2L TS Balance belt removal = more bhp? - Alfa Romeo Forum
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(Post Link) post #1 of 104 Old 27-12-08 Thread Starter
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2L TS Balance belt removal = more bhp?

Sorry, not much of a tuning question but i thought i twas the best place to post this query.

In my inital quest for a few more bhp i've been reading that removing the balance belt, leaving the balancers in the engine, frees up a few more bhp.

Is this confirm or myth?

Do the balancer shafts, when the belt is removed, have to be locked in a certain position or just left to do their own thing?

can any damage occur by leaving these shaft rotate of their own free will?
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Re: 2L TS Balance belt removal = more bhp?

Feel like that Turboed' Croma, without the shafts, compared to my twin contra- rotating balance shaft Turboed' Thema, but harsher? Try it and see? :
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Re: 2L TS Balance belt removal = more bhp?

I don't think you will get any more BHP, but you will get a more free revving engine.

Its probably better to lock the shafts after removing the belts rather than have them rotating due to the vibrations.


Also removing the shaft operation may have long term affects on the rest of the engine through vibration.
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Re: 2L TS Balance belt removal = more bhp?

One question: Why would you not remove the shafts themselves? :hmm:
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Re: 2L TS Balance belt removal = more bhp?

im sure this was discussed in the "lightened engine internals" thread.

pud, if you remove the belt, you then have the weight removed from the crank without having to do anything else, as they are then not connected to anything. if the balance shafts were actually removed, you would have to remove the engine to get them out, and then get the holes etc sealed up.
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Re: 2L TS Balance belt removal = more bhp?

S'right what aziraphale suggests, as at the belt/drive drive end, the bores for the bearings would need sealing, at the gearbox end they are core plugged off.Leave them in if you want to try it, with shafts bearings and seals intact? Something that's hardly worth bothering with,imho.:
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Re: 2L TS Balance belt removal = more bhp?

Apparently the engine uses quite a lot of power in driving the shafts; maybe 5-10 BHP or so? So might be worth doing. You'll get a little bit more vibration, but I can't imagine it will damage anything; there are lots of 2.0L engines around without balance shafts which get by quite happily...
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Re: 2L TS Balance belt removal = more bhp?

i want to do it but not sure i dare
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Re: 2L TS Balance belt removal = more bhp?

You will gain a few bhp by removing the balance belt, but there will be more vibration.

With the balance shafts, the 2.0TS is a very smooth engine and on the road you won't use the extra power 99% of the time.

So I won't be removing mine.

On a race engine the priorities are different, in that case the balance belt would be removed.
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Re: 2L TS Balance belt removal = more bhp?

For what extra power you will get is it really worth it? The t.spark engine has a very weak bottom end anyway and the balance shafts are obviously there for a reason, In the past few years we have had many many engine jobs in with bottom end failure, out of them all we had two, one with a balance belt missing one with the balance shafts really badly timed by a local main dealer, whether it was connected or not is questionable but it has to be considered.
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Re: 2L TS Balance belt removal = more bhp?

OK, thinking about it as I go so I may be wrong, but.... The secondary out-of-balance forces of the conrods are still going through the crankshaft, the balance shafts essentially deliberately shake the whole block so the 2nd order effects don't get felt at the engine mounts. The balance shafts might actually make bottom end issues worse because to cancel the forces, they have to provide an opposing force, which increases the force at the crank

As an analogy; let's assume the crankshaft is a foot kicking a football. What the balance shafts do is provide an opposing force to stop the football moving. If you kick a football, it hurts a lot more if someone kicks it at the same time from the opposite direction!
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Re: 2L TS Balance belt removal = more bhp?

Quote:
Originally Posted by mave View Post
OK, thinking about it as I go so I may be wrong, but.... The secondary out-of-balance forces of the conrods are still going through the crankshaft, the balance shafts essentially deliberately shake the whole block so the 2nd order effects don't get felt at the engine mounts. The balance shafts might actually make bottom end issues worse because to cancel the forces, they have to provide an opposing force, which increases the force at the crank

As an analogy; let's assume the crankshaft is a foot kicking a football. What the balance shafts do is provide an opposing force to stop the football moving. If you kick a football, it hurts a lot more if someone kicks it at the same time from the opposite direction!
You may have a point with this.

