Cracked Cylinder Block / Cost of Repair

[BackForty]

Howdy Fellas,

After 18 months, I seem to have reached my first major impass with this 79 XS Standard of mine. I didn't inspect it properly when I purchased, because of my lack of experience with older bikes (and my lust-at-first-sight for the bike, winning out over common sense). Had I given it a good look over, I would have seen that it was definitely a bit of a Frankenstein project, though not horribly pieced together.
The biggest problem I have now is, what I was certain was a CCT issue forever, is a persistent oil leak in the front center of the engine. After following all CCT maintenance and repair recommendations (i.e. gaskets, sealed cap, new CCT, Auto CCT conversion) I finally had the sense to do a baby powder leak test. As it turns out, it was a motherfreaking crack directly above the CCT in the underside of the ear when the head bolts to the cylinder (see picture below).
After calling a couple mechanics in San Diego, it looks like to do a swap on the cylinder block (not including parts, which I may be able to get from a fellow XS member in town) I'm looking at some unknown cost figure, upwards of $1200-$1500.
My question is: Does this sound right? Should I go a different anlge or Sell this thing for parts?

Note: The Auto CCT is not pictured here because I changed it back to the OEM thinking it was still related to the leak.

p.s. I know I don't know much about complex engine work on these bikes, so forgive my ignorance. (but I love this bike!)

[BackForty]

Pics of the Bike and Cracked Area

[BA80]

That crack is NOT in the block (cases) it is in the jugs (cylinders) and with the right tools and a little knowhow can be replaced without removing the engine.

That type of damage is caused by improper tightening of the head bolts, or in this case studs. There ar 2 of those studs that go down from the head, one in the front and one in the rear. It's quite easy to break them right there. Some of the most experienced XSives have done it.

Some people have patched that type of crack up with epoxy or JB weld. There isn't any oil pressure there, it's just the cam chain tunnel and oil is slung around in there.

Try cleaning it up real well and putting some JB weld on the crack.

The only REAL way to fix it is replace the jugs. It ain't $1200 - $1500 worth though. Maybe a couple hundred and some elbow grease.

[TopCatGr58]

Hey there BackForty,

Regrettably that price quote is probably right for a SHOP/Pro Mech to do that level of work....it is a lot of work, pulling the head which involves pulling the cams, then pulling the jugs, then putting a new set of jugs on it, and then putting it all back together, retiming the cams/crank/chain.

Now someone correct me if I'm wrong since I'm not a real mechanic, but even though that part of the head is bolted from underneath, with only 14 lbs of torque, so it's not necessarily needed for sealing the head around the pistons, but more just to secure the head for oil/cam chain tunnel.

So...possible options: 1) Clean it thoroughly, and then apply a nice layer of JB-Weld all around it to seal it....or RTV?

Do the work yourself.....we always recommend this...either with just a manual, or also with a fellow knowledgeable Xsive neighbor showing you the way...I think there are a few in your area...usually willing to assist for a meal and a cold one or two!

2) Pull the head, then the jugs, and take it to someone that can weld aluminum to fix it.

3) Get a spare set of jugs. Here's the tricky part...to save you having to at least hone the new jugs, and get new oversized rings $$$, The Sleeves will come out of the jugs with just baking in an oven...just ask Tod/TrBig!!

Bake the new jugs, remove the sleeves, then bake the old jugs with the broken tab, remove those sleeves and then put them into the new jugs with the intact bolting tab. Keep the same cylinders in the same location...ie. 1-4. Then reassemble the engine with the new jugs with the OLD sleeves, no honing required...same sleeves with same pistons and wear!

Now we hope to hear from the REAL MECHANICS on their suggestions... ie. Crazy Steve, BikerPhil, etc.!

T.C.

[BA80]

Even if the cylinders are kept in the same positions disturbing them will disrupt the wear pattern that's alread been established. The cylinder surface glaze will need to be broken so the rings can reseat. You shouldn't necessarily need to swap the sleeves if you get a decent set of jugs.

The old rings should be fine if they aren't damaged although new ones would be better.

[jwhughes3]

Talk to Mike in San Diego - he has a whole good engine for FREE you can just swap it in. Much easier and simpler than trying to fix the crack.

look in the xs parts section.

John

[BA80]

Talk to Mike in San Diego - he has a whole good engine for FREE you can just swap it in. Much easier and simpler than trying to fix the crack.

look in the xs parts section.

John

There ya go. How good is it I wonder?

