Gonna hav'ta get another connecting rod!

[WATERWINGS]

I took this one off of the motor I was just running, (one of the cyls. that wasn't damaged) and when the rod bolt was stiff screwing in, I looked closer.

What would cause this and would it have failed anyway sooner or later?

[RichS]

You need to get a tube wire brush to go in there and get the red loctite out of the threads and then see what the threads look like:eek: :D

[Gordie Miller]

git youself one of dem dar soopa doopa heli-coils!

[Capt.Insane-o]

Not to be getting off subject, but what kind of camera was that? Get the loctite out and see what it looks like then.

[STV_Keith]

Is that a small rod (636-8118) or a big rod (625-5250)?

[WATERWINGS]

Actually all the locktite is out, those are the threads (but now you make me wonder)

It is a Sony (I think) I'll double check tomorrow at work.

I think it turned out so good cause I used a small flashlight to light up the inside of the threads at the right angle to show some shadow.

Several others didn't turn out as good without the light.

Keith, that is a small rod

Gordie, what kind of soopa doopa drills do I use to tackle that soopa doopa HARD steel? (good one)

[Talon2.5]

now waterwings that kinda stuff should always be on the Inspection checklist!! clean and run a thread chaser through on teardown ;)

that penlight shure made that pic work!! good job!!

i would suspect over the years of re-builds possibly not being cleaned and checked in the builds prior to you owning it, just took it's toll on the threads? over torqued? rod overheated somewhere in its life and the threads got brittle? definately abused though :eek:

[WATERWINGS]

Captn. Insane-o, The camera is a Sony FD Mavica, It uses a regular 3-1/2 floppy disk

True Skip, do you know right off the top of your head the, thread size and pitch?

But if the tap is any bigger than the threads, (some do vary) I'm sure the tap couldn't go in due to the hardness of the rod????

[RichS]

I'd be real worried about running a HSS tap in that hard a.. ****. It is to easy to break one off:eek: If the threads are buggered up that bad it would be a whole lot safer to put in a good one rather than take a chance on marginal parts. If the threads are broken up where you can see them what about the areas that you can't see. But thats just me.

[Talon2.5]

who said anything about a freakin tap??

i said THREAD CHASER 5/16-28 see pic (also taken with a mavica FD88 floppy disk camera)....................

[Talon2.5]

5/16-28 on the small 2.4 rod (636-8118)

5/16-24 on the big 2.4 rod and the 2.5 promax rod

at least thats been my experience, and the 5/16-28 chaser i didnt have so i made one from an old rod bolt ;)

[STV_Keith]

If you need one (or more) I have 5 of those rods for sale.

http://forums.screamandfly.com/forums/showthread.php?s=&threadid=26912

[WATERWINGS]

Skip, I guess us country bumpkins have always called a tap a thread chaser, ("go get a tap and chase those threads")

Its good to know there is a real tool called a "thread chaser"

Where can you get those, are they always a full kit, or can you just get one at a time?

How much?

Is using a cutoff wheel good enough to make the groove, or will an end mill even cut it?

[ImbadBob]

John , I don,t wish to argue with anyone ,but there is no way I I could turn up a motor with a helicoil in the rod. I'm not saying it won't work , I don't know. A used rod is too cheap to risk the crank, block, or your hide. As to what to drill the hard material with, I had to convert some rods for my 260 , bottom guided to top guided. For the oiler holes I used a colbalt bit untill I got to the real hard inner circle of the rod "66" rockwell C" the used a carbide bit. But man buy a rod I'll sell ya one or at leat a dozen others have them on the board. If you come to the west side of the mountians send me an e-mail . Bob

[WATERWINGS]

Bad bob,

Gordie was "joking" about putting a helicoil in a rod, I don't think it is even possible to do.


How is it in Tenn. now, warm enough to ride yet?

It's been nice here, but my motor is waiting for rod bolts now,

don't that suck?

[Talon2.5]

yep you can use a thin cutoff wheel to make a "thread chaser" out of a rod bolt (make sure the threads on the rod bolt are clean after you cut the grooves though)

i forget how much they were had them for years now, got them from either snap-on or mac tools, kit or single

definately junk the rod you have in the picture, but for cleaning the rod bolt holes those thread chasers are great :cool:

[ImbadBob]

The weather has been great, We've out 3 times in shorts and sunblock. It's supposed to be alittle wet and cool this weekend. Guess I'll spend some hours in the shop and maybe work in the greenhouse some. Summers is on the way. Bob