I was wondering how are the longevity of built motors, espeically FI ones. Because of the aftermarket pistons, rods, and being assembled by a shop versus a specially designed Nissan plant, will most built motors stand 100k miles of normal driving with the occasional romps? Does the quality and endurance of the built motor fall into the hands of the person assembling it, the machinist, or what combination of things?

Id like to be part of the 500+ rwhp club but i would first like to know if it is still feasible to keep the car as a daily 70 mile commuter or do these types of cars wear out much faster from just daily wear and tear.

 

I was told that at 400 rwhp, a properly tuned coupe with an SC should last about 80% as long as a stock motor. I hope that is true. With my estimates that would mean you could get about 120K without a rebuild

 

That's funny Enron, I was pondering that exact question recently.

My trusted mechanic friend told me that basically, if done properly it can last very long, but it's going to be taking more risk for a daily driver, because the engine's probably going to be tuned towards the edge of its capacity. And if it isn't tuned on the money, any piece can easily go. So it will all depend on proper tuning and install...

I suppose you just have to live with the fact that it's much more susceptible to risk, like a bad tank of gas, or whatever life might throw your way...

For a daily driver that doesn't sound too reassuring, though =( I'm trying to figure out that option myself..

 

Done by an expert, a blueprinted motor will be better than a factory motor. That's because the hand built motor can be made with all tolerances very close to +/-0. An assembly line motor never gets everything right on the money, so its power output, reliability, etc won't be as good as a fully blueprinted motor.

*However*, if you attempt to routinely push the motor beyond factory power levels, there will be greater stress placed on the components, greater wear, etc. Pushed hard enough, the motor can quickly wear out or break.

Example, a NASCAR race motor is pushed hard enough that, ideally, it will fly apart at 500 miles and one foot. In other words, if it could last for many more miles, it wasn't being pushed hard enough, and you'd be losing races because you weren't getting everything you could out of the motor.

OTOH, if you drove it gently on the street, it'd last longer than a factory motor. That's because every critical part has been magnafluxed, stress relieved, or replaced with a stronger part, and all assembly tolerances have been optimized.

So the answer to your question is that it depends mainly on how you drive it whether a built motor will last longer, or die much more quickly, than a factory motor.

 

Thanx shopdog, that answered exactly what i was wondering! Are there any shops in Houston you would reccomend? What are some signs of a good shop versus a bad one?

 

If I were going to add FI to the car I would definately want a good boost controller with different maps for daily driving vs drag strip driving. That way you could drive around town without "pushing it to the edge" and still have a lot of "usable" power. With 500+ rwhp the car would be have too much power for the street in my opinion. The drag strip is another story however.

 

Yeah, if you tune it well a stock block / mounts / etc should be able to handle 2x the stock power. It depends a lot on how it's built. For example piston to cyl clearance. Forged pistons expand, they like heat. They have a silicone compound that makes them strong, but also causes them to expand. I usually bore about .033" but for a race application (Say N2o & Boost, high output) I would leave a lot more clearance so that the pistons to not score the cylenders.

That's another thing about a built motor, Your going to have to let it warm up to operating temperature before driving. If you don't you can damage the motor. So yeah, your going to have to let the car idle for about 10 minutes after a cold start. I let all my cars warm up before driving them, even the Z with a stock motor. But some people do not.

 

I don't know the Houston area, so I can't give you any names. The main sign that a shop is good is the large number of happy customers running their engines. This is one area where you want references, and check those references thoroughly. A reputable shop will be glad to supply you with references. A poor shop won't want you to know who their customers have been.

However, you can pick up a vibe from walking into a good shop. All the people working there will be meticulous and committed to excellence. There will be a real pride about the place that you can sense. Generally, the shop will be clean and well organized, though that's not a sure sign. There are clean and neat shops that turn out horrible work. But it is extremely rare for a dirty haphazardly organized shop to turn out good work. People who don't care about their work environment probably won't care about the quality of the work they do there either.