Crate vs. U-build-it
05-07-2017, 11:30 AM
#1
Senior Member
Thread Starter
Join Date: Nov 2003
Location: Gary, In USA
Posts: 586
Likes: 0
Received 1 Like
on
1 Post
Car: '85 Camaro
Engine: LG4 305
Transmission: T-5
Crate vs. U-build-it
My goals:
Keep my T-5 manual transmission (no more than 330 lb-ft)
Keep my 10-bolt. Put in a 3.73 posi.
Rev to 6500 rpm
With the above I can go to an autocross or road course, and the engine can breathe.
I have seen a bunch of crate engines that will produce the power I am looking for, but are all done by 5100-5500 rpm. Those engines can be had for $3500 or less. Whether it is a new crate engine from GM or a rebuilt engine from whomever that is about where you end up.
How much more does it take to get the extra thousand rpm?
The cam seems easy to pick. Get a hydraulic roller cam with a power range from 2500-6500 rpm.
The Edelbrock manifold says it's good from 1500-6500 rpm.
I am having a hard time figuring out what heads to use. It is all too easy to go too big.
Can you even do this with an engine with less than 9.5:1 static compression?
Keep my T-5 manual transmission (no more than 330 lb-ft)
Keep my 10-bolt. Put in a 3.73 posi.
Rev to 6500 rpm
With the above I can go to an autocross or road course, and the engine can breathe.
I have seen a bunch of crate engines that will produce the power I am looking for, but are all done by 5100-5500 rpm. Those engines can be had for $3500 or less. Whether it is a new crate engine from GM or a rebuilt engine from whomever that is about where you end up.
How much more does it take to get the extra thousand rpm?
The cam seems easy to pick. Get a hydraulic roller cam with a power range from 2500-6500 rpm.
The Edelbrock manifold says it's good from 1500-6500 rpm.
I am having a hard time figuring out what heads to use. It is all too easy to go too big.
Can you even do this with an engine with less than 9.5:1 static compression?
05-07-2017, 11:54 AM
#2
Re: Crate vs. U-build-it
To breath that high you will need a pretty stout valve train and big heads. You will lose low end with big heads and big intakes.
That's why people use turbochargers. You can stay with smaller heads, long small runners (like TPI) and then shove the air through them under pressure on the high end. I'm building my 383 with 8.5 compression ratio and it will still make near the top of what TPI can flow (350 HP) NA. I'm doing this specifically to add a pro charger later on. Compression ratio isn't that big of deal - you will lose 3-5% going from 10.5 to 9.5.
GD
That's why people use turbochargers. You can stay with smaller heads, long small runners (like TPI) and then shove the air through them under pressure on the high end. I'm building my 383 with 8.5 compression ratio and it will still make near the top of what TPI can flow (350 HP) NA. I'm doing this specifically to add a pro charger later on. Compression ratio isn't that big of deal - you will lose 3-5% going from 10.5 to 9.5.
GD
05-07-2017, 02:32 PM
#4
Re: Crate vs. U-build-it
Years ago I put a set of World heads on a 305 TBI and stock suspension with street tires, AKA not making much power and not putting down much power. I was still able to break my first world class T5. The T-5 is only good for stock-ish level power and non-aggressive driving. If you start to improve the engine and the suspension you will break the T5, easily. If you have to replace or pay to have someone rebuild the T5 you are halfway to a complete T56 swap ($800-1400).
Do not con yourself into believing that you are going to have a 300+ rwhp vehicle and not break the T5. The T5 is only rated at 330 engine hp, not 330 rwhp. The only way it will live through autocrosses or Road course is if you granny shift and really feather the clutch, in which case you will burn the clutch and flywheel.
Being a 305, I wouldn't install any aftermarket part that you can't easily resell. Look for a set of 416 heads, an aftermarket cam and headers and intake.
I would just enjoy the life left in that engine and start to plan on an LS swap unless you can find some decent and lower mileage Vortec truck engines. But even those engines are 10+ years old now and probably all have over 100,000 miles. Not worth it to build a SBC anymore unless you already have lots of good, reusable performance parts.
Do not con yourself into believing that you are going to have a 300+ rwhp vehicle and not break the T5. The T5 is only rated at 330 engine hp, not 330 rwhp. The only way it will live through autocrosses or Road course is if you granny shift and really feather the clutch, in which case you will burn the clutch and flywheel.
