GRRR! Busted piston, please help, pics attached

[FlaBoy]

Hey guys,

as you may recall im in the middle of what I hoped would be a relatively simple HG replacement. Well, when I popped the head off this weekend, turns out its worse than I thought. I posted a thread in the general tech section with all the details and pictures. Pleas read it and help me figure out how to get this car back on the road.

I really really appreciate all the help so far with this beast, and any more you could shed would be very welcome


Heres the link to the other thread
http://www.turbobuick.com/forums/ge...iston-easiest-best-way-fix-pics-attached.html

 

[Jerryl]

Man, that sucks!
Very typical signs of Detonation.
Looks very similar to my first “HG change”, only a LOT better! :tongue: LOL

Since this is a std. bore, if the cylinder is good, deglaze the cylinder, get a set of std. rings and install with another piston.
Of course, this avenue will now take you further down the road than “just a HG change” since you will need to drop the oil pan at a minimum ……..
In the end, you will learn more about the car though.
And you may as well change the beatings in the cylinder, if you pull it out.

I have a piston with rod you can have for free. :smile:
I am sure you can get one local as well, but PM me if interested.

 

[fyrlt67]

Looks just like mine when I bought the car!!! Wish I had a picture of because that is like 25% of mine, the whole edge was gone looked like some had taken an arch welder to it. Guess I shouldn't complain thats how I got a deal on mine, bad motor, great body/interior.

 

[FlaBoy]

I have a piston with rod you can have for free. :smile:
I am sure you can get one local as well, but PM me if interested.

Jerryl, I very much appreciate the offer, but I was concerned that the pistons currently in the engine may not be stock. If I have some aftermarket brand of piston in there, and put in a stocker in the bad one's place, wouldn't that mess with the balance job on the rotating assembly? Or are most aftermarket pistons close enough in weight that it wouldn't be an issue?

I guess my next step is to pull out the bad piston and get some pics of the whole thing up on here so that someone can confirm if its stock or aftermarket, and if so what kind.

Also, as far as honing the cylinder, I've seen two different types of hones, one with three long stones attached to a central shaft, and one with a bristle brush where the end of each bristle has a metal ball on it. I'm not familiar enough with hones to know which is better, if they are designed for different applications, etc. If anyone knows a little about hand honing, please fill me in.

Thanks again guys!

 

[Jerryl]

Jerryl, I very much appreciate the offer, but I was concerned that the pistons currently in the engine may not be stock. If I have some aftermarket brand of piston in there, and put in a stocker in the bad one's place, wouldn't that mess with the balance job on the rotating assembly? Or are most aftermarket pistons close enough in weight that it wouldn't be an issue?

I guess my next step is to pull out the bad piston and get some pics of the whole thing up on here so that someone can confirm if its stock or aftermarket, and if so what kind.

Also, as far as honing the cylinder, I've seen two different types of hones, one with three long stones attached to a central shaft, and one with a bristle brush where the end of each bristle has a metal ball on it. I'm not familiar enough with hones to know which is better, if they are designed for different applications, etc. If anyone knows a little about hand honing, please fill me in.

Thanks again guys!

Looks like a stock piston to me.
By the way ........ you can use a ball hone in the car, but ....... you get **** everywhere and if you do that, you will need to make DAMN SURE you get all the debri out.
Getting it clean is not a small task by any means.
Easier to pull the motor and hot tank it, but I know you do not have the eqipment to pull the motor.
So, you can deglaze it, but you are rolling the dice.

For the record;
The advice I gave earlier is a "cheap roll the dice fix".
To do it right, you need to pull the motor and go through it.
In the long run, that may be cheaper, depending on your goal(s).

The offer on the piston still stands.

 

[charlief1]

I agree with Jerry on this but if you get the engine out go forged for sure. More expensive but it does come with peace of mind after all. "Build it for the 11's and run it at 12's and it will live".

 

[Boostnitup]

I am betting...

that the cylinder took a beating too.

He will have to have that cylinder magnifluxed and checked out to see if there isn't a long crack down it. Visually it doesn't look good to me.

When pieces let go... they go somewhere! A cracked cylinder head too is a possibility.

 

[Jerryl]

I agree with Jerry on this but if you get the engine out go forged for sure. More expensive but it does come with peace of mind after all. "Build it for the 11's and run it at 12's and it will live".

