MADScientist

iTrader: (3)

Ok gang,

I am finally getting down to the wire on building this engine... I would like some advice from the different engine builders on this forum so I can make up my freaking mind about a few things...

My goals are pretty modest. I will be having this tuned at Forged on their dyno, so I am looking for a solid 550whp and even more happy with 600whp. Basically approaching the limits of pump gas, the stock greddy turbos, and the 650cc injectors that I currently have. I am also already running a UTEC.

I am also trying to do this build with on a budget and don't want to put parts in this engine that I don't need to support a ceiling of 600whp. I mean come on... this a street car that sees the strip about a dozen times a year I will never be able to put down any more power to the ground than that!

I already have the following mods:
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-greddy turbo kit
-Crawford intake
-APS oil pan
-AAM return fuel system w/ 650cc and walbro pump
-UTEC
-AAM 3" down pipes
-APS 3" dual exhaust
---------------------------------------

I made 452whp at Forged @10psi on the stock block...



My mind is pretty much made up for the short block:
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-Arias pistons
-Eagle rods
-ARP main studs
-Rev-up oil pump
-L19 Head studs
------------------------------------------------------------

Here is where I am not sure what to do...

(1) The piston sizing... Has it been most people's experience that the STD bore pistons will drop right in with just a hone of the cyl to bring the clearance in spec? Or should I just go with a .020 over bore piston? Reason I ask is the machining costs are quite a bit different... This is assuming the block is in good shape to begin with.

(2) I am pretty sure that the stock heads will support the power levels I am seeking. I am also pretty sure that I am going to need to do a cam upgrade to get there. What should I do? Keep in mind I am working on a tight budget and don't want to buy one thing and then have to buy 5 more things to support it (it is a slippery slope!). I hear great things about the C2 cams from JWT, but don't want to have to get the ECU flashed for an idle bump ($500 extra). Any feedback on "most bang for the buck" cams would be great! Can I get away with C2s and no idle bump? Or would I be better off with the GTM or S2 cams?

(3) At these power levels and using the L19 ARP head studs is it still required to upgrade the head gaskets? If memory serves me right, back in the day, most guys were using the OEM head gaskets with out any problems for this level of power. Reason I ask, if I am buying a OEM engine rebuild kit that comes with the head gaskets, why not use those and save the extra $400 from buy the HKS or similar aftermarket ones?

(4) The additional cooling mods... I live in Indiana, and have been boosted for almost 2 years and never came close to over heating (as far as I could tell) I realize the importance of upgrading the cooling system, but being on this budget, what mods work best? If I use the OEM radiator and the rear cyl cooling mod with lower temp therm will that work best? Or would just upgrading the rad do the trick? I will be doing some sort of DIY oil cooler as well...


I hope to have this project finished by March, so any insight you guys can provide would be very helpful.

Thanks!!!

DaveFunction2ND

iTrader: (8)

Overbore is the best way to go unless you plan to dissemble the motor and measure everything BEFORE ordering the pistons. Otherwise you will potentially have to order a second set of pistons if there is damage or out of roundness to the cylinder walls.

The heads should be upgraded to achieve the power levels you are looking at reliably. Yes the stock heads will get to 550 or 600 BUT the issues is that using a free flowing head will generally allow you to run a LOWER boost level and make the same power. Is this going to be a daily driver? Also cost wise it is much less expensive to install heads once, not twice (say you decide ot upgrade in the future) and while the motor is out of the car (less potential for an installation issues down the road). You can drill the TB to get the idle bump although I don't recommend it. There is also a mod you can do to the vaccum line system that JWT has posted on their website although that "fix" was for the S1 cams it may help with the C2's.

You can get the Cometic head gaskets for $88 a piece.

phunk

iTrader: (21)

Definatly go .020 over or the engine will be a rattle box. the other solution is to go stock bore and coat the pistons to make up for the slack and set the bore/hone around the coated piston.

stock valvesprings are pretty loose, i would get the ferrea upgrade on the springs and retainers for stock valves. you can use JWT S1 cams and get the idle bumped at the dealer for a lot less (if you haev an 03), I paid 75 bucks to my dealer to bump the idle.

HKS headgaskets are the only way to go if your staying in the area of stock bore. tons of people, including myself, did run power on stock headgaskets, and they failed. everyone that was into power early has had to change out the stock headgaskets. The HKS have a stopper ring that is somewhat like o-ringing the block. I assume you have seen my writeup and comparison of HKS versus stock headgaskets.

Audible Mayhem

iTrader: (48)

+1 on the hks gaskets, this isnt really even a choice...

MADScientist

iTrader: (3)

Thanks for all of your comments... just an FYI I have a seperate debate going in the forum about the head gaskets...

As for the heads and cams... keep in mind I am working from a budget. I guess I should have stated the question a little different then based on the comments so far... If you could only afford to do one or the other woudl you have head work done or a cam upgrade?

Alberto

iTrader: (14)

I chose cams + valvetrain as opposed to full blown oversized valves and port/polish work. We all know the work mentioned above would make more power at a lower boost pressure but IMO it isnt necessary for those looking for less than BIG numbers. My car made 580whp on "stock" heads with S1 cams + valvetrain on pump gas! With a Stage 2 fuel system and race gas I would say 700whp or close to it easily, all with no port work. I vote for cams + valavetrain as a minimum during a build, downside is the labor to redo the timing on the motor and adjust the valves but trust me its worth it.

