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New Ford 351 with GT40 heads overheating at idle need help bad

Deshet

Member
Hi All,

New Ford 351 with GT40 heads

The impellor is new and the pump is pumping water, (Sherwood pump G-21 or G21)
The impellor has been installed twice to ensure that it was oriented correctly. I also disconnected pump outlet while running to verify the flow. The flow of a water was similar to that of a water hose at idle. Not sure how to check if the flow is enough.
The cooling system has been primed.
The exhaust system is new (risers, elbows, even hoses)
Even installed spring in coolant hose to ensure that it wasn't bent or reducing flow,
The heat exchanger has been cleaned and acid dipped, it is original but looks to be in good condition and doesn't leak
The thermostat has been removed for testing only
The strainer has been cleaned
The risers are hot to touch
The belt to the water pump is tight.
The alternator belt is tight voltage reads low

The engine will start to run hot sitting in the water at the dock idling.
If I connect the water hose and let it idle it will stay at about 180 degress.
I would think at idle in the water without a thermostat that it would be extremely difficult to overheat.
The ignition coil is cool to touch although I think the timing is bad. It falls flat with no power after 2,000 rpm (I need to have the distributor checked although it is new)

The transmission oil cooler was back flushed for about 30 minutes.
It did not seem to overheat on a garden hose before while on the trailer.

The engine sounds stout, it sounds like a fox body mustang with the exhaust.

If someone can tell me how to check if the flow of the system is adequate that would be great.

Please don't derail things over the thermostat it will be re-installed once I figure things out. (Fully understand the purpose of the thermostat)



Is anyone running a stainless steel or titauium heat exchanger, I am fairly certain that my heat exchanger isn't the issue but I would like to get a permanent solution as everything else on the motor is new?

Thanks

Thanks, for any and all help
 
[video]https://drive.google.com/file/d/1HuN1cxg9jIhFQZmG6sdQ9QCOZtJi2brY/view?usp=drivesdk[/video]

1st video running on clear hoses to head
 
are you certain the heat exchanger side has been purged of air?

there shouldn't be any air in either side of the cooling system....air doesn't cool very well.

regarding "risers are hot to touch" - that typically indicates a flow issue on the raw water side....you should be able to touch them with your hand for a few seconds - ~ 130 deg F is the max I find works...an IR gen will help with that measurement...

make sure the intake side of the raw water system is tight (clamps, lid gaskets, etc) and the valve is fully open. How long has it been since the sherwood pump had a major kit installed?
 
Thanks for the information about making sure to purge the heat exchanger. I have never heard of that and it could be the problem. To purge do I remove the zinc and run water until all of the air is out? Please explain to the process.



I bought the boat recently with the new engine and don't have a lot of history on it. I don't mind having the impeller overhauled professionally if it looks like poor flow could be the issue.

Thanks
 
sounds like you bought a project.....hope you got a real good deal....

I'd say your best bet is to buy a factory manual....it won't answer everything but will likely get 95% of your concerns...the internet can be your friend there.

Hopefully, whoever put the engine together had a clue where it was going to be used and built it accordingly...if you got a car engine, you may have more work in the future.

as far as adequate raw water flow goes, the best way is to measure what the pump produces...using a bucket and a stopwatch.

On the pump, the internal parts will wear out after a period of use...the cam in particular...if its worn you can put new impellors in all day long and it will never cool the engine properly...

as far as filling the heat exchanger, there may be a purge fitting on the thermostat housing...if not, usually a couple hot and cold cycles will do it...as the engine and heat exchanger get filled, some air may be trapped in the cavities...once the engine is running and comes up to temp, the flow will usually push any air into the exchanger....so, if you know the exchanger was full recently, check it now - if its low, refill it. then run the cycle again...
 
Never heard of purging the raw water side of things and it doesn't sound like it is a common thing. Not remotely a project boat, everything is new on the boat and built to marine standards. Motor was built by a marine engine builder in Florida. This boat was purchased for a specific reason.

Not new to boats or boating. Currently have a twin diesel blackfin, a parker, a diesel topaz, a boston whaler, and a mckee craft. I haven't owned a gas inboard in some time, maybe 20 years. Please watch the videos you can clearly see that this is a marine engine.

I appreciate your advice on the master rebuild kit and will be having that done soon.

Thanks
 
Regarding the Closed Cooling System, the correct thermostat will have an air bleed within the flange.
This tiny opening allows the continued flow of coolant by allowing air to escape.
9k=




Regarding the seawater side of the Heat Exchanger, that side should "self purge".

