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Discussion Starter #1
Hey guys looking for some advice on if i screwed up.
just got my head ported, polished,new guides, new valves, seals , shimless buckets, valve job etc. it’s a 1jz vvti with 272 cams

I was rushing, stupid me set crank at TDC and bolted cams down at the dot marks on the cam gears.

i bolted this down Friday and didn’t turn the engine at all.

i thought about it all weekend and I got in today and tried to see if i could move the crank with light force and i couldnt so i pulled off cams, property set timing. Set crank at 60 btdc and lined up camshafts with the dots. It rotated smooth everything lined up. Then i did a leak down test.
#6 was loud out the exhaust. (both cam lobes pointed up)
i checked valve lash and it was .001or a Very tight .002 bigger than what i measured before
So I pulled the head. I filled the exhaust ports with some gas to check for leaks and only #6 leaked. I could see a little gas leak from the 11th exhaust port only.

with the head off i put the cams in and rotated it a bit,pulled cams off and checked again.
This time #6 stayed bone dry 🙃 and #2&5 seemed to leak a little.

so i this point i was confused. If the valve is bent it should always leak right? #6 leaked then after i rotated it and pulled cams no leak.

Im trying to figure if it was a fluke. I checked and definitely at tdc piston 6 was all the way up, and at the dots on camshaft, the valves were down.

Maybe it was a speck of dirt? As the lash was only about .001 off?

any advice? should i let it run for a little?
I don’t know how i made this mistake, I’ve probably set timing 100 times already never an issue. Maybe just rushing.
 

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A bent valve would definitely not seat without leaking, regardless of cams in/cams out.

If you pull the cams and it seats, normally that means there's something wack about the bucket/shim/cam combo that was drastically tightening up the valve lash on that valve.
But you saying the lash was .001/.002 larger (which I took to mean wider e.g. more space between the shim and cam) is the total opposite of what I'd expect there.

I would double check your ports and combustion chambers for any loose carbon or other BS - I've seen carbon shaken off of piston tops end up pinning a valve open temporarily.

The valve reliefs are usually deep enough to accommodate the valves, but it depends on the amount of lift those particular cams have. Advertised duration is meaningless in determining whether or not the engine is now interference.

Best guess is that the valves stuck up enough to scrape a bit of carbon from the valve reliefs on the piston, and thereby got pinned open that time - but just barely missed the 'bend' threshold. At least, we'll hope so :)

Double check the piston surface on #6 and carefully reassemble, double check the leakdown once you get the engine timed.
 

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Discussion Starter #3
Thanks !!
i put it all back together and took it for a drive. Seems to run perfectly fine. Ill do compression test tomorrow before dyno session. I assume if bent it would of drove like trash or the bend would be audible
 

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If you had a bent exhaust valve it would idle like it was misfiring, and it'd be noticeably hesitant and down on power. So yes, I think you got lucky and this was just some random weird crap :)
 
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