Sharif@Forged

iTrader: (92)

^^^Alberto is right^^^
His buildup was a good example, of what can be accomplished with stock cylinder heads, and simply a JWT camshaft and spring/shim package...all tuned on pump gas.

Joe has been a long time customer of ours, and I know his goals pretty clearly. He is not the type of person, to suddenly decide that he needs more than 600whp down the road. So I say....build the engine to meet your max goals, and enjoy the extra money in your pocket.

Oh, in regards to bore, .020 overbore is the only option I can recommend. As others have mentioned, there is no way to insure that all cylinder wall to piston clearances are perfect. Anything else is half-arsing it, IMHO.

350zDCalb

iTrader: (21)

fortunately motor builds have been done soooo many times now, that we can definately guide through the correct way to build a motor...the bottom end: definately go .020 over...cleans up the standard bored cylinder walls, makes a fresh surface for the 96mm, or .020 over piston... and the bore AND hone must be done with use of torque plates (see http://www.builtzmotors.com/tour_machining.php#torque )

make sure the balance job is exact, it may not make a noteable difference now if the crank is off a few grams, of the rods don;t weigh within 1/2" a gram of one another- but the bearings will take less wear, the engine will make more power, and everything will be happier...the downside, the cost..it will cost more to have a crank and rotating assembly balanced to perfection! while you are at it, take your flywheel/clutch combo and harmonic balancer, have those put on a balancing mandrel (good machine shops-like ours-shameless plug) have these..they cost about $1500, so some shops will not have one...

that way, the motor will be internaly balanced, and the accessories that bolt to the crank (clutch/flywheel and harmonic balancer) will also be balanced to themselves..so the end product will be a perfectly balanced engine...

the L19-1/2" head stud debate...well, thats why they call it a debate...no one knows for sure...several guys out there making big power on L19's...the theory (read=fact) behind a larger surface area clamping force-generated with a larger, 1/2" ARP stud being superior and that the threads going into the aluminum block are reinforced with steel timeserts making the anchor stronger, is the compelling reason that we use 1/2" head studs with timeserts on 90% of the engines we build..

the headgasket debate..don't be silly, hks are the best design so far, spend a few more bucks and go with those...

my $.02

-TODD

akcraig85

iTrader: (9)

to bring back from the dead and to get some info what is the point of Ferrea Oversize Intake and Exhaust Valves? hope i dont get to chopped up on this. TIA

Adam

ImportPartsPro

iTrader: (512)

The valves are what allow air into the cylinder and exhaust gas exit. So by going to a bigger valve you are allowing more air in and out of the heads. This is very important on a FI car since you are forcing air through the engine.

synth19

iTrader: (11)

As far as your cooling issues go, I'm live in a similar region and don't necessarily think you need to upgrade your radiator unless you do track the car. If it's going to be a DD, you'll be fine. Just my opionion and coming from my experience.

rocks

iTrader: (1)

1mm is not big enough to justify the cost.

MADScientist

iTrader: (3)

Well since you guys brought this back from the dead... Thought I would let you all know what I decided to do.

-----------------------------------
-Eagle Rods
-Cosworth Pistons (.020" overbore)
-Cosworth Bearings
-ARP L19 Headstuds
-ARP Main Studs
-Rev-Up Oil Pump
-Cosworth Heads
-JWT C2 Cams
-Nismo Therm
-AMS Radiator
-OEM Gaskets
----------------------------------

I had a local machine shop that I have worked with on several previous build do all of the machine work and I assembled the engine myself. I am getting ready to put this thing back in the car this weekend and get some miles on it to I can retune down at Forged Performance hopefully middle of April.

I am still planning on adding an oil cooler to the mix as well. I will be doing this from scratch since Earl's is located here in Indianapolis so I can pick and choose what I will need to make it work. With the V2 bumper I plan to locate it on one of the side vents on either side of the intercooler, and I am considering locating the OEM power steering cooler on the other side and ditching the Greddy cooler.

I know I originally planned on a budget build, but we all know how that goes! LOL!! I plan on getting 600whp with this thing and I think that the head/cam combo will be what I need to do this at a "reasonable" boost level on the stock 18G turbos. I would like to see how close I can get to this number on pump gas (93 oct) we will just have to wait and see. With the UTEC controlling everything it maybe a stretch, I am hoping that the firmware update Turbo XS is going to release will have more resolution to the fuel maps... If not guess I will be going FCON...

I plan on posting a complete write up once I have the car up and running with a good tune... More to come!

synth19

iTrader: (11)

^ Very excited to see how things go. I'm also going to be on UTEC once I retune & get a better fuel system in a few weeks.. Speaking of... which fuel system are you going to go with? I'm decided on the CJ Motorsports Stage 2 with 650cc injectors.

MADScientist

iTrader: (3)

I currently have 650cc injectors on the AAM fuel system. Once the dual pump setup comes I will go with that. I will be right on the edge of the injectors will the higher fuel psi these cars run... so we will see, probably have to go with 750cc.