Being a 305, I wouldn't install any aftermarket part that you can't easily resell. Look for a set of 416 heads, an aftermarket cam and headers and intake.
I would just enjoy the life left in that engine and start to plan on an LS swap unless you can find some decent and lower mileage Vortec truck engines. But even those engines are 10+ years old now and probably all have over 100,000 miles. Not worth it to build a SBC anymore unless you already have lots of good, reusable performance parts.
05-09-2017, 03:28 PM
#5
Senior Member
Thread Starter
Join Date: Nov 2003
Location: Gary, In USA
Posts: 586
Likes: 0
Received 1 Like
on
1 Post
Car: '85 Camaro
Engine: LG4 305
Transmission: T-5
Re: Crate vs. U-build-it
Losing torque to gain more rpm is a fair trade to me. It isn't like it will only have 150 lb-ft at 2500. I have a couple of cars rated around there, and I am having a ball with them.
Where does one get 416 heads?
Will they take a hydraulic roller cam setup?
I have Hooker 2210s waiting to be installed, but I figured they were too big for a 305.
At the point I have to start considering replacing the entire drivetrain it is time to think about an entirely different car. That is far too extensive a project for what this car is worth. Better to get an '05 Z06.
Used 350s are $200-500, and a brand new service 350 from GM is under $2000.
I built an engine before. A 408 with Dart Pro1s, forged internals, and a Crower 280R cam. I never got to hear it run because T-5, 10-bolt, and everything else that was necessary to support it. I had the car for 2 years, and didn't even drive it enough to change the oil a 2nd time.
Not again.
Maximizing what is already there with modest tweaks is sufficient. There will always be a faster car, and since this is not about competition I do not feel beholden to do what everyone else thinks is cool.
I am not looking to set the world on fire here. I just want a thirdgen that can keep up with my "10 Cobalt SS.
300hp at the crank is perfectly fine. That's ~50% more than it came from the factory with. If I can hear it scream a bit that's cool too.
Where does one get 416 heads?
Will they take a hydraulic roller cam setup?
I have Hooker 2210s waiting to be installed, but I figured they were too big for a 305.
At the point I have to start considering replacing the entire drivetrain it is time to think about an entirely different car. That is far too extensive a project for what this car is worth. Better to get an '05 Z06.
Used 350s are $200-500, and a brand new service 350 from GM is under $2000.
I built an engine before. A 408 with Dart Pro1s, forged internals, and a Crower 280R cam. I never got to hear it run because T-5, 10-bolt, and everything else that was necessary to support it. I had the car for 2 years, and didn't even drive it enough to change the oil a 2nd time.
Not again.
Maximizing what is already there with modest tweaks is sufficient. There will always be a faster car, and since this is not about competition I do not feel beholden to do what everyone else thinks is cool.
I am not looking to set the world on fire here. I just want a thirdgen that can keep up with my "10 Cobalt SS.
300hp at the crank is perfectly fine. That's ~50% more than it came from the factory with. If I can hear it scream a bit that's cool too.
05-10-2017, 11:22 AM
#6
Re: Crate vs. U-build-it
The 2210 is bigger than you need and for the amount of room they take up I don't think it's worth it for you. 1 5/8" is all you really need and in a shorty header would give you less headaches since it could use a stock routed exhaust system.
416 heads are just the last digits from a production cylinder head known to have good flow. Years ago a friend of mine (Momar on here) ran 416 heads on a carb'd 350 with a stock cam and headers and could keep up with the LS 4th gens. I believe any 1.94 valved head will work on a 305 but like you said you really don't want to pour much money into this.
With gears and aftermarket suspension set up correctly a thirdgen with a bolt on engine shouldn't have trouble keeping up with a Cobalt, especially short distances.
416 heads are just the last digits from a production cylinder head known to have good flow. Years ago a friend of mine (Momar on here) ran 416 heads on a carb'd 350 with a stock cam and headers and could keep up with the LS 4th gens. I believe any 1.94 valved head will work on a 305 but like you said you really don't want to pour much money into this.
With gears and aftermarket suspension set up correctly a thirdgen with a bolt on engine shouldn't have trouble keeping up with a Cobalt, especially short distances.