As for the impeller "naturally making air as it spins"..... it would need to have a suction breach somewhere in order for that to occur.


Have you checked the engine circulating pump impeller?
If at one time this engine was raw water cooled with an Automotive circ pump, the steel or cast iron impeller could be rust compromised.


Mark touched on the seawater pump's impeller cam.
The cam must be able to properly fold and un-fold the impeller vanes/blades.
The impeller itself must be correct for the pump body..... (the correct impeller will sit proud of the housing by approx .010")
It must also be of the correct diameter for the pump body.
Also, both impeller thrust surfaces need to be in good condition.


Regarding over-hauling the Sherwood pump..... these are very user friendly.
Keep in mind that this style seawater pump is reverse rotation capable.
It can be used for both REV RH rotation and STD LH rotation engines simply by switching it 180*.
For a Std LH rotation engine, the cam screw will be on the Port side.

(I recently repaired a Sherwood seawater pump whereby the owner had re-installed it 180* out-of-phase)

G_21__22606.1457989750.jpg

.
 
I have some pictures in the link above showing that the Sherwood g21 pump is in the correct direction. (Cam towards the motor) I really don't understand what sitting proudly means but I made sure the Sherwood name on the impeller was facing towards the pulley.

If I understand things correctly, the impeller will not move water if it installed incorrectly. It is moving water but not the amount that I believe that it should.

When I replaced the impeller I didn't have to remove in c clips or anything to to swap it out. I am not sure if my is an older design or if something was removed along the way. I only had to remove the back plate remove the impeller from the body lube the new one an install it. Nothing held it to the shaft except the shaft key.

I would be interested in a pump upgrade if something newer provides more cooling.

You can see pictures of the pump here.https://drive.google.com/folderview?id=1Hpd6zrnQjeFtj-NF1UAE7-MZv8YoKs0Z

Thanks for any all help
 
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When I mentioned purging, I never suggested the raw water side, only the closed side.

In the videos, one had a shot of the voltmeter w/ the engine running - looks like the alternator isn't charging...

what did you have the clear hose routed between; in other words, where in the cooling system was it connected to?
 
............
I have some pictures in the link above showing that the Sherwood g21 pump is in the correct direction. (Cam towards the motor)
I'm not following you on that one.
The cam will be either towards the Port side or the Stbd side (depending on engine rotation) ..... not facing the engine.
In your case, it will be as shown on the left side below.
Sherwood bi directional seawater pumps.jpg

I really don't understand what sitting proudly means but I made sure the Sherwood name on the impeller was facing towards the pulley.
Sitting proud means that it will extend out of the housing by approx .010".
When assembled, it will be compressed a bit.
This is to ensure that it makes contact with the two thrust surfaces.

If the impeller does NOT sit proud, it is the wrong one.


If I understand things correctly, the impeller will not move water if it installed incorrectly.
Correct!
It is moving water but not the amount that I believe that it should.

When I replaced the impeller I didn't have to remove in c clips or anything to to swap it out. I am not sure if my is an older design or if something was removed along the way. I only had to remove the back plate remove the impeller from the body lube the new one an install it. Nothing held it to the shaft except the shaft key.
Correct!

I would be interested in a pump upgrade if something newer provides more cooling.
Look at the Johnson F6B-9 or F6B-9

You can see pictures of the pump here.https://drive.google.com/folderview?id=1Hpd6zrnQjeFtj-NF1UAE7-MZv8YoKs0Z

Thanks for any all help

When I mentioned purging, I never suggested the raw water side, only the closed side.

In the videos, one had a shot of the voltmeter w/ the engine running - looks like the alternator isn't charging...

what did you have the clear hose routed between; in other words, where in the cooling system was it connected to?
I was also curious about that!
 
The clear hose came out of the raw water side of the heat exchanger (exit/output of heat exchanger), it goes into a t fitting and hoses split and into the rear of the engine.

I was hoping that the videos were more clear.

The impeller kit I ordered from the marina was for this pump I will list the model number and part number once I find it. I used the pump housing to rotate the impeller into position. When removing it previously I don't believe that it set proudly. I will check that again this evening.

Thanks



Thanks
 
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https://drive.google.com/file/d/1HyQHqm1bk7ks4jtt4-W907FNIRLAfv4h/view?usp=drivesdk

In the first few seconds of this video you can see where the hoses coming from the exit of the heat exchanger and going into the clear hoses. I probably could have zoomed out a little more.

