Bringing back an 854

[squonk 41,155]

18 minutes ago, ebinmaine said:

I tried to tell @Handy Don Gorilla glue would work but my advice  "didn't stick".... 

 

 

 

 

   

[richmondred01 2,237]

I would consider taking it to a machinist. Taps that large will cost more for the tap itself then for them to do the job for you. 
Just my two cents. 

[Ed Kennell 38,227]

Any local plumber should be willing to tap it for you or loan you the 1"NPT tap.

[wallfish 17,012]

https://www.amazon.com/11-1-Tapered-Thread-Speed-thread/dp/B088RF8QXZ/ref=sr_1_8?adgrpid=1343603779563468&hvadid=83975476778414&hvbmt=be&hvdev=c&hvlocphy=51385&hvnetw=o&hvqmt=e&hvtargid=kwd-83975592430559%3Aloc-190&hydadcr=29613_14571321&keywords=1%2Binch%2Bnpt%2Btap&qid=1647692074&sr=8-8&th=1

 

 

Plus he can bring it to Zagray or the big show and sell it to me for $20 if he doesn't want to keep it!

[Handy Don 12,237]

Thank you all for the advice (except for the Gorilla clue ) and the offers.

Since even a phone call with my friendly plumber will cost more than buying a 1" tap, I'll be trying that first.

 

It looks like there's barely enough metal for carefully drilled and tapped holes for a flange like the one @Oldskool pictured. Could probably also do a flat ¼" plate with a threaded 1" hole (similar to an option on some 70's Tecumseh's to switch from the direct bolt-on mufflers to an exhaust pipe). Do you need special drills/dies for working the block? I have a set of cobalt drills I reserve for hard metals but my dies are carbon steel.

 

I'll post the results, for sure.

[sjoemie himself 3,068]

No special drills needed.

By the looks of it the head is cast iron, correct? If so do not use any lubrication. The dust will otherwise clog up your drill and/or tap.

[Ed Kennell 38,227]

I always use Kerosene as a lubricant when drilling and tapping cast iron.

[richmondred01 2,237]

Cast iron has hard spots and isn’t as uniform steel. It’s a different technique and not as forgiving. 

[Pullstart 62,913]

If you’re afraid of getting metal in the engine, you could just pop the spark plug out and blow air into the hole as you tap…. Grease also helps when tapping cast to keep the chips from moving too far.  @peter lena could tell you what spec, weight and color grease I’m sure   

[richmondred01 2,237]

Believe it or not we also used lard back in the day. 

[Handy Don 12,237]

I'm really hoping the tapping will work when I get my hands on a 1" NPT tap.

I like the idea of putting some air through the exhaust port while tapping--full face shield and safety glasses for that task!

[richmondred01 2,237]

11 hours ago, Handy Don said:

I'm really hoping the tapping will work when I get my hands on a 1" NPT tap.

I like the idea of putting some air through the exhaust port while tapping--full face shield and safety glasses for that task!

Remove the exhaust valve and block the valve chamber with a rag. 
When your done, Vaccum it out the prior to removing the rag. Once the rag is removed, put your finger on the top of the valve guide to block the hole, then blow it out. 
I don’t recommend  using air pressure while tapping. It’s an accident waiting to happen. 
Just my two cents from a guy that lost two fingers in an avoidable accident.

Edited March 20, 2022 by richmondred01

[wallfish 17,012]

or risk the Backyard hammer mechanic method which is NOT always the proper way. Just time saving and assuming you don't plan to go deep on that engine and just want to start and run it like it is.

Stuff a small damp rag in there and lay the engine on it's side ( Like using a milk crate or something) so the exhaust port is facing down and use gravity. But gravity also works against us older folks for getting up off the floor so plan ahead!

My philosophy being the chips and dust will fall, the rag keeps anything else from going deep and the exhaust blows out when it's started.

At least that's how I've done it sawing exhaust nipples to get those out.

[Handy Don 12,237]

1 hour ago, richmondred01 said:

Remove the exhaust valve and block the valve chamber with a rag. 
When your done, Vaccum it out the prior to removing the rag. Once the rag is removed, put your finger on the top of the valve guide to block the hole, then blow it out. 

 

7 minutes ago, wallfish said:

exhaust port is facing down and use gravity. But gravity also works against us older folks for getting up off the floor so plan ahead!

 

I am very appreciative of the continued advice, gentlemen, thank you! I've also been studying the Kohler engine manual.

 

I can see flowing air could be risky. Instead, I can see myself using the grease and rag method. Removing the valve seems like tempting fate as it makes an opening going down into the valve spring chamber. If it is out, though, then maybe a dollop of lard/grease in the guide hole that I can pull up and out after the tapping makes sense. As for the gravity thing, I've always hated working over head plus having the engine upright will help me keep the tap level going in. I have an adjustable height work surface that is pretty tall so I wouldn't have to lay on the floor, though (whew!)

 

I can see where this all this is leading now. Oh yeah, gotta get a valve compressor clamp. Oh, and I'll need a puller for the flywheel and bearing plate. And then a cylinder hone of course, and then who knows.... 

