
Probably a dumb question, but.

Since 1 and 7 are both port side of engine, any chance the header jackets are plugged on that header and the heat is actually transferring from the header back to the head?

MERPerformance
07-12-2009, 10:28 AM
Nothing really different on the system from anything else I have done. Pick-ups, sea strainers, oil coolers, cross-over kits, running with thermostats or without, except a restrictor plate. #10 by-pass hose instead of the # 8 they send, this includes the sizing of the fittings to match with no restrictions. Its a carb single plane, The header is not restricted CMI with # 12an hoses, no hot spots. The thing is the pressure bounces about 5-8# above 4000rpms. 20-25# @4000, 5500-6000 25-30# bouncing 5-8#, but the hull is running flat on flat water in the ICW, would think air is being picked up off the hull on a 99 non- stepped bottom, the water dumpsfrom Merc are not even open at 4000 and they are progressive opening before they reach 30#. I had a 2004 topgun with big oil temp issues that we fixed, but we modified the sportmaster lower and added air dump lines off the sea strainers from Marine Machine corrected the oil temps, the the engine had no by-pass, just cross-overs with restrictor plates, those engine were running 320 in the pan and they came down to 250-260. This set -up is running about 220 steady running with thermostat controlled.

BUIZILLA
07-12-2009, 10:32 AM
is it possible the intake hose interior is deflecting??

MERPerformance
07-12-2009, 10:52 AM
This happening on both engines, all the hoses are new, quality Sheilds Flex. Guys thanks for your thoughts on this, think about it. I have to go in and finish machining some heads for another 38 and get them on the dyno. I'am going to try Zul and Lipship monday maybe the have had this in the past. I really would hate to go to the drive for water supply due to the restriction in the hose size in the gimbal, we are using the drive for cooling it's self, with # 8 lines off the side of the water jacket on the upper instead of the cav. plate. I'll check back tonight. Thanks again! Mark

MOBILEMERCMAN
07-12-2009, 10:56 AM
Is it possible there is air entering at the pick up? A burr, a little caulking? Have you verified there is no air running thru the motor. Temporarily installed a clear hose between motor and headers and extend to cockpit to allow visual confirmation.

Like Buzilla asked. Are you using Braided hose in front of the sea pump?

The water entering the boat is under high pressure so a little air bubble can expand once it enters the engine. The gauge cannot tell if it is water or air. If it is fluctuating I would be looking for air.

Ratickle
07-12-2009, 11:02 AM
Both engines are doing the exact same thing with the exact same cylinders???

What would they have in common that is different than any other setup you've done in the past? Only the bleedoffs and the pickup?

Sean Stinson
07-12-2009, 12:04 PM
Mark I ran into this with a 42' Tiger with Big Power 1000+ HP and what the problem was is that the water pick-ups were too low and what was happening was that when the water entered the pick-up at high speeds was that it was creating a vortex maelstrom or whatever you have and it was creating an air pocket or turbulence in the pick-up thus creating steam pockets....it would burn the paint off of 3 and 5 on the head and when I stepped on it with a barefoot it burned the $hit out of my foot on the valve cover. If your valve cover is that hot that is bad!!!!!! Very Bad!!!!! Oil temp would climb to temps approaching 270-300 which was also bad....Anyway you already know all of this raise the pickup to about 3/16ths and see what it does that is where your problem is coming from I am sure of it!!!!

MERPerformance
07-13-2009, 09:08 AM
Sean, thanks for posting this after we spoke on the phone yesterday, it makes sence of my problem. Why this only happens on the odd # bank is werid, I have gen 6 blocks and I'am sure you had either bowtie or dart blocks which use a different gasket. Wewill see what happens after I get the gaskets in from my supplier.

Geronimo36
07-13-2009, 10:22 AM
How old are the blocks? I once had a big chunk of rust get stuck in an engine and it was effecting water flow. But you say it's both engines so I'd go with Sean's line of thinking on the water pick-ups.

#7 always seems to run hot regardless and is always the first to detonate if there's a fuel problem. The bleed lines off the rear of the intake will help with that.

MERPerformance
07-13-2009, 11:01 PM
The water-pickups are from Stainless Marine Square tube with 6 mounting holes, they are down 3/8"below the hull and 8"out from center.I believe Sean, is right. What concerns me is I spoke with Jerry, @ Stainless Marine, now they are telling me it's better to use their HIGH SPEED pick-up! The bad thing is I ordered these from them telling them they are for a 38 top gun with 775-800 hp. Not real happy about that, sure the customer won't be either. Going to raise them up to 3/16" and go from there. This one project has not been fun! But;you can't quit. Let you know how it turns out.

