Freshly Rebuilt 350 piston abortion LEFT ME CONFUSED

[Dannz71]

had my 350 freshly rebuilt ,new pistons, rings etc the whole lot, new cam manifold carb, everything... all done at a engine building shop in town. with a pretty price tag too
now last week we dropped it in my hilux, fabbed up an exhaust and ran the cam in... all went well was starting sweet and and that, drove it round the yard a couple times, and it was stil starting and running perfectly, absolutely no issues, so on sunday evening I drove it home and as I was driving, it suddenly lost power, made a loud ticking noise and backfired and spluttered to a stop,

so today since I had the day off I pulled the plugs out and number 2 and 8 were all smashed up...
so off came the heads and I found 5 pistons were buggered, the top skirt was cracked on some and completely gone on others leaving the top ring loose too smash around the bore. now im wondering y it all happened at once and y it happened at all, was it faulty pistons, was it that the engine builder maybe didn't have the ring compressor tight enough when putting in the pistons? I don't know..

Has anyone ever seen this before??

And before I march into the engine builders all angry and accusingly demanding a new rebuild, could this possibly be my fault some how?

What can cause this?

Please help....



.

[rob-mu]

Not sure if I would have disassembled the motor before contacting the engine builders?

[Dannz71]

number 8 cyl

[Dannz71]

number 5

[Dannz71]

and a couple more

[DieselBoy]

Makes me wonder if its had a bit of a seize. Tight new engine and all.

Would definitly be one possible explanation for several pistons to be damaged at once.

[Dannz71]

yea didn't realy know the severity of it so I figured id pull the heads (bout a 30 min job on a chev), to check if there was damage before pulling the engine out and taking it all the way into town incase it was only minor.

[fullthrottle]

Gees mate, that is a rather major.
I'll throw some questions at you...

- In that first picture, is the top of the piston sitting higher than the top of the block?
- When you first ran it were you using some special running in oil?
- Can you turn the crank over by hand and see where those pistons rise to.
- Apart from the smashed spark plugs, what does the rest of the head look like (cylinder for cylinder)
- If you have a parts list, do you know what crank, cam was installed?
- Had the heads plained down or increased the performance with other rockers, cam etc?

[Dannz71]

Makes me wonder if its had a bit of a seize. Tight new engine and all.

Would definitly be one possible explanation for several pistons to be damaged at once.

yea you could be bang on right there, but wouldn't the engine stop when it got up to temp while running in the cam???

mind you that no.8 cyl looks like it started going before the others... would have expected tho that me or 1 of the 2 mechanics helping would have heard an audible knocking before the splutter, tick, tick, bang, stop

[prado_boon]

Take it back, reassemble the heads back on first.Happened to me once, was a nightmare, argued and argued but eventually got my money back.


They said I didn't run it in properly, but that was utter bullshit. Took it to a more experienced engine builder and he told me it was due to poor assembly!

[Dannz71]

Gees mate, that is a rather major.
I'll throw some questions at you...

- In that first picture, is the top of the piston sitting higher than the top of the block?
- When you first ran it were you using some special running in oil?
- Can you turn the crank over by hand and see where those pistons rise to.
- Apart from the smashed spark plugs, what does the rest of the head look like (cylinder for cylinder)
- If you have a parts list, do you know what crank, cam was installed?
- Had the heads plained down or increased the performance with other rockers, cam etc?

In that first picture, is the top of the piston sitting higher than the top of the block?
nope sits flush.

- When you first ran it were you using some special running in oil?
Yes was running lucas high zinc break in oil as recommened and a high zinc cam running in additive, both supplied from engine builder together.

- Can you turn the crank over by hand and see where those pistons rise to.
yeap they all sit flush/ come up to the same height.

- Apart from the smashed spark plugs, what does the rest of the head look like (cylinder for cylinder)
yea all the heads look fine minus a few very small dints where bits of piston and plug have been smashed against, on cyl 8. however there was bits of piston all through the ports ...

- If you have a parts list, do you know what crank, cam was installed?
don't have the parts list anymore as the missus put it thru the wash when I left it in my work pants.. but the crank is stock, and the cam is a 'comp cams' 4wd recommended down low torque cam.

- Had the heads plained down or increased the performance with other rockers, cam etc?
heads were plained a touch but deffintly nothing big, as i wanted to have the choice to run 91 octane, rockers and valve set all standard, they only had a grind or lap in the rebuild.


thanx for your input

[Crash bandicoot]

yeah including the wrong piston/ bore match the following could be possible too.

Detonation. that's what it reminds me of. to much timing/ not enough fuel heating the piston up . the thin area being above the rings on the edge. heats up breaks away

[fullthrottle]

- If you have a parts list, do you know what crank, cam was installed?
don't have the parts list anymore as the missus put it thru the wash when I left it in my work pants.. but the crank is stock, and the cam is a 'comp cams' 4wd recommended down low torque cam.

Oh that is a bugger.
So its either poor assembly, or could even be a wrong match of pistons/rings to bore size. Causing the piston to vibrate inside the bore.
Or even bad crank??

