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Joytona
ETA: The initial piston problems have been solved and this is now a project log for the car. Things have come a long way since Joy bought the car a couple years ago.
The Joytona had very low compression in #4 after returning home from SDAC. I pulled it today and confirmed that it is indeed a cracked piston. It is a lightweight rod motor so I'm not thrilled about putting much time or money into its repair. Any ideas on the cause of failure? What would you guys do if you were in my situation. Joy will mainly drive it to a few car shows a year including SDAC. Pics to come.
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Re: Cracked Piston What Would You Do?
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Re: Cracked Piston What Would You Do?
How are the cylinder walls? If they are good enough that you could get away without haveong to bore the block, put in a set of used TII Pistons and rods. I have a set if you need them.
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Re: Cracked Piston What Would You Do?
Stick a used piston in it?
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Re: Cracked Piston What Would You Do?
rings to tight..
new old piston.. looser ring gap
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Re: Cracked Piston What Would You Do?
Quote:
Originally Posted by
ajakeski
How are the cylinder walls? If they are good enough that you could get away without haveong to bore the block, put in a set of used TII Pistons and rods. I have a set if you need them.
They're quite good. I was surprised. I can't hang a nail on them at all.
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Re: Cracked Piston What Would You Do?
Put a used piston in it and open up ALL the ring gaps (except oil rings :p). And then figure out why it broke before you push it too hard.
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Re: Cracked Piston What Would You Do?
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Re: Cracked Piston What Would You Do?
Quote:
Originally Posted by
Vigo
Put a used piston in it and open up ALL the ring gaps (except oil rings :p). And then figure out why it broke before you push it too hard.
I'm concerned that #3 and #4 look so lean. I wonder if it's a bad/failing injector driver caused it to lean out and get hot?
Quote:
Originally Posted by
tryingbe
Part it out.
Joy won't let me.
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Re: Cracked Piston What Would You Do?
That's a bad failure though. Were the broken pieces still "in place" when you pull the piston? What was she doing when it failed? Driving it hard or just driving around?
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Re: Cracked Piston What Would You Do?
It was one piece. It was in place and one probably wouldn't have noticed unless they were looking for it. She just drove the car normally. It has always been a bit of a dog IMO, but it got really bad on the way home and started burning a ton of oil.
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Re: Cracked Piston What Would You Do?
I'd say swap it out. It's possible it has been that way for a while, who knows when it actually happened or if it wasn't a small crack that just got bigger.
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Re: Cracked Piston What Would You Do?
man you guys like to hate on the lw rod motors but compared to the 6 rebuilt 85 motors I had .. that all spun the rod bearings in less than 6 months .. my 3 lw rod 86 motors were my best ones .. next to my new crate 93 2.5T motor
hell I hadda drive one of the 86's for 3 weeks with a stuck wastegate before I could kill it.. and with a TII top end on it it was quicker than a new in the day 98 vette - while bouncing off over boost shut down
in the day I had a garage full of disposable motors
I would really just stuff another lw rod and piston in and play on .. hell it probably dosen't owe you anything
and if you can score a piston still pressed onto the rod it saves a trip to have it assembeled
I'll add my reason for buying a set of BC rods was weight .. or lack of
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Re: Cracked Piston What Would You Do?
If Joy really likes the car, I would do a rebuild on the short block. Hopefully the bores are good and you don't need an overbore. Find a set of good TII/TIII rods, have a machine shop clean up/check the block and give it a hone and reassemble with another identical piston and new rings and bearings. I would go with the FSM ring gaps if you use stock(ish) cast pistons.
If you do end up buying all new pistons, have it overbored.
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Re: Cracked Piston What Would You Do?
OK, I found some pistons and rods in the basement tonight, so I think I'll go that route. What do you guys recommend for rings?
As mentioned, the engine doesn't owe me anything so I'll attempt this. If it doesn't pan out, I'll have a machine shop go through a common block TII engine that I picked up this last fall.
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Re: Cracked Piston What Would You Do?
I like the Sealed Power rings. Never had a problem with those. For the most part, they've checked out gap-wise right out of the box.
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Re: Cracked Piston What Would You Do?
if for some reason you need to bore it out I can help you keep things on the cheep side
I happen to have a set of .75mm os 86 style speed pro or sterling pistions I don't need
they're old enough to be pre hyper puke , cast
came outta one of those 85 motors I had
been sitting here with no reason for use for 27 years .. really low mileage , driven hard but little wear
if you need em holler .. you'll like the price ...
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Re: Cracked Piston What Would You Do?
Thanks for the offer. I love this site and the Shelby Dodge Automobile Club. Guys are always willing to lend a hand and help out with parts etc.
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Re: Cracked Piston What Would You Do?
no prob & yeah I know exactly what you mean
one reason I love the hobby too
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Re: Cracked Piston What Would You Do?
pop a used piston in it. and get back to driving it. I would pull the injectors and have a local shop clean and check them for you.
might look a bit lean over there.
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Re: Cracked Piston What Would You Do?