Blue Thunder
07-15-2009, 09:30 PM
It sounds to me like the timing is retarded and you are blowing the flame out the exhaust valves. Just a thought.

MERPerformance
07-15-2009, 09:55 PM
It sounds to me like the timing is retarded and you are blowing the flame out the exhaust valves. Just a thought.

Thats funny LOL.

Blue Thunder
07-16-2009, 12:13 PM
Thats funny LOL.

What do you think happens with not enough advance? It makes your exhaust gas temps high which could be why your paint is pealing. Like I said, it was just something to consider as a possible contributing factor.

MERPerformance
07-16-2009, 10:53 PM
Not to be a smart a!! timing only changes on cylinders 5&7 and burns paint, we have been talking about the water pick-ups and air entering the system. The engine would probably not even gain rpms under load, I guess since i'am on the dyno I'll try retarding the timing to the point that I burn the paint off the exhaust ports. Since I've been doing this for over 20 yrs I know what the timing is. Thank you for your thought on the problem.

Ratickle
07-16-2009, 10:56 PM
When are you testing next? Or are you changing the pickup?

Blue Thunder
07-17-2009, 02:19 PM
Not to be a smart a!! timing only changes on cylinders 5&7 and burns paint, we have been talking about the water pick-ups and air entering the system. The engine would probably not even gain rpms under load, I guess since i'am on the dyno I'll try retarding the timing to the point that I burn the paint off the exhaust ports. Since I've been doing this for over 20 yrs I know what the timing is. Thank you for your thought on the problem.

5/7 are next to each other in the firing order so they would show the most heat due to retarted timing. Not to be a smart a!! but everything in an engine is interelated. I would have thought in 20 years you might have picked up on this. My bad, carry on with the tunnel vision.........

Geronimo36
07-17-2009, 03:46 PM
To be honest, I haven't had many engines that over time didn't eventually burn the paint off the tops of the exhaust ports... If not totally burned off, definitely browned... Then again, we run up here for hours at a time.. ;)

I think his main question was the 5 psi fluctuation in water pressure in upper rpms??? I'm guessing it's either from a disturbance in the pick-up (air) or something causing bad water circulation out of the engine. He said he's not bleeding water off the rear of the heads but I'm not sure if the steam pockets can cause fluctions in pressure like that? At least I've never seen it. One things for sure, a few dumps would help facilitate some flow back there and help cool the rear bank of the heads.

MERPerformance
07-18-2009, 07:25 AM
Testing it today, raised the pick-ups to 3/16",to trailing edge below hull. these pick-ups were modified to make adjustments with them, they have a square sleve that slides over the outside with slots and allen head screws holding them. I blended the inner tube and removed the square edge leading into the pick-up. At this point until I test it today I wouldn't add blleed lines to the back of the intake. One change at a time, this has cost me alot of time and money. I have always seen the paint burn away on cast iron ex. ports, if it was just the port burning some paint I wouldn't have concerns, but; I,am talkiing about burning the paint between the ports also. we'll see this morning. Thanks again.

MERPerformance
07-18-2009, 07:42 AM
Blue Thunder, I understand what you are saying and agree with you, I just know for a fact that we have a water issue. The timing is set at 35 degrees, thunder bolt iv with a crane HI-6 Marine box hall effect pick-up which doesn't seem to pickup noises that i have found come from some magnetic triggers. Timing was the same on dyno and checked again in boat, the water temp on my dyno is between 160-170. I have seen Msd distributors retard the timing 10-15 degrees at about 2500-3000 rpms but,they run really bad and sometimes back fire if accellerated to fast. Thanks again

