Been on here for a few years now just reading up from time to time. I am finally getting ready to start my build and would like to know what I can expect from my build. I am aiming for 450-480whp 10.8sec NA (after drivers learning curve) and need any input as to what I may need to do to get to that number. I will list my current parts below and parts that I am planning on getting. This will be a street strip application that is heavy on the strip with good street manors. I want to run pump gas as well. I am aiming at a 11:5:1 Comp Ratio???? I am going to build it to handle spray also...later on though

Have
40 over 4bolt splayed block
JE Nitrous Pistons -14cc Dished
3.875 DragonSlayer
5.85 Compstar Forged Rods
Custom Grind Comp Cam 248/254 616/622 110lsa SR
AFR 227s 65cc with Race Ready Porting from AFR port matched to
Converted VIC-E
T&D Shaftmounts 1.6
Crower SD Solid Rollers
Comp Hardened 3/8 pushrods
Edelbrock Fuel Rails
7qt pan w/pickup tube$TCI Flexplate
MSD Digital 6
MSD Coil w/heat sink
Melling HV Oil pump w/driveshaft
Built TH350 Manual Valve Body
PTC Nitrous Convertor

Need
42lbs injectors
ASM Monoblade
S60 Rear (what gear for 29inch tall tire)
Intake Elbow..(havent decided which yet)
All supporting Suspension Goodies

I know there are things that I left off but you get the jist of what I am trying to accomplish. Are my goals realistic and if not what is limiting them? Will I benefit greatly by sending my heads off to get worked on or will they achieve my goal as is from AFR? I am limited to the Opti at this time but I know this will be a high reving engine so that will need to be changed. Do not worry about budget but please be realistic as I am in no way a wealthy man. I am still shoping a good house to build my shortblock.....hoping HKE since he is local...other Houston or TX area LT1 players???. Please dont thrash the newbie, I have been out of the game for a while (10yrs) and I am reading alot....I swear. Point me in the right direction if anything. I know I have a good start just want to make sure everything matches up. I look forward to any constructive comments and suggestions.

 

4.56 gear would do nice on nuts. Maybe a 3.90 for the nitrous. Shifts around 7k for that combo, those are FAST heads and will need quite a bit of cam to really rev past choke at 400 cubes. Joelster can tell you exactly how the motor will run... he's in the .50s with a new combo. 414ci and the 227s IIRC.

 

Why dished piston with a big chamber?

 

I got the dished pistons in a deal and will most likely end up going flat top. Its going to boil down to what the engine builder recommends or what I gather up from researching. That being said, if I can achieve my goals with the ones I have I will be happy to stay with them...although they are against the norm. The block is zero decked for the application listed so I really dont want to get into machining the block again.

Yep, I saw that Joelster was running the 227s. Maybe a larger cam is in order? How much larger we thinking?

 

Might want a aftermarket computer so you can shift over 7,000.

 

HKE just finished the refresh for a 398" LT1 I have, he's an awesome at what he does, just be prepared to weight.

 

Yes, I have corresponded with Eric via PM. I know he is extremely busy with moving his shop and building his house. I am not really in a big hurry as I have a pro touring c10 I am finishing up but I would like to get in line. I guess I need to just go see him in person and talk to him. How long was your wait on your 398?

 

1. You say you already have the pistons, but I hope you got the right ones for those heads. Those heads have a 60/40 valve spacing. Traditional valve notches don't line up correctly. You should eaily run 10's provided everything else chassis wise is up to snuff.

2. Ditch the HV oil pump. It's not needed. If you have quality machining and assembly, a stock volume pump is fine.

3. Keep the opti for now. Your engine will want to rev right at the 7k limit, possibly a little higher. I don't see it screaming to 7600 or anything like that. With an aftermarket pcm, you'll have the ability to do so, but I'd put money that it peaks below 7k.

 

Here's a pic of one of my pistons after I notched it. You can see how far off the stock-style valve notches were on these $800 Mahle pistons:

 

I am a bad person to ask because I told them I didn't care when it was done. I also stop by rarely to see it.

 

Pistons look right to me if my memory serves me correctly. I will take a pic and post up tomorrow if I get a chance.

I am glad the Opti will most likely work for the time being because I would much rather spend the money on suspension mods to get this thing hooking good.

Anybody need a good HV oil pump...lol

 

Opti works fine for me to 7600 or so Well its an MSD unit.

 

for only 450-500 rwhp arent those heads a little big. If I remember right thier rpm band starts at 4500. For a boosted motor I can see getting by with them. But on a NA motor that would seem a little doggy to me with that hp goal, and if your gonna drive it on the street and have some fun. I think 210s would be a better choice.

 

The OP wants 450-480rwhp. Figure 550-575hp at the crank. That sounds like a pretty healthy motor to me. There is no rpm band for a set of heads. It is application specific. The size of the motor has a huge role in what rpm the engine will see. My car doesn't seem doggy at all on the street. It pulls hard from every rpm. I'm running the exact same heads.

 

That is a solid build, but like Joelster said be careful to check not only PTV but radial valve clearance as well.

I also have big AFRs that needed to be flycut with a healthy SR cam, the generic valve notches were too far from the center to line up with the valves.

450-480 is no joke through a stalled auto, but you are on the right track .

 

The AFR lineup almost across the board has cross sectional areas that make for very fast velocity profiles. They act much smaller than the volume would suggest on the actual motor. Thus they run into problems with choke at high rpm (>7000 for some) buy make good midrange power where the airspeed isnt such a problem.

 

I already have the heads so they will be staying. I will modify my build as needed around my heads to reach my goals. sounds like i am pretty close what im looking for. My opti is a MSD as well so should be good from what i understand. Seems my only question will be the cam and pistons I currently have. I knew the pistons were a little against the norm but they are damn good pistons, however I could see a change if necessary. How do the cam specs grab you guys? I think they are just about right but my knowledge is very minimal.

I cant believe how many engine builders I talk to that give me completely backward advice from what the forums say. Its like everyone has forgotten about the ltx technology. These are reputable builders that keep telling me high compression and nitrous and pump gas dont work. They gey pissed when I tell them LT1 is different than other platforms. I always walk away discouraged. Suppose HKE will have to be the guy.....not a bad thing.

I appreciate all comments that have been made....some over my head and some I understand. I am figuring this build out though and that was my intentions.