What would I do...
If they are a good company to deal with and you've had a good feeling about them throughout this whole process, then take it back and calmly ask them to help work out what went wrong.

Does the work carry a warranty?

Otherwise, get a recommendation from someone for a good recon shop and get a second opinion. Obtain some facts.

Where are you based??

[Crash bandicoot]

Your best bet is to follow the consumer garuntees act. if they will repair it(accept liability) you can trust them redoing it, take it to another rebuilder for inspection.

[Dannz71]

yea I checked all the timing and it seemed to be fueling ok and not detonating or pinging, havnt checked the cam timing but..

im from up northland ways but the engine shop is down on the northshore in Auckland, the bloke that runs the show is a pretty gud chap, the missus dad used ta race falcons with him and said hes been buildn top notch 8s for over 30 years,
think 1 of his employees mighta muffed it up tho...

[Dannz71]

yea I havnt asked about the warranty as I never imagined that this would happen, however its a pretty good shop so they should have some form of warranty, and im sure they'll have public liability insurance or something,
and theres always the consumer guarantee act and what not,
I just hope they don't try put it on me and not accept it,
no 1 ever really wants to take the blame huh..

[churchill]

The ring end gaps might not have been set correctly, when the engine heats up they might start to bind.

Hold onto all the broken bits as evidence, even the smallest ones.

Edit: Ignore my first comment, it looks more like detonation damage as someone mentioned earlier.

[SMOKEY]

As has been said here many times, don't go blaming/flaming businesses on here until they have had a chance to put things right. My first action would be to give the engine shop a call, explain what has happened, what you have done and found and ask what they want to do about it, could be a simple matter of dropping the lot back to them and having the lot repaired. You have to notify them first give them a chance to check their work and then work in with them to a satisfactory conclusion to all.

THOSE THAT HAVEN'T MADE MISTAKES HAVEN'T DONE ANYTHING,

FITZY.

[Crash bandicoot]

errr fitzy...."the rebuilder" said it was his fault for not running the engine in.... in other words been there done that got told "not our problem."

However they still do need to look at it and have the right to offer or refuse first repair under the consumers guarantee act.

[suzolla]

errr fitzy...."the rebuilder" said it was his fault for not running the engine in.... in other words been there done that got told "not our problem."

This was refering to a different engine by a different person.

Cheers
Tim

[yael]

yeah including the wrong piston/ bore match the following could be possible too.

Detonation. that's what it reminds me of. to much timing/ not enough fuel heating the piston up . the thin area being above the rings on the edge. heats up breaks away

Exactly what i was going to say.. Timing..
I have worked on a V6 chev that had ongoing issues like this from fresh rebuilds by a reputable engine reconditioned turned out that the ignition pack was faulty and causing the timing to go all up the duff... cost the company I was working for at the time & engine rebuilders alot of $$ and and time sorting the issue.

[Dannz71]

As has been said here many times, don't go blaming/flaming businesses on here until they have had a chance to put things right. My first action would be to give the engine shop a call, explain what has happened, what you have done and found and ask what they want to do about it, could be a simple matter of dropping the lot back to them and having the lot repaired. You have to notify them first give them a chance to check their work and then work in with them to a satisfactory conclusion to all.

THOSE THAT HAVEN'T MADE MISTAKES HAVEN'T DONE ANYTHING,

FITZY.

yea your right mate, however I havnt realy acused yet or blamed, rather
just wondering if it was possible that it was a fault at their end,
and actually they are very well known as a highly acclaimed engine building shop, and im not trying to muddy their name.
yea I went down there today and took the engine in and spoke to the bloke, he was very good about it, and said that all their work is warranteed and all that, he also said that it was maybe possible that the pistons were a faulty set however he thorght that it was unlikely that 5 out of 8 would be faultly and that it may well be one of the newer employees, or any number of other things that could come into play, so hes going to strip it all down and check it all out, and he also told me that I was welcome to a second opinion and all that so wel c how it goes, he also said he knows the mechanics I was working with so he knew it was all timed and runn in right, so yea wel c how it goes

[Dannz71]

The ring end gaps might not have been set correctly, when the engine heats up they might start to bind.

Hold onto all the broken bits as evidence, even the smallest ones.

Edit: Ignore my first comment, it looks more like detonation damage as someone mentioned earlier.

yea I was wondering the same thing too

[muddyhilux]

sorry to hear bout this mate but glad to hear things are moving forward and hope you get it sorted asap,glad to hear the bell housing worked out for you

[Dannz71]

yea cheers mate thanx for the help with that, much appreciated, and yea bitt guttered ae, but as with every problem ive encountered with this build it seems to be working itself out slowly.
just hope this is my last problem haha

[getsum]

i wouldnt of thought that it wouldv been from detonating unless it was under load, and you wouldnt go put a fresh engine under load untill it had been run in and a fresh oil change... usually atleast 1000kms from rebuild

thats how we do ours and have never had a problem.


i would also be thinking that something has let go or the clearances were not quite right somewhere...


atleast the guy is being all good about it.