Well, I am in the process of buying ANOTHER z24, blown motor, 5 sp. I was wondering what I was going to do with it, but I think I am going to do a very mild 10:1 to 1 or possibly 10.5:1 compression build at .020 or .030 over, probably stock rods, will do secret cam swap, and may put my MSD ignition set-up from the turbo motor on it. Buy coils and blocks for this car, so when i want to drive the turbo car, just switch the box from one car to the other, put the turbo settings back in or vise versa. Now, for pistons, I wont need anything special, I just want something to meet the compression and bore that I want, but I cant find anything for the 2., other than JE and Weisco...too much money, and I dont need forged aluminum pistons. Also, what do you think about using the stock rods with aftermarket pistons? I dont see a probablem with it. I am thinking that I will probably have to pull a little timing out of it inorder to run 87 octane. A few more questions:

1. Do you think I would need ARP headstuds for the slight upping in compression?
2. How much for all new bearnings in the 2.4?

As you can tell, this is kind of a budget build, nothing crazy, I just want something with more drivable power. With this done, what do you think I should expect? 165-170 to the crank? Oh yes, this will have a built intake manifold, (one of my dads friends owns a machining business, does some CRAZY work, tons of CNC machines. He is machining me an intake flange out of aluminum, and one of my dads other friends owns a welding/fabricating business, and he will be makeing the rest of the manifold. This guy is amazing, if you gave him the drinking glass infront of you, he could find a way to make the damn thing. His welds are amazing) HO t/b, intake, MAYBE an exhaust.

Why pull timing out of one to run 10:1 on 87 octane when its not gonna see its full potential anyway? Might get a little more power but seems pointless to me.

I root for the underdog...figured I might as well be one

Why? Because I have an extra 96 motor laying around, it needs a rebuild, so I am going to do a very mild build. 10:1 or 10.5:1(which I will probably do) with a little timing pulled out, will still yield more hp. I'm not saying I will have to pull timing, we will see. I already have a fully built 2.4 that I am prepping to run 18-20 lbs of boost through via t3/t4. This one I want to go A LOT easier on, and do the motor ALL myself, except for machining. You can keep your comments to yourself, and build your motor a way that you dont see pointless.

If you aren't planning to run enough power through the motor to throw a stock rod, I personally wouldn't worry too much on the head studs. Stock head bolts will be fine for secret cams and bolt ons. You can always get the stock pistons cryo treated. I really don't know of anyone who sells pistons for our motor in different CR's that aren't forged, though.

You know, if you really wanted to build a N/A motor with a 10.5:1 CR, you could get an 086 head, and 9:1 CR pistons to bring the final compression around 10.5:1. This is what I am almost done doing. Unfortunately, I am waiting for Miller to build me an oil pan (been waiting for over 2 months now...he is in the middle of moving his shop...oh well). Being a 96' though, you'd probably have a problem with your ECU throwing a code due to your EGT.

As far as what you estimated for horsepower, that was about what I thought... Probably around 150 whp.

I have seen you around the .org alot, so I know that much of this info isn't news to you. Best of luck with whatever you decide to do.

I don't know of anybody who sell custom cast pistons. It's just too hard to do.

What you want really is a "stock" engine with a few modifications.

You need to find out what you want to run as far as compression. If you don't want to run 89+ octane gas, don't even bother getting high compression. You should be able to run 87 octane and 10:1 compression. The problem with running low octane gas is that you will most likely get a bit of knock and the Ecm will retard timing. So you better go with a bit more compression and use 89+ octane or stay with mostly stock compression and run 87. In the end, a bit lower compression and 87 will have more power than higher compression with cheap gas. Why? because the Ecm will be pulling timing and you WILL loose alot of power.

So once you decide what you want to do, you are ready to move to the other step.

How much money you got and how much time you are ready to spend in that engine?

Getting more power from the engine cost money. When you modify parts IN the engine, it cost usually more than bolt ons. If you don't have times to spend on your engine, you won't be able to get the result you want. A good engine is build slowly.

So if you got times and money, we can move to the other step.

What do you want to do?

You said:

a bit higher compression
no forged rods or pistons
oversize pistons
secret camshaft
head studs
165-170 to the crank

It's a good list but you don't need to modify the engine to get 165-170hp. A WELL desing header, complete exhaust and an itake will get you there. So you can just rebuild the engine to stock and put bolt ons. If you want to get that FROM the engine and then add boltons, we can work something out.

You said higher compression (10:1 10.5:1). You can get 10:1 with stock replacement pistons at 0.040" over. 10.5:1 is not possible unless you get custom pistons witch is almost impossible unless you got with forged. You can get the head shaved a tad to make it flat. You would need a set of 00+ pistons (flat top)

You can run any pistons with any rods. To be on the safe side, you can have them shotpen and have the big end cut and redone.

Have everything balanced.

You don't need head studs. The stock bolt are fine. It's a stock rebuild anyway.

You could also get a 086 head from the 2.3. You would get 11.4:1 compression with the stock pistons. Higher with bigger pistons. You would get a good gain.

You can also get the 2.3 oil pump conversion to get more power and reliability.

So basicly, rebuild it with replacement parts and take your time. You will get the amount of power you want.

Also, the cams will help.



Gilles
2.3 Ho

As already stated the hp you are seeking can be done on a factory motor with bolt ons. My 2001 Z24 put 139.8 at the wheels with a intake TB, and motor mounts and just a muffler. With 14% drivetrain lost that would be 159.372 horsepower at the flywheel. I'm sure with my cams, and full exhaust I'm at 165 flywheel horsepower.
For your goals I would do a stock rebuild some mild head work with cams, and then basic bolt ons (intake, header, TB), also a nice exhaust and then some HPTuners on top and you will be past your goal.



FU Tuning

Hey man, I think you took the tone of what I was saying the wrong way. I'm not making comments for any other reason than to try to help by personal opinion and experience. Just like most everyone else here posting and reading, I am here to learn, and to help wherever I can. Didn't mean for that too sound harsh or anything. I could have said, er typed it, like the others, but I guess theres a lot lost and misunderstood in the way of internet dialog. At any rate, wasn't trying to be a jerk, bro.


I root for the underdog...figured I might as well be one

Very good info MFK, to let everyone know, I sent MFK a PM to get in on this topic, because he is oh so very smart. But anyway, like I said, when i pulled the motor, I had the spark plugs out, and I had the motor in my dads shop, well..like always, his workers were cleaning for my grad party, and decided to move the engine outside(didnt know this for a couple weeks) found it out there, and I proceeded to get irate, wouldnt you? Now instead of a basic rebuild, new bearings and rings and such, it needs to be bored, .010 over would be fine, as there is only a TAD bit of pitting. I honed it hoping it would take it off, but...didnt want to get too crazy, so I might as well have it bored. I thought about the 086 head swap to get the compression up, but, I was on chase for one a while and couldnt get my hands on one. MFK I knew that I would probably start seeing some knock then the computer would start pulling timing on me, wasnt a big issue, at that point I would start running higher octane gas, and if I swapped over the MSD I could pull some timing, but, for 10 cents extra I could run higher octane no problem. And the dreaded 2.3 oil pump swap..haha....I HAVE to get this done on my other build 2.4, but no machine shop around here will do it for me, because the directions I had given them they said were vauge, and they didnt wanna bother with it, they told me I would be fine if I topped the oil off, and kept it there. I refuse to turn up the boost to where it could be until I get the oil pump swap done, so in reality, it probably wont even get in the car until I get it done. BUT, I think for this rebuild the stock oil pump will be sufficient, wont be hard on it, daily driver, obviously get on it every now and then (everyone like the kick in the a$$ when you stomp on it). I have pretty much all of the bolt ons laying around in my parts shipping container. My intentions are to build the motor to get there, then add the bolt ons I had here. SOO...here is what sums it up:

All new bearings
Stock rods
Stock oiling system
Stock head studs
Maybe 086 head swap if I could find one
If not, 10:1 .040 overbore stock replacements (MfK, where are these available from, GM?)
Have the head cleaned and inspected by machine shop
Secret Cams
All new timing gear
Everything Balanced
MSD ignition possibly


One more question, since I am not doing the oil pump swap, it would be pointless to use the HO cam towers that would come with the head because the powerband would be higher than what the 2.4 oil pump would allow, not to mention the ECU's rev limit, soooo....I will more than likely just put the 2.4 cam towers with secret cams ontop of the 086 head, is that the best route for that? Alright, I am done writing my book, thanks guys!

