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Hi my name is Harrison and I recently started rebuilding my first engine, I'm rebuilding the original gen 2 lt1 in the impala and was wondering if anyone knew if I should add a cold air intake so the engine can breath better and a new radiator too. I'm rebuilding the engine with 500 hp. If anyone knows what to do please reply. Thank you
 

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Hi my name is Harrison and I recently started rebuilding my first engine, I'm rebuilding the original gen 2 lt1 in the impala and was wondering if anyone knew if I should add a cold air intake so the engine can breath better and a new radiator too. I'm rebuilding the engine with 500 hp. If anyone knows what to do please reply. Thank you
A cold air intake can help almost every car. This is a good cold air intake, and a great company who continues to support our old cars: High Performance Exhaust Systems - Chevy Impala SS Cold Air Intake

I’m impressed you’re doing your first engine rebuild, that is great. 500 hp from a naturally aspirated gen 2 LT1 is possible, but not simple. I would think you might need to bump up the displacement to 383 cubic inches to hit 500 hp?
You will certainly need parts that work well together, as well as proper machining and assembly techniques.
Do you have a build list you can share?
What cubic inches are you shooting for?
Are you using Lloyd Elliott, Advanced Induction, or AFR heads?
Cam choice will be critical for you.
If I could give any advice, I would say: don’t worry about hitting any particular horsepower number. Instead focus on drivability for how you plan to use the car. Personally, I prefer low rpm torque as opposed to high rpm horsepower. I like the feeling of the car launching hard. What do you like?
 

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... If I could give any advice, I would say: don’t worry about hitting any particular horsepower number.
Instead focus on drivability for how you plan to use the car.
Back in the day, how many B-cars with naturally aspirated 5.7L LT1s 1/4Mile'd in 12.999secs or less?
Doubt any of them made 500horse.

Every single one of them was forced to improved on everything on the following list:
tires
wheels
suspension
axle
torque converter
transmission
entire exhaust
heads / cam / valvetrain
cold air intake
custom refined tune
and maybe a wee lil bit of a diet
to make the 1/4Mile in under 13secs.
 

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Discussion Starter · #4 ·
A cold air intake can help almost every car. This is a good cold air intake, and a great company who continues to support our old cars: High Performance Exhaust Systems - Chevy Impala SS Cold Air Intake

I’m impressed you’re doing your first engine rebuild, that is great. 500 hp from a naturally aspirated gen 2 LT1 is possible, but not simple. I would think you might need to bump up the displacement to 383 cubic inches to hit 500 hp?
You will certainly need parts that work well together, as well as proper machining and assembly techniques.
Do you have a build list you can share?
What cubic inches are you shooting for?
Are you using Lloyd Elliott, Advanced Induction, or AFR heads?
Cam choice will be critical for you.
If I could give any advice, I would say: don’t worry about hitting any particular horsepower number. Instead focus on drivability for how you plan to use the car. Personally, I prefer low rpm torque as opposed to high rpm horsepower. I like the feeling of the car launching hard. What do you like?
I am getting my block all prepared because I'm adding a 383 stroker crank shaft in it and I already have all the parts I need from golen engine he helped me gather all the parts I need to make roughly 500hp. I was just wondering if a cold air intake would help the engine breath better and you did give me Dan Ferraro for the which I am also buying my headers from him but I'm making my own exhaust. I was also wondering if you had any radiators that you recommended?
 

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... also wondering if you had any radiators that you recommended?
If I could afford a 383, I'd buy an all-aluminum radiator with no-plastic endtanks, even with no other goals in mind.

By the way, forgot to mention above:
1. Upgrade the LT1-KD1 ATF cooler with a larger cooler AND a fan that activates
a) at or over a desired temp
AND
b) at will with a manual override
1a. Do Step 1 before Step 2
2. disconnect the ATF lines that run through the radiator.
Use only the separate upgraded external ATF cooler (except during the winter).
 
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Discussion Starter · #6 ·
If I could afford a 383, I'd buy an all-aluminum radiator with no-plastic endtanks, even with no other goals in mind.

By the way, forgot to mention above:
1. Upgrade the LT1-KD1 ATF cooler with a larger cooler AND a fan that activates
a) at or over a desired temp
AND
b) at will with a manual override
1a. Do Step 1 before Step 2
2. disconnect the ATF lines that run through the radiator.
Use only the separate upgraded external ATF cooler (except during the winter).
Do you recommend any aluminum radiators?
Do you also recommend a cooler?
 