[DGXSER]

I would definitely agree with the theories here.
1. Easiest and cheapest, use some JB-Weld to patch the crack and ride it like you stole it!!

2. Replace the engine as a hole...It is not uncommon to find an engine for $2-300. IF Mike has one for no-denaro and a cold beer or two, how could you argue with that solution. Even if it needs some work, it would put you miles and lots of $$$$ ahead of the current plan.

3. Replace with a used set of jugs. IMHO, I would go ahead and hone the cylinders, even if you swap sleeves. Chances of keeping the orientation of the sleeves correct is not good, and rotating the sleeve even a few degrees will change the seating of the rings.

[jwhughes3]

He has not just one but THREE engines (2 complete) for free. He is moving and doesnt want to take them. Mike has tons of motorcycle knowledge and a garage full of nice running old bikes. He would tell you the history and which is best one for sure. He also has other parts including a rolling frame if you need stuff. Just for sending a PM and driving to Escondido. (Soccer4m)

Now I cannot argue with the JB Weld patch and just ride it. You can always get a free engine and swap later.

John

[daveyg]

Since you are close, go get all of Mike's stuff, give it a good home.
Then, JB weld. Either clean the cracked area very well with something like acetone, or use a die grinder to rough up the surface if possible (lightly, you don't want to make the crack worse!) and ride the crap outta it! It's a 20 minute and $10 fix that might hold up for years, maybe over a decade! (With careful prep) and then try to put together one complete bike outta the free score you got from Mike!

[BackForty]

Thanks to everyone who chimed in. I've spent the last few weeks reading about different fixes in this area of the engine. I didn't realize that since the cam chain tunnel is not under pressure, that the JB weld fix could work.

It seemed like a lot of oil coming out of a tiny crack. The picture (above), as you probably guessed, only shows the first of the leak. After riding it 15-20 miles and parking it, the drip from the oil-covered front and bottom enginge has got me smoking like Mad Max. After sitting for an hour leaves a puddle of about 2-3oz of oil. I have pined over this thing for a month and checked every area I can think of for other leaks (gaskets, oil filter, under timing cover, top end) , but found none.

Nonetheless, I am eager to try the JB Weld fix first. I will clean the area real well and apply the JB. I'm guessing the liquid mix is my best bet? Also, I talked to Mike last week about hooking up with him and looking at those enginges. I think he said that none of them ran, but I don't know how close they are to working till I go over there and talk to him. Keep ya posted on that.

Thanks again for all the input. Don't know a ton about these bikes but most all of what I've learned has been because of this site. I'm glad it's here and that I get to be a part of it. Whoa, now that I've gotten all touchy-feely about it, I better go do something that involves bikes or guns or baseball . . . lest I feel the urge to knit a sweater or something

[Courtney]

I would absolutely JB Weld it, you could even dremel a bit of a groove along the crack to push the epoxy into so it would grip better and contour better on the top part so it looks good. If you took the CCA out, could you reach in behind it with a good cleaner and a rag and clean that side too, so the whole area is spotless before you epoxy it? It's amazing how oil can ooze out even after you've cleaned the outside surface. Maybe rough up the outside too so the epoxy bonds well. See if there is an epoxy that is intentionally made for oil/gas resistance? I am willing to bet this will cure your problem no sweat as long as you do a good job of it!

[skids]

JB weld does soften with heat, but it may seal the leak OK.

[CaptonZap]

You might read post #21 and 22 in this thread, and see if the locktite mentioned might be a method of repair.
http://www.xs11.com/forum/showthread...ocktite&page=2
The only problem I can see is that the crack will be contaminated with oil, and might prevent the Locktite from affecting a grip on the metal, and thus not seal.
That and the heat might not be too good for the sealant.
A flush with acetone and a blow gun, repeated multiple times, would probably get the crack cleaned out, and the heat issue is an unknown.
Almost makes me wish i had a cracked head, so I could try it.

CZ

p.s. By the by, I asked the tech at JB Weld what the temperature range of JB Weld was, and he said that at about 230 deg F, it started to get soft. Since your patch wouldn't be under any pressure, the softening might not be an issue. The head at that position would be around that temperature, especially on a hot day and hard run. Oil is cooling it, and exhaust port is heating it. Interesting proposition.

[DiverRay]

On my first XS, with an oil temp gauge, it would rune about 300F, up to 330F oil temp. A cooler dropped it to 275F, but it never really went up above 290F. Look at some of the epoxy products, and I think you can find one that WILL work at 300+, and is oil resistant.