Ah, so you were running an underdrive pulley? As in no harmonic balancer? I was worried you blew a stock oil pump at 300whp, as that's my goal. If you're not running a balancer that explains why. Maybe my oil pump will be ok at that level then.

 

not just any underdrive pulley, this one is smaller than a *****'s dick. Unorthordox Racing Ultra R. I'll be using the stock pulley when the new motor goes in and may eventually pony up for the ATI pulley.

 

Hmm, well that expains it then. Why weren't you running a balancer? Sorry to hear your OP died, but relieved to hear it was from not having a balancer and not from shier crank flex. Well, one could argue that but the balancer is their for a reason, and it's my belief you need it for the OP and main bearings sake.

 

I had long ago read about the issues of underdrive pulleys on a more powerful motor, I think dynan bmw had an article on it. But when I installed my turbo last June anyone I asked didn't think it was an issue so I continued to use the thing. I think deep down I just wanted a reason to go back to a real motor, a 94.

 

Real motor? Meh, I like my 99' I guess you'll keep your 99 head though right? Only difference is head and compression ratio, no? Yea I've heard some people say no balancer doesn't hurt your motor. Others say it's important. One well written article by a seemingly knowledgeable person on the subject suggested it was needed for certain RPMs and loads, as there are certain harmonics that can amplify and cause damages. The balancer helps to dampen these harmonics (I know right, imagine that....). He suggested it takes the right combination to cause damage. IE, you have to have the right RPMs and right load for them to amplify, then you have to maintain those conditions for a substantial length of time. I dunno all the details but his point was it is needed.

 

well i have at my disposal(in my possession) a complete low mileage 99 short block and a complete lower mileage 94 short block and I'm gonna go with the 94 because it has the oil feed on the driver side.

 

Cool, I forgot the earlier 1.8's had the block taped for an oil feed. My block has the spot in the casting, but it's not taped. If I ever tear the motor down I'll tap it for sure. Better start post whoring more, I'm 3 post from passing you up!

 

nah, not my style.

 

Holy Shnikes, You did good....lol

 

Anytime I've read anything on failed oil pumps on m.net with high hp miatas, 90% of them were due to utilizing an underdrive pulley.

 

::aheam:: Apparently you didn't hear me.

You just loved that squeeky belt.

 

why's you gotta be like that?

...

as for the pump gear, are you saving the pieces? curious if there's any learning to be done on failure modes.

 

He should save some pieces. I can take them to work and have our metallurgist (sp) see what he things.

 

Paul, you should consider the gears Loki is trying to make for us.
As far as pullies go, they have been associated with OP gear failures, but Unorthodox claims that is not the case and that they fail even with stock pullies on both, the Miatas and Hondas B-series motors. To each his own but I do believe that lack of the stock (or better) balancer contributes to the gears shattering sooner and at lower power levels, it makes perfect sense to me.
Do you plan on upgrading anything in your block? Since you're in there, might as well do a little work. At least new rings for piece of mind as they are the very weakest link in there. Your car your call, but that's the way I'm looking at my block, I went ahead and got some ETD rods as well. I am still debating whether I should balance my rotating assembly or not, that may help a little as well.

 

I've only been at Jesel for 2 years and we mostly do testing on high HP big cube engines so it's not really apples to apples, but after a few conversations with ATI engineers and seeing what an improper damper does to crankshafts, I wouldn't run without one.

 

How high were you revving this engine?
Do you think redline might be a factor?

 

The intensity of the frequencies increases with revs, and higher rev limit cars are known to blow up gears more likely than lower.

 

Yes you should. Balance the pieces individually, then balance them as an assembly. With the clutch too if you can.