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A cold air intake can help almost every car. This is a good cold air intake, and a great company who continues to support our old cars: High Performance Exhaust Systems - Chevy Impala SS Cold Air Intake

I’m impressed you’re doing your first engine rebuild, that is great. 500 hp from a naturally aspirated gen 2 LT1 is possible, but not simple. I would think you might need to bump up the displacement to 383 cubic inches to hit 500 hp?
You will certainly need parts that work well together, as well as proper machining and assembly techniques.
Do you have a build list you can share?
What cubic inches are you shooting for?
Are you using Lloyd Elliott, Advanced Induction, or AFR heads?
Cam choice will be critical for you.
If I could give any advice, I would say: don’t worry about hitting any particular horsepower number. Instead focus on drivability for how you plan to use the car. Personally, I prefer low rpm torque as opposed to high rpm horsepower. I like the feeling of the car launching hard. What do you like?
I didn't know he still sold them.
 

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Do you recommend any aluminum radiators?
Do you also recommend a cooler?
If you have the patience to read this entire thread, you'll find your answers.
 

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Don't believe the hype about CAI. Running low 12's with a stock air filter in the stock air box with "swiss cheese" holes in it and "First Base" delete.

NA LE heads & cam Ellwein 357 with built trans, 410 gears, and slicks.

No change in ET and MPH at the track switching to an oiled S&B style cone filter.

Still not convinced? I'm racing with several 9-11 second NOS LT1's with stock filter and stock air box.

Save your money.
 

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Don't believe the hype about CAI. Running low 12's with a stock air filter in the stock air box with "swiss cheese" holes in it and "First Base" delete.

NA LE heads & cam Ellwein 357 with built trans, 410 gears, and slicks.

No change in ET and MPH at the track switching to an oiled S&B style cone filter.

Still not convinced? I'm racing with several 9-11 second NOS LT1's with stock filter and stock air box.

Save your money.
The key in Lance's experience is that he did get rid of home plate, and he did drill multiple holes in the stock airbox to allow more air in the system. A great point, and the price is free! I forgot all about the early days when guys were drilling the airboxes.

Lance, I am completely onboard with what you say about the stock airbox being good enough, but the cars with nitrous are a poor example, because nitrous itself is providing the extra oxygen.

For the OP: In 1994 I dynoed my car before and after (same conditions, same dyno session) adding a cold air intake system (homemade with a large cone filter, home plate was removed, and the corrugated flex was replaced with a smooth tube). I gained 7 horsepower with the CAI. I'm here to tell you that 7 horsepower cannot be noticed at all regarding performance.
A CAI is probably not worth the money on a stock car, but good intake airflow does become more and more important as you try to make more power than stock. Certainly with a goal of 500 hp, you will want to either swiss cheese the airbox and delete home plate; or add a CAI of some type. Or keep the stock cubic inches, keep the stock airbox, forge the internals, and run a healthy shot of nitrous. That is a quick way to 500 hp (y)
 

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Is the loss of HP from the home plate just due to it trapping heat? Otherwise isn't it just acting as a block off for the intake elbow?

My butt dyno felt no difference between the K&N CAI intake, the SLP dual cone intake and the stock setup with a swiss cheesed bottom, actually felt smoother overall with the stock stuff so I went back to it. But I am stock motor with stock manifolds so my scenario isn't the ideal one to look at.

 

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Is the loss of HP from the home plate just due to it trapping heat? Otherwise isn't it just acting as a block off for the intake elbow?

My butt dyno felt no difference between the K&N CAI intake, the SLP dual cone intake and the stock setup with a swiss cheesed bottom, actually felt smoother overall with the stock stuff so I went back to it. But I am stock motor with stock manifolds so my scenario isn't the ideal one to look at.
I don't know fluid dynamics, but it is my assumption that the home plate was a baffle to quiet the intake sounds. Same with the corrugated box between the elbow and the filter.
So the baffles do not restrict horsepower, but something can be gained from streamlining the air flow. 0 to 7 hp, I would guess. lol
The air intake does get noticeably louder when the baffles are deleted.

Finally, I don't know that any aftermarket air intake is better than (only) swiss cheesing the airbox. Heck, I don't know that swiss cheesing the airbox is worth anything either. I only know that I did one dyno test with a homemade intake that I machined and my mechanic installed on his dyno. A peak of 7 hp difference. 7 hp isn't anything. Not worth the effort on my (then) stock car.

I only say that air intake flow becomes more important when you are making more power. Right now, I have a centrifugal supercharger that is starving for air. I make 50 more hp when the air intake is removed, so I need a complete re-think on that system. :poop:
 

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My understanding:
Home plate is a Helmholtz resonator, but not much of a restriction.
My ex- preferred the OE intake because it SOUNDED like it was not working as hard.
(That's not THE reason why we divorced, but it might've had something to do with it.)

On a basically OE-spec 27 year old LT1, 1st base will never register as a restriction.
1.6 roller rockers, better valvesprings, a real-world-refined 91 octane tune, 1st base isn't too restrictive ... yet ...