I have a feeling that 1.6 and 1.8 TS's are just as likely to suffer bottom end trouble though.
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Re: 2L TS Balance belt removal = more bhp?

Just leave the belt off but dont remove them as you leave oil galleries open and then no oil pressure at all but never seen a problem with not having them on..
 
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Re: 2L TS Balance belt removal = more bhp?

don't forget that the balance shafts turn at twice the crank speed, which is 4 times the cam-speed... this'll take power, especially as they are per definition not very well balanced....

If you have the tools to time the balance shafts and timing belt, I'd give removing the belt a try... if only because quite a few engines have died because of snapped balance shaft belts getting tangled in the distribution.... if you don't like it the belt can always be replaced...
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Re: 2L TS Balance belt removal = more bhp?

Yes i have the alignment tools required, going to give it a go today.

thanks for all the replies
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Re: 2L TS Balance belt removal = more bhp?

hmm, why do the shafts need to be timed? is it not just a case of cutting the belt?
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Re: 2L TS Balance belt removal = more bhp?

Quote:
Originally Posted by aziraphale View Post
hmm, why do the shafts need to be timed? is it not just a case of cutting the belt?
They need to be timed when you fit the new belt.
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Re: 2L TS Balance belt removal = more bhp?

ah right ok.
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Re: 2L TS Balance belt removal = more bhp?

well the job is done.

been the '****' type I had to remove all the bits & bobs to get at this belt rather than just cutting it off.... its only 6 months old....also if i didn't like the mod I'd have to buy a replacement in order to re-fit.

anyways the good news, i won;t be refitting it, well not in a hurry anyways.

engine is definitely more responsive & much different sounding, rather snarly now

well pleased with the result
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Re: 2L TS Balance belt removal = more bhp?

y mate was up tonight getting GTA look-a-like headlight fitted to his car & we also decided to check his timing ... just in case.

As it turned out his timing was way out, got that sorted & we went for a spin in his car 1st, then mine.

He couldn't believe how much different my car sounds & responsed, all because of removing the balance belt.

IMHO, it was well worth done & can be refitting in an hour or so when ever i fell i need to.
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Idea Re: 2L TS Balance belt removal = more bhp?

In the past, there have been people complaining of poor performance which appears to have been traced to a broken balance belt. This tended to be confined to the earlier 155 engine (which was virtually identical). The thinking is that the balance shafts actually stop the knock sensor from activating on a 2 litre. I don't subscribe to that theory.

Having a completely rebuilt and modified my 2 litre engine, where everything is lightened and balanced, I can confirm that a standard 2 litre with the balance shafts running is indeed smoother. However, because my engine produces less primary vibration, it is safer to run at high RPM as the vibration is not merely masked.

The fact the balance shafts no longer sap a little power may have improved things, but the improvement in engine response will mainly be down to the lightened flywheel, and not the balance shafts. It will not make a huge difference, but I like the idea of less things to go wrong in the timing belt department. That and it is cheaper.
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how is your car without balance shaft belt now !!!

Quote:
Originally Posted by SEARs View Post
well the job is done.

been the '****' type I had to remove all the bits & bobs to get at this belt rather than just cutting it off.... its only 6 months old....also if i didn't like the mod I'd have to buy a replacement in order to re-fit.

anyways the good news, i won;t be refitting it, well not in a hurry anyways.

engine is definitely more responsive & much different sounding, rather snarly now

well pleased with the result

you said previously you had the alignment tools for timing bal belt, what are they, i am thinking of removing my bal belt, but would like to be able to replace it at a later date if required.
thanks Paul
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It's markers on the shafts, the belt has 3 marks on the side. You stick cam locks on first this will get the crank to TDC.
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o'k thanks for quick reply.
so let me get this right, so you lock the cams at TDC with the locking caps then fit belt around crankshaft and the two balance shaft pulleys, aligning marks on belt with the 3 pulleys. and the marks on the balance shafts will face the top of engine.

is that correct. ?
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I can't remember which way the markers point, they just line up with marks on the belt.

One mark on the crank and one mark on each shaft.
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