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Copper water pipe used for

E

elgineddie

Contributing Member
"Hello team,
Looking for some

"Hello team,
Looking for someone who really knows their stuff to tell me what this is (see pix). I have a 1998 5.0L and there is a flexible but stiff copper water pipe plumbed from the top of the intake manifold and goes to the starboard exhaust manifold. It's got a rubbery plastic shield running the length.
My SELOC manual doesn't show anything like this and my local marina just stared at me. There has got to be an expert who can shed light.

http://users.foxvalley.net/~spizzirri/h2o.jpg"
http://users.foxvalley.net/~spizzirri/h2o2.jpg""
 
"I would call Mercruiser on th

"I would call Mercruiser on this one. If it stays cool while running, and I suspect that it does, it would probably be for making sure the air/fuel charge stays cool, also. Cold air expands more than hot air and that yields more power."
 
"Actually, I should have state

"Actually, I should have stated that the tube itself gets and stay hot as sin. The engine runs perfectly within its normal operating temp. In fact, the only reason I'm wondering (aside from it not being mentioned in my manual) is because it pumps seriously hot water directly into my starboard exhaust manifold which makes it almost hot to the touch where the port exhaust manifold is cool to the touch.

-Ed"
 
it doesn't pump hot water

it doesn't pump hot water into the exhaust manifold. it runs hot exhaust gasses to the intake.
 
"Ahhhhhh, exhaust gasses. Now

"Ahhhhhh, exhaust gasses. Now it's clear! Thanks Scott!

OK, so you've cleared that up for me but now I gotta still find out why my starboard exhaust riser is hot while the port riser is cool.

Thanks again!
Ed"
 
That would be exhaust gas reci

That would be exhaust gas recirc for emissions considerations I believe.
Sounds like the water flow to your starboard riser may be restricted somehow. You should maybe pull the hose and check the water outflow at idle against the other side. Do this after she is fully warmed up so the t'stat is open.
Rod
 
"The 5.0L is a GM smallblock.

"The 5.0L is a GM smallblock. that means that the passages for the exhaust recirc should be cast into the block. There would be no reason to add an external pipe. Also, there doesn't appear to be an EGR valve in the line anywhere. Maybe part of an intake manifold preheat system that would send exhaust up through the egr ports and back out to the exhaust system through that hose? I've never seen it on a marine engine, but that doesn't mean it doesn't exist! I'll go with Jim N, may be best to contact mfr.

Dan"
 
TODAY i DISCUSSED THIS WITH A LONG TIME MECHANIC THAT STATED IT DIRECTS HEATED WATER TO THE INTAKE JACKET TO HEAT THE GAS BEING INJECTED BY THE TBI- MY PORT ENGINE HAS ONE BUT THE STARBOARD ENGINE DOESN'T AND i BOUGHT THE BOAT TO FIX 2 CRACKED HEADS IN THE STARBOARD ENGINE- IT WAS FIXED BUT HAD AN EDELBROCK INTAKE NOT SUITED FOR THE ENGINE- WHICH MAY HAVE SOMTHING TO DO WITH THE DAMAGE- IT DOESN'T FUNCTION PROPERLY SO WE ARE LOOKING FOR AN 8 BOLT INTAKE WITH THE HOLE FOR THE PIPE AND THE PIPE SO I CAN CONNECT TO THE EXHAUST RISER AND FINALLY AFTER TOO MANY HOURS OF TESTING ECU AND MONITORS -- AM ALSO TOLD THAT DOUG RUSSEL MARINE IN WORCESTER HAS A MILLION USED AND USABLE PARTS- SO IAM GOING TO CALL THEM AND HOPEFULLY GET WHAT I WANT THERE- 1996 ERA-ED
 
I JUST READ SCOTT'S REPLY THAT IT IS EXHAUST GASES FOR RECIRCULATION- BUT IT CONNECTS TO THE MANIFOLD THAT HAS A WATER CIRCULATION JACKET AS PART OF ITS CONSTRUCTION-I INCORRECTLY STATED THAT IT WAS THE RISER - IT IS THE MANIFOLD
 
