I've read a lot of threads on various forums about the long-term sustainability of built engines. This is a big subject with a lot of variables including parts used, style of driving, quality of tune, and so forth. One thing I'm hearing a lot is that built engines should last as long as OEM engines, but they don't, even in cases where they are not abused, over boosted, and so forth. Since many of the threads I've read go back a few years, I'd like to raise the question again for those of you who have built engines. With five + years of Evo X on the road, how is your built engine holding up? Please provide details about that type of build and power you are holding.

To sum up what I've generally found, it appears that most successful builds run 18,000 - 30,000 miles. If the engine does not just simply die, then it tends to die a slow death of needing more and more fluids. Is this accurate, or are there happy owners out there that DD their 500 + hp builds with OEM reliability? I really want to know.

 

Depends where the motor was built, by whom, what parts were used and did they use new seals, gaskets etc. This question has many variables.

 

I agree there are many variables. My point is that no matter what the variables are (partial build, full build, drop in long block, and so forth), if you read the forums it would appear that built engines just don't last. Maybe it is just a case of listening to people's blues, but that's why I'm asking. I'm looking to eventually build my engine, so I'm interested in hearing from people that have been motoring away for 60 - 100 thousand miles, I'd like to know what the magic variables or voodoo they are performing.

 

i'd like to know as well... i will hopefully be getting an evo soon and all info will help!

 

I've been interested in this as well.... I think part of it also has to do with people acting like built motors are indestructible. So they see harsh ignition timing and higher boost than usual.

I'm actually quite curious what would happen if someone built up a 2.0 with stock compression and absolutely *ZERO* other mods including the stock airbox and exhaust and tune. Now the tune may need adjusting just to make the car run, but assume you re-run a stock-like tune that runs way too rich and uses higher timing due to said richness.

I wonder if *that* motor would last like OEM..... It'd be easier to study if the variables were separated out a bit better I'll agree.

 

Well, you get what you paid for. If you want an OEM quality built engine, don't be cheap. Go to a renowned shop like the AMS, opt for the most reliable package, and be prepared to break your bank.

 

Also what you hear on a forum like this could be biased. The bias comes from the fact that we have many people here who don't make that much but want theirs car to push (much) more horsepower than they can afford. The cost they pay is called reliability and durability.

If you read the threads of a forum about much more expensive cars, where the owners are less likely to be on a budget, you will find that their built engines are more or less close to the quality of OEM engines and the blue stories are not as many.

 

Race motors are often rebuilt after each race.

Let that soak in.

 

any reason why anyone would build their engine for no mods? aren't the stock internals pretty stout if you just want to tune it in stock form?

 

mine running like a champ. Great builder and great tuner is a key. If you miss even just one of those two , then you doomed.
Race engines also running by hours not miles... (if you were talking about them)

 

for higher boost or power you need to run at least a stronger connecting rods.

 

Yes, but you'd have to rebuild an OEM engine if that was used at full blast for an entire race also.

I have a built motor pushing over 550 which I daily and the biggest difference would be the amount of heat my built motor generates in all driving conditions. I've only got 10K miles so far and only time will tell.

 

A built motor should have items added to it to keep it cool. Better oil cooler, better radiator

 

I wasn't saying someone would want to do that.... I'm saying it would isolate the variables a bit better if someone ran a basically stock tune on a built motor with no other mods.

Keep all variables the same except for the motor. Then see if a built motor lasts as long under those stock-like conditions. Just a test

 

Good question. I have always wondered about this also.