Rb30Dett Help

[pintaline]

I'm building a 30DETT, was up to fitting the timing belt and had just removed the harmonic balancer to put the belt on to find that the keys were not in the crank and the balancer wasn't lined up correctly. Turns out its 180 degrees out so when I bolted the head down, crank was out by 180. (and still is)

I'm just assuming its done some sort of damage.... how bad is it likely to be? or is there a slight chance nothing bad has happened? really hoping nothing has happened....

[Duncan]

How odd.....seems like it would be harder to do that wrong that it would be to do it right.

I'm no engine expert (I only bolt them together), but I suspect 180 degrees out will be no issue in terms of damage. Each piston will just be on the opposite stroke to what the ECU/Cam expect.

[pintaline]

Yeah I know.... But silly me just assumed the balancer was keyed in properly so in the correct position.

[Shoota_77]

It is possible you did damage. IF the piston is at the top when it should be at the bottom then the valves will be pretty much fully open. Did you turn it over before you realised it was out? If not that would reduce the likelihood of damage.

Hopefully your valve lift is not extreme enough for the valves and pistons to make contact.

If you're using an MLS head gasket then rip the head off and have a look. You can reuse the headgasket no dramas.

Might save you pooping yourself before you hit the key for the first time!

[pintaline]

I haven't rotated it at all, just pulled the balancer to put the belt on and realized how it was. Head gasket is a stocky. I'm trying to remember if the valves interfered when I was dummy fitting........ If not, just lift cams, rotate crank and all sweet hopefully.

[Shoota_77]

While you're at it, remove the cams completely then you'll be able to see if any valves are stuck down (they often stick when bent).

Another test is removing the buckets and giving the tip of the valve a light hit with a hammer (and punch to contact just the valve tip) You can tell the difference with a bent valve as they don't snap shut as nicely as a good one.

Other than that, hope for the best!

[pintaline]

Awesome, that's the sort of answer I was hoping for. I'll have a crack at that and see how she goes.

Thanks mate!

[GTRNUR]

At BDC 1 and 6, cylinder 2,5 and 3 and 3 are at least 1/3 of the way down the bore. Chances of valve damage are not likely unless you rotated the engine.

  On 17/08/2013 at 2:33 AM, Shoota_77 said:

While you're at it, remove the cams completely then you'll be able to see if any valves are stuck down (they often stick when bent).

Another test is removing the buckets and giving the tip of the valve a light hit with a hammer (and punch to contact just the valve tip) You can tell the difference with a bent valve as they don't snap shut as nicely as a good one.

Other than that, hope for the best!

A hammer... Your joking right!!!

The best way to test for bent valves if you have the manifolds off is to pull the cams, and then pump the cylinder up with an air compressor via the plug hole and listen at the intake and exhaust for leaks.

[Shoota_77]

Nope, no jokes....

You don't use a sledgey!!!

The key word there was 'light' hit just in case you missed it!