 

Yesterday got the tins and head off and, from the top, it looks good. No oversize mark. Very little carbon. Almost indiscernible piston wiggle and no ring wear ridge or cylinder wall scratches that I can feel. Valve seats are clean and the valve heads are nicely proud of the top of the head--no pitting or blow-by that I can see on the valves or the head gasket surfaces. It had a full metal-sheathed head gasket, too, which I haven't seen in ages. Plug was clean and tan but also looks like a recent replacement (it is the correct spec though!) Possibly the head had never been off this engine before. Crankshaft endplay is within spec (~.014) and side play is indiscernible. Absent finding something of concern, I think I won't go any deeper in this engine.

I was going to get the carb off and then check the valve adjustment and points today, but I think I've caught the cold that my DIL and granddaughter brought with them earlier in the week so I'll be taking it easy today. Maybe spend some mindless time checking the head for flatness!

[Oldskool 6,644]

@Handy Don something else to throw in the mix. I have added a magnet to my chuck for semi low speed drilling to keep filings out of places. The only drawback I've seen is you have to clean the drill bit tip alot. It wants to recut the shavings if left in place. Ive used the same idea tapping threads.

 

I hope you have good luck in the direction you take on this.

[Handy Don 12,237]

6 minutes ago, Oldskool said:

added a magnet to my chuck for semi low speed drilling to keep filings out of places

This sounds intriguing! What does it look like? 

[Oldskool 6,644]

4 hours ago, Handy Don said:

This sounds intriguing! What does it look like? 

It's just a standard magnet. I remove it when drilling "run of the mill" things.

I just let it stick to the chuck. That's why low speed. 

Edited March 20, 2022 by Oldskool

[Handy Don 12,237]

Quick recap and summary of Post #40 in this thread...

The exhaust port had badly rusted and would not accept a pipe nipple. An attempt to clean it up with a Dremel (wire wheel and light grind) confirmed the damage.

I asked for and got several useful suggestions--thanks again! I chose to go with creating new threads with JB Weld and a 1" NPT tap.

 

Spoiler alert: it worked. How do you spell relief? T H R E A D S

 

Long story, with pictures. 

I couldn't find a tap to borrow (everyone had dies, no one had taps) so I bought one.

Started with this. Barely visible threading on sides and top only.

 

Stuffed a rag in the back of the port, lubed the tap and port and started in. Was able to catch the beginning of the original thread to keep it aligned. Slowly ran the tap in ½ turn then back ¼ turn repeat until it hit the seat at the back of the port (I'd also measured the depth beforehand and penciled a line on the tap as a double test). It took very little effort so I knew it wasn't cutting much metal.

 

Yielded this. some faint threading that let the muffler nipple go all the way in, but with gaps around it and not a secure feeling that it'd stand up to regular use.

   

 

So on to Part Two of Plan A. I carefully Dremel wire brushed the inside of the port then applied a layer of Steel JB Weld around the inside. Allowed it to cure for 36 hours. (Edit: This epoxy is rated to 600º which I felt was adequate. "Extreme Heat" ceramic-impregnated epoxies can handle much higher heat but are more brittle. Choose which suits your preferences.)

 

As you can see, I went a little overboard with the JB weld. I couldn't even start the tap so I started slowly grinding away the epoxy to enlarge the hole at the front edge until I was able to start the tap. I thought briefly about drilling it out but I don't have a 1-5/32" drill and I doubted I could keep it properly centered even if I did. I used a caliper check the diameter and the Mark 1 Eyeball (corrected), to judge the circularity. BTW, I discovered that grinding JB Weld is a very smelly job--like dead fish smelly .

 

Eventually I was able to start the tap, get it in a half turn or so and then feel very strong resistance. I could see that the tap was butting up against the ridge of epoxy. That led to iterations of grind, vacuum, tap for a half turn or so, vacuum, repeat.

 

But I was making progress and I could see threads.

The last thing I wanted to do was blow out those threads by putting too much torque on the tap.

 

Finally, I reached the pencil marks on the tap indicating I was in as far as I could safely drive the tap (I didn't have a blind-style tap--the first parts of the cutters taper in). I backed it out nearly three full turns, vacuumed the dust and...

 

I had threads! Testing the muffler, I got to almost three turns before getting stopped with just hand pressure. It is strong, it looks like a good seal all around, and the epoxy is rated to temps well above what this K181 will throw off.

Thankfully did not have to go to Plan B, drilling the block to accept a flange. 

I'm calling it a win.

Edited March 31, 2022 by Handy Don

[richmondred01 2,237]

Outstanding……

[ebinmaine 67,628]

5 hours ago, richmondred01 said:

Outstanding……

Agreed!

[sjoemie himself 3,068]

 not only good execution of an idea but also very clearly documented for future reference. Win-win in my book

[Oldskool 6,644]

Excellent.... Thanks for the visuals and the step by step. Hopefully years of trouble free use to come.

[WHX?? 48,828]

Ok up to speed here Don and wished I'd been sooner. I have a 1" NPT tap I coulda loaned ya. 

Not to be debby downer on the JB but I tried it on a exhaust once and it didn't hold up to the heat. Actually melted off but maybe your using a different type of JB? 

11 hours ago, Handy Don said:

epoxy is rated to temps well above what this K181 will throw off.

Ok just caught that. Let us know how it shakes. 

[squonk 41,155]

 Put a 1" conduit lock nut against the block to help secure the nipple.

 

They make hi heat JB weld.

 

[Pullstart 62,913]

Best of luck with the longevity Don!