Help with F1A 355 LT4 build

Hi guys I've been searchin on this subject for a while now. I need to know some good info on this project before I start buying stuff.

Ok, here is what I want-

Forged 355
F1A Procharger
FMIC
water/meth injection
400 turbo tranny (I'm sure my built 4l60e wont hold up)

Here is what I have-

motor is a real LT4 so I have a 4 bolt main block
LT4 heads have stock valves but have been ported well (ARP head bolts)
LT4 intake was ported to match heads
LT4 Hot cam kit (yuck)
Double roller timing chain with electric water pump
Hardened push rods
High volume Melling oil pump with hardened shaft
Fluidamper
Hooker long tubes
Mufflex Y pipe
Dynatek opti
MSD coil and wires
NX wet kit (MAF system) with ALL options (I'd like to use this with the blower)
This motor only has about 5,000 miles on it and runs perfect. Everything about it is BRAND NEW.


On to the questions-

Can I reuse my heads?
If so what pistons should I buy to bring the compression down?
What cam, valve springs, rockers?
Can I reuse the rockers from the hot cam kit?
What size injectors?
will the dual walbro's in tank feed it? with the nitrous?
can I use my fluidamper with the blower pulley?
Does the balancer need machined for another key way?

Sorry for all the Questions..... but I just wanna make sure its RIGHT!!!!:D

Thanks

lt4 heads are great castings. they may need some more work tho.
Send them to Llyod Elliot for more porting. esp. with this build.

Pistons, get a quality one. JE, Ross, Diamond,
Rockers- re use
Injectors- 72, 84, 96. Depends on heads and pounds of boost.
fuel- you may need more pump. Dual intank 340's or 420's. You have some big plans here.
Cam- go custom

motor is a real LT4 so I have a 4 bolt main block

Are you sure about that ?

motor is a real LT4 so I have a 4 bolt main block

Are you sure about that ?

Yup, I bought the LT4 brand new in the crate and pulled it apart. I've had the current motor together for about 7 years but it's only been driven about 5000 miles. I'm positive that it is still in perfect shape. Heck it probably don't even need bored.

The heads currently flow quite well(lingenfelter). With a crappy hot cam it made 375rwhp with a auto and a 3200 vigilante. They still have stock valves though:think:.....


What kind of ring gap should I have? what brand of rings?
Should I stud the main caps? or is that over kill?
If I build avery strong rotating assembly, custom cam, and use my heads as is, do you think it would bite me in the arse?

I really want to take this thing to the next level. Any experience you guys could pass along would be really helpful. I wasted a butt load of money on the last build of my car. Luckily I think I can reuse alot of the parts on the new build.

Z28_LT4,

Personal opinion only:

Can I reuse my heads? Sounds like your LT4 heads are decent. I would not touch them but that's just me. Do you have flow numbers?

If so what pistons should I buy to bring the compression down? slomarao listed some nice ones. You'll need a large dished, forged piston to get down to 9:1 static with stock-chambered heads.

What cam, valve springs, rockers? Custom cam would be nice. There are a few off the shelf grinds that work good for people too, depending on what you want. Cam is going to be a compromise on streetability, trackability, gas mileage, maintenace...overall car behavior. Not sure from your post what your intentions are. Valve springs are cam dependant. Rockers, again depends on valvetrain loading. Consider ratio when selecting cam/springs.

Can I reuse the rockers from the hot cam kit? Dont know much about hotcam rockers, but understand ratio for cam/spring selection.

What size injectors? I believe that 60lb inj. are the largest high impedance injector out there (will work with stock PCM). Please correct me if I'm wrong, but should support 600 at the tire. If your talking F1 then you will need some low imp. with a converter etc.

will the dual walbro's in tank feed it? with the nitrous? Don't know but you're going to need a lot of fuel :)

can I use my fluidamper with the blower pulley? Not familiar with aftermarket dampers and how they effect crank pulley alignment

Does the balancer need machined for another key way? Is the fluidamper/hub one piece? Single key should be fine. I suppose dual key would be more robust with excellent machine work of the crank to match the hub. Anything less than perfect will load one key more than the second.

Should I stud the main caps? or is that over kill? Main studs offer better torque loading than bolts. Cost is not significant so why not build a bullet proof bottom end?

Take all of this with a grain of sand and do your research.

Regards,
Scott.

I couldn't find my old flow sheet for my heads but they are very good for still having stock size valves.

The hot cam rockers are 1.6 ratio aluminum roller rockers.

Where do I buy the low impedence converter??????????? I want it to be quality.