At extremely low tide my waterway goes to mud I tried to remove the seacock hoses to check for obstructions, I couldn't get the hose off but that allowed some air to enter into the system while making the video. I tighten those hose connections yesterday and had much less air.

I have an after-market flush kit plumbed into the boat which I believe also lets some air into the system. I will work on those this evening also.
I was able to fill a large bucket and the pump was able to suck the water from the bucket but I need to figure out how much water it should suck per minute.

Thanks
 
I looked at that Johnson pump you recommended but I don't fully understand how it would mount. I probably have more into impellers than what that pump cost online, if it is a better design I would be extremely interested in replacing what I have now with that

Thanks
 
The Johnson pump is a crankshaft mount pump. It bolts to through the pulley that sits in front of the harmonic balancer.
I have installed several of these on Ford engines over the years.
The crankshaft pump is a much better system!
 
I will be placing an order for one soon. It isn't obvious from the picture how it mounts it sounds but it sounds fairly simple. I will try to find a video or pictures of one mounted.

This sounds like it will allow me to get rid of the belt that supports the Sherwood Pump and add a second belt to the alternator.

Thanks

Thanks
 
view


Johnson F6B9 ordered. Is the amount of water moved by this pump significantly better. I have see some post mention that it is rated for big blocks.

Can you make any recommendations on the hardware to use to install it?

Thanks
 
Here is my firing orders is currently 18456273 this setup a month ago. I can pull each plug wire from the distributor separately and hear each cylinder drop out.

It looks like the older 351s were (1-3-7-2-6-5-4-8), the paper work from the marine rebuilder states standard rotation. This may have been the firing order when I bought the boat. It was back firing through the carb and would die when put in gear.

Does number 1 need to be at the very top of the distributor? I am not sure if the distributor needs to be rotated. See a pic of my distributor below

https://drive.google.com/file/d/1IkhXdQsr4vkNMkuHwdOxP7dBSYZnDvkk/view?usp=drivesdk

Thanks
 
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.............
I will be placing an order for one soon. It isn't obvious from the picture how it mounts it sounds but it sounds fairly simple. I will try to find a video or pictures of one mounted.

This sounds like it will allow me to get rid of the belt that supports the Sherwood Pump and add a second belt to the alternator.
Yes, and it will allow you much easier access to the impeller.

view


Johnson F6B9 ordered. Is the amount of water moved by this pump significantly better.
Over that of the Sherwood? Yes!

I have see some post mention that it is rated for big blocks.
The F6B-9 is the higher volume seawater pump.
You probably want to use the F5B-9.

Can you make any recommendations on the hardware to use to install it?
Visit this September 2016 thread

http://www.marineengine.com/boat-forum/showthread.php?434012-Johnson-F5b-9-youtube-vid


Johnson F5B 9 and F6B 9 pumps 2.jpg
 
Johnson Pump 10-24930-01 F6B-9 ordered and already shipped. I went off your initial recommendation, I don't think it will be a problem. It looks like this pump is used across alot of platforms and the extra cooling should help.

I am also looking at upgrading to a stainless steel heat exchanger but I want to get to reliable state first.

Thanks
 
The f6b9 has arrived.
Does this pump have a specific inlet port?
I called Johnson pumps and they are reaching out to the engineers in Sweden.
Do you reuse the same bolts that are used to mount the crank pulley to the crank to mount this?
Do i need to get long bolts? It looks like the base plate on this pump is half an inch thick

Thanks
 
................
The f6b9 has arrived.
Does this pump have a specific inlet port?
Depending on engine rotation (as in REV RH Rotation or STD LH Rotation engines) yes, it does.
(see my images below)


I called Johnson pumps and they are reaching out to the engineers in Sweden.
Do you mean that the Johnson Pump sales people could not answer your question? Sheesh!

Do you reuse the same bolts that are used to mount the crank pulley to the crank to mount this?
No.... you will want to use a hex-socket cap screw style in a longer length.

Do i need to get long bolts?
Yes and in a hex-socket cap screw style.
I would also suggest using 3 SAE washers.


It looks like the base plate on this pump is half an inch thick
That would be the mounting flange.... and yes, it is rather thick.

See my second image below to understand how the flange must be indexed correctly with the 2 raised dowels in the pulley.
Only 1 of the 3 possible indexing is correct.



johnson crank pump inlet outlet explained 2 .jpg

With regard to the 3 bolt pattern, this pump flange will mount in any of the 3 positions.
However, due to the pulley's 2 raised alignment dowels, only 1 position will be correct.