MERPerformance
07-18-2009, 10:27 PM
Tested it today with results! I raised the pick-ups 3/16 below hull took it out, tools, & thermo gun. 1-7 cylinders heads 180-198 degrees not good, removed thermostat same thing. Loaded it up took it back to the shop got some lunch came back to the shop. Went and bought some 1 1/4 clear plastic hose, installed it between the sea strainer and sea pump, put it back in the water got it on plan, no air still hot 1-7 bank 20 # pressure won,t push it. Why is the 1-7 bank getting so hot oil temp increasing engine won't cool down even at 2500-3000 rpms. My part time helper says; lets block the jumper hose between the cross-over and thermostat housing, I told him we need to remove the thermostat also so we don't burn the headers, this is going against everything I do to my builds, I use thermostats and try to use thermostat controlled oil temps. Here's are cooling system parts: Eddie Marine cross-over kits with thermostats, Stainless Marine water pick-ups, Hardin Marine sea-strainers, 3"oil coolers, stock merc sea-waterpumps, changed the -8an fittings on crossover and therm. housing to -10anso more water would cool headers when therm. is closed. We capped the 10 an fittings removed the thermstat bought upon plan 10#press @ 3500 rpm, temps all equal all 4 corners 110 degrees, oil temps down 160 degrees, took the center out of the thermostat installed it,need some restriction! ran it up 20 # at 4500 rpms still cool temps 120 degrees oil 160,ran itup to wot 6000rpms fingers crossed, perfect! Buy the way lowered the waterpick-ups to 1/2 below hull, going to raise them now to 3/16". I don't believe that a -10an hose which is 5/8 I.D. would take that much water awayfrom the block or was the jumper hose putting cool water on top of the thermostat cooling it to the point of not opening it. Looked at an other cross-over set-upfrom Stainless Marine,the jumper doesn't enter over the thermostat, same set-up -10an jumper,what do you do if you want to use the thermostat, listen to Jerry @ Stainless and go to High speed pick-up or maybe try the Stainless Marine thermostat housing off the other boat, guess i'll try that housing,lets see who, is right or wrong on the product they make. This whole deal has cost me pulling the engines and 2 new cylinder heads and porting them, valve job and gaskets plus labor all covered by me,guess I'll find out who's product works. Letyou know soon.My spacekey is giving me aproblem!

Ratickle
07-18-2009, 10:30 PM
Hang in there. Got nothing here....:(

Geronimo36
07-20-2009, 01:53 PM
Tested it today with results!

We capped the 10 an fittings removed the thermstat bought upon plan 10#press @ 3500 rpm, temps all equal all 4 corners 110 degrees, oil temps down 160 degrees, took the center out of the thermostat installed it,need some restriction! ran it up 20 # at 4500 rpms still cool temps 120 degrees oil 160,ran itup to wot 6000rpms fingers crossed, perfect!

Looks like you solved the temp problem, no???

Maybe you need to run a smaller hose to the crossover. I always thought the hose was smaller than a -10 though, no?

Silly off-the-wall question but was the t-stat installed upside down?

Chris
07-20-2009, 02:34 PM
Cooling problems AND a space key? That's $hitty luck.

Chris
07-20-2009, 02:35 PM
I thought that same thing until I started fooling around with jet drive boats. That's all the bigger the feed lines are and it cools 800 hp.

MOBILEMERCMAN
07-20-2009, 03:11 PM
Glad to hear progress. On the clear hose in the future, It will tell you more if it is after the motor before the headers.

MERPerformance
07-21-2009, 07:45 PM
It'snot over yet! Removing the thermostat and restricting it along with capping the by-pass isn't the repair, by far is it the way I want it. I know some guys don't like thermostats in the water or for the oil temp, but' I use both when able to. To many suppliers out there build stuff for the marine business and don't test it enough before they sell it or they copy someone elses product and make a change on it and call it theirs. I did some research on what one of the main players in the marine manufacturing does with theirs and what design engineering they put into it.They have been around for a long time and I know for a fact that, their product works and talked to the owner of the company about this problem, I have been having. There is a difference in the design between the two, I am making a change on the housing. I'll let you know how it works and post pics of before and after. This product may work on other smaller H.P. but not on 800 that turn 6200. As you well know this product was purchased because of cost, cheaper! When this is over and I have all the facts I will post it.

Geronimo36
07-22-2009, 09:09 AM
At least you were able to isolate the problem and now it's easier to fix!! :)

MERPerformance
07-27-2009, 11:56 PM
Found the cause of the problem! Thermostat housing. Tried to modify it to keep the cold water off the thermostat. The cold water cools the top of the thermostat sending a false temp on the water temp, making the water in the heads and block rise in temp and not cool down and develope a steam pocket on cylinders 1-7 also causing the oil temp to rise beyond to point of wanting to cool down, so hot the oil was tring to cool the cylinder head. This was a system from Eddie Marine' cross-over with by-pass to thermostat housing and a 140 degree thermostat. Here's what finally worked took a housing made by Stainless Marine, cast stainless. These are made with a diverter cast into the housing that keeps the hot water over the thermostat and the cold water away from it by directing it to the exhaust, we changed it to have 2 # 12 water outlets and a #10 or #12 by-pass fitting both off these worked on the other 2 boats, one was a 33' Fountain 1987 with 800s, #4 drives, original water pick-ups, the other boat 2004 38 top gun with 815s XR drives sportmaster lowers with modified water inlets, Marine Machine strainers with air dump check valves going over board. Both equipped with Stainless Marine housings and thermostats 142 degrees. Taked with Mike @ Hardin Marine today about their kits, this problem seens to exist on higher hp set ups using this style housing, the have a housing that is spring loaded to 10# allowing the water to mix and dump out the exhaust. I'am ordering 2 housings tomorrow from Jerry, Tried of being a test subject for non proven products. So if you have encountered this problem in the past with thermostats and cross over kits maybe this will help. I 'am sure this product works for stock power applications but, not higher HP set-ups.