Speed pro have the 2.4 pistons in .040 over.

You can get a complete engine kits from www.flatlanderracing.com

Check in the engine kit section.

Don't go with the Ho cams. You do know that you need to modify some coolant passage on the 086 head to fit your 2.4 block?



Gilles
2.3 Ho

Listen to John. You do not need a rebuild for that HP goal. Hell, I dyno'd 157hp at the wheels with bolt ons. All you need is some head work on top of the usual bolt ons and your set






Jason
99 Z24

Racers Edge
Johnny Mack Turbo Systems
Engineered Performance

mfk-223 hey iam also looking to build my 2.4l and looking into a engine rebuild kit but www.flatlanderracing.com doesnt have them for a 2.4l ld9 in the hp section so what would you suggest? anywhere else i could look for a rebuild kit ? i want all forged pistons and rods

Thanks
Paul

Listen to me, it needs a rebuild anyway, if people would read threads b4 posting, miracles would happen. Not only was it ran low on oil and spun a cam bearing, but it sat outside in the rain for two weeks with the plugs out, this motor needs a rebuild. Anyway, MfK, I knew I had to do something with the coolant passages, if I found an 086 head, I was just going to go get a head gasket, and match it up with my block, and go from there, modifying what was needed. Also, what cars did the 086 head come on??? -92 something I thought...

90-92 Ho/W41. So check for GA, Gtz, Calais and achieva,

I can get a 086 head but it may be more expensvie than what you can find on Ebay or closer to your home. They are rebuild and they are 450$ canadian.

Flatlanderracing.com have a materkit for the 2.4. It's in the pontiac section. It's for the 96-99. I cna check but I'm sure I can get you some Speed Pro 00+ pistons. Should be around 30$ canadian each. Or maybe check summit racing. Or I can get you the part number and the price, then you can check around see if it's cheaper (probably would be).


Paul - If you want pistons and rods forged, check Carcustoms.net for those. You won't have them in a kit.



Gilles
2.3 Ho

Say on car-part.com, if I search for a 92 Olds Achieva cyl head 2.3, if it is a 2.3 DOHC, will it be the 086 head, or did they offer 2.3 lo's and what not. I know they offered the crappy SOHC in those years.

Also, for future reference, how do those heads like boost, such as the valves and springs?

Fst Cavy wrote:Listen to me, it needs a rebuild anyway, if people would read threads b4 posting, miracles would happen. Not only was it ran low on oil and spun a cam bearing, but it sat outside in the rain for two weeks with the plugs out, this motor needs a rebuild. Anyway, MfK, I knew I had to do something with the coolant passages, if I found an 086 head, I was just going to go get a head gasket, and match it up with my block, and go from there, modifying what was needed. Also, what cars did the 086 head come on??? -92 something I thought...

I think what he meant as did I is not need for a expensive rebuild.
here is a qoute from what I said earlier

Quote:

For your goals I would do a stock rebuild some mild head work with cams, and then basic bolt ons (intake, header, TB), also a nice exhaust and then some HPTuners on top and you will be past your goal.

I read your post and realize you have to rebuild. I would not worry about a 086 head and use a stock head with a nice port and polish. Heck a stock rebuild with stock head and bolt ons and HPTuners would put you past what your goal is, and less trouble.



FU Tuning

Quote:

My intentions are to build the motor to get there, then add the bolt ons I had here

People, read what he said before.

Fst cavy- The achieva had the SOHC, DOHC Lo, DOHC Ho, DOHC W41. You'd have to ask them for a 086 head. Even an Ho can have a 955, 753, 456 head.

The 086 head compinent are strong. No problem at all with them. It can take boost and Rpm no problem. The max rev with the stock springs is around 8000rpm.



Gilles
2.3 Ho

If you do an 086 head swap, don't just match the head to the gasket. Use the gasket and your old head as a guideline for how large each hole should be drilled or bored. Also, DO NOT buy a GM head gasket for the 2.4L. The GM head gasket will overlap the fire ring in the head which will lead to a blown head gasket. Either get a Felpro for a 2.4 w/o EGR (99-01) or a 2.3L head gasket and modify it as well. I don't think the Cometic head gasket will work either. Talk to Merlin Fontaine about that one.

