13 replies to this topic

[cressey]

Looking for a few projects to keep my hands busy over the Xmas period. Already done a few small mods and am looking to do a few more. I'm keen to fit the underdrive pulley and short belt mod and am also considering a high flow plenum before getting it mapped. Been looking at the balancer shaft deletion kit but its the one I'm most nervous about. Does it significantly increase vibration to the point where it can start to cause damage? I'm looking for stories good and bad from anyone that's done this mod. Have done a search but couldn't find the answers. If its been covered, please post a link. Thanks in advance. Ben

[Rickwoo118]

Do a search on here. There are loads of posts about this.

[Nev]

The vibration issue is more theoretical than actual IMO, in practice dozens of car owners on this site have eliminated the balancer shafts and I've not heard of any ill effects at all. You will notice the pick up of the engine is improved slightly and frictional losses will be reduced, personally I didnt notice any extra vibration, though the idle can be slighly less even due to less rotational mass. As background, a pre-cursor to our Z20LET engine, the X20XEV had no balancer shafts at all. In fact the strengthening girdle and splash pannel that you will fit in the 'kit' comes directly from the X20XEV (as does a whole host of other parts). HTH.

Edited by Nev, 21 November 2012 - 08:14 AM.

[rob999]

I've not heard of any engine failures linked to the removal of the balance shafts. Mine seems fine, I did it to lose the 4.5kgs of extra heavy weight.

[Pidgeon]

There are millions of straight fours out there with no balancer shafts. For me the benefit is simply not worth the cost and risk, it is a tiny benefit and the risks involved with removing and drilling main bearing caps are huge. Are there not some more straight forward mods you could undertake?

[siztenboots]

the astra vxr does not have them either

[fiveoclock]

When I fitted the underdrive pulley a rattle appeared from the bottom of the engine. When I removed the balancer shaft mech it disappeared. I'm sure I've heard of other people having this problem. Doing both transformed the engine though, much quicker rev up and no extra vibration.

Edited by fiveoclock, 21 November 2012 - 09:12 AM.

[Cookies220]

I've had no problems with this mod. Add in the short belt mod and lightweight fly and pickup is sooo much better. Idle is a little lumpy but not a real issue. You'll notice more vibration fitting the engine mount inserts than all of those mods put together.

[Bargi]

So no, it won't kill your motor...

[MrSimba]

the astra vxr does not have them either

This.

The Astra VXR Z20LEH has the ballancer shafts deleted from the factory!

[cressey]

Thanks for all the replies folks. I've already fitted the poly inserts front and rear and noticed a huge difference. Wondered if that, coupled with the deletion mod would make it too unpleasant to be a daily driver. Didn't know there were so many engines out there without these balancer shafts and its reassuring to know that the predecessor didn't have them. I like the idea of increasing efficiency and performance by reducing weight and eliminating unnecessary/redundant ancillaries from the engine but wouldn't want to compromise on reliability or driveability. I'm a fairly practical guy and work in the Engineering sector so am confident in my abilities to drill, tap and blank the redundant oil feeds. My dad has a pedestal drill I can use. Simon, I may be in touch soon as I'd like to find out a bit about your air box, intake pipe, catch tank and plenum. Thanks again all. Ben

[Dashwood]

I have front and rear poly mounts (vibey) then flywheel (very vibey) then bal delete and ali crank delete kit. (no idea mmg or other) no vibes worth mentioning just brilliant.

[dw1]

Simon, I may be in touch soon as I'd like to find out a bit about your air box, intake pipe, catch tank and plenum. Thanks again all.

Ben

Dont listen to him. He will ply you with facts, indisputable dyno plots and back to back tests and then force you to buy one of those lovely bits of airbox kit from DH/DG.
I know because I just did, you have been warned

Edited by dw1, 21 November 2012 - 11:25 PM.

[cressey]

Simon, I may be in touch soon as I'd like to find out a bit about your air box, intake pipe, catch tank and plenum. Thanks again all.

Ben

Dont listen to him. He will ply you with facts, indisputable dyno plots and back to back tests and then force you to buy one of those lovely bits of airbox kit from DH/DG.
I know because I just did, you have been warned ;)/>

Thanks for the heads up. Although I fear it may have already begun. I spent the other weekend dribbling into his shiny engine bay and after he took me out for a spin, I've decided I want to throw a bit more money at mine.