2112
07-28-2009, 01:07 AM
XR drives sportmaster lowers with modified water inlets,



Marine Machine strainers with air dump check valves going over board.

How did you modify the sportmaster pick ups and do you have a picture of the air dump/check valve attachment point on your strainers?

What raw water pressure are you looking to get?


Much appreciated :USA:

txriverrat2001
07-28-2009, 08:51 AM
Found the cause of the problem! Thermostat housing. Tried to modify it to keep the cold water off the thermostat. The cold water cools the top of the thermostat sending a false temp on the water temp, making the water in the heads and block rise in temp and not cool down and develope a steam pocket on cylinders 1-7 also causing the oil temp to rise beyond to point of wanting to cool down, so hot the oil was tring to cool the cylinder head. This was a system from Eddie Marine' cross-over with by-pass to thermostat housing and a 140 degree thermostat. Here's what finally worked took a housing made by Stainless Marine, cast stainless. These are made with a diverter cast into the housing that keeps the hot water over the thermostat and the cold water away from it by directing it to the exhaust, we changed it to have 2 # 12 water outlets and a #10 or #12 by-pass fitting both off these worked on the other 2 boats, one was a 33' Fountain 1987 with 800s, #4 drives, original water pick-ups, the other boat 2004 38 top gun with 815s XR drives sportmaster lowers with modified water inlets, Marine Machine strainers with air dump check valves going over board. Both equipped with Stainless Marine housings and thermostats 142 degrees. Taked with Mike @ Hardin Marine today about their kits, this problem seens to exist on higher hp set ups using this style housing, the have a housing that is spring loaded to 10# allowing the water to mix and dump out the exhaust. I'am ordering 2 housings tomorrow from Jerry, Tried of being a test subject for non proven products. So if you have encountered this problem in the past with thermostats and cross over kits maybe this will help. I 'am sure this product works for stock power applications but, not higher HP set-ups.

Good info!! I have a client with a 38 Fountain - not real big power - but the same scenario. One bank gets way much hotter when the T-stats are in the housings (generic aftermarket with crossovers) and the bypass does dump directly on top of the T-Stat - I agree with you on running T-stats - control is always much better!

Keep us updated and thanks for sharing.

2112
07-30-2009, 10:10 PM
how did you modify the sportmaster pick ups and do you have a picture of the air dump/check valve attachment point on your strainers?

What raw water pressure are you looking to get?


Much appreciated :usa:


ttt

MERPerformance
08-01-2009, 11:47 PM
How did you modify the sportmaster pick ups and do you have a picture of the air dump/check valve attachment point on your strainers?

What raw water pressure are you looking to get?


Much appreciated :USA:
Remove lower set-up in milling machine, use an end-mill and cut lead-in groves and blend.
You have to buy, top caps from Byng, that are for dumps, they are coned and are theaded in the center. You can buy, brass 3/4 check valves at a plumbing supply store,install them with over board dumps to the rear of the hull, I used #8an fittings.

MERPerformance
08-02-2009, 12:09 AM
I called Eddie Marine , after doing this to advise them of this issue, they said; wish I would have called sooner, I told them, I wanted to know what was causing this problem. They say, drill more holes in the thermostat, that might be fine for 500 hp, so we talked about blocking the cross-over and taking the water from the front of the intake manifold, the flat area on the front, I already had it drilled and tapped for 1/2 npt, ran a short jumper from there to the top of the thermostat housing which keeps the water temp from confusing the thermostat. It worked great, no more than 150 degrees, cylinder heads even in temp all four corners. They said;they wouldn't modify it because they don't sell many of them. My advice; buy them from Stainless Marine, they will cost more but, worth it in the end.
Water pressure is 30 psi, have to raise pick-ups some more, I like to have about 25 psi@ wot

2112
08-04-2009, 02:36 PM
Remove lower set-up in milling machine, use an end-mill and cut lead-in groves and blend.
You have to buy, top caps from Byng, that are for dumps, they are coned and are theaded in the center. You can buy, brass 3/4 check valves at a plumbing supply store,install them with over board dumps to the rear of the hull, I used #8an fittings.


