New Engine - Same 4.107 over heating problem.

[Capt Gill]

Originally Posted by Lepke

One thought... My 4108 would get an air lock when filling because of the thermostat. It happens in a lot of engines. If the coolant isn't completely filled, the thermostat has an air volume below, leaving the cylinder tops/head w/o coolant and keeping the thermostat from getting enough heat to open until the engine is really hot. After opening, the super hot coolant hits the upper part of the waterjackets/head and turns to steam appearing to be a boil over.
The solution is to drill a small hole 1/16" or so thru the thermostat plate so air can escape to the tank and be purged.

Someone must have used the wrong stat the correct stat has a hole in it,however it's purpose is not to vent air,but to insure a some circulation to the HE. When doing a coolant change, to insure there's no air pockets, after initial refill run engine with press. cap off and add coolant as needed,but do carefully monitor this as when the stat opens it'll need
a big gulp of coolant.
Caveat:
My advice and comments have not been peer reviewed,therefore it would be prudent to seek additional opinions.

[jimbunyard]

[QUOTE=Capt Gill;2421474]

Originally Posted by jimbunyard

So what you're saying is that the tube bundle you have is not like the one illustrated in these two pictures


and has four holes on each end, for a total of 8 holes for the circulation of fresh water?


If this is the case then certainly there is no chance for an air pocket to form within the freshwater-side bronze tube.

But if your and Joe's tube are as illustrated in the above two pictures, then the situation for forming an air pocket remains the same, as I've previously described.


"So what you're saying is that the tube bundle you have is not like the one illustrated in these two pictures" No, the two photos are to show the difference between what's used on the 4-108/7 (Top) and the one for the M series Perkins (Bottom),since the photo is not 3 dimensional,only 2,you can't see the other 2 holes opposite the holes shown. I can try to take a photo of mine,maybe with a mirror,to show a 360* view or you can call Bowman to verify.
"... and has four holes on each end, for a total of 8 holes for the circulation of fresh water?
If this is the case then certainly there is no chance for an air pocket to form within the freshwater-side bronze tube" That is the case.
Not having the bundle in the bottom photo I can only visualize what would happen if I did your experiment,i.e., upon turning it over the trapped air would be displaced by water causing air bubbles to rise to the surface.

Originally Posted by jimbunyard

Joe,



...This is the only picture I could find of the bundle, so if there are large holes all around each end, then you'll have to look further. But if there are only the two large holes in each end, and especially if there is no bleed hole opposite the red dot as shown in the picture, orientation of the bundle in the casting is likely crucial. If the two large holes weren't meant to direct flow in some way, the manufacturer wouldn't have enclosed the bundle in a bronze tube...

Would have been nice to have just advised from the beginning that there are holes evenly spaced around the circumference, as was queried in post 63, highlighted in red above. If Joe's HE bundle is the same as yours (and there's no real reason to expect otherwise), then he'll have to look elsewhere, as previously warned...

It would be unusual for a head gasket to be leaking on a newly rebuilt engine, even from someone with as bad a reputation as Foley, but of course mistakes happen.

As previously mentioned though, given that the problem mirrors rather closely the overheating problem with the original engine and installation, if it were me I'd be looking very closely at the overall system setup, to make sure the root cause is not actually several small contributing factors.

It could just be 'the head gasket'. It would be interesting to know how the engine actually runs...I've specifically asked but got no reply, but if the engine starts easily, runs smoothly, doesn't steam and accelerates linearly, well, that might tend to indicate good top end condition...not an absolute of course, but enough, for me at least, to give pause before tearing the whole top end apart...

[joesail]

Thanks for all of the great response. Jim the engine starts easily, runs smooth and strong. With the engine having only maybe 15 or so hours on her I haven't been brave enough to try a wide open throttle but she has responded appropriately all the way to 2500 RPM which quickly brings the temps to 175 and I back off. Once I back down she levels off at a steady temp relative to the RPM.

She accelerates as expected and I see no steam or smoke from the exhaust.

[joesail]

Correction Jim. She has about 20 hours since the first start.

