Help me with my build

[M_Juntti]

ok, so everyone im sure has heard about my build, a few people from this site agreed with it but most have had big issues, the 396 lt1 with the 292 xfi and 227afr heads. the edelbrock intake is out. i read that the 227 afr heads are mainly for engines that will be continuously running high rpm and NEED the huge airflow. my question is, why cant you have heads with oversized intake and exhaust ports? wont it allow as much airflow as i need? can you really be flowing too much air into the CC? help me understand this.


and no my goal is not just 11s what i said is i FOR SURE want to beat my boss who is running 11s but i want to go faster

[Phantom409]

You have to have a BALANCED combo!
You have to have the Heads, Intake and cam work as a whole.

Remember when I said you will fall flat?
Well that means that the heads or intake are not right for the combo so if the heads can out flow the intake then when you hit say 3000 RPM your car will stop making pwr and fall flat and be a dog.

Stay with the stock intake!
A ton of trick parts don't make a combo.
Heads, I would drop down to a 195 like I said before.
You can bump the compression up a bit, say 11.5 and that will get you close to the 500 HP level.

But like we all said before:
You have to know what you are going to use the car for?
Race? Street? or both?
Get John Linginfelter's book on modding the SBC, he covers the LT1 in that book.

If you want to do an LT4 intake then start searching for the one that is just like the LT1's intake, that would be your best bet unless you mod a single plane FI carb style intake to fit your car.

[ThreeHonks]

I think everyone agrees with me on this one:

1.) let us know your real-world budget.

2.) how fast do you want the car to be? Theres a difference in making 9.0x power to running 10's

3.) is it going to be driven on the street?

4.) whats the idea for suspension/drivetrain (theres more to a car than the motor)

[Phantom409]

I think everyone agrees with me on this one:

1.) let us know your real-world budget.

2.) how fast do you want the car to be? Theres a difference in making 9.0x power to running 10's

3.) is it going to be driven on the street?

4.) whats the idea for suspension/drivetrain (theres more to a car than the motor)

[M_Juntti]

my budget is somewhere around 8000 on the engine, i already bought a tubular k frame with a arms, will have the frame ties, driveshaft loop, saving for an airbag suspension right now, i havent decided on the rear axle, eric l recommended a dana axle for around 500hp with a t56. im thinking 3.73 or 3.90, idk help me out here, i want it to be streetable but wtill run great at the track. preferably with my 396

i dont have the heads or intake yet so i guess this was a good time for this discussion to start, but i do have the 292 xfi, i can get a different one if need be

[Phantom409]

Is the block work done?
Do you have the rotating Assem?
Do you have all the gaskets?
What LB injector are you planing on running?

Sounds more like you want a Street/Strip car so the 227 heads are OUT!

That cam is decent and is what Red (Old Fart) is running in her 383 and it's a monster
And she is running 195's from AFR.

[M_Juntti]

i have the assembly, about to do work on the block.. just realized something.... im going to need a small base circle cam for the 396 arent i? its a 6 inch rod. i was thinking about using the 32 lb/hr injectors. sound alright?
and no gaskets at the moment

[Phantom409]

i have the assembly, about to do work on the block.. just realized something.... im going to need a small base circle cam for the 396 arent i? its a 6 inch rod. i was thinking about using the 32 lb/hr injectors. sound alright?
and no gaskets at the moment

No, you shouldn't need a Small Base Circle cam.
Red is running the 5.7 rod and it cleared hers just fine.
The only reason you would need a SBC is if the LSA was smaller than 110, that puts the lobes closer.
Why the heck are you running a 6" rod??
That puts the wrist pin into the oil ring and is not ideal for a street car.
Are you running a H-Beam rod?

32 are to small to support that amount of HP.
42lb is what you are going to want.

[DETROITMUSCLE]

IMO no need to do an airride suspension that is only gonna add weight and won't be ideal for a real fast strip car, look into some AFCO shocks and use the stock springs with V6 ones in the rear. If you really wanna go all out I would call Madman and talk directly with them concerning your setup. As for a rear your gonna want a moser/strange/MWF?ect. 9" made for a 4th gen or a M9 or Dana S60. Do not buy a 12 bolt, it will break with that kind of power under a T-56. 4.10 gears are usually the ones of choice but tire size and shift RPM will be the deciding factors.

[M_Juntti]

yes its an H beam, and the 6 inch rod with the 3.875 cranks give me the 396 and i wanted a 396 stroker. i know going into the oil ring will burn a little oil, i read that when stroking an engin you want to go with the longer rod because it slows the piston down by kicking the rod on more of an angle

[Phantom409]

Yes that is true but for for a street car a 5.7 rod is best IMO.

[M_Juntti]

IMO no need to do an airride suspension that is only gonna add weight and won't be ideal for a real fast strip car, look into some AFCO shocks and use the stock springs with V6 ones in the rear. If you really wanna go all out I would call Madman and talk directly with them concerning your setup. As for a rear your gonna want a moser/strange/MWF?ect. 9" made for a 4th gen or a M9 or Dana S60. Do not buy a 12 bolt, it will break with that kind of power under a T-56. 4.10 gears are usually the ones of choice but tire size and shift RPM will be the deciding factors.

true it will add weight and it wont help me much down the drag strip but im sure there will be a few times im on the highway and feel the urge to see what it can do, and air ride suspensions have way better handeling, i know i have been involved in a few street races before,,,, although i didnt last long in my 3.9 dakota

--Double post auto merged--

Yes that is true but for for a street car a 5.7 rod is best IMO.

well its not going to be a DD for me just something i take out every now an then so i think a 6" would be alright, i was thinking about the same thing before but that would give me a 383, dont get me wrong still badass, but i like the idea of a 396

[1BADAIR]

i dont see a problem with 6" rods? ls1 strokers usually have 6, 6.100, 6.125 rods with the pins in the oil ring with no issues.
why do lt1 use such small runners? 220-260 are common with ls's
260 is stock on a l92(376 CI)

[WMCCjames]

why do lt1 use such small runners? 220-260 are common with ls's
260 is stock on a l92(376 CI)

Port geometry....Old school SBC's don't tolerate the larger volumes as well, the velocity suffers.

[JoeliusZ28]

i dont see a problem with 6" rods? ls1 strokers usually have 6, 6.100, 6.125 rods with the pins in the oil ring with no issues.
why do lt1 use such small runners? 220-260 are common with ls's
260 is stock on a l92(376 CI)

look at the port height and its obvious. Its where the LS design has its advantage.

And to answer the OP's question about flowing too much - what I have read in the past is that if you want peak HP you need peak runner volume. if you want overall power you need overall flow... or in other words a smaller port that flows efficiently. Runner volume and CFM are NOT a directly related function. tons of other physics involved. auto-x cars / street cars usually have smaller runners for that reason. I cant really explain why though, maybe because an oversized port causes the air to lose velocity??? Im not a physics expert, but im sure theres a good reason for it that someone can explain better than i can.

But like james said once your port volume gets so large you become limited to the places you can port. (or you will hit a water jacket, etc.) and if your port isnt a good shape you'll create turbulance and have a negative effect.

so what all this means for you is that the largest runner heads might not be the best choice for what you want to do. I would say 195s or 210s are probably the best for what you are looking to do.