Exhaust manifold temp

Rockxx
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Exhaust manifold temp

Postby Rockxx » Thu Jun 15, 2017 4:10 pm

Well, it's been a long summer already, having the ongoing problem (over a year now) getting rid of a miss. Reworked heads, rebuilt distributer, on and on. Had a new mechanic look at the boat Tuesday and thought we had made progress except after running for about thirty minutes at the dock, I found the exhaust manifolds seemed extremely hot. When I checked the temp with my Lazer thermometer starboard was up to 245 degrees and port 210. Can someone tell me what's normal. Engine temp however never got over 160 degrees on the temp gauge and 135 degrees when I checked the thermostat housing temp. As I have the two chamber Sherwood pump, assumed one of the impellers was bad, even though both were replaced when the heads were pulled last year. Maybe one hour run time since. PO had a spare pump he gave me that he said was rebuilt so I spent the morning swapping out the pump. No change in the water flow and temp was the same as before. Took the boat out to see if it might cool a bit and found the damn miss is still with me. Ray with the 32' Marinette Brown Eyes, if you read this post would you send me a pm with the mechanics name that rebuilt your engines when Al owned the boat. Any of you Marinette mechanics reading the forum that thank they might like to visit Nashville, Chattanooga or the Smokey mountains, I'm 1 hour away from all of these. I'll furnish you and your family, up to four people, room and board in exchange for a few hours at the boat.

Sorry for the long post.
Rockxx
1972 28' express "Safari"
Single Chrysler 318
Center Hill Lake, Tennessee

Tuggle
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Re: Exhaust manifold temp

Postby Tuggle » Thu Jun 15, 2017 4:45 pm

How old are the exhaust manifolds? Had a similar problem and found mine to be not completely clogged but very restricted, rust, corrosion, etc. Pulled the end caps and the risers off, rodded the manifolds out, LOT'S of rust, reassembled. Engines ran cooler for a very short period of time then started dumping water back in the engines via the exhaust manifolds. Ended up replacing the manifolds, guess all that rust was the only thing holding them together.
"Deplorable", 1975 32' Express, Twin 318's, Raw Water Cooled, Lake Lanier, Ga.

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TinChips
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Re: Exhaust manifold temp

Postby TinChips » Thu Jun 15, 2017 7:46 pm

My starboard manifold also runs hot. We took it off and had it acid dipped and pressure tested and the machine shop could not find anything wrong with it. Can't offer any help on the miss, sorry.
1987 32 Sedan Bridge | "Sea Jul"
Craig & Julie Purnell | Home Port: Sandusky Ohio
President, Great Lakes Marinette Club
http://greatlakesmarinetteclub.org

Rockxx
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Re: Exhaust manifold temp

Postby Rockxx » Thu Jun 15, 2017 8:53 pm

Starboard manifold is brand new, port was cleaned when the heads were off. Had really never paid much attention to the Rube Goldberg hose assembly until now and am surprised it ever cooled. Flushed the lines when I had the pump off and no obstruction there. Would like to know what an acceptable temp would be.
1972 28' express "Safari"
Single Chrysler 318
Center Hill Lake, Tennessee

Fastjeff
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Re: Exhaust manifold temp

Postby Fastjeff » Fri Jun 16, 2017 7:06 am

That's WAY too hot! You'll burn up the hoses and etc. if that continues. Mine ran about 130-140 degrees (after a long run).

Not sure how that dual chambered nightmare works, but something isn't pushing anywhere near enough water through.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

ddependo
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Re: Exhaust manifold temp

Postby ddependo » Fri Jun 16, 2017 10:03 am

Mine run 110 -120 deg.
Wayne
1973 32 express fly bridge
Chattanooga
"Southern Lady"

BlueSkye
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Re: Exhaust manifold temp

Postby BlueSkye » Fri Jun 16, 2017 7:22 pm

I was advised when I got my first Marinette to put my hands on all of the exhaust manifolds once the engines were warmed up to see if they were OK. I believe that you can't keep your hand on anything over 140F. Mine are always cool enough to keep my hands on them, except for once and it was a big problem.

Rust flakes are not your only enemy. If the water pump impeller ever blew up, those vanes are stuck in the engine somewhere. Suggest you pull the hose off the top of the transmission cooler to see if there are pieces of rubber or anything. Also, you can pull the hoses off the exhaust manifold to see if the hose sprays water with the engine running for a brief time.

On the missing, there are only three things; fuel, compression and spark (timed properly). Get a couple tools and get to know your engine. Check compression and look at the sparkplug on all cylinders and you should learn something. Check the spark if the plugs do not tell the story and check your timing. Distributor cap posts and rotor clean? Timing advance right for both idle and cruising rpm? Always confirm proper firing order. Inspect all your spark plug wires. They lay against the exhaust manifold (on the Chrysler anyway) and if you melted any of the insulation on them by running a hot manifold (would explain missing) you have to replace them and fix the hot manifold problem first.

Just some thoughts. Good luck Southern Lady. I expect your boat is very similar to mine.
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau

BlueSkye
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Re: Exhaust manifold temp

Postby BlueSkye » Fri Jun 16, 2017 9:19 pm

Sorry, Good luck Rockxx. What's your engine?
1971 32ft Express 2x318
Seneca Lake, Erie Canal, Lake Ontario, Rideau

Rockxx
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Re: Exhaust manifold temp

Postby Rockxx » Fri Jun 16, 2017 10:42 pm

Single 318, original, showing 1160 hours. Plan on pulling the plugs (again) next week. New points just this week, heads reworked last summer and very few hours since the rebuild. Anyone got any suggestions as to the best way to get in a position to actually check the timing. I'm too old and to get were I need to be to read the timing light. The engine itself runs at normal temp so my problem is on the lines that feed the exhaust. Figure I'll pull all the hoses on that side of the system and look harder. Sure appreciate the help you guys provide.
Rockxx
1972 28' express "Safari"
Single Chrysler 318
Center Hill Lake, Tennessee

Ray4713
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Re: Exhaust manifold temp

Postby Ray4713 » Sat Jun 17, 2017 1:22 pm

Rockxx,

Sent you a PM with the info I have

Regards
Ray
1987 32' Sedan Flybridge "Brown Eyes"
Twin Chrysler 318s
Center Hill lake, TN