Johnson F5B 9 and F6B 9 pumps 2.jpg

NOTE: if you do not have the above style pulley (with the 2 raised alignment dowels), you will need to have 3 precision bushings made, and use cap screws with a non-threaded shank.

Johnson F5B 9 and F6B 9 bushings in lieu of raised dowels .jpg



.




johnson crank pump inlet outlet explained 2 .jpgJohnson F5B 9 and F6B 9 pumps 2.jpg
......................
 
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Thanks for the quick reply.
I have a ford 351
I believe that is a Chevy pulley
I just have 3 bolts holes.
No raised sections.
I bought bolts yesterday that were a 1/4" longer than what was removed, the pump flange is roughly a quarter of an inch

I am looking at your alignment rig and i am a little confused.

The Pulley mounts to the harmonic balancer and the pump mounts to the pulley. This seems like the only way to key my belts aligned.

I will upload a picture of my pulley soon. It only has three bolt holes
See below


https://drive.google.com/folderview?id=1Keel05jT6TCP66zf7HIYnbDkZq3QHHSc
 
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.............
Thanks for the quick reply.
I have a ford 351
I believe that is a Chevy pulley
Yes.... the pulley in my image is a GM SBC pulley.

I just have 3 bolts holes.
No raised sections.
Understood.

I bought bolts yesterday that were a 1/4" longer than what was removed, the pump flange is roughly a quarter of an inch
You will also find that the three bolt bores (in the mounting flange) are slightly larger than the bolt diameter.
This is where the bushing idea comes into play.
You may need to have the bushings custom made.


I am looking at your alignment rig and i am a little confused.
..... re; the raised dowels?
..... re; the bushings?


The Pulley mounts to the harmonic balancer and the pump mounts to the pulley. This seems like the only way to key my belts aligned.
The three bolt pattern aligns your pulley.
The same three bolt pattern secures the pump's flange to the harmonic balancer.

I will upload a picture of my pulley soon. It only has three bolt holes
See below

I have installed the F5B-9 on the 335 series Fords... i.e., the 5.8L Ford engine.
I don't recall having any issues with the 3 hole bolt pattern.


https://drive.google.com/folderview?id=1Keel05jT6TCP66zf7HIYnbDkZq3QHHSc
 
Do I need the bushings? Since my pulley is not a Chevy pulley? I have been running around for the last couple days trying to find these parts without success.

Thanks
 
Do I need the bushings? Since my pulley is not a Chevy pulley? I have been running around for the last couple days trying to find these parts without success.

Thanks

First off, is your Ford 3 bolt pattern a match for the 3 holes in the pump mounting flange?

I realize that you do not have a pulley with the 2 raised dowels.

The holes in the pump's mounting flange are likely a tad bit larger than the bolt shank diameter, and is why you may need the bushings.
If you can't find a bushing that fits correctly, have a machine shop turn them out for you.
Brass or Bronze is very easy to tool!
They will first bore the hole in the stock.
Then they will turn the OD.
Lastly they will cut the stock into 3 individual sections of the correct length.

It will probably take more time to locate the stock and the drill bit than it does to cut them out.
Once they have that, they should be able to cut 3 bushings out in 30/35 minutes or less.

hqdefault.jpg




You'll end up with something that looks like these.


HTB1FZmxMVXXXXXSXpXXq6xXFXXXD.jpg_350x350.jpg










.
 
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First off, is your Ford 3 bolt pattern a match for the 3 holes in the pump mounting flange? Yes

I realize that you do not have a pulley with the 2 raised dowels. correct

The holes in the pump's mounting flange are likely a tad bit larger than the bolt shank diameter, and is why you may need the bushings.
If you can't find a bushing that fits correctly, have a machine shop turn them out for you. holes are larger on the flange
Brass or Bronze is very easy to tool!
They will first bore the hole in the stock.
Then they will turn the OD.
Lastly they will cut the stock into 3 individual sections of the correct length.

It will probably take more time to locate the stock and the drill bit than it does to cut them out.
Once they have that, they should be able to cut 3 bushings out in 30/35 minutes or less.

if you picture above you show hex head bolt with out threads on the first 1/2 or so, does that part matter? I assume that the bushings has to be lose enough for the threads to clear.

Thanks for your help, I hope this solves the problem.

 
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