Byng? Is that someone at MM? Could you just drill and tap your current lids or is the cone top critical?

Thanks


:USA:
.

MERPerformance
08-07-2009, 08:40 PM
Byng? Is that someone at MM? Could you just drill and tap your current lids or is the cone top critical?

Thanks


:USA:
. Doc. Byng, is M.M., the top is critical to keep the air centered. I know Stainless Marine has a dump valve also for air. I would be afraid to drill a clear top like Hardin, plus the hold-down is in the center.

2112
08-07-2009, 08:45 PM
Doc. Byng, is M.M., the top is critical to keep the air centered. I know Stainless Marine has a dump valve also for air. I would be afraid to drill a clear top like Hardin, plus the hold-down is in the center.


I will call him Monday morning. I already have MM strainers, hopefully the cone top just spins right on what I already have. Did you get the Dump valve from Stainless Marine or did you just use brass check valve?

Thank you!

MERPerformance
08-08-2009, 11:54 AM
I will call him Monday morning. I already have MM strainers, hopefully the cone top just spins right on what I already have. Did you get the Dump valve from Stainless Marine or did you just use brass check valve?

Thank you! Yes, you'll get new tops that spin on, powdercoat to match. Tell Byng,I sent you Mark from S.C. we go back to 1995. You can get the check valves from the hardware store, try to get something like 1/2 npt, I could only get 3/4, its a backflow preventor, the tops are going to be 3/4 npt, use a 3/4 -8an 90 degrees, then use -8 push lock hose run it to the transom with thru hulls and adapt the check valves there, that way you won't see the brass or you can try to locate some stainless ones. I take it you have a step- bottom, are you getting air in the system, have you checked it with a clear plastic hose first?

2112
08-08-2009, 01:26 PM
Yes, you'll get new tops that spin on, powdercoat to match. Tell Byng,I sent you Mark from S.C. we go back to 1995. You can get the check valves from the hardware store, try to get something like 1/2 npt, I could only get 3/4, its a backflow preventor, the tops are going to be 3/4 npt, use a 3/4 -8an 90 degrees, then use -8 push lock hose run it to the transom with thru hulls and adapt the check valves there, that way you won't see the brass or you can try to locate some stainless ones. I take it you have a step- bottom, are you getting air in the system, have you checked it with a clear plastic hose first?

Thanks,

Yes stepped bottom, Pressure stays constant @ 15lbs but that doesn't mean it is all water. No, I have not done the clear hose test, but I recall seeing it mentioned somewhere, maybe this thread. I will go back and check.

Of course at idle and cruise, everything is fine, it is on hard runs that my temps spike and when I slow to cruize, they come right back down pretty quick. I highly suspect air in the raw water.

On a related note, when I took Tres' course a few years back, he told me to put drive spacers on my Gladiator for "many reasons". I thought at the time he meant handling, maybe better water intake was also a factor?
.

2112
08-08-2009, 01:38 PM
I forgot, Is there a specific pressure setting on the check valve or just make sure it a one way proposition.

Thanks for your advice. Will call Byng Monday morning. :USA:

MERPerformance
08-09-2009, 11:30 AM
I forgot, Is there a specific pressure setting on the check valve or just make sure it a one way proposition.

Thanks for your advice. Will call Byng Monday morning. :USA:
I think maybe 5psi. It's really only there so you are not sucking air back through the dump lines.

MERPerformance
08-09-2009, 12:07 PM
Thanks,

Yes stepped bottom, Pressure stays constant @ 15lbs but that doesn't mean it is all water. No, I have not done the clear hose test, but I recall seeing it mentioned somewhere, maybe this thread. I will go back and check.

Of course at idle and cruise, everything is fine, it is on hard runs that my temps spike and when I slow to cruize, they come right back down pretty quick. I highly suspect air in the raw water.

