ABA pistons damage, is this bottom end usable?

[carpathianwolf]

Info:
Received a free ABA motor and was told it had valve damage. He told me that the crank bolt snapped, he cranked the motor couple times and nothing. I guess the 4 bend valves happened since he had a 262 cam. So I pulled the Cyl. Head to see the damage.
4 Valves will need to be replaced but I also noticed indentations on the pistons.
Pics show damage on all cyl.






I turned the bottom by hand and it seems that is turning ok, no problem.
My question is, is this bottom end usable? Meaning, if I just replace the valve and put it all together, will it run just fine despite the nicks in the pistons?

Thanks for the help

[tauntedmonster]

I've heard stories of pistons cracking and **** stemming from small dings like this before. I guess I can't tell how deep the marks are, but what does an ABA bottom end cost, $50? Better safe then sorry imo

[Glegor]

i would measure piston protrusion, and then run it if everything checks out. as long as the pistons are all the same height.

those marks look like the valves didnt even contact the pistons hard.. file down any sharp edges, and run it i say..

ive seen diesels munch valves and pre-chambers, and they had pistons much worse looking than those, and still ran fine..

what do you think they do at the auto shop when you bring in a jetta with a snapped t-belt? throw new pistons in there cause one COULD be cracked? dont think so..

there gonna file down the marks, so theres no hot spots while running, throw a new head, and head gasket in, and fire it back up and tell you its fixed..

[Anony00GT]

I'll second what Glegor said. I've never changed pistons on an engine that bent valves due to a broken timing belt. Fix the head and install it, you'll be fine.

[greyhare]

i would measure piston protrusion, and then run it if everything checks out. as long as the pistons are all the same height.

those marks look like the valves didnt even contact the pistons hard.. file down any sharp edges, and run it i say..

ive seen diesels munch valves and pre-chambers, and they had pistons much worse looking than those, and still ran fine..

what do you think they do at the auto shop when you bring in a jetta with a snapped t-belt? throw new pistons in there cause one COULD be cracked? dont think so..

there gonna file down the marks, so theres no hot spots while running, throw a new head, and head gasket in, and fire it back up and tell you its fixed..

Agreed. Check the keyway on the crank for damage. The crank bolt broke? Someone reused it.

[carpathianwolf]

I'll check everything out, file down the sharp edges and give her a try. I guess only one way to find out. Thanks for input guys.

[Two . Slow]

ive seen worse and they work fine...now if you had a valve head say stuck in the top of the piston then youd have a problem haha and 2.0s are pretty bullet prof so i cant imagine youll have any issues

[yorgerg]

i would measure piston protrusion, and then run it if everything checks out. as long as the pistons are all the same height.

those marks look like the valves didnt even contact the pistons hard.. file down any sharp edges, and run it i say..

ive seen diesels munch valves and pre-chambers, and they had pistons much worse looking than those, and still ran fine..

what do you think they do at the auto shop when you bring in a jetta with a snapped t-belt? throw new pistons in there cause one COULD be cracked? dont think so..

there gonna file down the marks, so theres no hot spots while running, throw a new head, and head gasket in, and fire it back up and tell you its fixed..

glegor's right! especially on an aba, seeing as how its a noninterference motor. i have only seen one aba bent a valve with a broken timing belt, and that was because they were slowing down from highway speeds. we removed the head and found a slightly bent intake valve. replaced valve, zippwheeled the indent in the piston, reinstalled head with new head gasket, flanges, valve cover gasket. havent seen that customer back here for anything other than an oil change, and blown light bulbs...

[1997SLOW]

if its non interferance then why did the vaves hit the pistons

[t.moe]

Cuz it was cammed?

[1997SLOW]

thats my point i was being sarcastic 2.0 aba are interference engines i can send you picture of 3 heads and three blocks with valve damage and piston damage i had my last one crack the piston im getting it polished as a momento

[t.moe]

thats my point i was being sarcastic 2.0 aba are interference engines i can send you picture of 3 heads and three blocks with valve damage and piston damage i had my last one crack the piston im getting it polished as a momento

When I did the t belt on mine I had the timing COMPLETELY out. No bent valves, no troubles, purred like a kitten. Til the intermediate sprocket bolt backed out and had to do another t belt. Started right up. And that happened during a very spirited drive

[1997SLOW]

YOU GOT LUCKY ASK NY OF THE GURUS ON HERE THEY WILL SAY ITS INTERFERENCE oops caps in order for it to not be inteferance at top dead center with the valves in the fully open position they cannot touch and i know for a FACT it will touch

[EuroFreek_AZ]

yes they are interference engines. had a lower sprocket key shear at idle (long story) and i herd the valves hit the pistons before it died. however it didn't bent any valves at least not that bad cause it runs good haha.

[1997SLOW]

yea if they hit lightly it my not be enough to bend valves but if under high rpm the centrifical force of the motor say at 6grand then i woud assume the belt breaks for whatever reason the cam shaft woud slow to a stop alot quicker then the bottom end which is balance and designed to spin the weight would keep it spinning faster and if the valaves are in the open stage it will smash those bitches up pretty good

[t.moe]

I'm gonna go ahead and say that I'm one lucky bastard then. Cuz the belt snapped the first time around. And second time around I was beating the poss out of it when the sprocket came off.

[AnthonyLawson]

Just confirming, it is an interference engine...currently getting a big valve upgrade kit done on my head. Ordered it, adjusted timing gear back to -10 drove fine for a day... went to leave a stop light, car just powered down. No fire, no bang, no clank clank clank.... bent three valves. Two days later the big valve upgrade kit comes in the mail. Timing?!?....pun intended