Pin hole in cast iron head
- Thread starter Earlie A
- Start date
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My 452 heads have the entire short side ground out and flush where the pushrod bump used to be. .485" off set rockers moved the pushrod over, so that area could be filled.
I put a piece of duct tape over the opening on the port walls and back filled them with JB Weld (24-cure) they have lasted over 10-years and that's a nothing special epoxy.
Tom
I put a piece of duct tape over the opening on the port walls and back filled them with JB Weld (24-cure) they have lasted over 10-years and that's a nothing special epoxy.
Tom
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Here's the wire you need posted in the thread I posted for an exhaust manifold repair.
[WANTED] - Big Block A-body Exhaust Manifolds
Tom
[WANTED] - Big Block A-body Exhaust Manifolds
Tom
mygasser
Well-Known Member
i've mig welded cast iron blocks and heads before with just normal steel mig wire. i always grind the area into a v for the weld to 'root/bite' into first. i flush the weld back with a die grinder knowing the weld is down in the v anyway so....
neil.
neil.
Lots of great ideas and suggestions here. I appreciate all the input. I have some Belzona 1212 on the way and I'm trying to get some MIG wire coming (at least for experimentation). My retired mechanic buddy has some cast iron welding repairs he'd like to try. Thanks again gentlemen.
So the short side of your heads is just JB between port and water passages ?
Most Mopar head numbers are not worth hardly anything!
(I know as I have several hundred cores).
If you do not have work and time in it = I would just replace it
with another core.
(I know as I have several hundred cores).
If you do not have work and time in it = I would just replace it
with another core.
Too much work in it. Gotta try to save it.
Newbomb Turk
Well-Known Member
That’s exactly why I won’t do iron any more.
All that work and no real good way to repair it like aluminum.
And then you get boxed on trying to fix it.
I was doing the very last work on one of my heads and a little dull spot showed up. I knew I was screwed.
I poked it and a nice hole was there.
It went right into the scrap pile. I’d rather port another casting than try to save one that at any time down the road can bite you in the ***.
I won’t grind or repair iron heads any more.
No, Just ground thru where the pushrod used to be. I grind the wall back so the pushrod bump is gone in the port. Then duct tape the inside of the port, stand it up, and fill the back side in with JB Weld. Since it's thicker on the outside of the head than the slot in the port the epoxy is in a wedge shape that vacuum is pulling against. You have gasoline on one side and hot oil on the other side. I've never had any sealing issues with this process.
My point to all of this was JB Weld does a really fine job without issue, so if there are even better products to be had you'll have great success using an epoxy.
That said, If I can get to it with a MIG or a TIG for that hole in the OP's port, welding would be my first choice, but if the OP doesn't have that option available just epoxy it.
Tom
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$212
Tom: I generally just sleeve that area.
What are your thoughts on that.
However, I just have mainly race stuff
I don't see the need to sleeve that area on a big block head with it being so easy to fill in with just epoxy.
I've done this on race and street heads for more than 20 years and never had any issues doing it this way.
Tom
I would drill the hole out to 1/8", not critical. Machine a piece of steel dowel [ or an old bolt ] with a slight taper to fit the hole. Push into hole by hand, & mark the point on the dowel where 1/16" sits above the hole. Cut the dowel at the 1/16" spot. Use Loctite, & punch/tap the dowel into position so that it is just below the adjoining surface.
I have used this method for plugging holes more times than I car to remember & it works everytime.....
I have used this method for plugging holes more times than I car to remember & it works everytime.....
mygasser
Well-Known Member
Even crazier is open or not open a lot of epoxies have a shelf life.
The hole turned out to be of my own making and not a casting defect. With a little probing I was able to open the hole up to 3/16 quite easily. I had hoped to try some MIG patching or even brazing but the metal is just too thin. In the end it was drilled out to 5/16" for the attempted repair.
I realize this could be a spectacular failure but it is something I am willing to try. If I don't try the repair on this motor (smog 360), when will I ever attempt it again?
With the hole so large and the metal so thin I did not think a port side (low pressure side) epoxy patch had much of a chance of success on its own. I wanted some solution that formed a plug on the high pressure (water) side. See the pictures for what I ended up trying. It is basically a jack nut anchor for blind holes + Belzona epoxy. The jack nut spreads out on the back (water) side of the hole and pulls the washer head tight against the intake port side of the hole. The jack nut and flat head screw are sealing the hole and taking the force of the water pressure. The epoxy is acting as a gasket. That's the hope anyway.
Picture 1 is the back side of a jack nut installed in a test piece of scrap aluminum.
Picture 2 is the back side of a second jack nut test piece but this time filled with epoxy before insertion and expansion.
Picture 3 is a dry run of the jack nut and screw inserted in the hole in the port.
Picture 4 shows the jack nut after sand blasting and the hole in the port.
Picture 5 shows the Belzona, the jack nut and screw and some fiberglass reinforcing mesh.
Picture 6 shows the completed repair after a light sanding with a cartridge roll.
Flow testing after the repair showed no change in flow up to and including 0.400 lift, then about a 3-5 cfm change at high lifts. Total thickness of the high spot of the repair is about 0.100" or a little more.
I just hope there is enough wall thickness in the repair area (and in the other 7 ports) to stand up to the water pressure.
I realize this could be a spectacular failure but it is something I am willing to try. If I don't try the repair on this motor (smog 360), when will I ever attempt it again?
With the hole so large and the metal so thin I did not think a port side (low pressure side) epoxy patch had much of a chance of success on its own. I wanted some solution that formed a plug on the high pressure (water) side. See the pictures for what I ended up trying. It is basically a jack nut anchor for blind holes + Belzona epoxy. The jack nut spreads out on the back (water) side of the hole and pulls the washer head tight against the intake port side of the hole. The jack nut and flat head screw are sealing the hole and taking the force of the water pressure. The epoxy is acting as a gasket. That's the hope anyway.
Picture 1 is the back side of a jack nut installed in a test piece of scrap aluminum.
Picture 2 is the back side of a second jack nut test piece but this time filled with epoxy before insertion and expansion.
Picture 3 is a dry run of the jack nut and screw inserted in the hole in the port.
Picture 4 shows the jack nut after sand blasting and the hole in the port.
Picture 5 shows the Belzona, the jack nut and screw and some fiberglass reinforcing mesh.
Picture 6 shows the completed repair after a light sanding with a cartridge roll.
Flow testing after the repair showed no change in flow up to and including 0.400 lift, then about a 3-5 cfm change at high lifts. Total thickness of the high spot of the repair is about 0.100" or a little more.
I just hope there is enough wall thickness in the repair area (and in the other 7 ports) to stand up to the water pressure.
What is a "goonie weld"
A colder weld used to fill a hole when the material you are welding is to thin to melt in and nicely lay on.
Please keep us updated .
So far the jack nut + Belzona has survived the FT cam break in and 3 short drives. Total run time close to an hour I suppose. No indication of any water leaks yet. My daughter is getting married this Saturday and wants me to drive her to the aisle (outdoor wedding) in the old truck. I'm praying the head can survive long enough for that. After Saturday a leak won't matter as much.
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