16V balance shafts.

Competition engines and ancillaries - general discussion
Post Reply
brrrrm
Posts: 4
Joined: July 25th, 2010, 8:34 am
Location: Auckland NZ

16V balance shafts.

Post by brrrrm »

Hi Guys.
First Post.
I have the engine out of the Integrale to do a list of jobs including the belts. I'm aware that many race engines have removed the balance shafts, but I'm interested to see the previous owner of this car has just removed the balance shaft belt. As a race car ,this season we will run the eng standard but next winter will build something more serious and remove the balance shaft system at that point. Does anybody know what the downside is of leaving it all there but not in use. Are there oil feed issues to journals downstream of the balance shafts. thank you Neil
WhizzMan
Posts: 459
Joined: August 13th, 2010, 8:05 pm
Location: Amsterdam, the Netherlands

Re: 16V balance shafts.

Post by WhizzMan »

If you leave the shafts in, make sure they don't rotate on their own. Some people have reported unwanted vibrations due to the shafts moving on their own (16V turbo at least). If you take them out, make sure you put the correct plugs in so you do not disturb oil flow.
Book #348
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

You can fix them in place, see photo.

GC
Attachments
with the locking straps in place - when you bolt the pulley on it will lock the shafts.
with the locking straps in place - when you bolt the pulley on it will lock the shafts.
8.136_16v covers_2.jpg (226.93 KiB) Viewed 14159 times
brrrrm
Posts: 4
Joined: July 25th, 2010, 8:34 am
Location: Auckland NZ

Re: 16V balance shafts.

Post by brrrrm »

Thank-you Guy. thank-you Whizman.

Have you seen them freewheeling on the Dyno Guy. Or are you clamping them for some other reason.

thank you
Neil
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

Why do you ask? Is this being discussed on some other forum?

I ask because increasingly - every time I proffer a solution, I am asked, 'why's that then'?

No offence intended - I should simply like to know.

G
WhizzMan
Posts: 459
Joined: August 13th, 2010, 8:05 pm
Location: Amsterdam, the Netherlands

Re: 16V balance shafts.

Post by WhizzMan »

I have been told by a person that is regarded as very knowledgeable on the Alfa 155 Q4 forum. He seems to know quite a lot about tuning the 16V turbo engine and advised quite strongly against just taking the belt off and letting the balance shafts spin freely. Because of his reputation, I always have taken his word on this being true. On the 16V TwinSpark engines I've never seen anyone have issues with it, nor have I had them myself on my own cars.
Book #348
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

OK.

I was probably the first to 'pin' the shafts like that and I did it quite simply because I (personally) did not like the idea of 'freewheeling' balance shafts. And I removed the belt in the first place because I did not like seeing a device like that running in proximity to the cambelt.


GC
brrrrm
Posts: 4
Joined: July 25th, 2010, 8:34 am
Location: Auckland NZ

Re: 16V balance shafts.

Post by brrrrm »

Just naturally curious Guy. I'm a question asker by nature (as I'm sure you are)
I'm new to forums and certainly have no knwledge of the subject being elsewhere, mainly because the only other place my name apperas is with a small group of Lancia guys out here in NZ
No offence taken, just a bit curious to realise they will even rotate , as mine have quite a bit of "stiction"
thank you
Neil
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

Rotation (per-se) would not matter. But there is the issue of vibration: who knows if a forcing frequency might not exist in the engine that will cause the shafts to vibrate (at their installed natural frequency)?

That would definitely not be a good thing. They are heavy.

G
Honza
Posts: 85
Joined: June 22nd, 2006, 8:04 pm
Location: Lomnice nad Popelkou (60 north from Prague), Czech Republic
Contact:

Re: 16V balance shafts.

Post by Honza »

There is some nice video-compilation on youtube - long for about 40minutes total wich maps Lancia Delta Integrale - engine building, dynoing , building of the body etc.. and there is short shot from dyno room with running engine. That engine has removed balance shaft belt, but front shaft rotate freely.

So only one problem couldd be the vibrations caused from uneven rotation of that shaft (I have also removed belt on my tipo, and didnt lock the shafts..)


Better option is remove shafts from block, and blank the oil feeds of bearing - you get higher and stable oil pressure under all possible circumstances.
#100
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

Better option is remove shafts from block, and blank the oil feeds of bearing - you get higher and stable oil pressure under all possible circumstances.

Honza I'm sorry - and I very rarely do this (it being a forum) - but it is not a better option. It is an expensive and completely unnecessary one and the risk of contamination of the oil galleries is VERY high.

I do not advocate the practice so do not propose to elaborate on how it can be done.

if I do not assert myself from time to time I will have even more clients preaching me 'best practice' than I already have just because they read it on some forum or another.

GC
drmo
Posts: 2
Joined: October 7th, 2010, 3:12 pm
Location: Ljubljana, Slovenia

Re: 16V balance shafts.

Post by drmo »

Hi everybody!

We are building a street/track car with a peugeot 2.2 16v engine out of peugeot 607. The engine (EW12J4, 86mm bore, 96mm stroke) also has balance shafts, but are easilly removed. They're under the crank and driven by the crank. This is how they look:
DSC00434-pomanjšana.JPG
DSC00434-pomanjšana.JPG (304.06 KiB) Viewed 13713 times
As I understand they are there only to smooth out the engine vibrations and have no other purpose, so we thought we wont fit them when the engine will be assembled together. What are your opinions? I think that any unneeded rotating mass should be avoided.
WhizzMan
Posts: 459
Joined: August 13th, 2010, 8:05 pm
Location: Amsterdam, the Netherlands

Re: 16V balance shafts.

Post by WhizzMan »

As Guy stated, take care not to mess up any oil galleries and lubrication pressures. These shafts have bearings that need lubrication. If there are oil galleries to and from the bearings, make sure that the pressures and flow of these are the same before and after your modification.
Book #348
tricky
Posts: 101
Joined: July 6th, 2010, 5:41 pm

Re: 16V balance shafts.

Post by tricky »

" The risk of contamination of the oil galleries is VERY high. "

Guy, without elaborating on the methods as such, could you please explain just this point in a bit more detail ?

Thanks.
Twice as many valves
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: 16V balance shafts.

Post by Guy Croft »

metal debris in oilways

GC
Post Reply

Who is online

Users browsing this forum: No registered users and 36 guests