On a related note, when I took Tres' course a few years back, he told me to put drive spacers on my Gladiator for "many reasons". I thought at the time he meant handling, maybe better water intake was also a factor?
. If you are running thermostats, that seems to be the readings you would get. As we have talked about, many do not like thermostats, running with out them hides alot of problems. I'am almost sure you are getting air in the system. With a sportmaster drive even with the water inlets, they will need to be opened up to allow more volume of water. I know from Bob, that you can handle a small grinder. I'll try to get some pics for you. As far as the drive spacers go, I don't know! not a correction for water issues for me. Have you done back to back testing on speed and slip factors. If you have a standard lenght lower and it's a sportmaster, it was designed for hi speed, but: it has more area which is causing drag. Example: the 2004 Top Gun I just did some 604 for has standard lenght sportmasters, before this boat ran 92-94 mph @ 5450-5600 rpms, we are still playing with props, have tried a P5x 32 92mph @ 5050 rpm, 34 bravo one 91mph @ 5000rpm, going to try 32 bravo ones lab from there. Probably get 95-96 mph@ 5500rpms. These engines were 735hp@ 5600 rpms now we are at 815 @ 5900, we are only going to give him 5600rpms max, the owner only knows two positions idle& W.O.T. We were expecting higher speeds,but without a 2"shorter lower not going to happen, two other boats out there one with 850 hpmax speed 101mph, the other 750hp 2"shorter same speed. If we raised the rpms, we could get closer, but with out the - 2" falling way short.

2112
08-09-2009, 01:04 PM
Yup, I have Sportmaster shorties. And they are mounted high. I have not calculated slip because I am already knocking on the door of desired speed with 30" P5s (labbed) at 6,000-6200rpm or 32" 4 blade B1s at 5700-5900 .

My issue is having to get out of it due to climbing oil temps. My closed cooling never exceeds 180 but I have to slow when my oil hits 260-270. As I said, dropping to cruise cools it down fast (220-230). (I have the big Teague oil coolers). PSI stays at 15 but I am relatively convinced I am not getting enough raw water when @ WOT. I also measure temps in the pans BTW.

You have given me a lot to work with here. Thanks.
.

MERPerformance
08-09-2009, 03:34 PM
Yup, I have Sportmaster shorties. And they are mounted high. I have not calculated slip because I am already knocking on the door of desired speed with 30" P5s (labbed) at 6,000-6200rpm or 32" 4 blade B1s at 5700-5900 .

My issue is having to get out of it due to climbing oil temps. My closed cooling never exceeds 180 but I have to slow when my oil hits 260-270. As I said, dropping to cruise cools it down fast (220-230). (I have the big Teague oil coolers). PSI stays at 15 but I am relatively convinced I am not getting enough raw water when @ WOT. I also measure temps in the pans BTW.

You have given me a lot to work with here. Thanks.
.Dump the air first, than go for the pick-ups on the drives.

MOBILEMERCMAN
08-09-2009, 04:33 PM
I suggest you always put the dumps below the waterline. It only takes a small piece of grass or debris to hang open a check valve. Once on plane you have pressure in the strainer. Off plane is when you suck in the air.

Also, if you try the clear hose install after the motor before exhaust.

2112 I don't know if you are aware of the potential problem with the intake line restriction in salt water. The place where the intake line comes through the transom. The intake hose tends to get pinched from corrosion. It is easy to inspect if you don't have extension boxes. The cover where you attach the intake line is where you can see the problem if it exists. Two hex head bolts hold the cover on if it is pinched it is immediately obvious when the cover is removed. You should have a new gasket on hand.

2112
08-09-2009, 06:26 PM
I don't have extension boxes but I do have ITS. They have rigid (aluminum?) intake pipes coming in through the transom. Is the pinch in between this and the Drive helmet?

Also, are you saying have the air dumps coming out the bottom or just below the water line on the transom? Probably smart to put a screen over the air vent hole in the strainer.

On a side note, I run 1&1/4 raw water lines through everthing untill the y-pipe that feeds my headers, then it is size 12 all the way out to the dumps. Each pipe has a 3/16" hole to mist the exhaust as well.

Thanks

MOBILEMERCMAN
08-09-2009, 06:33 PM
The part I am referring to is where the water hose from the drive bellhousing goes through the transom. It is the forward end of number 15

http://www.mercruiserparts.com/Show_Pictures3.asp?dnbr=880951002&ivar=images/COMMON/8273.png&inbr=11210&bnbr=60&bdesc=Gimbal+Housing

I believe it would be a pita to check on an ITS. My only suggestion is to back flush through the transom and see if it will take a full stream of a garden hose. The actual passage is only about the size of a finger at that moment and if it is corroded it obviously gets smaller. I think there was another thread on the subject that included pix.

2112
08-09-2009, 06:38 PM
And that part feeds into part # 20 in that picture? For ITS, # 20 doesn't exist, it is a long tube that makes a sweep inside the boat.

Either way, I assume there is a corrosion build up at that junction?
.

MOBILEMERCMAN
08-09-2009, 06:48 PM
Also, are you saying have the air dumps coming out the bottom or just below the water line on the transom? Probably smart to put a screen over the air vent hole in the strainer.



