High oil pressure after balance shaft delete?

Hey guys,

Well, the day has finally come. The balance shaft stubby finally arrived today and the package is sitting on my desk.

However, I read a thread on here recently that discussed the need to port the oil pressure relief valve after the delete. Am I 100% likely to have high oil pressure after the delete, or does this only happen to some engines and not others?

Just asking because I'm already burning a lot of oil as it is, and getting that high pressure relief valve ported around here will be $$$. The stock oil pump in my car has 140k on it. Thanks!

I never had a problem with the higher oil pressure but im also running a built motor thats in very good working order. I would check over on DSM tuners since alot of 1g/2g guys delete their shafts, you'll get more feedback over there since more people have first hand experience with ti.

I don't see how it can build too much pressure, the pump has a built in pressure relief valve. I just put a new high volume oil pump on but don't see the need to port. I have not run it yet so guess we will see and hope for the best.

It builds more pressure because the holes oiling the front balance shaft are blocked by the turned bearings. With the holes blocked off the system builds up a lot more pressure and the only the relief valve is there to bypass the extra pressure. You can consider that valve a wastegate for the oil pump. The oil pump builds up or reduces pressure with the rpms go up and down, and the general rule is 10psi of pressure for each 1000rpms. So the relief valve is spring loaded so when it sees more pressure than the spring can handle, it collapses and the oil is relieved to the oil pan. The problem is that the rpms change so quickly and the oil port is just that big and can handle only the pressure it is designed for. So porting this hole just makes the bypassing quicker than usual. When you open the valve you'll see that the piston opens and shuts a hole which can not be ported, but you port the hole that returns the oil back to the oil pan. Its easy, I did it in like 60 seconds with the dremmel. Then you have to roll up a piece of sandpaper and sand down the sharp edges inside the cylinder

You shouldnt be seeing anymore than 80psi at the most and thats at 8000 rpms or cold start, if you have a gauge.


This is how it looks. The thing is to port wider around the hole the piston closes. The bottom part of the hole doesnt need to be ported.
http://www.dsmtuners.com/forums/atta...1&d=1283291074

Look at the attachment. The red is where its important to port, the blue isnt.

One more.

http://www.dsmtuners.com/forums/atta...3&d=1264621392

got a pic of the other side of that thing? I am curious to know which piece I'd have to remove...I really need to do this or have it done because of my oil consumption

Thanks for the insight, MKO. I'll probably end up using an electric drill with a 1/2" drill bit to do the porting. I'm definitely going to port it cuz I don't need to burn any more oil :grin:

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Originally Posted by evil-G-nius

got a pic of the other side of that thing? I am curious to know which piece I'd have to remove...I really need to do this or have it done because of my oil consumption

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You're looking at the other side of the oil filter bracket. To remove it, take off the lower timing cover, and remove the 4-5 bolts holding on the metal bracket for the oil filter.

did your stubby shaft have the oil relief in it? or was it a smooth stubby shaft?

http://i19.photobucket.com/albums/b1...n/P1060463.jpg

The one on the left. That is, "the oil relief stubby". Came directly from the Mits Dealership.

so the oil relief one would work as far as relieving the high oil pressure? Instead of porting the oil filter housing I mean

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Originally Posted by evil-G-nius

so the oil relief one would work as far as relieving the high oil pressure? Instead of porting the oil filter housing I mean

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If you only delete the rear shaft and leave the front one in like I did, you only get a rise in oil pressure of ~5psi or less. If you remove the front balance shaft and the rear, you'll get about 10psi more oil pressure, because you must replace the front stock BS bearings that have oil passages in them with new bearings that don't have them. That's where the rise in pressure comes from.

I would go out on a whim here and say that the oil pressure difference between the OEM mitsubishi stubby and the aftermarket stubby is negligible. Only difference the two is that the aftermarket stubby is a piece of crap made from low grade metal and can destroy your oil pump journal...so I hear anyways.

If you just remove the back BS like I did, it might not be necessary to port that bracket, but do it if it makes you rest easier lol. I didn't port mine. The how-to guide I followed said that the +5 psi in oil pressure is a GOOD thing for engines with high mileage, because the oil pump has wear in it.

well my engine was made without it...but at the time I had no idea there were two balance shafts so I really dont know what the deal is with mine. But my oil consumption is off the charts and I have some leakage without an actual leak...meaning its forcing its way out I suppose. Oil pan has been resealed, no head leakage yet and still there is oil on the bottom of the pan and some of the under carriage. And if I was to be full with oil, head to LA...i'd need like 3 quarts before I rolled into LA

Quote:

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Originally Posted by evil-G-nius

well my engine was made without it...but at the time I had no idea there were two balance shafts so I really dont know what the deal is with mine. But my oil consumption is off the charts and I have some leakage without an actual leak...meaning its forcing its way out I suppose. Oil pan has been resealed, no head leakage yet and still there is oil on the bottom of the pan and some of the under carriage. And if I was to be full with oil, head to LA...i'd need like 3 quarts before I rolled into LA

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Have you ever hooked up an oil pressure gauge to check how much pressure you're actually getting? My guess is that you're leaking oil out of your valve stems and it's burning in your engine. That's where my engine is burning oil anyway.

Normal oil pressure is +10 PSI for every +1000 rpms

A TGC Super Hero should be able zap it to fix the leaks. If not try replacing the front seals and oring the one that covers the rear balance shaft is often the problem

evil, no leak and losing oil? id say valve stem seals or maybe piston rings. compression test it and if a cylinder seems low, add a cap full of oil into that cylinder, then if the compression raises its the rings

and man ur alternator going so you are going to the timing belt? i just did my belt and man is it much easier to just do the alternator lol. its not hard by any means to do the timing belt just setting the tension without the tools will suck for you. good luck. are you doing anything else while in there? i did all new belts and pulleys tensioner water pump etc.

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Originally Posted by Galanttuner10

and man ur alternator going so you are going to the timing belt? i just did my belt and man is it much easier to just do the alternator lol. its not hard by any means to do the timing belt just setting the tension without the tools will suck for you. good luck. are you doing anything else while in there? i did all new belts and pulleys tensioner water pump etc.

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I went ahead and deleted the rear balance shaft while waiting for the alternator to arrive by mail, since my car would be out of commission during that time anyway. I set the tension on the T-belt by using a foot long crow bar. I pry on the tensioner pulley with the crow bar with one hand, then tighten down the pulley bolt with the other hand.

So all together, I replaced the alternator, the serpentine belt, checked the water pump for any signs of bearing failure, pulled out the rear BS, replaced it with the stubby, then threw the whole thing back together. I'm all done now and she's up and running great! :orangebiggrin:

I'm sorry to bring up an old thread again!!!

I just wanted to say that my car actually burns less oil now than it did when I hadn't remove the balance shafts.

With both OEM balance shafts installed with the balance shaft belt: oil consumption was 1 quart every 600 miles

With both OEM balance shafts installed without the balance shaft belt (and severe engine vibration): 1 quart every 200 miles. I could see blue smoke while idling.

With the oil pump-driven balance shaft removed and the balance shaft belt gone: 1 quart of oil every 1000+ miles. I've driven over 1000 miles since I did both an oil change and deleted the oil pump-driven BS. I still have not burned a quart of oil!!! :bouncy:

Now, I don't exactly understand the technical details as to why my engine burns less oil, but I'm definitely not complaining about it! :orangecool: