I took my cylinder to the shop to get honed, and they said that this piece "might" be cracked, they had no way to tell for sure he offered to hone the cylinder anyways and see if it goes away or possibly bore it if needed to get rid of it if it was a deep groove. IDK what to do I'm at a stand still idk how to definitively tell if its cracked or not, I will post pix on here and give me your best opinion. if there is another way to tell please let me know, i dont want to buy a new cylinder if its not needed or pay bor boring if it may ruin the cylinder. So please any help I would appreciate.
Crack in cylinder or not?
- Thread starter jasindude1
- Start date
Pictures dont work, but there are a few members on here with extra cylinders, maybe donate and make a wanted ad if you do need one.
Looks like a crack.
It depends if it is also gone into the Alum wether it is serviceable or not.
There is nothing down there that can snag if you choose to run it as the rings do not get that far down.
If the crack does not go into the Alum I would be tempted to run it. OOOOOOh on looking at the other pix maybe not there is a chunk missing.
That chunk is possibly what ended up in the top end.
It depends if it is also gone into the Alum wether it is serviceable or not.
There is nothing down there that can snag if you choose to run it as the rings do not get that far down.
If the crack does not go into the Alum I would be tempted to run it. OOOOOOh on looking at the other pix maybe not there is a chunk missing.
That chunk is possibly what ended up in the top end.
you know, I was thinking just to chance it and run it while I look for a new cylinder. I knw there is really no way to for sure tell tho... oh and BTW i guess i dont have enough of a rep to post a wanted ad on here yet, thanx for the advise tho i might try craigslist
would you recommend if i did run it to modify my mix ratio to increase oil or decrease oil to help cool it more to keep the crack from growing? or to allow more lubrication? the bore guy said he would do it and see if it will go away, something i should chance?
If I was considering running it I would be easing the crack open, like chamfering a port to stop the piston touching it.
Do not change any ratios, extra oil is not going to do anything.
Keeping it cool is not a good idea either as if it is going to grow it is going to grow more when cool.
Has the machine shop not got a crack tester.
Wrap 30 or 40 turns of insulated wire around the cylinder, sprinkle some iron filings on the crack and briefly connect the wire across a 12 volt battery, the movement of the filings will detect a crack.
Beware the wire gets very hot to the touch.
If I was considering running it I would be easing the crack open, like chamfering a port to stop the piston touching it.
Do not change any ratios, extra oil is not going to do anything.
Keeping it cool is not a good idea either as if it is going to grow it is going to grow more when cool.
Has the machine shop not got a crack tester.
Wrap 30 or 40 turns of insulated wire around the cylinder, sprinkle some iron filings on the crack and briefly connect the wire across a 12 volt battery, the movement of the filings will detect a crack.
Beware the wire gets very hot to the touch.
Home brew magnaflux.
it wasnt a full machine shop, it was a guy that does boring and honing out if his home, i will call around and see if anyone can detect a crack, i will buy some wire this weekend and try that trick, what do you mean by chamfering a port? is thats something i can do on my own or will a shop need to do it, Im gonna post an ad on CL to see if i can find another jug in the mean time. worst case what could i be looking at if i rebuild it as is?
chamfering MUST be done if its bored. It's putting an angle on all the ports that the piston rings pass so the rings don't catch on the edge of the port. If not done, the rings will catch on the edges and be pulled out of the grooves in the piston. Make sure that the guy doing the bore work understands that this needs to be done and done correctly. When calling around to see who can check for a crack, tell them that you need it Magnafluxed. Here's a vid that will give you an idea of what Magnafluxing is.
How to Magnaflux a cast Iron cylinder head or block - YouTube
How to Magnaflux a cast Iron cylinder head or block - YouTube
is bored to .04o over. its a 67mm. Here is my dilemma, Its between either buying a new jug, or just running it as is. Ebay has jugs for $60-$120 so, idk if i should invest the $$$ on getting it checked and inspected just to find out i need one anyways then I'm out that money either way
Cracks can be detected with Dye penetrant, legit shops should know this. Dye penetrant inspection - Wikipedia, the free encyclopedia
I use it at work to detect cracks,fractures,welding flaws ect.
Simple easy and effective take a look
I use it at work to detect cracks,fractures,welding flaws ect.
Simple easy and effective take a look
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Sure does look like a crack to me.As said magnaflux it and you will know for sure. But as you said sometimes it is easier to just get another cylinder and be done with it. I have a few cylinders on 66.50 bore that I would sell. pm if interested.
To quote an old saying "when in doubt, chuck it out"
If it was a $1,000 head it would pay to have it checked, but for a $50 jug, hardly worth the expense.
Take DUALSTROKE up on his offer.
If it was a $1,000 head it would pay to have it checked, but for a $50 jug, hardly worth the expense.
Take DUALSTROKE up on his offer.
Well honestly worst case with a crack like that what could I be looking at? Loss in performance? Another seized motor? What are the kind of problems that would come with running it as is?
Worst case scenario is that a crack may appear at the other end of the bridge and drop the bridge section into the crankcase wrecking the whole motor.
The chances of it failing, who knows, how long is a piece of string?
Loss of performance none, but always that niggling feeling in your mind that it will fail miles from home where there is no Taxi service.
I have always been lucky with my choices over 60 years in running a suspect component.
I understand what stresses components experience and treat them accordingly.
If it were mine and it was to be used as a daily putter around, I would run it.
If I was expecting to thrash is as I used to when riding MX I would choose not too.
What caused it to crack in the first place, who knows, but I would guess lack of warm up or piston slap.
With a new piston and running in the hands of a caring operator the jug could last for many hours of pleasurable riding, but in the hands of a Drongo fail on the first ride.
It is now up to you.
Your choice!
The chances of it failing, who knows, how long is a piece of string?
Loss of performance none, but always that niggling feeling in your mind that it will fail miles from home where there is no Taxi service.
I have always been lucky with my choices over 60 years in running a suspect component.
I understand what stresses components experience and treat them accordingly.
If it were mine and it was to be used as a daily putter around, I would run it.
If I was expecting to thrash is as I used to when riding MX I would choose not too.
What caused it to crack in the first place, who knows, but I would guess lack of warm up or piston slap.
With a new piston and running in the hands of a caring operator the jug could last for many hours of pleasurable riding, but in the hands of a Drongo fail on the first ride.
It is now up to you.
Your choice!
