What upgrades would you do to make a good n/a engine? say one a k20.

 

standard I/H/E stuff, then hotter cams, better engine management, etc.

but a k20 is pretty decent straight out the box.

 

to add to the list:

higher comp. pistons, longer rods, new oversized valvetrain (optional), port/polish, angled valve job, larger injectors, etc.

 

Screw custom rods, just use the right crankshaft for the block you have.

Also, I believe oversized valves to be a gimmick. I made a post in here explaining my logic on it, but I'm too lazy to dig it up (feel free to search). Point is use stock valves.

Also, avoid porting if at all possible. It is expensive and unnecessary in some cases if you use the right stock cylinder head.

To the OP, it really depends on the motor. Generally though, the right block/head combo, high comp pistons (which may be stock or otherwise), cams (or cam), IHE, a tune (very important and often neglected), and a close geared transmission are what make a good NA vehicle.

 

i think boring out the engine will help a n/a engine along with a bigger throttle body. im not sure though on the boring, someone might have to inform me about this.

 

most honda rods aren't the strongest, and i've been looking at some N/A articles, a guy named larry widmer out of texas builds lots of n/a honda motors, he's been building for a long time now and i think he knows his stuff a little better than most of us here. he's pretty much done all of what i listed above to a b20 dart block and came out to over 300 whp. but in a budget project, most of the stuff isn't nessecary what i listed, just a few things.

and boring is ok to a certain degree on some blocks, but on some applications, when you bore the cylinders, you're weakening the cylinder walls, and if you resleeve it, you'll have two different materials that expand and contract at different temperatures, therefore making the bottom end not as reliable as normal. the greatest thing is ring size, if you don't get it right, then you have a crap motor that's not going to be reliable, that's why some racing applications use a little on the oversize side.

 

two part question here.

If u do a good n/a build cant u still put a turbo are sc it?

When u say avoid porting i mean port/polish, right? but if i wonted to add a turbo are S.C it, i thought it was a good itea to port/polish befor adding?

 

are you trying to say "turbo OR sc"?

and no, it's not recommended, because a good N/A setup has too large of compression for a turbo setup.

and secondly, no, you can port/polish before turboing, but it's definitely not necessary

 

Larrys company's name is Endyn out of Dallas. You can see what he does here: www.theoldone.com

Basically, he's a mechanical engineer who's been working on cars since before we were born. His motor uses a forged 92mm crankshaft from Crower, so he had to get custom rods for it (it made 296 crank hp btw). LS 89mm is a way better option per dollar (Crower stroker = $2000+).

As for the valves, I got less lazy: https://www.hondacivicforum.com/m_396336/tm.htm

I even dug up the 86mm bore engine mentioned in that thread: http://forums.evans-tuning.com/viewtopic.php?t=3179.

 

if you have the pistons/rods with lets say a 10 something compression you can boost that motor you "need" to run race gas and it will last a good while if its done right. now if you just slap in pistons and boost the motor then you are gonna have some problems