Quote:
Originally Posted by
masterjr33
pop a used piston in it. and get back to driving it. I would pull the injectors and have a local shop clean and check them for you.
might look a bit lean over there.
This, plus I'd throw rod bearing at it as well. Too cheap and easy not to tighten up the bottom end just a wee bit.
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Re: Cracked Piston What Would You Do?
yes that is a great idea too. might even wanna slap all new mains and rods while it is apart. or at least look at the mains. and rods to decide if you want to do the rest.
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Re: Cracked Piston What Would You Do?
Correct: Sealed Power E453K
Thanks
Randy
Quote:
Originally Posted by
iTurbo
I like the Sealed Power rings. Never had a problem with those. For the most part, they've checked out gap-wise right out of the box.
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Re: Cracked Piston What Would You Do?
Thanks for the part number. Amazon had a seller which was way cheaper than any alternative.
What do you guys do for a hone? I've done the three stone type hone in the past, and still have it. I've heard that a ball hone is a much better way to go though. Would that be a way to go here? I'm trying to get all my ducks in a row. I would like to have this project finished up before August, but a lot of the little things I always like to do will be piling up on this car as it is.
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Re: Cracked Piston What Would You Do?
if the cylinder might be tapered and have some ring ridge I might go with the ball hone over the three stone one as the ball should give a more consistant cut where as the stones might bridge any gaps and not cut some areas the same as others
for giggles I'll add you would be shocked at how I deal with a stored motor that has a little rust in the cylinders
I put it on an engine stand , turn it upside down and "hone" it by hand with some wet n dry sand paper and a squirt bottle full of varsol
yep , that's with the crank rods and pistons still in it
I wash it out from below then again from the skirts of the pistons towards the tops , with it still upside down
never had any issues doing this and the last motor I did it to was the engine in the blue 86 that used to be pictured in all my posts on td - I drove that for three years
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Re: Cracked Piston What Would You Do?
Thanks for that info. I'm feeling a lot better about this now. I just don't want to put the time and money into it only to have things go awry. I've done it before with total success, so I guess I should stop being a baby about it.
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Re: Cracked Piston What Would You Do?
oh it's ok to feel ya have to say waaaaaa once in a while
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Re: Cracked Piston What Would You Do?
OK, hopefully last question for a while. Where do I get some replacement locks for the wrist pins?
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Re: Cracked Piston What Would You Do?
if it was a 2.5 mahle i would just mail you one of mine.
someone has a spare. or just re use yours
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Re: Cracked Piston What Would You Do?
Quote:
Originally Posted by
cordes
OK, hopefully last question for a while. Where do I get some replacement locks for the wrist pins?
I might be missing something but aren't the lightweight rod engines press fit?
Not sure about the lock, they typically come with pistons, I'd reuse, just make sure it goes in snug.
Oh and I broke many pistons like that back when, typically from detonation or too much cylinder pressure. In my case too much boost and throwing nitrous at it.
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Re: Cracked Piston What Would You Do?
Yes, the LW rod pistons are a press pin. I'm swapping to TII rods and pistons which I have had in my basement though. I'm not sure I have all the retainers. That's not good I guess.
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Re: Cracked Piston What Would You Do?
You should be able to get circlips for the TII pistons. They are more secure than the snap rings.
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Re: Cracked Piston What Would You Do?
Let us know how it goes. The last set of e453 rings I purchased had a different style oil expander and it was very tight in the bore. I ended up using the expander rings out of a set of na rings.
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Re: Cracked Piston What Would You Do?
Gaboon is right, that's detonation. Seen it many time before. Recheck base timing, maybe back it off a touch, maybe time for install a wideband to keep an eye on a/f ratios.
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Re: Cracked Piston What Would You Do?
I really wise everyone would look at the cylinder heads and not the piston. its lean as hell on two cylinders..
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Re: Cracked Piston What Would You Do?
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Originally Posted by
masterjr33
I really wise everyone would look at the cylinder heads and not the piston. its lean as hell on two cylinders..
That's my thought. It has been a while since I've read up on the batch fire ECUs, but it does fire 1&2, and then 3&4 right? Both Cylinders being that lean make me think that there must be a problem with either the ground/12v for those two injectors, or the power module itself?
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Re: Cracked Piston What Would You Do?
Do you have a code 26? Yes 1-2 are paired, as are 3-4 injector drivers.
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Re: Cracked Piston What Would You Do?
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Originally Posted by
shadow88
Do you have a code 26? Yes 1-2 are paired, as are 3-4 injector drivers.
I didn't pull the codes, but I will when I get everything back together.
The CEL wasn't on to my knowledge.
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Re: Cracked Piston What Would You Do?
it looks like those two cylinders are crazy lean.
wouldnt want you to bolt it back together just to have the same problem.
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Re: Cracked Piston What Would You Do?
Quote:
Originally Posted by
masterjr33
it looks like those two cylinders are crazy lean.
wouldnt want you to bolt it back together just to have the same problem.
I will be watching it closely. I think I'll attempt to flow test the injectors and I may redo that section of the harness.