Charlie,
If I recall correctly, the OP will be putting in a TA33.
He is not out to set any records, and the stock cast pistons have been in the 10's, and are some of the toughest pistons you can get your hands on.
BAsed on his goal, I do not see any need for forged.
Of course, if you have to bore, there is not much choice, but, I'd sleeve that cylinder before I bore all 6.

that the cylinder took a beating too.
He will have to have that cylinder magnifluxed and checked out to see if there isn't a long crack down it. Visually it doesn't look good to me.
When pieces let go... they go somewhere! A cracked cylinder head too is a possibility.

The piece that is missing if from an "erosion effect" as a result of detonation.
It did not break off, and "yes", the pieces went somewhere. But htese are small pieces, one exhaust stroke at a time.
While it is best to have the block checked out, and while it may not be flat, I bet it is not cracked. These are some tough little blocks.
Results and experiences may vary. :wink:

 

[dr_frankenstein]

I say swap it with another stocker and boost er up!

if its your daily driver get it going, save 500$ go and buy a ford tempo and then pull you GN engine and rebuild it later.

A.j.

 

[FlaBoy]

I say swap it with another stocker and boost er up!

if its your daily driver get it going, save 500$ go and buy a ford tempo and then pull you GN engine and rebuild it later.

A.j.

Thats kinda the plan (though I'd get an old beatup pickup before a friggin tempo anyday )

My main goal as of now is to get the car running as soon as possible and as cheaply (within reason) as possible. I can't afford the expense or time of pulling the whole motor, getting the block magnafluxed, and a professional rebuild (at least not at the moment). My plan is to get it running so I can get a another year or so out of it until I can afford to treat the motor right (nice rebuild with good new internals, and either alky, a TA33 or both, etc.).

The cylinder bore seems pretty clean... there are some visible scoremarks on the bore right where the major missing piece of the piston is, but I cant feel any of them with my fingertips, and I can't get anything (fingernail, etc) to catch on it. I even rubbed some old nylon stockings over it and it didn't catch, so I'm hoping a simple hone job will clean it up. Does anyone know the difference between the old-school hones with the 3 long stone shoes and the newer "Flex-Hone" style hones (bristle brish with abrasive balls on the end of each bristle)? I don't know enough to know which is best, etc.

As far as the cylinder head possibly being cracked, I've already budgeted to have my heads crack-checked and a simple valve and cleanup job done, so hopefully no bad news there. Visually, the head looks okay on the bad cylinder, though who knows what flaws the magnaflux will expose

Also, does anyone know if (assuming the rod journals on my crankshaft are okay and undamaged) its okay to put a new set of rod bearings on without resurfacing the crank? I wasn't sure if putting new bearings onto a crank rod journal that has already mated and broken in on the old bearings would cause any issues (not sure if this is clear enough, hopefully you understand what I'm asking )

 

[dr_frankenstein]

LOL, i hear ya on the tempo.... i had no idea why i choose that car.

As for the hones,

the old 3 stone will work but require that you pay more attention to the speed and up down movement. it is easy to learn but better if you have an experianced hand to guide you.

the bottle brush is reccomended for beginners hands down and will leave you a better finish with less hone time.

if you give the main the same look over as you did the bore, it should be OK. so look for grooves, burnt spots etc etc. Just check the back of the old shell to confirm rod size before ordering. then a few minutes to plastiguage and you should be good to go.

:biggrin: A.j.

 

[charlief1]

Charlie,
If I recall correctly, the OP will be putting in a TA33.
He is not out to set any records, and the stock cast pistons have been in the 10's, and are some of the toughest pistons you can get your hands on.
BAsed on his goal, I do not see any need for forged.
Of course, if you have to bore, there is not much choice, but, I'd sleeve that cylinder before I bore all 6.

Not arguing with you one bit Jerry. I was just saying the "if" he had to pull it and do a rebuild he would be better off in the long run, that's all.

LOL, i hear ya on the tempo.... i had no idea why i choose that car.

As for the hones,

the old 3 stone will work but require that you pay more attention to the speed and up down movement. it is easy to learn but better if you have an experianced hand to guide you.

the bottle brush is reccomended for beginners hands down and will leave you a better finish with less hone time.

if you give the main the same look over as you did the bore, it should be OK. so look for grooves, burnt spots etc etc. Just check the back of the old shell to confirm rod size before ordering. then a few minutes to plastiguage and you should be good to go.

:biggrin: A.j.

While you have the rod out check to see if the crank is egg shaped with a mic or calipers. It might save some time and it is good insurance to check.

 

[Jerryl]

Not arguing with you one bit Jerry. I was just saying the "if" he had to pull it and do a rebuild he would be better off in the long run, that's all.
.........
While you have the rod out check to see if the crank is egg shaped with a mic or calipers. It might save some time and it is good insurance to check.