I'll call Racetronix on the fuel pumps and see what they suggest.;)

Yes the Fluidamper is a single piece. I've read about people using the big block hub before on a ATI balancer but I've never heard of anyone using a Fluidamper before with a blower.:no:

What about RING GAP???? and what kind of rings will hold up to this much boost and Nitrous?

I would LOVE! to hit 800rwhp with this thing.:eek:

Thanks guys keep the suggestions coming.

I'm currently talking to a board member about buying his F1A and several other supporting mods. So this project may get started earlier then I was originally planning.:D

Huhh?? Find an engine builder in your area to work with.

-Scott

My fluidamper did NOT work with my blower pulley. The bolt alignment was not correct. That was an old ATI blower pulley with an old ATI superdamper.

if you want 800rwhp than your going to needs heads that flow 280ish. on the intake. I would really send them out for some more work unless they already have been ported.

Call Racetronix for injectors, fuel pumps, etc.

Huhh?? Find an engine builder in your area to work with.

-Scott


Easier said than done.........I live in the middle of nowhere:cry:

I recommend you talk with ProCharger directly. They have probably see most of the build-ups out there and know how their product performs. For this kind of horsepower I imagine you will need an aftermarket PCM to control the injectors and ignition. I didn't notice an aftermarket rearend but you'll need that also.

What you want to use the car for will guide a lot of how you build the motor, tranny, rearend combo. Vehicle use greatly affects things such as RPM operating range, torque converter selection, rear gearing (especially with no over-drive), tire selection, shifter selection (reverse pattern maybe?).

The addition of juice only complicates things since that too will affect cam selection and head flow requirements. Using the two together can be done but it takes a lot of up-front thinking to get it right.

Since you seem to want "MORE POWER" then definitely use studs for the heads and the crank. You won't get a second chance to build it "strong enough".

Later ... Larry S.

Check out the posts by Call911 and 97WS6Pilot in the stickies here:

http://www.camaroz28.com/forums/showthread.php?t=566122

The only thing you really need to change is your fuel setup and pistons. LJ sells the accelleronics high imp box on the net to run the bigger injectors. The damper I would recommend is an ATI big block damper and you will need to get your timing cover bored for the bigger damper. Lonnies Performance sells these along with the specs for the spacer for the crank pulley.:)

Check out the posts by Call911 and 97WS6Pilot in the stickies here:

http://www.camaroz28.com/forums/showthread.php?t=566122

The only thing you really need to change is your fuel setup and pistons. LJ sells the accelleronics high imp box on the net to run the bigger injectors. The damper I would recommend is an ATI big block damper and you will need to get your timing cover bored for the bigger damper. Lonnies Performance sells these along with the specs for the spacer for the crank pulley.:)

Wouldn't I need a different cam?

If I'm takin it apart and doing machine work, I'll definetly put a nice rotating assembly in at that time.

But....How long do you think it would last with just a set of pistons?:think:

Wouldn't I need a different cam?

If I'm takin it apart and doing machine work, I'll definetly put a nice rotating assembly in at that time.

But....How long do you think it would last with just a set of pistons?:think:

The beauty of supercharging is that you don't need a big cam or heavily ported heads to make good power. I'm making close to 600rwp on a CC304, mildly ported lt1 castings, stock rotating assembly plus -20cc forged pistons. With increased manifold pressure you might want to make sure you have good seat pressure on your current springs.

I'm not sure how high you are planning on spinning your motor. Rpm is what kills rotating assemblies. Boost is what kills pistons. :)

Here is a short spec of my set-up that looks to be similar...

97ss 383 ATI D1 Procharger 4.44:1 gear head. M6 trans.
Callies 3.75 D_slayer crank. Eagle ESP H beam 6" rod/ JE 2618 -28cc dish.
AFR 190 heads 56cc chamber. (About 9.5:1 static Comp ratio)
1.460 dual springs with AFR Rev kit/ CM cam 231/240*@0.050" & .530/.560" lift on 144lsa. 110* Intake CL. Engine makes power to 6800 rpm with he blower pulley ratio @ 7.6 --> 3.4" pd.
72# Seimens injectors with Acceleronics driver.
Cooling system modified to a Be-Cool rad and Evans waterless with electric pump and 2 12" flex-Lite fans constant run.
Pressure side 3" small gage steel pipe with a large spearco (28x9x3) and water/ methanol injection.

FI can generate alot of heat. The F_body cooling system is designed for air flow with the design of low rad placement and all the cooling air intake @ road level. These cars need movement to move air thru the rad assembly.

I believe the cooling system is very important, and, is usually the last thing people think about. It usually gets neglected. A good read on this is the Ray Bohacz HP book... HP1425 Cooling systems.
Hopes this helps. B.