Ideally below the waterline at idle and on hullside where you can monitor while underway. Most have screens of some sort. But as you may know silly things happen. If the dump line is exposed to air the slightest debris will allow air in and create a problem. In the race boats ten years ago we tried many different types of pop off valves eventually we just dumped the air with no valve.

MOBILEMERCMAN
08-09-2009, 06:56 PM
And that part feeds into part # 20 in that picture? For ITS, # 20 doesn't exist, it is a long tube that makes a sweep inside the boat.

Either way, I assume there is a corrosion build up at that junction?
.

That is an ITS break down I shared. The hose 15 connects the bellhousing where the drive mounts to the transom plate. the insert 16 expands the hose and holds it in place. 20 shows where the larger hose attaches and it runs forward where you can see it and it eventually attaches to the seapump.

When the corrosion builds up it pinches the hose ,collapses the insert, and restricts the inlet of water.

It should take a full stream of a garden hose. If it won't it may be worth checking . I will look for the other thread I mentioned after I eat. My dinner is on the table. I be back soon.

2112
08-09-2009, 07:17 PM
That is an ITS break down I shared.

It Looks just like what I have on my Fountain but Cigarette must have eliminated it because # 20 is not anywhere to be seen on my Gladiator.

I back flush this with salt away after every outing and the flow appears strong, I am apart at the moment so I have access to everything. I will check it.

I would be interested in that other thread if you find it. Thanks BTW. :USA:
.

MOBILEMERCMAN
08-09-2009, 07:30 PM
It is in the extension part of the assembly. You can see it on the fountain because it is with in the transom of the boat . On the ITS it is in the set back. I don't think it is visable unless the engine is out.

Here is a pic of the a corroded one. It has been my experience it is not a problem before say 5 seasons. Every place is different I have no experience with west coast saltwater. The salt collects between the hose and the housing and flushing has no effect because it is external to the hose spraying soap and salt away into the hidden areas of the gimble ring area may help.

http://www.seriousoffshore.com/forums/showthread.php?t=7931

I only mention this to make you aware. Your boat is likely too new to suffer from this yet.

2112
08-09-2009, 07:36 PM
It is in the extension part of the assembly. You can see it on the fountain because it is with in the transom of the boat . On the ITS it is in the set back. I don't think it is visable unless the engine is out.


I only mention this to make you aware. Your boat is likely too new to suffer from this yet.

Ah, that would explain it. :sifone: I appreciate you making me aware. It will be a whole lot harder to check when everything is back together.

So, did I read you right? you just eliminated the check valve on the air vent? Did you keep the lines small, like a # 6 to keep water bleed off to a minimum?:bigear:
.

2112
08-09-2009, 07:40 PM
http://www.seriousoffshore.com/forums/showthread.php?t=7931



Wow, That is closed off. I do back flush the inside but I hear you about the outside. Another thing to worry about. :ack2:

Luckily, we are a little less salty out west.
.

MOBILEMERCMAN
08-09-2009, 07:46 PM
So, did I read you right? you just eliminated the check valve on the air vent? Did you keep the lines small, like a # 6 to keep water bleed off to a minimum?:bigear:
.

They were 120+mph race boats but, yes no valve #8 line. 100mph offers 144lbs of pressure. I think a valve on a pleasure boat is good. Just don't rely on the valve and put the outlet under water off plane.

MERPerformance
08-09-2009, 08:54 PM
I suggest you always put the dumps below the waterline. It only takes a small piece of grass or debris to hang open a check valve. Once on plane you have pressure in the strainer. Off plane is when you suck in the air.

Also, if you try the clear hose install after the motor before exhaust.

2112 I don't know if you are aware of the potential problem with the intake line restriction in salt water. The place where the intake line comes through the transom. The intake hose tends to get pinched from corrosion. It is easy to inspect if you don't have extension boxes. The cover where you attach the intake line is where you can see the problem if it exists. Two hex head bolts hold the cover on if it is pinched it is immediately obvious when the cover is removed. You should have a new gasket on hand.
I agree, with below the water line is a better installation than what we had on the Top Gun, sorry the thru-transom fittings were already there.
What makes the difference on the clear hose after the engine or between the sea-strainer and the pump if looking for air coming into the system?

MOBILEMERCMAN
08-09-2009, 08:59 PM
I have two reasons that immediately come to mind. First the pressure before the motor will be greater that the clear hose is designed to handle. Second the water is under pressure collapsing the bubbles. By the time the water has entered the engine the pressure has fallen, the bubbles have expanded and it is easier to see them.