Charlie,
Its all good man. We all have the same goal here; Try to get a HA brother back on the road.

And about the "egg shape" (I know you meant the "crank end of the rod" instead of "crank" ) ....... resizing is a good idea.
I have a piston with the rod, and it will be easy to do, if needed, which I doubt on the one I have.

 

[charlief1]

Well I figured that you wouldn't sell him junk so I really did mean the crank. If he detonated and the engine is a high mileage one it is possible to have it happen. Not likely but it's best to check the crank.

 

[Jerryl]

Well I figured that you wouldn't sell him junk so I really did mean the crank. If he detonated and the engine is a high mileage one it is possible to have it happen. Not likely but it's best to check the crank.

Actually, I am not selling him anything ....
At stock boost levels, even with the piston, I bet all is well with the crank and rod itself. But I agree; ALWAYS best to have it checked.
Matter of fact, always best to have the crank ground.
If it twisted or bend a bit, it will get the timing events back to specs.
From the sounds of it, it is not in the budget.

When I blew the first HG on my car, the piston was much worst!!!
I ended up using the crank with some light polishing .......... Machine shop said it was fine.

 

[boostmaster]

Busted Piston

FlaBoy, looks like you got yourself the common grenaded piston due to severe detenation. As far as the debris is concerned and damage to the cylinder walls there is probably little to none that a good honing won't clean up. Now back to the real issue, the reason you didn't find much in the cylinder is because most of it escaped out of the chamber via the exhaust valve but some never left. How is this you ask? Because the piston has been super heated to the point that it actually melted around the ring lands trying to escape around the gaps in the rings. Therefore some of the material is still there but sagging or dropped into the pan through gaps in the rings.

Now enlies two bigger problems. The first is you have a definate fueling issue. Or lack of fuel I should say. In order for the piston to get that hot where it superheats the piston can only come from one thing, lack of fuel. Think of a cutting torch when you add oxygen to it and watch it go from flaming red to blue and then its hot enough to cut. That's what happened to your piston and if you don't get the problem fixed whether it's a tuning issue on you part or a mechanical issue your bound to be repeating history or at the least buying a ton of head gaskets.

The second problem is a by product of all the little metal residue floating around in your oil stream while you where trying to figure out what the problem was. I tell you right now your bearings are more than likely toasted even if you don't hear anything. So if you don't have access to pull the engine and you still want to patch up the problem there is nothing wrong with that. I'm not saying it's perfect but it will work, I have done it before. But if you have the skill to do so I would at least put a set of bearings in the car and be done with it. Mains and rods, it can be done if you are skilled enough. But if you are unsure if you can handle such a project with the engine still in the car better to just replace all the rods be done with it and take your chances.

That's my 2 cents, Pete

 

[FlaBoy]

I have a feeling the cause of the detonation was due mainly to my lack of a functioning knock sensor (so no knock retard) and the car overheating a few times due to the coolant leak (which prompted the whole HG swap). Needless to say, I have a new knock sensor installed. If inadequate fuel was also an issue, it shouldn't be by the time i get it all back together. I already have a walbro 340 pump hotwired in, and while I have the top end apart I went ahead and ordered a new set of 42 pounders to replace my stock injectors (with a chip from TT) and also got a new injector wiring harness from caspers to replace the stock one that was looking a little more ragged than I was comfortable with. Oh, and when I did the pump a few years back I put in a nice adjustable fuel pressure regulator on the car as well, so my fuel delivery system should be in pretty good shape.

Like I said before, I know the best way to handle this would be to pull the motor and give it a nice rebuild. Unfortunately, I dont have the time or money for that right now. I figure I'll drop the oil pan, take a look at some of the bearings and go from there. If they seem okay, I'll hopefully put the new piston in and be done. If need be, I ill replace some of the other bearings if they look suspicious. I'm just hoping the bearings and crank journals aren't trashed, I really would like to avoid the hassle of rebuilding this thing from the bottom up.

 

[Jerryl]

Piston/rod assembly shipped today.
Should be a "drop-in deal".

 

[charlief1]

Go Jerry! (sound of crowd cheering in the back ground) LOL

 

[FlaBoy]

Got the piston over the weekend, thanks again SO much Jerryl!!

Now all i need to do is pick up some rings and bearings and drop the sucker in (after I do the hone job, of course).

Anyone have any recommendations on which rings to run?

I think I've settled on the fel-pro 1000 head gaskets, though if anyone has any of the stock shim gaskets laying around I'd be interested