From what I know and asked around in regards to the balance shafts it depends how high you want to rev the engine. If you want to go more than 9000 then yes remove them. But then again if you wanted that why wouldn't build the engine properly.

I am doing a drop in and I kept them. My engine is almost a virgin. Less than 19,000 miles without abuse. It has seen 8 oil changes and 4 plug change usingthe best stuff

 

i'm revving to at least 8500rpms and maybe more depeding on how my power band looks....car feels great and you wouldn't even know they were gone w/the AMS delete kit

 

just curious to what made you change your stance on installing drop-ins since when this thread started you posted up pics of how you did it?

jeff

 

I did it on my own car. Since that time a few years back we have learned how important precision machining and measurements are. Another shop in town has lost at least 4 engines due to drop in builds. We are currently replacing engines in two of them. Needless to say they will not be having the other company work on their Evo's again.

 

I used some wiseco std bore pistons and eagle rods in my last evo and it held 37psi and almost 9k rpms all summer before spinning a rod bearing so I don't know if I would do it again but it did work well for a while though.

I never did find the cause of the rod bearing failure

 

We have two cars in our bays now, both big power cars and both getting drop in pistons/rods. I have personally not had a single drop in piston/rod engine fail that we did.

Mitsubishi built these engines to last 100,000+ miles, that's pretty good precision machining right there haha All that is involved is checking the rod bearing clearance, piston to wall clearance and ring end gaps. The rest of the engine remains "as built by Mitsubishi" and it doesn't get much better than that.

I'll try to remember to post up the dyno results of these two cars we have at the shop when they hit the dyno. One should be tomorrow.

 

Finished my drop in build last week. My motor had 19,000 miles with some strip time (40 passes to be exact) and mostly highway driving. Never saw over 30psi ever and saw over 25-26psi only on the dyno. The car was mostly a 23-25psi car.

When we removed the stock internals they were like brand new. Even the piston coating was almost intact. no marks, no scars, nothing!

Followed all proper steps, everything was triple checked, motor started. We even did compression test, leak down test, etc and everything is good to go. And of course no 3000 miles break in crap. The motor will be tuned on pump 25-28psi and then we will have some Q16 fun!

Its all about the builder. Actually they had a block open from another customer who came from another shop in the area with a bad motor. Why? Because on their drop ins they were putting the rings without sizing them!!! Never seen that before! Needless to say that the block needs major work if can be saved at all!

 

David, I am pretty sure that those cars will PERFORM!!! Can't wait to see a new thread!

 

My engine recently overheated and everthing is taken apart, I'm was running a fpred at only 25psi.
this week I'm going with a drop piston rod combo with a balance shaft delete kit, after my break--in Will low 30psi be pushing it?

 

bump

 

Sorry to bring back an old thread but I was told to come by and check this out and it has given me a lot of information because I'm in the same boat but I'm starting to think that my car has to many miles for a drop in. Here is some info on my whip:

2003 Evo
76,700k miles
Not daily driven but I like to drive it when weather is nice as if it was a daily.
Running FP Green right now but want to move up to the RED.

 

i have a 30,000 mile 4g64 block in front of me that was just measured. the deck is out of square .003" front to back and the bores are worn .001" on the thrust sides where the skirts wear. its getting honed with torque plates and decked.

 

i just hit 70k miles last week and im still going with drop in pistons and rods!

 

the only way to be sure is take it to a reliable honest shop...and have them check to see it your cylinders are too far out of round for them to feel comfortable doing it...

 

Drop-ins are not always a bad idea, really just depends on what kind of shape the block is in. But, if you're going to do a drop in set-up, you really have to make sure it's all measured correctly and that a lot of care is taken to insure proper installation especially when it comes to bearings. There is very little chance of a drop-in piston or con-rod failure(under normal conditions), that's not the part you really worry about....it's everything else(bearings, clearances, rings...etc) and the condition of the rest of engine. Again, the rest of the engine must be up to the task and everything must be assessed, measured properly and installed properly to insure this.

Another thing that people don't always think about(but they should) is the tune. If the tune is ****ty, it doesn't matter what kind of build you're doing....it's going to drastically shorten engine life-span. It only takes a few good detonation or pre-ginition events to start things in motion too.

I have seen many drop-in engine builds last a long time, most of which i tuned conservatively, as i was known to do. It's a fact, the more a customer wanted me to push the envelope of their set-up, the less reliable the engine got..no matter how it was built. There is a lot to be said for that alone. I would just about always insist on leaving a few HP on the table in the name of reliability, using less aggressive timing and safer AFRs and occasionally less boost, especially if this engine was a road race motor, where it would see extended periods of high cylinder pressures, high RPMs, high temps, and high load forces.

~Cary