steam out exhaust
 

Hey guys i got my new motor n today and fired up and timed great. But the driverside exhaust (thu hull) is steaming when gets warm Im kinda confused. So any help will b great. Ps also i dont no if impeller bad to but it wasnt get n hot about 150s thanks

It may help us out to know What engine do you have? and what side is hot starboard side [Right], Port side [Left]? Thank's:party-smiley-004:

Maybe a picture how it looks like ,,on the transom!!

And what is it thats steaming???? the outside of the pipe or at the transom ??

Its the starboard side and the motor is a 454mag that i built up new cam intake carb ext. It is the water coming out out the exhaust the water is hot and steam n i have silent choice to so the water dumps down the y pipe to the transom and out the sides. I put on a new mercruiser thermo to i went from 6 hose to the 4 hose and also bought used imco thumper manifolds. I also shot the thermo and it was any were from 140 to 160f and i was also run n on earmuffs so if that makes a diff. I just dont know it never did it before.

I had the same problem at the worlds ladt year and burned a piston!!!!
It runs to hot,,( in my case it was the timing ) was way to high !!!
But then also my valves where touching the pistons ?!

Hope that helps !!:cool:

Head gasket ,cracked head,or crack in a cylinder on that side.Pull the plugs on that side and see if any look different than the others.

even if i just got the engine back from the shop complete refresh and they put it together from oil pan to intake. I hope that wouldnt have missed something like that. I just pulled the impeller out of the sea pump and nothing gone but 3 fins were cracked and from the looks of it could have been folding over when runing so could this have cause this problem due to like low water press or not? Geting to close to memoial day weekend...........:eek:

My engine came from the shop as well,,,,,i hope it was not the same shop. LOL:rolleyes:

But i would check it ,,cam timing, timing,valves ,,,and so on !!
I say it can be !! I did not say thats your problem !
But definitely running to hot !!!!!!

o also put msd blue box complete ign. and the shop set adv. in the cam also so i guess ill grab a new impeller and go from there. thank you o now that i think about it when i would rev up to around 2000 rpm the steam would stop would that b cause to the pump moving faster idk and what should be normal temp.

:eek::eek::eek:
OK,,,,,,here is your problem,,,i bet u used a digital timing light !!!!!!!!!

NEVER DO THAT ON A MSD BOX.

I bet your timing is @ 45 + !!!
Exactly what happened to me !!!
Use the cheapest 30 bucks timing light on a MSD !!!!!
Go check it and u be surprised !!
Hopefully u did not lean it out yet !

Pump should have nothing to do with it beings you say it is only heating to 150 degrees.That's perfect with that thermostat.Good thing your changing that impeller though sense it's showing some cracks.They take on that folded back look from running in the pump body.It still probably fits in there tight though.New ones are perfectly straight so when you install it make sure you fold them back the right way for the rotation of the pump.Also that wouldn't explain the steam only coming out one side.

How cold was the water you were putting into it? I was winterizing my boat last year and the garden hose water temp was probably around 40 degrees. Of course it's gonna steam when it hits the exhaust then.............. But mine was steaming out of both pipes, not just one. Are you talking out of one motor, or one pipe of one motor?

Thanks for all the info guys. I put the new impeller in and a new sending unit on the thermo and that got that fixed. So i took it to the lake and did a few trial runs and now i have to do some tuning and timing. Anyone have any words of advise on msd ign. Wasnt very happy with speed and power :angry-smiley-038: kinda doggy. Hope i can get it out. Thanks all agian for all the info.

MSD,,definitely use a reg timing light !!! NO DIGITAL OR ADVANCED LIGHT !!!

MSD's work great.They really helps keep your plugs from fouling at idle speeds around the dock when running bigger cams and carbs.What cam,intake and carb are you running now?Do you know what your compression ratio is?I don't know how you are setting your timing but you should set it when it is fully advanced.Hook up your timing light and direct it on the timing mark.Have some one throttle it up while you watch the timing mark advance.When it stops advancing and holds steady,usually about 2500-3000,set it at 38 degrees.If your balancer isn't numbered that high you can get a timing tape to put on it at your local speed shop.Need to know your balancer diameter though.This would be a beginning for your tuning.Your doggieness surely has nothing to do with the MSD.

38 ???????:eek: mine is at 36 and i run racefuel,,,are u kidding ?!:party-smiley-004:

That's what it says in all my books on building high performance big block chevys.That's what the guys at all the local speed shops have told me also.I've been running my engines at 38 degrees total advance for 25 years and have never had a problem ,and that's on pump gas.

Merc Carbed 500's are listed at 36 if I remember correctly.

If you bought used exhaust manifold then that might be a problem. If they are cracked, or the riser/manifold gasket is leaking, you may be getting water dripping back into the head. When it hits the exhaust valve it creates steam. You may also be getting reversion. Same steam condition.