EDIT- NOW I DON'T KNOW WHO IS RIGHT- I DO KNOW THAT THE EXHAUST COMING OUT OF THE OUTDRIVE SMELLS OF GASOLINE- AT THIS POINT NO MATTER WHO IS CORRECT , THE PROBLEM IS THE NEED TO HEAT THE INJECTED GAS TO FIRE EFFICIENTLY AND NO DOUBT IS TIED TO THE MONITORS EFFECTING THE CONTROL RESPONSE OF AIR AND FUEL MIXTURE FROM THE ECU- ED
 
THANK YOU SCOTT- I AM TRYING TO REPLICATE THE PORT ENGINE THAT HAS NO PROBS- SO I NEED THE MERC INTAKE AND THE PIPE TO SEE IF THIS IS MY PROBLEM- WHICH IT PROBABLY IS- I DO NOT WANT TO REDO THE ENGINEERING OF THE MOTOR WHICH IS 2 BBL TBI- CIRCA 1996- DOUG RUSSEL MARINE IN WORCESTER MASS IS AN HOUR AWAY- WORD IS THAT THEY ARE THE USABLE USED PARTS KING- THOUSANDS AVAILABLE- MAYBE I'LL GET LUCKY- IF YOU KNOW OF AN EASIER FIX- AS YOU DID TO YOUR BOAT -PLEASE LET ME KNOW- THANK YOU-ED
 
Hi there, welcome to marine engine.com boating forums. Please know it's offen best to create a new thread of your own vs bringing up an archived thread that's often-considered high jacking threads and then becomes confusing should someone start to help the original poster elgineddie while someone else is trying to help you especially if the thread needs to go on for a while or you need to come back a year from now..< it happens more than you'd think....

Just know that while Scott is correct vs the guy you talked too, Scott hasn't been online since May 28, 2012. ;)

If desired, feel free to start a new thread within the following link where it reads thread title, turn off the cap locks (big letters vs small) give us some detailed notes regarding your engine/s models, years, HP stern drive model name, and best of all if available, the MerCruiser engine serail number/s....


In quick searching it appears possibly that the years may be off somewhere as it seems/I recall that Merc didn't originally start using the 8-bolt intake with exhaust pipe until 1998 as you'll see in the following parts guide of possibly a near similar engine model that you may or may not have that can be seen yet used just as an example.


MerCruiser Engine & Stern Drive by Engine Model

Lookup MerCruiser engine & stern drive by engine model and buy discount parts and accessories from our large online inventory.
www.marineengine.com www.marineengine.com
 
a carb`d intake uses a crossover passage to warm the intake manifold.
a TBI or MPI uses a tube from the stbd exaust manifold to do the same thing .It does not heat any water or have water flowing thru n it.
 
Fun Times said:
Hi there, welcome to marine engine.com boating forums. Please know it's offen best to create a new thread of your own vs bringing up an archived thread that's often-considered high jacking threads and then becomes confusing should someone start to help the original poster elgineddie while someone else is trying to help you especially if the thread needs to go on for a while or you need to come back a year from now..< it happens more than you'd think....

Just know that while Scott is correct vs the guy you talked too, Scott hasn't been online since May 28, 2012. ;)

If desired, feel free to start a new thread within the following link where it reads thread title, turn off the cap locks (big letters vs small) give us some detailed notes regarding your engine/s models, years, HP stern drive model name, and best of all if available, the MerCruiser engine serail number/s....


In quick searching it appears possibly that the years may be off somewhere as it seems/I recall that Merc didn't originally start using the 8-bolt intake with exhaust pipe until 1998 as you'll see in the following parts guide of possibly a near similar engine model that you may or may not have that can be seen yet used just as an example.


MerCruiser Engine & Stern Drive by Engine Model

Lookup MerCruiser engine & stern drive by engine model and buy discount parts and accessories from our large online inventory.
www.marineengine.com www.marineengine.com
Click to expand...
it seems that DIETER is the gentleman who responded to say SCOTT was right about the fact that it is exhaust gas that is getting recirculating- however he changed his engine to a 4bbl , where I am trying to match the port engine as previous owners have messed up the starboard intake model and eliminated the crossover pipe- my boat is a 1996 Sea Ray-- 8 bolt intakes- which doesn't seem to match the 1998 date you refer to- a recent Merc mechanic told me on Friday that Merc was famous for putting stuff together just to make it work- my search in Merc archives with the data on the engine info tag brought me to a 12 bolt intake of which there was a picture- but it doesn't match my 8 bolt- so I disconnected the port tbi screws and lifted it to see the intake design- and sure enough it is a 4 bbl opening and the bottom plate of the tbi matches the starboard tbi- and no where can I find a reference or picture of the intake with a hole for the recirculating pipe- but as I have stated Doug Russel Marine of Worcester Mass - who advertises in magazines - has an expansive array of usable used engine parts- I will also reference the site you sent - thank you-Ed
 
