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Hole in the engine block- What to do?

14K views 10 replies 8 participants last post by  stephen44 
#1 ·
I am restoring a 1974 Ford F100 -360 engine. After the rebuild- full engine restore- we put the engine in the truck and made the minor adjustments and it started and ran good, but we noticed water/anti-freeze dripping from the back of the engine at the block - bell-housing seam.
We ran two treatments of Bars Stop Leak tablets through the system and could only slow the leak down. We re-pulled the engine and the freeze plug was OK, but we noticed a small dimple in the cast iron where a small bead of water dripping. I was able to take an awl and with a little pressure put the awl into the block - water jacket area. The hole is approximately 3/16" diameter.
Discussed this situation with a cast iron welder and he stated to risky to weld, it appears to be to weak of a spot. ANY IDEAS?
Could I set a screw in the hole and epoxy the screw to plug the hole? Would I need to tap the hole? Any suggestions or ideas are appreciated.
Thanks.
 
#3 ·
hey,

Let me type this out:

Cracks in the cylinder head or block can often be repaired by either brazing, welding, or pinning.

Sometimes solder can be used on water jacket cracks.

The use of threaded pins is quite popular because no heat is required.. no chance of warpage.

If the pins are to be effective, they must reach slightly past the ends of the crack.

Use threaded taper pins designed for crack repair.

Start by drilling and tapping a hole that centers on the crack line, just beyond the end of the crack.

Thread the correct size pin.. pin may be coated with special heatproof sealant if desired into the hole.

When tight, notch the pin, about 1/8 inch above the casting.

Use a sharp chisel. Twist off the excess.

In some cases a hacksaw may be used to cut the pin.

Drill and tap for the next pin so the hole just cuts through the threads of the first pin.

Installl plug and twist off excess.

Repeat this process until the full length of the crack is pinned.

Each pin must cut part way into the preceding pin.

If steel pins are used they should be lightly peened.

Grind pins nearly flush with work and finish with a clean sharp file.

If the area cannot be filed, grind flush.

When a crack passes over an edge such as across head and down into combustion chamber insert pins in the order shown in figure 8-54.

Figure 8-54;

Insert pins in the order shown. Pin #6 will lock pin #5 in place in case pin #7 does not properly overlap.

pages 141-142 Auto service and repair Martin Stockel @ 1984
 
#4 ·
TWCarpentry said:
I am restoring a 1974 Ford F100 -360 engine. After the rebuild- full engine restore- we put the engine in the truck and made the minor adjustments and it started and ran good, but we noticed water/anti-freeze dripping from the back of the engine at the block - bell-housing seam.
We ran two treatments of Bars Stop Leak tablets through the system and could only slow the leak down. We re-pulled the engine and the freeze plug was OK, but we noticed a small dimple in the cast iron where a small bead of water dripping. I was able to take an awl and with a little pressure put the awl into the block - water jacket area. The hole is approximately 3/16" diameter.
Discussed this situation with a cast iron welder and he stated to risky to weld, it appears to be to weak of a spot. ANY IDEAS?
Could I set a screw in the hole and epoxy the screw to plug the hole? Would I need to tap the hole? Any suggestions or ideas are appreciated.
Thanks.
You put 2 cans of bars in a new engine. Whatever you end up doing to fix it make sure you flush all that crap out. It will ruin your radiator or heater core in no time at all.

If you can drill and tap the hole and put a plug in it with some sealer on it
 
#5 ·
Cant hurt to try a pipe plug(a straight thread plug may not seal under presure). The block is scrap as it sits, so if it doesnt work youre still in the same position. If this appears to be rust thru of a thin spot, try to drill/tap to a size larger than the thin spot(1/4"npt). Drill in steps, its easier, and will allow you to check the thickness of the wall as you go.
 
#6 ·
Heck, a 3/16 hole - I would just drill and tap it out for a 1/4 or 5/16 NC bolt, slobber the bolt and a flat washer with J-B weld and bolt it in place. The pipe plug fix will work as well but many folks just don't have those taps. Either way will hold just fine. Unfortunately there will probably be more rust holes coming.

I would probably start looking for another 360-390 engine as well, preferably a 390 as they are s-o-o-o-o much better.
 
#7 ·
Several years ago I helped put a 331 SBC in my friends Vega the night before a race and found a crack 4 inches between #3 and 5 cylinders. At 8 PM we wire wheeled it, cleaned with acetone and did a big smear of JB Weld. Put heat lamps on it over night. At 6 AM we fired it up..no leak, ran it the entire season. If you do like others suggested, drill, tap and plug, then JB over it all, I think you'll be OK.
 
#8 ·
Clint Cumings outlined it pretty well. Pinning it properly will give a lifetime repair.Drilling it and tapping to a 1/4 or 3/8 pipe plug would be permanent too.If it is close to moving parts , like the flex plate , just grind it flush after installed.
 
#10 ·
TWCarpentry said:
Thanks for all the helpful information. Has anyone heard or used Hard-Blok? It is an engine block filler for racing engines. Could I use this to close the hole?

Thanks again.
HardBlock is used for completely filling the waterjackets to increase the strength of the bottom of the block. It is very cement like. It blocks off the cooling passages, which tends to render the block useless for street use(no cooling). It is not a patch of cracks or holes
 
#11 ·
TWCarpentry said:
I am restoring a 1974 Ford F100 -360 engine. After the rebuild- full engine restore- we put the engine in the truck and made the minor adjustments and it started and ran good, but we noticed water/anti-freeze dripping from the back of the engine at the block - bell-housing seam.
We ran two treatments of Bars Stop Leak tablets through the system and could only slow the leak down. We re-pulled the engine and the freeze plug was OK, but we noticed a small dimple in the cast iron where a small bead of water dripping. I was able to take an awl and with a little pressure put the awl into the block - water jacket area. The hole is approximately 3/16" diameter.
Discussed this situation with a cast iron welder and he stated to risky to weld, it appears to be to weak of a spot. ANY IDEAS?
Could I set a screw in the hole and epoxy the screw to plug the hole? Would I need to tap the hole? Any suggestions or ideas are appreciated.
Thanks.

how far further has it rusted out though than the hole you made ?
What about the other waterways - time for a new block I fear

Stephen
 
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