Water flow question

[delgrad59]

Posted this on scream and fly as well but looking for as many opinions as i can. Just ran my new to me Allison GS and am trying to determine whether the water flow is typical for the plumbing configuration. My previous merc only had one water outlet. My new engine has three so I am trying to see if what I saw is typical. The one port hole was very weak/non existent from a pressure perspective whereas the two starboard holes had great flow. The water temp was about 100 - 110 degrees. The water pressure was about 5 - 7 psi at 3k rpm and went up to about 10psi at 4.5k rpm. Is this typical. I included a picture that hopefully shows the set up.
Attached Images

Might have to post the pic again
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[patches]

What kind of motor? Sounds normal for a hi perf Mercury

 

[delgrad59]

Here is a pic of the motor. Dont know the extent of the mods to the engine. Supposedly rebuilt by randy pierson at GPI. Wondering if this is a stock mod he makes?

 

[whipper]

Sounds normal to me. You temps are great and will get a little higher in the summer months. At idle or lower rpm because your temps are so low and your T stats are normaly 120,s-143 range you wont get to much comming out the pissers untill your stats open up alowing more water flow past there range.

 

[delgrad59]

Thanks. I believe that in addition to only one pisser on my old motor the thermostats were removed so the water flow was always strong. makes sense that the water flow would be a little off if the thermostats are not kicking in.

Got a question about the steering on the allison. At speed, the wheel is easy to turn left but you almost have to jerk it to the right to get it to move. Is this typical?

 

[delgrad59]

Oh ya and what do you have to do to get the nose up? The boat runs real level. Had to sky the trim to the nose up. Wonder if I was running too "slow" so the nose didnt want to get up.

 

[patches]

Allison's will often give you the illusion of running very flat or "downhill". You were probably running higher than you think.

 

[Bobalouie]

That is not a typical setup for the water hose routing on the high perf engines. Most of the time the hose coming off of the stbd head goes over to port and tees in with the port head, so that you end up with two water evacuation points. That being said, that is the same way that my engine is set up as well. The mod just eliminates the restriction of pumping water out of both heads into one hose. I am sure there are other reasons for doing it, but I dont know what they are.

Your readings are the same as mine, no press at idle, probably 4-5 psi at 50 mph, around 10-12 psi at 65 and up.

 

[mtolley]

what engine is it? 1 or2 piece plate? stats or no? the picture appears to be a steel sleeve motor. there are mods to puttin steel sleeves on 1piece adapter plates.

 

[delgrad59]

Been emailed back and forth with Randy at GPI. Great guy. Responded to my email right away. He did work on the motor and has indicated that it should be pissing much more than what it is doing right now. Motor is a 200 2.5 that is ported to Mod VP spec. 34cc heads a 2.4 bridge port tuner.

 

[Allyfishing]

delgrad69, I had water issues at first on my 225PM and learned a few things as a result. that being what Bobalouie stated. My Starboard water comes over to the port water and expelled thru one hose and that hose is then T'd. One expels the water thru the telltale pee out the starboard side and the other goes behind the skirt and joined at a hose union in the adapter plate area to dump water into the mid section to cool off the tuner and the can.

So where is that other hose on the starboard side coming from? Is that the water from the poppet valve fitting?

 

[patches]

Looks like somebody replumbed that motor like a nicasil motor is done. May be out of necessity if it's on a one piece exh plate. If it's still on a two piece plate I, personally, would return it back to stock.

What is your intended use?
Is it a two piece or one piece exh plate?

 

[Volatile]

You said then port side was ow on flow. NOT NORMAL! that side has a lower outlet and the Starboard head is the one that should be low on output if its plumbed like a Nik motor as it is higher and then block will not fill all the way at idle. Pull the thermo covers and see if it has restrictors ( drill them to 3/16" if so) and be sure there is no poppet valve. This is correct for a 1pc adaptor. If it is a 2pc, you should be running the prefered poppet and thermos for a steel sleeve motor spinning 7500 or less. Also hopefully they moved the water drains to the warm water side under th block to help against cold seizing. Glad to her you got your boat finally!! Call me if you want. 815-590-6738

 

[delgrad59]

I will try to get some close up shots of the engine when I get over to the storage unit. Randy seems to think it is clogged. Suggested to take out the thermostat housing and clean it with either air or water. Hopefully it is something minor.

 

[Volatile]

Exactly what I believe as well, plugged line or thermostat / washer. Call me , we will bring some props for you to try when we get over your way if you want.

 

[delgrad59]

I believe it is a one piece plate. I have tried to include some more up close photos to show the plumbing. The first shows the hose going under the starboard head and the second shows where it enters the block.

 

[Allyfishing]

OK, that "other" blue hose under the starboard head is coming off the poppet valve. On mine that hose on the poppet fitting is fed by the fitting on the top of the block to take the extra flow of water up thru the feed in the block.

This is interesting. I'm following this to hear the results. I'm no mechanic but eager to learn.

 

[Volatile]

Allyfishing: Yours is a stock fishing motor or ProMax with a poppet valve. Usually we take the hose off the top of the block, add a plug and allow the hose to dump out the cowl. Motor cools better at higher rpm this way and poppet opens sooner.
delgrad59: Your block is setup as a race motor with no poppet and a plain cover. This does not mean you have a 1pc plate. You need to look underneath the cowl. Does it have seperate motor mounts or are they cast into the adapter?
1pc>>> must use the cooling setup as you now have it. Check for a plugged line or restrictor. It should NOT have thermostats with a non poppet motor as they will never open. Should have restrictors with 3/16" holes.
2pc>>>can use either style cooling system, but with a steel sleeved block turning under 7500, best to run a poppet, thermos. Higherrpm, use 130degree or 120 degree thermos. Over 7500,must run non poppet to get enough water through the motor.
BOTH should have the water drains moved to the warm water side under the block to prevent cold seizing. Be sure to warm your motor before extended running!
One more thing..... check that port side for temperature. If its cool then its likely a plugged restrictor or hose. If its hot, it could be a plugged exhaust divider plate or the block inlet holes under the divider. That would cut way down on the amount of cooling on the port side and could lead to engine failure. Its not uncommon to have gravel or wood or other objects plugging the holes. Check the restrictors and hose first.

 

[delgrad59]

I have pics of the underside at home. I will post them later tonight. It looks like the temp probe is on the port side of the motor and the temp was consistently at or below 110 degrees. Hoping that means that I was getting sufficient cooling on that side of the block. Is there a temp that I should allow it to warm up to before running? After running I did feel "by hand" both the port and starboard heads. They seemed to be similar in temperature. I am really hoping it is a plugged hose. I have heard the term cold seizing a couple of times. What does it exactly mean? Failure of the motor due to temps that are too low? Volatile - Thanks again and when are you coming down?

 

[Bobalouie]

On a cold start up, I usually let mine idle for 4-5 minutes and then just get her up on plane pretty easy, not flogging it or anything but not wasting time either. Then I cruise for another 3-4 minutes at around 3500 RPM or until I see my temp gauge has come up off the bottom. After that it is go time. On a warm start up I will idle for a minute or two then up on plane about the same way then cruise for a min or two before I open her up.

Your engine is likely not going to reach WFO temps until you are flogging it a little bit, at least mine doesnt. I just let it build some heat before I hammer it, but I am pretty sure my gauge doesnt read right, so I cant give you any temp numbers. I just know where the needle should be when WFO and dont let it get past that point. My numbers off due to non merc gauge with a wierd temp graduation as compared to most.