Hey Monty and Raider pilots. I am rebuilding my GenI Raider after it took a dump for the second time, and this time I may go with a balance shaft eliminator kit because my driver's side shaft really took a beating when it all died.

Anyway, I noticed some feedback on this in some other posts, and wanted to get some current feedback on this. I'll be running the 2.6L non-turbo and stock specs, and I was curious as to the buzziness / accessories breaking off. What about a little more power put to the wheels by getting rid of those dastardly shafts? Any feedback would be appreciated.

Incidentally, I KNOW my crankshaft is going to at least need some quiet time at the machine shop and at the worst will be unservicable. If anyone has or knows of a joint selling cheap cranks, please let me know.

Thanks in advance!
SpideyRaider

I got rid of the balance shafts when I did my rebuild -- 15,000 miles as a daily driver since then with absolutely no vibration related problems. In fact, it's still one of the smoothest 4 cyls I've ever had!

Terry

Terry,

Thanks for the reply! One more question, since yours was a smooth as buttah, did you have the engine balanced or anything to accomplish this?

Thanks!

The new pistons were all matched as to weight when I bought them, and the piston/rods were balanced when the machine shop assembled them.

Terry

I'm the one who bitches about the vibration without the b/s's. It wasn't as bad until I went turbo, and I'm quite sensitive to engine NVH - and I spend a lot of time at 3000rpms+ (Atlanta is a great place to cruise FAST), where it's worse. That said, a LOT of people find it perfectly acceptable, and it should free up a few ponies, which the 109hp carb 2.6 can really use. My broken brackets were for the p/s pump (and those probably were aggravated by a ever loosening back bracket bolt, which is almost inaccessable), and an overly fragile cast aluminum a/c compressor bracket, and many of you have the cast iron one as I now do, which apparently is indestructible. Since your shaft is totally chewed, I'd go with the b/s elim. kit, but get the good one with new sprocket for the crank and oil pump, and file the central slot in the only remaining chain guide (bottom left hand one) out a little oval to give you some tension adjusting room to avoid noise and short chain life (remember the chain drives the oil pump!). Locktite the sprocket bolts, too, and don't forget to have a bearing shell pressed into the driver's side b/s front hole to block off the oil passage there, or you'll have disastrously low oil pressure. Also either buy a new oil pump, or make dead sure that the clearances in yours are tight, and remove the oil pressure relief plug, spring, and piston and thoroughly clean out the bore to keep it from sticking (that's the big hex plug at about 1:00 on the pump). I shimmed my pressure relief spring with a plain flat washer of appropriate diameter to get a higher hot oil pressure, but if your pump is sound and oil clearances are correct, you should get the proper 10psi/1000rpms oil pressure at least up to 4500rpm, beyond which the carb 2.6 is out of breath anyway, and it's time to shift. I can get up to 5500 with the turbo (higher, actually, but the turbo runs out of max boost maintainabiltiy there), so I shim the spring.

Since it's a big I4 engine, with a long stroke, proper static and dynamic balance is very important, and 87's point is well made.

I'm going back to balance shafts on my rebuild, but they have no real effect on reciprocating balance, just on the inherent 2nd order shaking force inherent in big 4's, so I'll be having all my parts professionally balanced, too.

Happy wrenching!

i got rid of the balance shafts and my Montero is smoother than my '02 Subaru. Hmmm, that can't be right... maybe I better take the Subaru in.

dan

oh - i do get a little vibration around 1100RPM. nothing major though. I did NOT have the engine balanced although it is a rebuild.

Eddy's right -- I put in a new oil pump and all new gears. The elimination kit I used came from NAPA, it didn't include the gears but they were available at Car Quest. The kit NAPA offered looked to be the highest quality of any I could find offered upon physical examination.

And remember -- Loctite is your friend when it comes to the oil pump gear bolts!

Terry

I did mine after oil starvation ate the b/s bearings. The engine is balanced and I am happy with it. I do not discount Fasteddy's input though.

Fasteddie complains about it, and I'm one of the "ones" that say "Don't do it". The reasons the Manufacturer did it are almost too numerous to list, But Mitsubishi DID pioneer this technology, and several others havs Purchased the rights to use the design from them, including Porsche. They don't rob any power, they last forever, and they work very well. Almost every Manufacturer uses them in at least one engine design, and they cost money to design, and put in. When a Car manufacturer will spend money to put them, when there main focus is profit, they MUST see the need/reason for them. We could go into all the detail that you want, but just do a search on balance shafts (google/Yahoo) and do some reading, and then form your own opinion.
I leave them in, and when I looked for the 4.3 that is in my rig right now, I looked for the "balance shaft version", as one of my requirements.
Kary

I have run with and without ballance shafts.

A good reason to get rid of them during a rebuild is the parts add up in cost. Two shafts, chains ect can be around $350. Less complexity can be good.

Why keep them? Well the motor is smoother (ok duh). When the 2.6 was designed the engineers were able to use a much longer stroke and heavyer rods than a normal 4 cyl engine since they new they could cancle the second order (actualy a secondary effect of a second order vibration) vibration out with the ballance shafts. The 2.6 is built like the old slant six... Long stroke small bore for good low end torque. this is also why it makes a great turbo motor, inherant torque and a turbo to help out after that. But unlike a slant six all fours are inherantly out of ballance...

If you dont have ballance shafts then you must tune the mounting system to keep the vehicle smooth. If I were building a 2.6 for no ballance shafts I would put the rods and pistons on a bit of a diet, this will reduce the forces.

I have driven 2.6 engines with and without shafts... And could be happy either way. I chose to put them in on this motor. As long as you keep oil to them they will be happy and live as long as the rest of the motor.

Plenty of people on the Starion board get rid of them and it does not seem to be a problem. If you get rid of them fresh motor mounts will help isolate the motor from the rest of the vehicle.

I kept mine, no regrets so far,

Kevin