Hole in intake port

50Trucking

50Trucking

Member
In the process of porting and polishing my intake and exhaust ports, the number one intake port developed a hole in the port. See picture. Is there a way to repair this hole? All of the others are ported with no problems.

The hole opens into the water jacket in the block. There is no pressure in the system and very little heat in this area.
 

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50Trucking said:
In the process of porting and polishing my intake and exhaust ports, the number one intake port developed a hole in the port. See picture. Is there a way to repair this hole? All of the others are ported with no problems.

The hole opens into the water jacket in the block. There is no pressure in the system and very little heat in this area.
Click to expand...
If the wall was that thin in that place then likely the surrounding area is eroded or corroded away in the water jacket as well. If that happened to me, I think I'd be looking for a new block right about now.

A really good welder (which I'm not) might be able to build that area up using nickel rod.
 
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JayJay said:
If the wall was that thin in that place then likely the surrounding area is eroded or corroded away in the water jacket as well. If that happened to me, I think I'd be looking for a new block right about now.

A really good welder (which I'm not) might be able to build that area up using nickel rod.
Click to expand...

"that's hot roddding!" no doubt core shift during the foundry process. even though, maybe the 'high volume' pattern tooling allowed for such, knowing that the wall would never be ground thinner! lol :)

it would not hurt to have a very good well, exceptionally very good welder look at it. but if it was mine, i would just plug it. clean it up real good both sides. that is an art unto itself, for sure! take advangage of the core/sand shape on back side for adhesion needs and create s bit of a button with the repair, that is some of the filler would protrude into the port and lock itself on edge. then give both a mechanical and chemical bond/repair. I wouldl suck up any cfm flow lost due to the small button! lol, as if it would even be noticeable. I have a b-i-g Super Flow flow bench if need be for testing!! lol...

and then give it a try! it will work or it will not! its only air one side, water the other! and the engine temps should keep well below the upper limit of 500F of the JB Weld.


if it was mine the only JB i would use or consider is the original 2-part mix.


Good Luck with your grinding/port work! other than the hole, looks pretty good! :cool:
 
AI follow up:

Z

Custom cylinder head porters often fix holes in aluminum heads by using TIG welding (Tungsten Inert Gas welding). This method is well-suited for aluminum due to its ability to create strong, clean welds without melting the base material too much. Other options include using epoxy putty, JB Weld, or even drilling out the hole and tapping it to accept a larger bolt with a Heli-coil or Time-Sert insert


Google search topic:

how do custom cyl head porters fix holes in alum head
 
First choice would be to weld up the area. Consider some kind of backing that is heat resistant but would wash out with water, such as the normal ceramic clay. Let the clay dry for days and then help the drying with some warmth (220 F). If the dry clay is protruding into the port it can be scraped away and scraped to be below the surface of the hole. Paper clay is a little stronger than normal clay. This is clay that has about 20% paper fibers added which work like glass fibers in epoxy. Do not weld on wet clay because the steam that develops will make the clay explode.

The clay will shrink as it drys so it should be below the surface when you get to the welding.

The dry clay should not get hot enough to vitrify. Use a high temperature clay (cone 10).

A filled epoxy patch would be the second choice. Consider a stronger material than JB Weld. Again consider the clay as a backup. The epoxy patch can be placed over wet clay.

After you are done welding wash out the clay with lots of water and a piece of coathanger wire or screwdriver. Some people have washed out coolant passages with an old speedometer cable attached to an electric drill motor. Dry clay will soak up water and revert to mud that should be easy to remove. From the photos it looks like you will have good access to the coolant passage.

I believe there are ultasonic devices that will measure wall thickness of cast iron. If you do this in the future you may want to research that.

I ported the intake ports in my Burtz block but only where the bores did not match up to the cast passages. It was just to remove the lip. A sharp edge that protrudes into the passage can restrict the flow more than the edge protrudes into the passage because of the momentum of the air. Fluid dynamics 101.
 
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There is a company called “Belzona” that makes products similar to jb weld. They make several specialty products, I’d call them and see what of their products they recommend. I used one of their products to build up a worn shaft and it did a great job!
 
Goodson has a product PRK-99 that is specifically used in intake ports. The down side is its
$46.00 it is good to 500 degress. Moroso AB epoxy has been used for ports but its only good to 250 degrees.
Rector-Seal also makes a good one their EP-400. They have a 4oz size that might work for you. It is only $7.00 from Amazon and it is also good for 500 degress.
They are both epoxies.
I think its too thin to weld.
 
question is- once you "fix it" will you worry about the engine letting loose, everytime you drive it?


if so just replace the block..... no lost sleep.
 
HERE is what I use, and many head porters use the same. It used to be, -and likely is the same now that JB is not really the product to use in this application. With that said, additionally you likely will need to use a non-methanol fuel from now on. Methanol & Fuel engine builders typically only use alloy rod to add weld filler material in places they need to add material.

