Why Did My Engine Break...why?

[ahh 33 s2]

Its a good think that the bottom end turns freely.

Might just need new guides and inlet valves and you're off again

yeh i was just pondering that in the shower just now, almost cracked a smile,

a little of topic but how do u get ur head stud nuts and washers out of the head, just a magnet thingy mcbob.

and will i be right to pull the girdle and big end caps off just to look for damage and then put em back on with the same bearings if all is ok?

[zebra]

ye a magnet or a pair of long nose pliers.

and yeah can reuse bearings providing they are ok

[JonnoHR31]

did it make any bad noises when it died? if its mashed valves you would have heard it.

and assuming the bottom end was at tdc when you took the pic of the cam gear before removing anything theres no way its timing related. 4 degrees is nothing

[ahh 33 s2]

Yeh it made a screeching noise, at first I thought it was a wiring issue with the starter as it kinda sounded like when u turn the car on when it's already on, it didn't sound like what I would imagine it to sound like when shit hits each other,

The pic was not at tdc I just had the camera on an angle

[blue_vl_t]

Screech noise of the timing belt jumping teeth is my guess

[ahh 33 s2]

Certainly pointing to that at this stage, must have done well to do so coz it was dam tight when trying to take the thing off

[TiTAN]

if the belt is too tight for too long you can snap the tensioner/idler bearing studs and make a real mess, keep it to spec.

[Guilt-Toy]

any news?

[ahh 33 s2]

Wa time and am at work, will have head off this arvo and girdle off to inspect bearings, pics will be up later

[Gerg_R31]

Ferrea valves don't have any other collets that fit them, im thinking its dropped a few valves, the machine shop may have noticed it and ordered the right collets

[ahh 33 s2]

Interesting, so they wouldn't have been compatable with eithe the standard nissans or tomies, strange that only the inlet side seems to be affected then,

Didn't see anything like that on the invoice,

[mico]

sorry to hear mate, i feel for u. when i first put my motor back together, and after the first drive, the timing belt done itself up reeeeal fuggin tight. no idea how but when it was hot it was tight. your tensioner may have snapped because even if it comes loose it should not really skip teeth. its still pretty tight even with the bolt loose. im not sure about huge cams like yours, but mine which are stock can not come into contact with the piston if the cam gears come completely loose. really hope its nothin too big mate.

[Gerg_R31]

(i snapped a collet during assembling a rb head at work, we replaced it but at the time none were in stock and any aftermarket and genuine collets wouldn't match up)

But you are right how its odd it only affected the intake side,

You know how close the valves come during overlap? Exhaust valve may have held intake valve from closing

do a comp test

[ahh 33 s2]

(i snapped a collet during assembling a rb head at work, we replaced it but at the time none were in stock and any aftermarket and genuine collets wouldn't match up)

But you are right how its odd it only affected the intake side,

You know how close the valves come during overlap? Exhaust valve may have held intake valve from closing

do a comp test

Engine is out and wouldn't turn over by hand or starter motor, head will be off this arvo do pics will be up this evening

[ahh 33 s2]

ok so the head is off and dame they is heavy when u leave the intake on and trying to go up and over ARP studs,

and the news isnt good,

11 bent valves and 1 is now a limied edition 3 piece valve,

so clearly cam timing is to blame, its something i never considered, i now wish i could have checked cam timing before the belt came off, but i couldnt turn the engine over to get it all back to TDC any way,

it looks like all the intake valves have had a kiss with the piston and now are all sitting flat, and appear to be jammed against the head it self, hence why the lifters are sitting up againd the lobe, still able to rotate the exhaust cam and thats not fouling on the intake valves,

so hear are the pics,

number 1

number 2

number 3

number 4

number 6

and finally number 5

if there is any positives, the bottom end is not siezed, yay

so where to go from here, i had to sacrifice a lot to do this build as i mentioned in the first post not alot was not upgraded is some way, and cannot afford to wuickly get this fixed, as theres prolly not to much salvagable, so maybe try pick up a second hand RB26 and strap the 6boost and 35R on to it, its really the only way i can see myself staying in a skyline,

[zebra]

OUCH!

Bottom end would've been ok if #5 survived

[ahh 33 s2]

yeh would need new piston, if u can get a new piston, but with the CP locks, the dont look the easiest to get off, as the not actual circlips, so yeh dream over really

[PaulosECR33]

feel for you man

how is the bore of the cyl that dropped valve,i cant tell in pics that well is the R/H side of the bore scored of just lines from oil?

Edited October 26, 2011 by PaulosECR33

[75coupe]

I can imagine how you must be feeling...

really sucks, but surely after coming so far you can find a way to continue with it...

[zebra]

so maybe try pick up a second hand RB26 and strap the 6boost and 35R on to it, its really the only way i can see myself staying in a skyline,

Do this, peg power at ~300rwks and just enjoy the thing for a while