Running out of ideas

[Baltimore Sailor]

In the last two years I have replaced my old water pump with a new one from Moyer, rebuilt my entire hot section, replaced the exhaust manifold, replaced all the hose lines, and given her a muriatic acid bath. I had put a bypass valve on her years ago.

However, she still runs hot: 180 up to 195 as best I can tell on my temp gauge. Considering that most people report having trouble getting theirs to warm up, I wonder why I'm so "lucky." She also puts out a bit of steam in the exhaust, even on a hot summer day. My plugs always look good though, so I don't think I'm getting water in my cylinders from a leak.

She also throttles right up, so I don't think I'm suffering from an exhaust blockage, either.

Considering everything I've done to this point, what should I investigate next?

[Mo]

Hey there Baltimore Sailor,
I would suggest check the elbow after the pump heading into the engine. You have no water in the oil right? ....are you raw water or freshwater cooled. If raw water cooled pull that T-stat out and run with the by-valve open 1/2. If freshwater cooled I would consult with some of the guys with FWC...I know some take the T-stat out and run within acceptible limits under load...that's what count.

Wish I could be of more help but that's it for now. Let's see what we come up with.

All the best there bud.

[Baltimore Sailor]

I'm raw water cooled. The oil is clear, still very clean from my start of season change, no milkiness at all. I have good pressure at 35-40 psi.

Pull the t-stat? I can do that on Wednesday when I'm down at the boat. Can't hurt, right?

[Mo]

Just a quick note: I can run my beast (RWC) and still touch and hold my fingers on the head and / or block as she is running full out. No t-stat and FIW I don't put allot of faith in the guages....my fingers tell the tale. Personally, my feeling is that we try to run everything at max tolerance...these engines were never built to max tolerances of today's standards so I think we need to listen and cut them a little slack here and there. They were not and cannot sustain the abuse that us younger folk have demanded of engines / motors...we need to lean in there and touch and listen...I think that will help allot ..........

Just my ramblings but my point is to make everything well withins operating range.

EDIT: Yes, take the T-stat out, leave the by-valve open 1/2 and I think she will work like a dream...and you can throttle up in a storm and she will hold her own....finger tips on head on block tell the tale...regardless.

[Mo]

Pull the T-stat and put in a by-valve if you don't have one...then she will do everything she can for you when it's all going for sh!t....my has done above and beyond.

All the best.

[ArtJ]

sometimes there can be little pieces of broken off pump vanes that get stuck
in places where the coolant makes sharp turns. These can be in there
for many years, sometimes blocking cooling, sometimes not. Could be there
from before you owned the boat as well. Worth checking out.

Are you fresh water or salt water cooled?

Are you a early model engine with the dole thermostat? if so, there
can be steam coming out while the engine is warming up without
water flow and this is characteristic of the early model cooling system.

If you have a heat exchanger have you taken it apart and cleaned all the
internal baffles?

Be careful to use two wrenches if have mmi exchanger and removing
sacrificial zinc, otherwise can break off.

Best Regards

Art

[ndutton]

I think it's time to pull the water jacket side plate behind the starter and alternator and muck out the water jacket by hand.

I acid flushed mine twice two years apart, the last time right before FWC conversion. My conversion required me to pull the side plate and there was still plenty to clean out. After probing, scraping and vacuuming I covered the boat's interior with plastic sheeting and went after it with a water jet.

I also found my diverter cap had popped off. It was laying inside.

Be prepared for broken bolts, not uncommon.

[ArtJ]

IF, As Neil mentioned, you remove the side plate and find broken off bolts,
be sure and get the mmi side plate bolt repair kit. ALSO BE SURE AND
place a Socket across the drill before redrilling bolt holesas a depth gauge. as there is very
little space between the cooling passage and the cylinder wall. It is
easy to drill to far and into the cylinder itself.

Regards
Art

[Baltimore Sailor]

I neglected to mention that when I replaced the water pump last year I took the side panel off and cleaned everything up inside and made sure the diverter was all a-tanto.

So, to reiterate:

new water pump (raw water cooled)
all new water lines
side plate off, all cleaned up inside
bypass valve
new exhaust manifold
new hot section
acid bath

I'll definitely take out the t-stat and see what that does.

[romantic comedy]

Did you cover the gauge? Are you sure that the temperature reading is accurate.

What happens when you block the by-pass loop?

[Mo]

let us know.

I think that may sort it out for you....by pass open about 1/2...and to be honest I just leave it there. Let us know how you make out with it. I did it to mine (removed the T-stat) as soon as I got the boat 5 years ago. The guy that told me had an atomic 4 since 1980 and I think he must have bounced off every guardrail on every curve in the book

[Baltimore Sailor]

Did you cover the gauge? Are you sure that the temperature reading is accurate.

What happens when you block the by-pass loop?

Not sure what you mean by "cover the gauge." I have a valve on the bypass loop, and right now it is completely closed off so that all the water is going through the block and none through the t-stat.

[romantic comedy]

I think I meant, did you cover checking the gauge in the thread. Sorry.

I mean check the gauge for accuracy, that is all.

[hanleyclifford]

I predict that the removal of the thermostat will produce a dramatic change. Thermostats are for engines that want to run too cold.

[Carl-T705]

Baltimore, What does the raw water intake look like internally? Possible restriction? hose collaspsing? Thru hull plug with growth? just some thoughts