Mercury 410 Overheating

[Porkchop]

Here is a picture.

It ran well before the manifold swap so I know it isn't a head gasket issue. maybe now after the overheating there's an issue, but not before.

[My427stang]

Water flows from water pump outlets into block and comes up to the back of the head on each side

It enters the head at the deck and flows forward to the front of the head

It enters the intake manifold at the front and simply funnels toward the bypass and thermostat from each side.

For the intake to be an issue, it would have to be blocking that last step.  All of which you could easily see with removal or maybe through thermostat housing and fish something through to head.

If your rear ports are blocked, it's not an issue, if your front ports are...there's the issue.  I'd take a drill to the thing if that's the case.  Use the gasket as a template and make the passage.

Probably seems like a good idea to have the intake surfaced too.

[Porkchop]

Tried to take some better pictures. Second picture is cast iron manifold. If you right click the picture and select "open in new tab" the size is better. At least for me.

There were actually 2 small holes in this "wall" (1/16") that were letting water pass when I filled it with water. So I broke it out a bit further with a punch. But it will take more than a punch to get it all out and the walls smooth as intended.

Additionally, if I do grind it out so that the walls are smooth the port will be smaller in comparison to the S cast iron manifold. Maybe this is normal? Is this how the Edelbrocks are (which this manifold is a rip off of.

I need to do more investigation to determine how water entered the oil. Would the blockage cause back pressure that would overcome the manifold or head gaskets? The manifold gaskets aren't blown out, but I will further inspect.

I'm not sure what I trust at this point.

[jayb]

Thanks for the pics, that is a typical fin left from a broken water jacket core.  I would break the rest of that out of there as best you can, and run it.  You won't have any problems.  The size of the water passage through the intake is not that critical.  In fact, with some manifolds like injector manifolds that have a braided steel line coming out of each side and into a remote thermostat housing, a #8 AN line is more than sufficient for cooling.  That is a 1/2" inside diameter line, maybe 2 feet long, to feed water through a racing-oriented engine.  Just bust that fin out of there with a punch and you should be good to go - Jay

[SSdynosaur]

My real concern from info revealed in your photos is the porosity of every feature that is visible on the casting. I can tell you from experience that is NOT a FEPower casting and needs to be pressure checked everywhere it is exposed to coolant.

[My427stang]

Are we looking at the rear of the intake or the front?  Just want to make sure as the rear ports don't connect on most American V-8s

BTW, EVERY FE intake is crooked.  If you have water flowing correctly, you may still need a couple cuts.  I also agree that a pressure test before that is owrth it, all easy for a machine shop

[Porkchop]

All pictures are of the front, driver's side port. The front, passenger's side is clear. There are no rear ports.

I agree, I am suspicious of the rest of the manifold given this issue.

[Porkchop]

Thanks for the pics, that is a typical fin left from a broken water jacket core.  I would break the rest of that out of there as best you can, and run it.  You won't have any problems.  The size of the water passage through the intake is not that critical.  In fact, with some manifolds like injector manifolds that have a braided steel line coming out of each side and into a remote thermostat housing, a #8 AN line is more than sufficient for cooling.  That is a 1/2" inside diameter line, maybe 2 feet long, to feed water through a racing-oriented engine.  Just bust that fin out of there with a punch and you should be good to go - Jay

When you say this is typical, do you mean typical of any aftermarket aluminum FE intake or any aftermarket intake in general?

My concern at this point is the quality of the rest of the manifold.  Another issue I had with it was that the distributor hole was not on center. However, I've seen that is common with the Edelbrocks which this is obviously a copy of.

[Porkchop]

My real concern from info revealed in your photos is the porosity of every feature that is visible on the casting. I can tell you from experience that is NOT a FEPower casting and needs to be pressure checked everywhere it is exposed to coolant.

I know that it is not an FEpower part.  Maybe it's inappropriate for me to post this here... This is the only forum where I found these manifolds mentioned so I thought maybe someone had tried them out.

[machoneman]

Maybe the intake is warped as well? Take a steel straightedge and with a feeler gauge, check both sides from end to end and top to bottom (length wise and height wise). 

[jayb]

Thanks for the pics, that is a typical fin left from a broken water jacket core.  I would break the rest of that out of there as best you can, and run it.  You won't have any problems.  The size of the water passage through the intake is not that critical.  In fact, with some manifolds like injector manifolds that have a braided steel line coming out of each side and into a remote thermostat housing, a #8 AN line is more than sufficient for cooling.  That is a 1/2" inside diameter line, maybe 2 feet long, to feed water through a racing-oriented engine.  Just bust that fin out of there with a punch and you should be good to go - Jay

When you say this is typical, do you mean typical of any aftermarket aluminum FE intake or any aftermarket intake in general?

My concern at this point is the quality of the rest of the manifold.  Another issue I had with it was that the distributor hole was not on center. However, I've seen that is common with the Edelbrocks which this is obviously a copy of.

No, not typical in a good casting, just typical in a defect.  The water jacket core is made of sand and is long, curved, and narrow on FEs, and it can easily be cracked or broken if handled improperly at the foundry.  If cracked, the force of 30-40 pounds of aluminum being poured rapidly into the mold may be enough to break it entirely, resulting in a fin like you have seen on your manifold.

Pressure checking would be a good idea, but the presence of porosity itself doesn't necessarily mean that you have a leaker.  To get a general idea you can seal up the thermostat housing hole and one side of the water jacket opening with duct tape, spray the area with soapy water and blow compressed air into the other water jacket opening.  Even with the minimal pressure that this provides you will see bubbles in the soapy water if there is a significant leak.  You would have to fully pressurize the water jacket passage with 30 PSI or more to find any very small leaks, but doing it the quick and dirty way will tell you if you have a junk intake.

[Porkchop]

I put a straight edge across the manifold ports (straight across ports and angled up/down) and measured at most 0.003" around cylinder 3's and 7's port. That was going straight across. Angled it was less than 0.002".

I could not get a 0.001" feeler around the water ports.

I am crudely trying to measure the angle of the manifold with a square. It's less than 90 degrees, but visually appears the same as the S manifold. I will use a feeler gauge to try to put a finer point on it.

I will consider rigging up some type of system to do a pressure test.

[Porkchop]

I rigged up a pressure test on the water jackets in the manifold and found no leaks.

I blocked off the ports with steel, rtv, and some clamps. Supplied compressed air through the bypass port. Went up to 60psi.  I sprayed the manifold with soapy water, and I submerged the manifold under water. I found no leaks (except for my homemade block off plates).

There is wetness between the heads and the intake gaskets. It is both oil and coolant. There was wetness in various places across the head, but notably around #1 and #8 coolant ports. I know coolant doesn't flow into the manifold around 4 and 8.

I can not say whether this would have happened when I removed the manifold. Like I said, I drained the block, but I know some coolant came out of the manifold when I lifted it.

Earlier I was wondering whether the plugged manifold port would cause high pressure which would cause the gaskets to leak. But that wouldn't really be the case, would it? There was still flow on the passenger's side and through the bypass so pressure should be the same everywhere in the system.

[Porkchop]

Pic #1 - Coolant port near #8
Pic #2 - Coolant port near #1 in gasket
Pic #3 - Coolant port near #1 in head
Pic #4 - Passenger's side gasket. You can see wetness around #2 intake port. The coolant port by #4 looks dry

[jayb]

Sounds like you have no issue with leaks in the manifold.  Can't tell from your pictures but did you use RTV around the water jacket ports of the gasket, on both sides?  If not, that could explain the water leaks.  I would recommend a good RTV around all the ports on both sides also.