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Major Timing Issues...

MBS206

By MBS206,
in Engines & Forced Induction

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MBS206 Grand Master

MBS206

Posted
Posted

Hey All,

Just threw another RB30 block into my car after destroying the last one, everythign is being used exactly the same, same sensors etc as before.

Problem I now have though, after putting timing belt on (Tensioners are in the "stock" spot, and also where everyone says to put the second one (Drill and tap) as the "spare" spot wasnt machined flat...

Anyway, timing is SAVAGELY retarded... Like, way more then a single tooth... As in, I need to throw 50 degrees at it from the ECU + advance it on the CAS, and I'm only getting 12 degrees of timing...

We've redone the timing belt, it was all "fine" (Well, inlet was half a tooth retarded, exhaust half a tooth advanced...)

I checked the keyway on the CAS... That was all fine...

BTW, the only way this car would "start" is with the timing as I said above, but it would only do so at full throttle as the cold start tune is so shit... But when it did, the exhaust got quite hot, quite quickly...

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Duncan Grand Master

Duncan

Posted
Posted

well at least i get a point for guessing the problem was timing.

is the drive for the cas on the end of the zorst cam intact? if its broken the cas to cam timing can be random.

sorry not many ideas why

lachlanw Veteran

lachlanw

Posted
Posted

you know one is a tensioner and one is an idler ? have you got them in the right places ? one cam be half a tooth advanced and one half retarded . that equates to one full tooth out from each other .

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted

Timing on a RB30DET is a pain in the ass. I had to play around with mine for a while before i got it right. take it all off and try again. harmonic balancer needs to come off and keep trying. good luck with it. I know your pain

MBS206 Grand Master

MBS206

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  • Author
Posted
What cam gears are you using?

Are you using a tensioner and an idler or two tensioners?

You should avoid using double tensioners on the 30's

Unfortunately, at this point in time, I didn't get the choice to put an idler on.

I'd already drilled and tapped the block for the tension to be in the upper region, when I went to put the idler on in the spare lower spot, I realised this location was not machined. I attempted for a few good hours to make up "washers" to make it sit flat, but found after a while, there was no chance I'd get it right.

Hence, now running two tensioners, one in factory spot, one in the spot advised by the DOHC guide.

I do have standard gears on at the moment, going to throw one of the adjustable gears on either today or tomorrow and re do everything again.

Does anyone know how I can check if the timing marks on the harmonic balancer are still correct?

The Dan Grand Master

The Dan

Posted
Posted
Unfortunately, at this point in time, I didn't get the choice to put an idler on.

I'd already drilled and tapped the block for the tension to be in the upper region, when I went to put the idler on in the spare lower spot, I realised this location was not machined. I attempted for a few good hours to make up "washers" to make it sit flat, but found after a while, there was no chance I'd get it right.

Hence, now running two tensioners, one in factory spot, one in the spot advised by the DOHC guide.

I do have standard gears on at the moment, going to throw one of the adjustable gears on either today or tomorrow and re do everything again.

Does anyone know how I can check if the timing marks on the harmonic balancer are still correct?

WTF?

So you're running two tensioners on one side of the belt?

I'd advise getting the correct block with the machined spot for the idler bearing and do it properly.

Either that or the T866 belt has the wrong number of teeth for the setup you want. You need to make sure the timing marks all line up and after two rotations they will line up perfectly again.

MBS206 Grand Master

MBS206

Posted
  • Author
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So, the two cam gears are actually in time with each other...

They sit on their timing marks whilst the harmonic balancer says 10 degrees BTDC.

Will be pulling the harmonic off tomorrow once I pick up the puller and checking it on the actual bottom gear...

But things are seeming strange... :S

Duncan Grand Master

Duncan

Posted
Posted
...Either that or the T866 belt has the wrong number of teeth for the setup you want. You need to make sure the timing marks all line up and after two rotations they will line up perfectly again....

you tried this right? I guess it wold have mashed stuff by now if it was wrong

MBS206 Grand Master

MBS206

Posted
  • Author
Posted
you tried this right? I guess it wold have mashed stuff by now if it was wrong

Didn't have the puller with me tonight to rip the harmonic balancer off.

It'll be off tomorrow, but it appears they all still line up as they did when we put it on... Something is SOOO bloody weird!

Hoping when I get the balancer off it's a few teeth out or something simple... But I bet it all lines up perfect...

MBS206 Grand Master

MBS206

Posted
  • Author
Posted
How could the cams have lined up in your previous post if they were off by 60 degrees?

I'd be surprised if you even made compression.

Have you done a compression test afterwards to confirm no bendies?

There are two extra marks on the backing plate. First time EVAR I've farked it up (Done that timing belt 100 times before) throws each gear off by exactly 4 teeth.

Will be 100% checking for any damage tomorrow, but it "ran" with WOT (Poorly, but it "ran")

No noises... Nothing...

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