Daredevil, my whippled 540 is timed at 36!!:eek:

Could be ,,,but a stock 454 .......36 ???? more like 32 !!:party-smiley-004:

Its almost always something really, really simple and cheap.

Sounds like you found it with the impellor.

For me, sometimes its just junk in the sea strainer: a slightly restricted cooling water flow.

:Its a 454 mag mark 4 block forged intenals. A msd complete ign. (dis,coil,wire,ect) blue box, holley DP750cfm carb upgraded fuel pump,roller rockers, roller lifters, hydro roller cam 283 290 223 230 .566 .575 114° and a single plane hp500intake all brand new parts and fresh rebuild from KEITH EIRCKERT PERFORMANCE (parts). Also anyone have any idea on horsepower rating kinda trying to figure out so i can get back with the GREAT PPL AT B BLADES:ernaehrung004 thanks

o comp is around 9. 3/4 or close to stock not really sure.

First of all i would get rid of the 500 intake and stick a dart or Team G on there if u really go for power ?!

Also ,,who built the engine ???
That would be the guy to ask about timing !

Something just does not make sence !!

I don't know if you changed pistons or not but a 454 mag only has 8.6:1 compression.That's a pretty stout cam for that compression and 454 inches.Lot of lob separation too.Probably should have at least 10.5:1 compression. Also good headers.I'm not familiar with the thumper manifolds.That motor probably won't hardly run going silent.Single plane manifolds are usually good for higher RPM's.A good dual plane will give you better acceleration and mid range.Single planes are for WOT.Be sure you have a good fuel pump.If mechanical at least a holley high out put marine pump.If not you can lean it out at WOT and then you'll be dropping exhaust valves.Best in a marine engine to use Manley Inconel exhaust valves.Marine engines have extreme exhaust temperatures.How many RPM's are you getting at WOT?What size boat and prop?I would think it would make around 500 to 550 HP.You need to know your WOT rpm's to determine you prop size.

I know you guys kinda got off the steam subject, and on to timing. But depending on water temp, wouldn't you see a certain amount of steam regardless?

Shouldn't see steam at all really. With a constant flow of water no part of your engine will be hot enough to create steam. The only time you will get steam is if water goes where it is not supposed and comes in contact with parts it is not supposed to.

I dont know where you guys boat but up in Seattle I see steam coming out of everyones exhaust (especially this time of the year). Water temp is 55-60 degrees and you will see steam!

i think lake temp would play a big part in steaming,

OK,,,but why does 1 engine run fine and the other one steams ?????/ mmmmmhhhhhh:party-smiley-004:

Ya its a 236 rinker sport cuddy and im not sure about wide open is yet need to get timing set about 3000 rpm with load backfires and so lake like 5 mi from house so put back on trailer to set time and go over everything an been raining since. On the steam i had no steam on the lake ran around 140 150f ish so thats good. On the the prop its an old prop buddy had i know its a 23pitch but not sure what brand it says turbo on center and its pretty rough. This weekend is going to be nice so hope to have the bugs worked out. HOPE

I wasn't referring to this guys boat for say, just in general.

And i agree, cold ass water, hitting a hot exhaust elbow and tailpipes equals steam.

What drive are you running on that boat?That motor when dialed in should be able to turn at least 6000 RPM with that 23P prop.You could probably run a 25P easily.Mirage Plus would be a good prop for that boat.Also you should be sure you have a prop with a solid hub.Might want to plug in a soft touch rev limiter to that MSD box too.Should prop it down to about 5500-5600 RPM to get some life out of that engine.


P.S. The dude's only got one engine and it was only steamin out one side!!!

Could condensation build on the inside of the exhaust pipe due to cold cooling water, then become steam when heated?

I have twin 454 Magnums too, both rebuilt. The port side of the starboard engine steams a lot more than the other three exhausts. I've been through everything, can't find anything wrong. Been that way for two years so I guess it's okay, but I don't run them very hard.

OK,,but then 4 cylinders run in the cold lake water and the other 4 in warm water ,,,,,RIGHT ??????:bsflag:

Look ,,if 1 side is steaming ,,meaning that side runs way hotter then the other ( to hot ),,,reason i think is running lean ,,maybe jets on that side and a little timing issue !!

I'm stick'in with leaky exhaust and/or reversion.

But that would not make 1 side run hotter and steam,,,by now he would of hydro locked it !!!:party-smiley-004:

But hey,,,he should look into it no mater what !!!!

Also the reason me thinking its timing or jetting,,,HP 500 need 4 different jets in the carb most of the time an engine never runs the same on each side ,,very rare !!!

Happened to me. Imco powerflows corroded and leaked down into the head. Water hits the exhaust valves and instant steam.