Also, I bought my head completely rebuilt from a company on Ebay for $220 shipped. If you search for "quad head" you should be able to find it.

I was going to get a 2.3 gasket, match it up to my 2.4 block, and see what I needed to modify, its only coolant passages, not a huge deal. Max rpms:8000, haha, I think I will be fine with that. I need to find myself an 086 head. I typed in 086 cylinder head on ebay, and it sent me to a SOHC 2.3 cyl. head, that cant be right. But, I think ebay is my best bet, as the junkyards aroudn ehre are terrible, I have run into so many problems with them.

Would a 955 head do anything for me?

I have located a 086 DOHC, rebuilt, resurfaced, for 325 shipped. Good deal you think?

What do you think^^^?

$325 Canadian or American. Either way I'd say go for it.

Also, if you come across a guy on Ebay selling brand new 086 heads w/o valves and springs: I have heard that there is something very wrong with the molds, but I don't recall what that was. This was discussed in a post a long time ago.

Don't bother with a 955. It will take just as much work to do with minimal gains. Check the library section of NY-Jbodies...Under Quad 4 heads, it will give you an idea of the flow rates of both heads (at least the intake). Be careful the way you read it, they start with the 086 head at .050" lift and the 955 at .100" lift.

Concerning when you said:
its only coolant passages, not a huge deal

Quote:



This is a common misunderstanding. Some people who have done the head swap have had problems with overheating the head. This is probably from not drilling the holes large enough, but boring the water passages too large can be dangerous too. If the holes are too large, there is a good possibility that the head won't be evenly cooled. You might starve the front (left side) of the motor due to a larger pressure drop in the head, and less water will flow there. I don't know how critical this is on our motor, because the size of each water passage in the block will ultimately regulate the most water that will pass through that particular passage. Correct me if I'm wrong Gilles, but this is how I have come to understand this.

Whoa... I did that completely wrong... here you go:

$325 Canadian or American. Either way I'd say go for it.

Also, if you come across a guy on Ebay selling brand new 086 heads w/o valves and springs: I have heard that there is something very wrong with the molds, but I don't recall what that was. This was discussed in a post a long time ago.

Don't bother with a 955. It will take just as much work to do with minimal gains. Check the library section of NY-Jbodies...Under Quad 4 heads, it will give you an idea of the flow rates of both heads (at least the intake). Be careful the way you read it, they start with the 086 head at .050" lift and the 955 at .100" lift.

Concerning when you said:

Quote:

its only coolant passages, not a huge deal

This is a common misunderstanding. Some people who have done the head swap have had problems with overheating the head. This is probably from not drilling the holes large enough, but boring the water passages too large can be dangerous too. If the holes are too large, there is a good possibility that the head won't be evenly cooled. You might starve the front (left side) of the motor due to a larger pressure drop in the head, and less water will flow there. I don't know how critical this is on our motor, because the size of each water passage in the block will ultimately regulate the most water that will pass through that particular passage. Correct me if I'm wrong Gilles, but this is how I have come to understand this.

I run a LD9 everyday with 11.5:1 compression on 87 octane.....

I still have the stock cams in it with a GRD head with a 5 angle valve job in it. It runs like a trooper, the only thing that I ever notice is that when it is extremely humid, it tends to get a little cranky or when it gets too hot in the engine bay.... (my car runs at a constant 185 and barely passes the middle mark when sitting in traffic) I will be doing the HP tuners soon to see if I can extract more power from the car, but stay away from 2.3 heads if you want to drive the darn thing without much worry.

do a pnp
do secret cams
do an HO manifold
do a full exhaust
do HP tuners
do Individual TB's if you want
Hybrid quads are headache's and the 2.4 is a pain in the @$$ anyways...

go simple and reliable and you have more fun with it. Also spending big money is not always the key to having a fast car it's about how you set up what you have.

My car is what I would call a mild build... and I LOVE drving it everyday.... minus my extremely blown struts right now I suggest the same if you already have a turboZ.




This months projects: Completion and Installation of Homemade Turbo System, Brakes, Fiberglass sparetire enlcosure and amp rack.