Rep Power: 248

OK, I'm not sure if this is the exact right forum, but you guys in here would know better than anyone else.

I'm considering taking some engine-building and repair classes at TCC this summer, just for kicks, and I'm considering building a new motor for my car as a project, just for kicks, you know? I know it's not a small task by any stretch of the imagination, but that's why I'm forking over the cash to go to school to learn how to do it. I want to learn how to do it right, but I'm not planning on making a living as a mechanic.

But what are the advantages/disadvantages to building an engine with hardier internals but not using any form of forced induction? I'm not really anticipating any significant power gains, I may boost later on down the line if I want more power. I'm just curious what the end result will be.

Thanks in advance.

 
Rep Power: 287

I've always been under the impression that replacing components like internals without going into the forced induction market wouldn't be worth the hassle & money. Stronger cranks, valves, rods, and pistons don't increase the horsepower in a vehicle. They allow more abuse for things like superchargers and turbochargers, and well regular bolt on's of course. Other items like pulleys, drivetrain components like clutchs and valvetrain components like cams can in fact extract more power from the engine, but are still, in my opinion, on the far end of the spectrum of modifications. (you should get other stuff before these.)
Don't get me wrong, replacing your engine parts is always a good idea, it just cost money. And remember, you can get the turbo system first, and then build the engine....which will allow you to get more out of what you have. I donno, if you wanna have a hobby of building engines for a long time, I think the class is a good investment.

 
Rep Power: 424

Forged ones tend to be a little lighter too... less weight, less inertia = more power.
But honestly, unless you're gonna bump the compression up, or drop it and boost it, you wont have much of a point to just rebuilding it stock and beefy.

 
Rep Power: 248

Well, that's what I would like to know.

What would be the pros or cons of going with forged internals, either of higher or lower compression? Don't I remember hearing somewhere that it is indeed possible to have a powerful N/A D17, but it has to be rebuilt from the inside out with higher compression pistons, new cams, etc.?

 
Rep Power: 350

Its realistically up to 3 things to make power. Air/fuel mixture, head's ability to flow air and ignition timing. A stock d17 head isn't going to flow that well even if its forced induction. The reason I always tell people to drop the cash on standalone is because you realistically pick up so much "free power" just by adjusting the air/fuel mixture and ignition timing. No matter what you do, you can always use that engine management and pull more power.

As far as building goes, yes, higher compression is the way to go on an n/a build and you'll want somewhere around 9:1 for turbo on a d17. Your power goals are totally relevant here. I wouldn't bother building a motor if I didn't know what I wanted, you may very well be wasting your time and money for nothing.

 
Rep Power: 248

Let's a operate under the assumption that I AM going to build an engine. What is going to be the difference between building for N/A and building for boost? I mean, like what is going to be the end results and different parts involved?

Sorry if I'm not understanding something here.

 
Rep Power: 350

Dude, it would take entirely too long for me to explain to you the differences. If you really don't have a clue, I would suggest doing some research on turbo and n/a motor builds and what makes power....

 
Rep Power: 248

No, I have a clue. I know the basic principles. I should have been more specific. Like, number-wise, what would be the differences with the components involved?

 
Rep Power: 350

Well this is basically what it boils down to:
Higher compression=more n/a power, but less tolerance for f/i
Lower compression=less n/a power but more tolerance for f/i

There are alot more factors to consider but this is the general idea. Heat and the ability of the engine to tolerate the power you're making are keys as well as the heads ability to flow. That's what I'm getting at, there are so many variables, it would take way too long to try and break it all down. Take the engine class, you'll learn alot.

 
Rep Power: 248

Yeah, I probably will. I'll see how my finances are looking, but I plan on it.

I appreciate all the help here. +1.

 
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na on a d17 like intake, race header, k-pro with cam gear, stg2 camshaft with supertech valvetrain, port n polished head, built block and tranny work would be a fun d17 allmotor car but hella expensive for whp and tq compared to turbo

 
Rep Power: 248

Well, I found out I can't take those classes, they're not offered over the summer, and I'd have to be in the "career plan" or whatever, so I couldn't take just one or two classes. So much for formal knowledge, guess I'll have to just subsist on forum info for a while.