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oil snding unit area on engine split

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ichthos

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Hello,
I have been trying to get my TR6 to run since last September. I have either been short money or time. My big moment was going to be this weekend.I was just adding a few finishing touches before firing it up for the first time tonight. I was tightening the oil sending unit, apparently too tightly, when the area on the block that the sending unit screws into split in three places. Needless to say I am fairly sick about the whole thing and would like to light the car on fire at the moment. Can anyone offer me any ideas on how to repair this, or am I just screwed at this point?
Thanks, Kevin
 
You can try JB weld or another metal epoxy product. You will basically have to sterilize the area which will be difficult since it is an oil journal. You might have to fill the hole, drill and tap. I'm guessing you should pull the oil pan and catch the residuals so they don't circulate through the engine. Then you would really have problems.
Another two part epoxy product that I have seen used successfully is in a stick form. The inner core is the second part. Twist it together, fill your cleaned hole, etc.
I've seen it at auto parts stores. It might be called magic metal or something like that. I sell a similar product that I have gotten positive feedback on from users.
Another option is a machine shop or engine builder. They would tell you if they can fix it. Unfortunately, they would be much more expensive, and you may have to pull the engine for them to work on it. But then you may to pull it to get enough room to work on it yourself.
Not knowing exactly how these splits look on the engine, if the threads are unaltered, you may be able to just very carefully screw the sending unit back in to open up the splits and press epoxy into the cracks. Back the unit out allowing the splits to close, and let it dry. When reinstalling it, use a thread sealant and just screw it in by hand and maybe and extra half turn or so. Let the sealant do the work.
Not seeing the damage, I can't say if any of the epoxy methods will work. The quality of iron in your block will determine if it can be welded. Some casts will take the heat, others won't and crack.
Good luck!
 
Kev,
Are you saying that you actually split the cast iron block! Are you sure? This seems to be virtually impossible but I guess anything is. Drop the pan and with a good strong flashlight you should be able to see from the inside whether the "cracks" go all the way through. Could it be that you are mistaken. If indeed the block is cracked, a good (translate that as REALLY good) welder might be able to repair in place. I know that I have had a capable welder repair cast iron for me before. The cracks will continue to travel if not repaired so I don't see the use of a glue-type repair as anything permanent. Good luck.

Bill
 
Welding cast iron requires the entire block to be heated to approximately 1000 degrees for a period of time. This is done to eliminate the possibility of additional damage from heating the weld area. Without the preheat, when the weld cools, the metal shrinks and can cause additional cracking. Very few if any welders have the resources to do so. Some welders claim to be able to weld cast iron, but their technique is not correct, and the risk is high.
There is an old technique called metal stitching that does not involve welding. Holes are drilled into the cast iron and a tapered, threaded metal plug is inserted. The next hole drills the crack as well as a little of the first plug. This is continued until you reach the end of the crack, where you unstall one final plug that is slightly past the end of the crack. The plugs are machined to match the surface of the block. The Ford Flathead was well known for cracks in the block on the deck. Stitching was the common method of repair.
IMHO, this is not a repair that can be done with the engine in the car. Depending on the length of the cracks, you may be able to drill a hole large enough to include all of the cracked area. If so, tap the hole and install a threaded plug, or bolt. Machine the plug to match the surface of the boss. Then drill and tap to accept the sender. If the cracks extend out from the boss you are into the thin area of the casting. There probably is not enough material to use this technique.
If your engine is approaching the point of requiring a rebuild. Your best option may be to buy another engine. Engines are not too difficult to find.
 
Giving more thought to my earlier response, bevel out the edges of the cracks making a trough for the epoxy to bite into. Drill the ends of the cracks to keep them from growing. Keep your surfaces rougher to allow the epoxy a better bite. Many people don't like the newer technologies because the they are ever changing and hard to keep up with. I deal with these things on a daily basis and am amazed at the regularity of new things coming available to the market. A customer of mine had a crack in a high stress area of a 427 drag race engine that he fixed with epoxy. Hoped it might last a race, but he finished the long season with it successfully. Much more stress than we are putting on our engines.
After more thought, don't attempt opening the crack. Not worth the risk of further damage.
 
hi kevin, i would not use jb weld or any epoxy on this area or have it welded since you really cannot weld cast iron well and if you do the entire thing needs to be heated and welded and slowly cooled because of its nature. anyway there is another way. it is a process called cold stitching this is a specialized permanent repair for cast iron. the crack is stress relieved and cross ties are put in place and then where it split is filled by a threaded piece which is then screwed in and ground even. they can add a new piece of metal in this place. i am not doing this method justice by my description and it is hard to find people to do this but it is the best repair. look in your area. if you would like i can put you in touch with someone who can do this in the mass area if you have questions on the process.
Randy
 
I know you already said you were short of money and or time, but if all else fails, you can get a new block for $500 from TRF (UKC902).

Most of these other fixes are going to require you to pull the engine and strip it, so it's not the stupidest suggestion in the world, just check out how cost effective it is compared to a welding or stitching job.
 
I'm with you, VD. It is hard for me to fathom that that little threaded device would crack a cast iron block. I think that a really good cleaning of the block in this area, a very strong light and maybe, just maybe, it might just appear to be cracked. Let's hope...

Bill

Are you going to the show this Saturday?
 
Hello All again,

Thanks for all the input and suggestions.I am just now getting to read most of the suggestions. (My wife decided to take me out for an overnight stay to get me away from the TR so I didn't do anything rash.) I don't know if the engine blocks are different, mine is a 69, but if you look at where the oil sending unit bolts into the block below the distributer, there is a shoulder that gets thin only toward the bottom of the plug. It is this thin area on the bottom half that split in three places. The block is not split. As far as anything on the block goes, I didn't think it was possible to do this either. I tightened it with one hand and didn't think I could put that much force on it to crack anything. The plug was loose (and the electrical tab broken off).When I removed it, it was covered with oil and dirt that has accumulated - it could have already been cracked. At this point there is not enough thread to hold it in place at this point. Now that I have clarified things a little, does anyone have any suggestions? I don't want something that is going to go wrong when I'm out on the road somewhere. I am not thrilled at pulling the engine out, but I'll do it if needed.I don't want to do some shoddy work on the engine after doing so much mechanical work on the rest of the car. Also, I would like to stick with this engine if possible because it is original.
Thanks, Kevin
 
Heres a product that may help; its; 'HOLTS WONDERWELD' found at;..https://MOTORTRADERS.COM search there site for this item it will then describe what it does.A UK product $13.00USD This may be just the ticket.It says it perminatly fixes engine blocks cracks.Goodluck Ken.....Or just Google it.
 
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