nine-44

Anyone on here have their balanceshafts deleted? From what I've heard, the rotating assembly is balanced and the balanceshafts only smooth out the vibrations from cylinder pulsations. One of my 944's had a broken belt and it didn't vibrate that bad, so I'm contemplating on deleting them.

tinman944

Yes I have taken mine out completely.Scott Gomes has a kit that works great.I have not seen any problems at all.I am pretty sure he takes them out of all his motors.

David Floyd

Mine are deleted, no vibration problems

Huntley Racing

We have many many motors out there minus balance shafts. No problem but lots of benifits: More HP, less oil taken from the crank, less chance of the balance shaft belt failing and taking out the timing belt, less weight etc....

Edman951

How much does a balance shaft delet kit go for?

Huntley Racing

The balance shaft delete option is done during one of our engine builds and is a $425 option on a turbo which includes AN fittings and braided line to feed the turbo oil. For N/A cars it is $275 because there is no oil line requirment and the feeds are simply plugged. We ditch the shafts, covers and seals too.

CarreraCup03

According to John Milledge balance shafts should not be deleted from a four cyclinder motor. The secondary not the primary harmonics will destroy the motor. The Porsche built 944 race cars all had balance shafts ... they spent alot of money to develope these engines .. and decided that they needed balance shafts.
On a secondary note .. John Milledge also does not recommend a lightened flywheel on a four cyclinder engine .... once agin because the counterweights help to minimize secondary harmonics.

Yes I am sure your car will work fine with balance shaft delete and lightened crank ... but you are scarificing the longevity of you motor.

944turbo

Huntley Racing

I have to disagree with J.M. on this one. Forget opinions lets just stick to one very simple fact. Why don't the hundreds of thousands of straight 4 cylinder Toyota, Datsun, Honda, BMW, Ford, Chevy etc... motors shake themselves to death at low miles!?!?!

fusionsport

because they arent half an eight cylinder engine that is 2.5 litres. When Mitsubishi made its 2.6 litre motor it had balance shafts, and come to think of it they did another smart thing- they used a timing chain that rarely failed.
Norwood left out the balance shafts on his 968 powered DOOM cars, but that is a high performance engine that has little bearing in the real world.
Personally I think without proper re-balancing deleting the balance shafts is a bad idea.Rebalancing the engine helps. Harmonics are a serious consideration and I wish Porsche had doen some research into a sort of true damper for the 44 engine- but they didnt.

David Floyd

Well, guess I can be the Rennlist balance shaft delete longevity tester.

Daily driver ( about 10,000 miles a year ) with
2-3 DE's in there

2400 miles so far so good

Anything in particular I should pay special attention too ?

I have a lightened flywheel,knifed and lightened crank and 106mm bore.

This should be a good test engine, sure hope I can post positive results.

CarreraCup03

I made a typo ... John Milledge did not believe in lightened cranks .. I wrote flywheel.

944 turbo

fusionsport

I think the setup Dave has is key to any longetivity in the 44 engine with balance shafts removed. What we all like to forget is that this wasnt Porsches top-of-the-line car, and as such despite the improvements over the 924 engine it is in reality just a bodged together quick fix that happened to work out better than expected. With that in mind we can infer that Porsche never intended nor did they in fact ever spend the sort of money that it takes to get a relaible amount of power out of a large 4cyl. They were using parts on hand, which is clearly explained as the reason why they chose to use half the 928 motor as the basis of the 44 motor. Now then- if you do in fact balance and lighten each and every part and inspect it carefully then there is no reason you cant get a 44 engine without balance shafts to last- in fact tossing around the idea today at the shop we theorize that any lightening and balancing carried out in the engine would be difficult to transfer to the balance shafts, in which case the balance shafts could actually lead to destruction. 4cyl motors are inherently unbalanced and the bigger they are the more wear they incur- esp considering what was high-tech in the early 80s when the motor was designed is now nostalga. At any rate I think a properly balanced motor without shafts is ok, but it is tempting fate to remove them without re-balancing the motor

John Anderson

I ran my 951 for about three years without the shafts, never had an issue, it was my dauly driver and I piled a ton of miles on it like that.

If the motor is built right, get rid of them. When we build race motors, its something we talk to the customer about, and its an option we don't charge for. We don't have a kit, but when you look at the cost of building a motor...its cheaper to delete them than it is to install them, when you look at the hours it takes to install seals, torque the cover, install the rollers and tensioners, then align the shafts, with the cost of the belt, you can see that just filling the oil galleys with titanium putty and leaving the shafts out is much easier, takes less hours and at least on a race motor, it takes one potential belt failure out of the loop.

We tried welding, but had cases of warped matting areas where the girdle and oil pan seals. After many telephone calls to all the main machine shops and fabricators in the area, we were told over and over (for many reasons), that welding our block is not the way to go, fill it with titanium putty, or something of the like.

Take Care!

Matt

John - tell us more about this titanium putty - I haven't run across it, but it sounds interesting.

Matt

M758

I have spoken to a well respected 944 Turbo racer and shop owner on the balance shafts. I asked if it was worth it. He said they get you 3 hp and will work fine if you don't mind changing the oil pick-up tube every race. <img border="0" title="" alt="[Eek!]" src="eek.gif" />

You guys can believe what you want, but I am not risking my engine for 3 lousy hp!