Jump to content
SAU Community

Put Engine Out Of Time? Have I Bent A Valve?

Noco92

By Noco92,
in General Maintenance

 Share

Recommended Posts

Noco92 Newbie

Noco92

Posted
Posted

I have began to remove my camshafts without first putting the engine to no.1 tdc . I removed the timing belt and when removing the vct gear the camshaft turned a small amount.

What is the possibility I have pushed a valve into a piston and damaged it?

I felt resistance that I am assuming is just compression but want to be certain I haven't damaged a valve..

Also now that the engine is out of time how am I to get it to no1 tdc without and valve/piston interference

Duncan Grand Master

Duncan

Posted
Posted

You almost certainly haven't hurt it already if you were just turning it by hand, valves are pretty tough.

To put it back you just need to time it like always.....have the balancer and both cams on the 0 degree markings. If it was nowhere near the 0 marks when you took the belt off you made it hard for yourself, so turn both cams and the crank evenly and in small increments until you get to 0.

jiffo Mentor

jiffo

Posted
Posted

You don't want your cams on their timing marks/engine at TDC when removing or installing cams.

You should deliberately take the crank slightly passed TDC so all pistons are down the bores, check with a screw driver down the plug holes.

Then there's no chance of interference as cams do like to find their happy spot, and it's not exactly where their timing marks are.

(No 1 firing at TDC has No 6 changing over inlet/exhaust. If you're winding down cam caps and things move a touch, you can push those valves into the piston)

As Duncan posted, it's just a matter of turn and check to get things aligned again when fitting the belt.

Duncan Grand Master

Duncan

Posted
Posted

Sorry I didn't pay enough attention to your first sentence :) If the cams are out you are fine.....just turn the crank to where you want it (on the timing marks, or as jiffo said just past if you want a margin of safety) the put the cams in and turn them to the same place. You wont have valves touch pistons until the cam caps are tightened down, until then the valve springs will hold every valve closed (up)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Wazmond
      Stock rb25det neo questions

      By Wazmond · Posted

      Hows your intake piping? Are you still running stock? Having in the stock AFM position would mean, if the BOV was shut/venting out, it'd create the almost stalling kind of effect right // "the rich pulse behaviour" due to MAF thinking air is flowing ? But this would be better than having the bov in the stock position + MAF on/just before cross over piping right?
    • GTSBoy
      Stock rb25det neo questions

      By GTSBoy · Posted

      Essentially, yes. Although I wouldn't put the AFM on the crossover pipe. I'd want to put it into what amounts to the correct size tube, which is more easily done in the intercooler pipework. I bought a mount tube for card stile AFM that replaces the stock AFM - although being a cheap AliExpress knockoff, it had not flange and I had to make and weld my own. But it is the same length and diameter as the stock RB AFM, goes on my airbox, etc etc. I don't have a sick enough rig to warrant anything different, and the swap will take 5 minutes (when I finally get around to it and the injectors & the dyno tune).
    • Wazmond
      Stock rb25det neo questions

      By Wazmond · Posted

      So to summarise, the best thing to do is to move recirc to between turbo and IC, and maf on the crossover pipe. Meaning I'd need a recirc flange, drill a hole in the piping on turbo outlet area. And drill hole on crossover to fit/weld maf sensor? Either that or put the MAF on the turbo inlet right?  Is an aftermarket recirc/blowoff valve recommended? Do currently have family in Japan so could probably bring something back with maybe a cheeky lil SuperAutobacs run?
    • tsuokun
      Lets play a game - What is causing my oil consumption?

      By tsuokun · Posted

      Yep, so far most have said that it looks like corrosion on the wall from piston not moving. Which then has probably damaged the oil rings and caused those vertical marks. The longest the engine was still after the rebuild, was the winter of 2018 - 2019, plus the boat trip to Japan. When I shipped the car, it had normal gas in the tank but before that winter pause, it had E85 in tank.  In any case, even if either one of those was the cause, it happened close to 6 years ago and the car has been driven something like 30 000kms after the fact. Again, apart from the plugs and the dip stick, there is nothing in the way the car runs that would indicate what has been going on in the engine. I am going to consult a shop and ask their opinion, what would be the best approach. I do have some access to a garage I could use to diagnose further myself, but time is very restrictive. Might end up buying another engine that could be used while this one is being remedied. Without pulling the head, it will be impossible to find out if it needs another bore, but here's to hoping a hone would suffice.  Goddamnit, I would really have preferred this not happening.  
    • 25RBGT
      Got this r31 silhouette flood car to rebuild.

      By 25RBGT · Posted

      Boot is going to be replaced eventually. I just wire brushed what I could and rust converted. Then painted in rust kill primer. the spoiler also got repainted and plugs replaced on the ends. The under side of the bonnet is going to be black also, currently white. But red on the top side, same colour code as the silo to begin.
×
×
  • Create New...