[Three Sisters]

Originally Posted by joesail

1. Thruhull Inlet size. I have a 3/4 inlet which is the same size as the input port on the raw water pump so I believe that should be OK. My strainer is a Groco and I never see bubbles in the glass so I assume it is not starving for intake water flow.




I am planning to pull the head, have it tested, and replace the gasket. Thats my only thoughts unless someone here can think of another possibility.

In the 3 plus weeks since the start of your thread the thru hull could be fouled with growth at the bottom of the hull.

[Capt Gill]

I agree, I see no reason to blindly tear the engine apart.
OP: Proper diagnosis is in order which requires a decent working knowledge of the engine. Head gasket ?
Do the testing for blown h/gsk. Not that,think of other possibilities & do the testing. Nothing pans out ? Go back ,there's a good chance there's an error in testing. Here's one that is kinda rare: the opposite of restricted RW flow is TOO much flow or in other words the raw water is going through the HE so fast it does not absorb enough heat to cool the FW adequately.
Attached is a guide for testing ANYTHING.

[joesail]

Originally Posted by Three Sisters

In the 3 plus weeks since the start of your thread the thru hull could be fouled with growth at the bottom of the hull.

I wish it were that simple. This started on the day I splashed her fired up the new engine.

[jimbunyard]

Originally Posted by joesail

Thanks for all of the great response. Jim the engine starts easily, runs smooth and strong. With the engine having only maybe 15 or so hours on her I haven't been brave enough to try a wide open throttle but she has responded appropriately all the way to 2500 RPM which quickly brings the temps to 175 and I back off. Once I back down she levels off at a steady temp relative to the RPM.

She accelerates as expected and I see no steam or smoke from the exhaust.

That the engine runs smooth and strong is a reason for cautious optimism.

Don't worry about running the engine in neutral up to full RPM, which in your case would be either 3600, or 4000 if you have a high speed engine; when an engine is first started from rebuild, after checking for good oil pressure, leaks and warm up, one of the first things you do is run it up to full rpm to check 'high idle' speed.

With a new (or newly rebuilt) engine the two things to avoid are sustained operation at a single speed under load, and sustained full throttle under load.

With 20 hours you are approaching full break in times so it's not as important to follow a strict break in procedure, but it's still a good idea to vary your speed as much as possible, and avoid sustained full load high speed operation for long periods of time. After about 50 hours so it's (within reason) "Katie bar the door", run it as hard as you want...sounds like you're been rather more conservative than this so I don't think you've much to worry about on this front...

Still wouldn't hurt to check that HE bundle, though it doesn't look much like that is the cause. I would also definitely make absolutely sure the freshwater side is completely purged of air.

No need to worry about temperatures until they get over 200-210F while chasing this problem, once you get it sorted out I like to run about 180-185, but some engines are specifically designed to be run at around 195...my new-to-me Jeep 4.0 liter engine's 'normal' operating temperature is 205, it scares the hell out of me...

[Three Sisters]

Originally Posted by joesail

I wish it were that simple. This started on the day I splashed her fired up the new engine.

The raw water intake thru hull was carried over from the previously over-heating engine, correct ?

Exhaust components were carried over from the previously over-heating engine, correct ?

You can break it all down into sections and check things off as verification is made, it's one way to do it, right ?


I. Overheating

a. Raw water system
1. thru hull
2. hoses
3.
4.
b. Fresh water circuit
......
c. Head Gasket test
......
......
d. Exhaust System
......
......

Whatever works to find the culprit.

[billfred]

I had the same issue. Perkins 4108. Couldn't go over 1/3 throttle or temps would climb. I pulled the tube bundle out of the bowman heat exchanger manifold and noticed that the hole machined in the divider plate was a bit oversized. (Or the tube bundle was undersized). Anyhow, the gap between the tube bundle shell and the divider was letting the coolant short cycle right to the output, instead of being forced down the tube bundle first. I wrapped a turn or 2 of silicone rescue tape around the bundle shell to fill the gap and now i can run close to full throttle without overheating.

[roberttigar]

If this is the style with heat exchange on the back of the engine, and its the std 12" length, then the HE is to small. Sendor makes a larger HE that solved my prob. Bob