Now with all that said, you have several issues as I see it. First, it is my opinion that the exhaust port (-and valve) is already too large for the application in a Banger motor, -and enlarging the exhaust bowl & port area actually decreases scavenging. So in other words, what you are doing is likely going to decrease Hp instead of increasing it. Secondly, (s)low flowing ports, -especially when you have Intake ports that are siamesed. With a simesed intake port, you will have a form of reversion which is easy for the fuel to fall out of suspension and the fuel begins puddling on the walls & floor of the ports. Again, you are losing Hp when this happens. Blending ports is not a bad thing however polishing ports and bowls is. A great example to illustrate this is when you look at a baseball or a golf ball. Both are designed with dimples or threads to disrupt the air to increase air flow or decrease resistance. A golf ball will actually slow down if it has a smooth surface. In the case of a flathead Banger, you already have poor volumetric efficiency. Slowing down the air or having puddling just decreased the VE even more. That means less horsepower. :mad:

Personally, depending on your goals, I would back-up and start over with a different block if you are seriously trying to make power. Do better on your seats and consider using larger intake valves. Epoxy is a great product for tweaking flow however in most applications it is done for short periods of run time. I think in your scenario, the EGTs are going to cause the epoxy to fail.
 
Dodge said:
Goodson has a product PRK-99 that is specifically used in intake ports. The down side is its
$46.00 it is good to 500 degress. Moroso AB epoxy has been used for ports but its only good to 250 degrees.
Rector-Seal also makes a good one their EP-400. They have a 4oz size that might work for you. It is only $7.00 from Amazon and it is also good for 500 degress.
They are both epoxies.
I think its too thin to weld.
Click to expand...

Hey Dodge, I had seen that PRK product in Goodson's catalog but I have never used it. In looking now I see it also states that it is good to 500° however it also states not to use in exhaust ports. Have you used it in exhausts, -and if so has it held up? Why I am asking is this might be a product to use on pitted port flanges on a Model-A. I am currently using the JB ExtremeHeat to fill small pits but I think the main reason why it works in this application is because it is sandwiched between the block and the manifold.
 
If it was mine I feel the best solution would be a good cast iron weld from a cast iron welding professional. You could fill that hole with a big lump of brazing material. Brazing is pretty permanent if done properly on CLEAN cast iron. Since you're not running a pressure cooling system that definitely help. I really seriously doubt that it would leak but opening the ports up huge like that actually is a mistake. In a flathead the flow is already mismatched and screwed up in reality you just wanna clean the ports rough areas up a little bit any major grinding is actually like Brent said is not actually gonna help you with port velocity. The intake port does run much cooler than than the exhaust so high temp epoxy usually will survive. There’s more free power gains in the valve seat angles and the valve face angles and back cuts!
On the Ford flathead V8, most people think that the exhaust ports are extremely horrible but yet if you put it on a flow bench in stock form, the intake ports are worse. They’re more restricted than the exhaust. You can actually leave the exhaust alone and just port the intakes and make a much closer intake to exhaust port balance. Anyway that’s unrelated to the Model A engine, but today’s technology proves that a lot of the older beliefs that people were doing in porting shows that hogging out the ports actually destroys your port velocity, and you lose horsepower unless you got a really large cubic inch engine, which most of these old motors cannot even obtain that size to be more efficient when it comes to racing.
 
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Having tried many of the options noted, I found there is no good way of fixing this.
The material around that port is not going to support welding or brazing or silversolder.

What I have had success with is converting the motor to an OHV, not exactly budget friendly but it works.
When going OHV you need a pushrod, if not OHC, and this allows for filling the offending port with devcon or JBWeld.

Since it sounds like the bottom end has been rebuilt it should be able to handle the HP increase, which of course is what started this adventure.

J
 
Brent - check up on the Belzona info - I've used it on water jackets & block pitting for years - good stuff but pricey !
 
Make a round patch from brass / bronze sheet and solder it into place. After soldering, overcoat the patch with a smear of JB Weld. I do not understand why you are porting & polishing the valve ports? The volumetric efficiency gain from doing this is infinitesimally small and not worth the effort.
If you have made the casting too thin in the ports, an intake backfire is liable to blowout the port. If the block is a Model "B", you have trashed it as the Model "B" castings are thin-walled as built!
 
10 U C - This is to be a Jalopy I am building to drag race at TROG. It will have 1.7 in Intakes and stock size exhaust with new style guides and adjustable tappets. I will be running twin 81's with a Jim Briley cam. Engine is overbored 80. Rods and mains are newly poured babbit with a Burtz 6.5 head and a FSI distributor. I will be using a V8 clutch with lightened A flywheel bolted to a 39 3 speed ******.

With the larger intakes, dual carbs and higher lift cam, do you feel the porting to match the intake and exaust gasket will be OK and I will not loose that much power?

What rear end ratio would be recommended for this setup. it will be driven on the street also.
 
That intake bowl does appear to have been worked on before. Since it has been smoothed with a sanding cone or stone, it makes it harder to tell about that little lump down in there. The first post mentions it's an intake bowl but as has been mentioned, the fuel mix going passed it can affect any epoxy material. Most epoxy products will soften with heat but there are some that can take a lot of heat but work time on those is short so a person needs to be prepared to coat the area quickly and with accuracy. If you try it, super clean that casting in there before any attempt at filling it. It wouldn't hurt to try but would be a lot of work for naught if it leaks.

I've heard of guys using stuff like the PRK-99 to ramp the backs of the bowls to get flow to have a better curve upward in the back there. The flatheads have so many changes in angles of flow that is really does a number on the flow characteristics for them. That was always one of the main problems for them. If you went the OHV head route, a person could fill ports around the push rods to pretty much seal them off. It just depends on what head is used.
 
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Years ago I worked with a fellow who had previously worked in a shop that built race car engines for Pontiac Motors back in the 50's and 60's. His main job there was porting exhaust ports on over head valve engines. I asked him what he done when he ground through the casting. He said he used solider and with water on the back side it would never melt out. He also stated he used a large nail by pecking on the casting to see if he was getting it ground too thin.
 
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