jdraughn

I bought a 1990 Coupe and after less then two months, the engine went. Very frusturating because the person I bought it from had gone through so much trouble to hide a ton of crap that was wrong with the car. Im still discovering all kinds of interesting looking problems that are also leaving me a little concerned and alarmed.

Anyway, rather then just reusing my original block, if it's even still good, im actually in the process of pulling it out of the car right now so I don't know yet, I found a 400ci block for 100 bucks, which is now in the machine shop. The machine shop checked it out, and it's ok. It will need to be line bored, deck squared, cylinders bored and a few other things.

I plan on mildly building up this engine, using my stock intake and heads for now. If my stock heads are junk I will probably go ahead and spend 1200.00 and get some AFR heads, but only if my stock heads aren't reusable.

I wanted some opinions on how to build up this engine while on a budget, but I don't have a set budget in mind though, I guess I am hoping to keep it under 2k, machine work not included, but under 1k would be better.

My main goal is just a fun streetable car. I don't plan on doing any racing, although I may take it to the drag strip for fun. I am afraid if I do that though, that I may get bit by the bug and start pooring thousands of dollars into my car in the quest for more power

I don't really know what I want other then having a fun streetable car. I am not too terribly concerned with it passing emissions, although it would be a nice bonus, I just don't think it's going to happen.

Tell me what parts combo you would choose, and why. The why part is very important because that will help teach me. What are the pros and cons to the way you would do it? My dad is a mechanic and has put lots of engines together, but as far as selecting components, he is pretty useless

Mainly I want to know:
1. What rods you would use, and how much displacement I would be seeing with those rods and a 400ci block bored .030 over.
2. What cam and or cam grind?
3. Any estimates on how much more power I will put out with said components and everything else being stock (I am going to get a new exhaust system and headers).
4. When buying the pistons or a crank, will I need to get anything special (forged?) to handle the extra power?
5. Will the stock injectors ok with this setup, or would a different size be better? I plan on replacing them anyway.
6. If my stock heads are still good, I will get dished pistons to reduce the compression ratio.

I am trying to play on my TPI's strengths and build up massive low to mid range torque. Also, I remember reading that a new torque converter can really help out, especially with the torque that you really feel when you hit the gas from a stand still.

LD85

A budget build up would use a stock 3.75 cast crank, a set of 5.7 Eagle SIR rods that cost @ $180, and .030 over Hyperutectic pistons that will make it a 406ci engine. At this point with machining you will be close to $1000 from the start.

Your intake is going to restrict the heads and your heads are going to restrict the engine, So if you get a set of heads for @ $1000 that leaves you with an intake that wont support the rest of the package.Then you would need a set of headers and hopefully you have a cat back already.

So your budget would need to be @ $3500 would be my guess for a budget setup. Below is a partial list


Rough Estimates
Cast crank = $200
Cam = $250
Pistons $ 300
Rods = $180
Heads = $1000-1200
Intake = $800 used miniram
Headers = $250 = Hedman
Machining = $ 500
Cam, rod and main Bearings = $120
Gaskets = $150
Driver side dipstick oil pan = $ 100

bjankuski

If you want to keep it cheap and have a good torque package this list will give you a good start:

-Stock crank
-Stock rods (They will work fine in a low RPM<6000 RPM application), You could upgrade the rods bolts to ARP fastners.
-Cast or hyperutectic pistons will work fine (You will need a dish to keep compression down ratio near 10:1)
-The stock heads will need steam holes added to them to work with the 400 block
-Pick a Hyd flat tappet cam with .050 duration numbers between 210/220 on the intake and 215/225 on the exhaust, on a 112 seperation and lift in the upper .400 to low .500. You may need to change valve springs to run that much lift. If you don't want to change springs pick a cam lift of no more then .470.
-Stock injectors will work but you will need a custom tune for the combination.
-The stock torque convertor will work fine with the 400.

jdraughn

Thank you both for your replies. I had talked with the machine shop and told them what I wanted, and he did give me a good number of about 1000.00 for machine work, plus they already had a crank they would give me if I just paid to have it machined, plus pistons and rods, but I wanted to get some other opinions.

What about making the 400 a stroker? I think I read you could stroke it to like 420something, but then you start to run into problems with rings getting mighty close to the top of the cylinder in operation?

Also, what does it take to tune a 1990? Since it's not OBD2 does that basically mean I have to swap preprogrammed chips? Any chance I can program them myself if I buy the hardware and find the right values to change? Speaking of my computer, how much info can I see in real time on my car compared to a car with obd2?

Iroc57

You want budget then stick with the crank that they gave you. 400ci will give you the cubes and will twist pretty good down low. Thinking about a tune right now is like signing your name on a blank canvas...stay on task or you will never get it done and worry about the short block first.

LD85

400's have lots of TQ and if you keep a long runner intake, you will have what I would term, excessive TQ, if there is such a thing

Iroc57

To the OP - If you adjust your driving to shift out before it runs out of air and select your gears with this in mind you can build a quick setup using the low end grunt.

Remember..there's no replacement for displacement
Just don't jump on it with the roof off...don't ask how I know this

johnno!

I'll bite, how do you know this

Iroc57

I cracked my car in two places

pologreen1

PFFFFFFFFshow off

GREGGPENN

If I was playing the match game, I'd consider this a match!

ch@0s

I just sent my stock chip to this guy.

http://www.scotthansen.net/

He was referred to me by the guys at third gen.
$60 to reprogram your stock chip.
I should have feedback within a month or so on the programming.

Nathan Plemons

To answer your question on the tuning, you can see a lot with your computer and you can get all the stuff to tune it yourself. It doesn't cost THAT much to get into it and you'll certainly need it. No disrespect to anybody who does mail order tuning, but the odds of them getting it right if you're doing what you say you're doing are slim to none. Sure they'll make something that may run, but it could always run better.

Get what you need and you can data log and adjust, data log and adjust, over and over until you get the tune nailed down.

There are plenty of us on the forum here who tinker with tuning who would be glad to help.

Firevette

I guess you got your cam/heads finished? Hit me up man, I want to check it out. I still have the Y-pipe if you want it too.

T. Wayne Nelson

jdraughn, stroker from the utah vettes forum has a friend who can burn your chip. Send him a PM on the forum

LD85

FYI I have a cam for sale that came out of my 406 and would work well for your setup.

ch@0s

yes, I have it all and plan on doing it over the spring breaK. I do want the y pipe.
so I will call ya

ch@0s

I agree, and plan on doing my own tuning in the future. For now this is a simple and economic way to get a basic tune. If you go to his website you will see he will work with you to get it perfect if you can do data logging.
I am looking forwad to this because it will help me learn.

all show and more go

heads wont work so dont even bother, patriot hears are 900 for a 400, go carbed!!!!! tpi wont let u even hit 3600 rpm lol. well those 2 are where most of the cash is spent, what are you gonna do for a trans?

all show and more go

im an idiot, i should of mentioned why the heads wont work. i have a 400 60 over, the cylinders are each at least a 1/4 inch bigger then a 350, do the math (pistons are way bigger then the chambers)