Not like a coroplast SSRI3- / RAISS- knockoff is restrictive, so long as the filter(s) is (are) big enough.
Please feel free to correct.
 

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I want to know what the OP is building...
You said you bought some parts from Golen; I always think of them as providing a complete engine (not necessarily “parts”). Golen does great work, are they going to do the necessary machining on your block?
What are you planning on doing for tuning?
 

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Discussion Starter · #15 ·
I want to know what the OP is building...
You said you bought some parts from Golen; I always think of them as providing a complete engine (not necessarily “parts”). Golen does great work, are they going to do the necessary machining on your block?
What are you planning on doing for tuning?
Oh when I said Im getting my parts from golden I meant he helped me pick out parts. and he is doing all the necessary machine work. I don't know what I'm doing for tuning yet.
 

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A CAI, IMHO, is just 1 link in the chain of "supporting mods" that together = more HP when used with better flowing heads/cam, exhaust (including headers)

Yeah swiss cheese the stock box, eliminate the resonator between intake and TB and install a smooth inner surface tube, preferably plastic, is likely = within a few HP of a purchased one

I have had the K&N FIPK on for 23 years now but slightly modified as I run the larger F body MAF Ed Wright (RIP) advised many years ago. I eliminated the large rubber adapter that connected the tube to cone and just clamp cone filter direct to tube. Then bridge the connection of the tube to MAF with a SS wide clamp I bought at Home Depot and the MAF clamps direct to the larger F body TB elbow

For a radiator I run a FSR full aluminum with no cooler provisions. I have a T56 and use the 9C1 external "wet" oil cooler. I suspect FSR can/does make the radiator with the trans and r the oil cooler. Their site does list a radiator for the B body Four Seasons Radiator. Stock EL fans fit perfect

Given Ed has passed, for tuning I would use moehorsepower
 

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I love rehashing the old days.... i only felt more throttle response from my butt dyno, with all the intakes i messed with on a stock motor with mild exhaust tweaks.
Like others said when you have all the other supporting mods [ tune, exhaust, valve springs, gears, etc...] going from stock to a CAI is noticed by the butt dyno.

Here are some pics of what i tried....
Have FUN !!
-ALF out...
 

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... some pics of what i tried ...
Regarding the 1st 2 pics; the airfilter-MAFsensor-throttlebody stack ...
To optimize it:
1. Rotate MAF sensor 90 degrees to move its electronics to the driver's side
angelo's MAF looks like it's warmed by radiator breath AND radiated heat from the H2Opump
2. Any barrier under the air filter will minimize or avoid inhalation of the radiator's work product
Coroplast is cheap, cardboard is free if you like pizza. Both are also decent infrared heat sheilds.
3. For best results, use SSRI3 and/or RAISS as template; raise barrier edges to seal with hood.
(I only made it to step 2 with coroplast on the bottom and cardboard on top.)

Deleting 1st base (NOT homeplate) improves throttle response & high RpM potential, especially with other mods.
 

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My understanding:
Home plate is a Helmholtz resonator, but not much of a restriction.
Home plate may actually improve performance in the same way an X-pipe helps with exhaust. The first base was the restriction once heads and cam had been added. I think most folks removed home plate because they didn't understand how it worked back in the day or they just didn't like its looks.

OP, the best thing you can do for your LT1 is to change over to a modern coil on plug ignition. The weak point on this engine, as we all know, is the optispark distributor, where GM attempted to combine a cam sensor with the distributor. Problem is the distributor creates a ton of ozone, which corrodes the optical sensor parts. GM added a vent system on later models to vent the ozone and any water leaking onto the opti. If your opti is one of the earlier non-vented style, MAKE SURE you upgrade to a vented cap. But switch to a coil on plug ignition in any case.

Also, if you're looking for 500 hp (I assume you're talking at the rear wheels), it's going to be quite a bit cheaper in the long run to go with forced induction instead of building a bad-ass long block. 1) The stock crank can handle it, and the stock rods are capable of it, assuming you have everything magnafluxed to check for stress cracks; all you really need are 4032 alloy forged pistons. Aluminum heads wouldn't hurt either. 2) Fuel cost. The mods you'd have to make to get 500 whp out of a naturally aspirated motor is going to send your gas mileage to ****. You will actually recover the cost of the supercharger/turbo over 15-20,000 miles simply on the fuel savings alone of being able to run a milder cam and tighter converter.

In either case, your stock transmission won't hold up, and neither will your driveshaft, so put those items in your budget. Get a 4L80e if it's in your budget, or at least a fully built 4L60e. The stock driveshaft has a resonance issue somewhere in the 140-150mph range (don't remember the exact number off the top of my head), which will drop to a lower mph if you change the rear gears. A steel 3 inch diameter driveshaft will work just fine, although lots of folks like to go with aluminum or even carbon fiber if they have the budget.
 
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