Holden VR v6 - vacumm testing for unsmooth idle

[Pete30nz]

Morning

I have a mace harmonic balancer on the crank. I'm wondering if I should order a timing chain tensioner.

Got to get back to work now.

Cheers

[Pete30nz]

I've have a search about double row , I remember seeing some where about the double row chain needing a deeper timing cover.

I'm in search on Google for a chain tensioner.

[immortality]

Not a deeper cover, normally a machined oil pump cover..... or just double up the timing cover gaskets..... or just put it back as is and cross your fingers it clears. My VN did.

[vlad01]

A couple of things I want to address.

Firstly, the alloy intake gaskets are for ecotec only, so such gasket was ever made for the VN-VR Buick.

The rear of the balance shaft is splash feed needle rollers. No need to plug anything, there are no oil galleries involved in the shaft.

For the balance of the engine when deleting the shaft, absolutely a re-balance to 50% on the bottom end is a good idea but in reality the out of balance after removing it is entirely localized in a 50 rpm either side of 1600 rpm. It feels more like a shudder, same kind and feel like a mild clutch shudder when taking off. Doesn't feel like a balance vibration to me. I did this on my VR and I found it perfectly fine when driving. At high RPM the engine really loves having no shaft. Feels like a chainsaw in response.

For double row, you need to get a machined oil pump cover and double check the clearance, as even machined they are close. I don't think there is an easy way other than clay without removing the engine.

A balance shaft delete does not require a double row however, just remove the shaft and retainer and put everything else back as normal, leaving the gear behind the cam sprocket. This is what I did in my VR.

Double row should not use a tensioner. There are 2 types for VR, which also means there are two types of oil pump, and therefore 2 types of double and single row chains used. You need to confirm the engine number, or best is to remove it and look. Later VR use the ecotec double row, early used the VN II-VP set.

There are a few types of tenioner too. Narrow, short spring/bolt, narrow long spring/bolt, wide long spring/bolt. This is due to chain AND block combo.


For a stock engine I like the Melling timing set, they are top quality but very hard to find outside of USA. The common Cloyes ones are junk.

The balancer shaft rattle/noise is normal, this is gear lash up front and in turn a jiggling of the rear within the needle rollers.

If you want it quiet, DO NOT install a new chain, it's a tight chain that amplifies the whipping/lashing of the gears due to stronger coupling to the crank. My shaft on my shitbox was virtually silent. I replaced the set during a timing cover and gasket replacement since it was very loose and might as well be done. This introduced a rattle like you won't believe but everything is perfect fine and the idle is better and just runs a little better all round due to more stable cam timing.

Having a loose chain, as positive side effect is that it allows the shaft to maintain a more constant speed due to the give in the chain allowing variations in rpm to not as easily transmitted from the crank. But obviously there are negatives such retarded cam timing and inconsistent cam timing when the rpm changes up or down during driving, rougher idle etc...

[Pete30nz]

Potentially sounds like a few things to think of.
That's a fear bit of info to note.

I have got a new chain tensioner last evening on the way home. And also the gasket set for timing cover ect.
Edit: I havnt matched up the tensioner yet, they went off the year of the car.

Hopefully this evening or over the weekend I'll pull off the cover and remove the balance shaft.

Cheers

[immortality]

For the balance of the engine when deleting the shaft, absolutely a re-balance to 50% on the bottom end is a good idea but in reality the out of balance after removing it is entirely localized in a 50 rpm either side of 1600 rpm. It feels more like a shudder, same kind and feel like a mild clutch shudder when taking off. Doesn't feel like a balance vibration to me. I did this on my VR and I found it perfectly fine when driving. At high RPM the engine really loves having no shaft. Feels like a chainsaw in response.

For me in my VN this was at about 1800rpm but I had 3.45 gears. It was visible in the rear view mirror as that would vibrate at that rpm.

Fitting the Powerbond Race harmonic balancer eliminated the weird vibration for me.

[vlad01]

That's interesting. When I did the hot motor for my red VP. It was completely balanaced by my machinist and to the 50%. It has the race balancer too. But having solid engine mounts it does have vibration in a few rpm spots, but nothing too crazy, when stock mounts were in it, it was smooth as but the mounts couldn't hold the engine in place during cornering causing dangerous exhaust to steering binding.

[immortality]

Changing the balance of the rotating assembly won't eliminate the harmonics inherent in all 90° V6 motors, solid mounts will not help. Most people go to a single solid mount and stock mount. I guess those are the joys of having a 2nd gen Commodore, there is fuck all room around the PS rack with headers fitted although I had Coby headers (NZ brand) which didn't have that issue although with Pacemakers it might be a different story.

I just put headers in our Calais and there is a heap of room in the VX.

[vlad01]

Well all combos of 3 cyl have a rocking couple, not much to do with being 90 deg engine. Truth is also all V8 have a rocking couple too, due to the odd fire.

The 90 v6 has an interesting quirk that the 30 deg offset in the crank throws out the timing of the pistons in that pair so the 50% balance can not work correctly. But if you get a common pin crank, that fixes the issue and the balance is restored except of the rocking couple. However this now introduces an odd firing order which introduces it's own vibration.

A 120 v6 is also not ideal. It's perfect in firing order, but not in the piston pair 50% balance, the rocking couple is still there regardless.

60 v6 is the same as 120 but the banks are closer together for packaging and I think there is some canceling of one of the vibration planes somewhat.

So basically, no v6 has perfect balance but are a lot better than a 4 cyl and not much worse than a v8.

There is no perfect balance engine in real life. Even the inline 6 which everyone says is perfect balance suffers torsional vibration and also can not cancel the horizontal plane vibration of the crank due to not being a V engine. That's the annoying buzz at idle the inline 6 have, similar to the 2ndary buzz a inline 4 have at high revs but not related.


As for the engine mounts, I needed a solid on the driver's side as this is the side that lifted 30+ mm on hard cornering and cause the binding. This is the opposite direction to the torque the engine block experiences.

[Pete30nz]

Hi, I've found some time and got the timing cover off just now.

Q: Is it safe to clean the valley as it sits rite now, (photo attached) and can I use turps or wax and grease remover?

Q: also for the ports, can I clean these up, if so how would yous do this please.

I'm going to do an oil change either way.

Cheers