Mercury has recommended 25 lbs at wide open on most engines. In the race boats you only want to scoop what is necessary. I understand 15lbs is the bare minimum an engine will tolerate. If steam pockets are forming adding air to the water it is here where you will find evidence of it.

MERPerformance
08-09-2009, 09:44 PM
I have two reasons that immediately come to mind. First the pressure before the motor will be greater that the clear hose is designed to handle. Second the water is under pressure collapsing the bubbles. By the time the water has entered the engine the pressure has fallen, the bubbles have expanded and it is easier to see them.

Mercury has recommended 25 lbs at wide open on most engines. In the race boats you only want to scoop what is necessary. I understand 15lbs is the bare minimum an engine will tolerate. If steam pockets are forming adding air to the water it is here where you will find evidence of it.
First of all, I was asking a honest question, with no smartness intended. The clear hose I used is pretty thick, has been on with alot of time in use, yesterday to be a matter fact in the ocean. It's coming off anyways. Also with the issues addressed in this thread, I have read the water pressures at the cross-over, at the block drain and at the intake manifold they haven't been different than 5 psi. What I noticed, before this thermostat housing issue was found that the water pressure would bounce about 5-8 psi at the intake at cylinder # 1 location and that was the steaming affect of the water. I agree with you that 15 psi minimum for this, I also like 25 psi min. pressure we had 25-30 psi, what caused our problem is the cold water from the by-pass confusing the thermostat, allowing the water on cylinders 1-7 to develope steam pockets, and you are right in saying that using the clear hose between the engine and the exhaust would show the bubbles. Our problems came from a part that wasn't engineered the same way that Stainless Marine designed their's. What have you seen for pressure drops from the sea strainer to the water inlets on the block. Thanks Mark

MOBILEMERCMAN
08-09-2009, 09:58 PM
Mark, I am not an engine guy, I am only sharing what I have learned while rigging and racing boats. I have been fortunate to work with some great people and have witnessed much in the progression of water systems in Fountain race boats.

The last thing I have to add with the clear hose is you can extend it into the cockpit and monitor it easily while underway.

Thank you for the thread, following it though, and sharing your results.

MERPerformance
08-09-2009, 10:02 PM
Mobilemerman, went back and read your post on the clear hose, at that time I was looking at the water pick-ups, merc water dumps and sea-strainers. I saw you said; between the engine and the headers. Sorry you had to repeat that to me, I over looked that.

MERPerformance
08-09-2009, 10:08 PM
Thanks Jim, you have great knowledge. I usually don't have to get into rigging issue of this kind, as you can see, something not tested for every application.

MOBILEMERCMAN
08-09-2009, 10:12 PM
What have you seen for pressure drops from the sea strainer to the water inlets on the block. Thanks Mark

I have only attempted to measure in the stainer unsuccessfully. AT test between 130 and 140 mph the 250 lb gauge would explode in one short test run. I would read the pressure in the block drain. I never experimented with the areas in between. The focus was on carrying just enough pressure to keep steam from forming and passing only water void of air through the engine. The engine guys we worked with dealt with the issues of flow through the engine as you have here. That part I have no experience to assist you with.

MERPerformance
08-09-2009, 10:22 PM
I guess I can close this subject one this. Heres the deal: Water cross-overs and thermostats housings are not created equal. Eddie Marine needs to change the design for HP, not drill holes in the thermostat until nothing is left of it. Stainless Marine has it engineered correct, keep the by-pass water away from the thermostat confusing it. What did it take to fix: plug the by-pass on the cross-over and drill & tap the front side of the intake to 1/2 npt and by-pass warm water to the thermostat housing with #10 an. Temps stay between 140 -150 degrees at all rpms and after bringing off plane back to idle in gear.

MERPerformance
08-09-2009, 10:26 PM
I have only attempted to measure in the stainer unsuccessfully. AT test between 130 and 140 mph the 250 lb gauge would explode in one short test run. I would read the pressure in the block drain. I never experimented with the areas in between. The focus was on carrying just enough pressure to keep steam from forming and passing only water void of air through the engine. The engine guys we worked with dealt with the issues of flow through the engine as you have here. That part I have no experience to assist you with.

I never knew the water pressure was that high at those speeds! that will for sure blow some hoses off. I thought maybe somewhere around 100 psi max. Shows what I know. Mark

MOBILEMERCMAN
08-09-2009, 10:36 PM
Not many boats have speedos anymore. Now its all GPS. According to Livorsi a speedo is a pressure gauge where 70 mph is the break even point 70mph =70 or 71 lbs,,,, 100mph=144lbs. Add a little compressed air from under the boat and a few pressure spikes and gauge went pop.