correction- I have a 1997 Sea Ray not '96- in searching for the Intake--- Merc archives show a 96 as 2 round 2 bbl holes where the 97 shows a 4bbl 2 rectangular holes ( both of these intakes have 12 bolt patterns)- but I have 2 bbl TBI's over these rectangular openings ( and 8 bolt patterns) - hence - I guess - the need to compensate with exhaust gas heat- however here is the info from the motor tag- MCM 350 MAGNUM EFI GEN+-----350 CID----ENGINE # OK150524---TRANSOM OK 205388---DRIVE OK240870 -- I appreciate all of the help and info that all of you have donated to help me out - but I guess I was in the middle of a change in engineering- thanki you-Ed
 
1995/1996 I believe was the transition time frame when Mercruiser went from the 1987-1995 standard chevy V8 ( millions of these blocks were manufactured) with 12 bolt intake pattern used with CAST IRON heads used for Marine, to the VORTEC V8 blocks which used the 8 bolt intake pattern. Note: Older cast iron heads could be used on the vortec blocks with the 12 bolt pattern. I have one!!

Also they transitioned from having Mechanical fuel pump capability to not (No machining done for pump rod) as they went to TBI and thus an electric fuel pump.

Seeing you boat is that old..................20 years, hopefully have the original blocks but if not then any issues may be because of a block swap some time in the past. So do go blaming merc unless you are 100% sure the blocks are the originals!!
 
Sir- thank you for your reply- I do believe the block is original- it is for an 8 bolt intake which matches the port engine- which I have been using as a model for changing cracked heads- at which time the cylinders and pistons were mint and there was no rust in the exhaust because it came from Lake Winnipisaukee- but an edelbrock intake for which they had to cut the plastic insert in the thermostat housing because the edelbrock did not have the cut to allow the insert to place below the attachment surface- and no place to attach the coil in front of the distributor-- I put it back together with the edelbrock intake when I replaced the heads - since then too much gas vapor in the exhaust out of the outdrives- assessment of the ECU showed it was ok but emitting issues related to messages from the sensors - so I am looking to match the starb engine with the port engine by installing the same tube from exhaust to intake - I have lifted the port tbi and it sits on a 4bbl opening with 8 bolt intake- so - its a hybrid waiting to be solved some where along the previous owner line which led to cracked heads-Ed
 
By fhe way, I live 15 mins away from Doug Russels. Be careful with that place. Whats advertised is just that, Adverised...

Be sure you know exactly what you want when ordering anything from that source.
 
that is the problem- since it was 20 years ago and not made anymore only a match will do- changing the system might incorporate the entire electronic control system also- or maybe just from the intake out taken from another engine that has a blown bottom end- thank you for helping-Ed
 
Using your engine serial number 0K150524 suggests your intake part number from Merc 807289A1 which looks like this,

Here’s your engine part’s catalogs,

www.crowleymarine.com

MerCruiser Stern Drive 1997 350TBI [ALPHA] 4350104KS [4350104KS] - Parts Lookup | Crowley Marine

View parts diagrams and shop online for 4350104KS : MerCruiser Stern Drive 1997 350TBI [ALPHA] 4350104KS. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.
www.crowleymarine.com www.crowleymarine.com

Genuine Mercury Marine parts, large inventory, fast shipping. 350 MAG. ALPHA EFI(GEN+) GM 350 V-8 1997 0K001509 & Up

350 MAG. ALPHA EFI(GEN+) GM 350 V-8 1997 0K001509 & Up
www.mercruiserparts.com www.mercruiserparts.com

Be sure to try and use Merc OEM base “gaskets” where possible for the TBI mounting basically 12 on down and make sure the MAP Sensor orange seal is in good condition number 21,

The pipe in original question is item number 4 and 5,
 
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