Ronald Mcdonald

Alright, so I plan on finding a motor to rebuild and swap into my car, but I had a few questions.

1. When finding a motor, does it matter if the motor has a spun bearing, or is it better to find one in good running condition? I am sure it doesn't make too much of a difference, but does it really matter?

2. When rebuilding a motor with the plans of boosting it, I want to use stock crank, rods and all that, just with low comp. pistons. When breaking it in, should I just use the low comp. pistons and use the stock manifold and injectors during the break in time, and then when it's time to tune it, put the turbo setup on? Or would it be good to run the turbo setup, and just not boost it, on a base-map?

I guess that's all I have to ask for right now, and I doubt it matters, but the motor that I plan on rebuilding/boosting is a Nissan single-cam KA24E.

truffle_shuffle!

Dude if you never had built an engine, get a buddy who can help you.. you may need machining on the engine, you have to check clearences and you May want to go from cast to forged internal if your going to boost a ka..

John

the better shape the engine is in to start with, the better it will be when you're done, and it'll take less work and parts. A spun bearing means new crank, rods, or both. A blown head gasket could lead to decking the block or the head being warped. A very high mileage motor will have tired valve springs and fatigued metal (bolts snapping, rods weaker, crank worn). If you're on a budget, just like any other project, its always best to start with something thats not broken

truffle_shuffle!

EXACTLY.. for you its better to buy one that works than rebuild it.. I know you can buy a Ka24e running for less than a rebuild.

EliteZ

I'd reccommend atleast rods and pistons. As for waiting to put the turbo on it, I don't see that being necessary, just have the waste gate open until the rings seat properly, if that even.

Chuck 98 RT/10

How much money do you have and how much HP and/or durability do you want to end up with?

Swifster

Chuck is right on point. Speed costs, how fast do you want to go?

While I'm sure there's always an exception, every OEM engine I've seen with a turbo or S/C has had at least a forged crank, and many also have forged rods & pistons. Consider these mandatory if you plan on turning up the wick a bit.

Engine building (or rebuilding) is all matter of attention to detail. This includes any machine work and the assembly process. As mentioned, if you haven't done this before, it wouldn't suck to have someone who's been through the process before, especially if they've been through the same engine. Cleanliness and the right tools are essential. If bearing clearances are off, you'll have problems that could cause the spun bearing you mentioned, or poor oil pressure, which could lead back to a spun bearing.

To summerize, you can't pull this apart in your garage, toss parts at it and expect it to run long. There are many good books that cover performance build ups , as well as sites on the internet. While most of the ones I'm concerned with are for V8's, the process is the same. I'm sure there are many that target cars that start with the 'H' word .

EDIT: By the way, the old addage that there is no substitution for cubic inches applies. Along with finding a good running engine, get the largest engine that will swap in. If you have a 1.6L and there is a 1.8L that will bolt in, get that instead. I know a lot of H#$&@ and Acura engines interchange, so look there as well.

Ronald Mcdonald

Ok, My motor is a 2.4 liter, and comes with about 140-150 HP stock.

I plan on adding a small turbo ( Nissan T28 ) and don't really want anything more than 200HP. When I said rebuild it, I didn't mean build it to handle 4-500HP. Just a fresh rebuild, to keep compression great and keep everything fresh.

TNathe

for shooting for 200hp man id just put supporting mods on your car now and leave the engine be unless you KNOW its worn now...
KA-T.org They have a section for the single cam KA engines Im not sure what needs to be done to those to support 200hp ish, but they would.

Swifster

You could re-ring it and hone it, but again, it comes down to detail. And I still wouldn't reassemble everything without inspecting measuring everything first. As for getting an extra 40-50 HP, you shouldn't need a turbo. Some head work and cam(s) should be enough to get to 200 HP, even in a N!$$@^.