Can pistons be magnafluxed? Since they are alum?

If not, how can a piston be checked for damages and cracks?

 

Yes they can be checked, but for what it probably costs to have that done, you can buy stock cast replacements for slightly more money.

A lot of discount places online sell them with rings for $50-$60. Heck... www.enginekits.com has hypereutectics (without rings) for ~$60.

I don't have a clue what it would cost to have them checked since I've never been able to reuse them. The block (cylinder walls) was always worn enough to need an overbore which requires new pistons.

Plus the skirts have always been too worn to justify buying new ones.

The circled areas are where the skirt is worn.

BTW, the other side is WORSE!!! It's almost completely smooth.

 

no you can only use MT inspection on something feromagnetic,(steel or iron) it won't work on colbot or nickle even if they are magnetic. best bet would be PT (dye penetrant) inspection. very simple and cheap a nd something you can do at home. buy a test kit from a welding or industrial supply. RT (xray) would alos work but be sort of over kill and expensive.

 

X-Ray? I s'pose you could also go all the way and ultrasonically test each one as well, but AJ is right. You can UV-dye test them as Ed suggests, or just get a new set of pin-fitted, cast hypereutectic alloys for under $200. The UV dyes are cheap, but the blacklight can be expensive unless you can borrow one.

 

Thanks for the help. This isn't for me. A friend of mine just bought a 3.8 TTA engine, and when we pulled the pistons out, two had broken ringlands. Now he's trying to get around not having to buy 6 new ones, but instead 2.

He's cheap.

Since they car was running 24lbs of boost, we're going to avoid cast/hyper pistons.

 

you don't replace pistons seperatly, only in sets

 

The other 4 have been subjected to the same abuse as the 2 that broke, whatever that was; they might just finish breaking the next time the motor cranks up.

Broken ring lands = detonation. That motor has been abused. I would not re-use the pistons. That's just asking for a very short-lived rebuild... one of those 1/8 mile wonders (halfway through its very first pass on a 1/4 mile track, don't know what happened, I'm going to sue the builder)

He'll save money by doing it right and buying all 6.

If he doesn't, I'm going to pray that next time I race, he's in the other lane.

 

I couldn't agree more, but it's very hard to talk cheap people into doing the right thing.

And yea, that engine has been put through some problems.

Cracked head, broken ring lands, bearings were trashed, wiped lope on the cam....

And the engine was sold as good running condition.

Suck to lose $2700 that way.

 

ede, I agree, but I was told that if you replaced only the broken ones, and then had them balanced, that you could use the old ones.

While I agree, I wouldn't do it. The person buying is somewhat cheap. With people telling him this (and he doesn't know much about the engine he's working with) he looks as that as an easy way out.

I think I've got him convinced anyways.

 

BTW...

The politically correct term for someone that cheap is "unrealistically optimistic". They're hoping for a free lunch when the sign clearly says - Pay now or Pay more Later

Tell him to shop around. From what he spends for just two individual ones (which last I checked is nearly impossible), he could buy a whole set.

Kind of like you can't buy just one piston ring that you broke when you were test fitting them, because you thought since they were moly rings, they were stronger and you didn't have to be as careful with them, and now I'm stuck buying a whole new set

AJ's List of Things to do:
1. Beat self on head
2. Continue until beating hurts
3. Once beating hurts, switch to kicking self in *** until foot gets stuck

 

He checked the price of them seperate. 48.99 a piece, or a full set for around 320.00 I believe.

It's not so much that he's cheap I guess, it's the fact that he bought a blown up TTA engine for 2700, and now he bascially had to buy everything over again, because someone lied to him. I think it's just hitting him all at once, buy the new cam, getting everything checked out, new pistons, and so fourth, when he originally thought he had a good engine.

I agree with the pay now or pay more later saying.

 

id personally find that guy who sold that to your buddy and rock his jaw...i bet the assualt ticket wont be 2,700

thats ****ed man..theres gotta be a law againts that...

 

I agree. But when he bought the engine he knew very very little about the engine. In fact, that's why he bought one used and "In good running condition" so he wouldn't have to build one.

I agree, it sucks for him, but there is very little he can do. Not to mention the guy lives in New Jersey while we live in Georgia.

 

Whatever you do,when he puts this thing back together make sure he gets new head bolts because they are torque to yield which once they have been torqued once they SHOULD NOT be used again unless he likes replaceing head gaskets.

 

I think he may have ARP headbolts, which we were told you can reuse?

But no positive, I believe he had planned to buy new head bolts.