Ktrim
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Equipment
B2400, lA352 loader,3pth quick hitch/z122r zero turn/restored 52 farmall super a
Farmall H restoration
- Thread starter Yooper
- Start date
Got most of the wiring done. Getting close to firing it up but I'd like to get the muffler on when I do. Found out today the exhaust manifold is tapped 2" npt taper with 11 threads per inch instead of 11-1/2 tpi. ??? Goofed around on the lathes this afternoon but I don't have a taper attachment to do it right. Will try again tomorrow with some straight threads but I ordered a tap just in case.
BAP
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Lifetime Member
Equipment
2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Is that a replacement manifold? Or the original? We always just used a piece of 2” npt pipe cut to length if we had to replace it.
Yes, this is a new manifold. Can’t remember where I got it from but I do recall going with the more expensive one for better quality. I tried threading some 2” pipe into it and it will go about half a turn. I assumed it wasn’t tapped deep enough so I tried threading some pipe on my big lathe by offsetting the tail stock for the taper and cutting the threads deeper. After two tries I suspected there was an issue and checked the thread pitch with a gauge. Absolutely 11 tpi. After fighting with the lathe all afternoon I decided to sleep on it and try again today. I suspect the manifold threads were thread milled by the looks of them. Just missed the tpi in the programming.
Looks like you got BSPT threads, British standard. Legend has it one of the colonies first act of rebellion was against British plumbing. The pipe sizes are the same, but the thread pitch and form are different.
I'd get a short BSP nipple, threaded one end, and weld it onto your exhaust. This one's stainless, but you should be able to find carbon steel if that's what you want.
Bingo! You nailed it! Thanks for responding. This will make things a LOT easier! Those Brits sure know how to take something simple and make it complicated. Worked on a BSA motorcycle in my teens. Imperial, metric and Whitworth threads. Sheesh!
Big set back today. Getting ready to put some fire in the holes and I noticed that it cranked hard. As in too tight. Pulled the plugs to see if it was compression and no change. Put my inspection camera into the cylinders and found water in all four. Checked the oil pan and water was there too. So I pull the pan to start checking for sources and I notice it was running down the oil pump. Well that is a good clue that it is coming from the top side so I removed the head and it is absolutely the head gasket failing almost everywhere. Going to have to do some research but I am relieved it is not a cracked head or worse yet, the block. I filled it with distilled water several weeks ago after I got the radiator installed to check for leaks. All this leaking happened as a result of gravity. There was no pressure in the system.
Out will come the pistons later on this week. Will post pictures of that.
Out will come the pistons later on this week. Will post pictures of that.
BAP
Well-known member
Lifetime Member
Equipment
2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
That stinks. Fortunately you found it before you got it started. There seems to be a lot of poor quality gaskets on the market now. Finding good ones is getting harder to do.
A couple of thoughts about this situation . In 20/20 hindsight I shouldn’t have used distilled water. With the lack of minerals in the water it becomes aggressive and goes after iron. And every part has been blasted setting up the perfect storm.
The manual calls out a tolerance of zero to five thousands stick out on the cylinder sleeves. I split the difference and have them at two to three thousands. I will clean up the block and remeasure but I am thinking about cutting them down to zero.
The manual calls out a tolerance of zero to five thousands stick out on the cylinder sleeves. I split the difference and have them at two to three thousands. I will clean up the block and remeasure but I am thinking about cutting them down to zero.
For a person as specific and detailed as you are that has to be a bit.ch. Thankfully you had a camera to see to problem quickly.
Pulled the pistons expecting an ugly mess and as you can see I was not disappointed. But they did clean up good and the rings were ok. Reinstalled them after lightly honing the sleeves. Also put some Devcon epoxy where there was pitting by the water passage holes. Kick myself now for not having the block decked when it was out.
Decided to run a fly cutter over the head and clean it up. Five degrees Fahrenheit for a high today so it is a good day to watch the table slowly move from right to left. The challenge was to get it clamped to the table. Best I could come up with was the water inlet and a pipe plug on the other side with blocks to raise it above the valves. I used paper to shim it level.
Since it was so lightly clamped, I only took .004" per pass but it did clean up at .020". Sprayed the new gasket I ordered through the Case IH dealer with Permatex copper and started reassembly.
Reassembled the head and wisely left the pan off. Pressurized the system and noticed some drops coming from underneath. After spotting the source with my camera, which of course was coming from the head gasket, I pulled the lifter cover plate and confirmed.
Soooo...
At the engine shop to get decked.
Soooo...
At the engine shop to get decked.
BAP
Well-known member
Lifetime Member
Equipment
2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Most likely the crappy head gasket replacements for older engines that you get nowadays. Everything has to be absolutely perfect or they won’t seal up properly.
Bought the gasket from the Case/IH dealer for some extra insurance and coated it with the copper. After what I had done to everything the leaks went from multiple places down to just one. But one is too much. Again, I am paying the price for not doing this the first time. Lesson learned!
And I agree with your statement that everything has to be perfect. This is proof!