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View Full Version : More HP from a 350 without turbo or blower



max46
06-12-2013, 05:28 AM
I contacted a engine builder by email the other day about increasing the hp in my 350. He wrote back to me mentioning turbo's, blowers. I don't want that stuff. I want it to be carb powered. Why do they mention that type of set up when I see on the net, crate engines with 500+hp using carbs and not turbo's or blowers? Is it a cost issue or what? I want to reply to him, but would like to hear from the members first.

chevynut
06-12-2013, 08:26 AM
It's a driveability issue. 500HP out of a 350 takes a lot of compression, a large cam, big valve/port heads, and big carbs that don't work well on the street. I personally would never use a carburetor again on any car. They are always a compromise at any RPM.

The main thing that drives the efficiency of an internal combustion engine is compression ratio. To get power out of it, you have to put energy into it in the form of gas, and that gas has to be mixed with the right amount of air. So the more air you can get into the engine, the more fuel you can squirt into it, and the more power you'll make. Of course you have to get the old spent fuel out of it too, so you can get fresh air into it.

max46
06-12-2013, 03:23 PM
It's a driveability issue. 500HP out of a 350 takes a lot of compression, a large cam, big valve/port heads, and big carbs that don't work well on the street. I personally would never use a carburetor again on any car. They are always a compromise at any RPM.

The main thing that drives the efficiency of an internal combustion engine is compression ratio. To get power out of it, you have to put energy into it in the form of gas, and that gas has to be mixed with the right amount of air. So the more air you can get into the engine, the more fuel you can squirt into it, and the more power you'll make. Of course you have to get the old spent fuel out of it too, so you can get fresh air into it.

Guess I am just old school. I read that a supercharger is better than turbo due to no lag time. My wife's car is supercharged and it hauls ass. No lag time with it. I never had a turbo. There is a shop around here that uses only superchargers for anyone who wants to gain hp. Maybe I need to see him. Sure would be cheaper than maybe a new engine. Although, the remanufactured engine sites have some good prices on high performance turnkey engines. Believe I need to get my engine on a dyno. I need to see what hp I now have before I make the leap to increasing hp.

chevynut
06-12-2013, 06:11 PM
Yes, supercharging is a good way to get more power in one big step. Again, more air in means you can squirt more fuel, which makes more power. It's a lot easier to push air into an engine than to pull it in. Smaller turbos have less lag, that's why some cars run small twin turbos to get more air in without the lag.

Another option is the Pro-charger type supercharger that looks like a turbo but is belt-driven.

warren57
06-19-2013, 05:53 PM
I have a magna inter cooled supercharger on my Corvette and there is nothing like it. But, very expensive. Have a friend that put a procharger on his Corvette and again awesome at about 1/2 the cost.
Turbos have been around forever, but I see two issues, first the exhaust piping required to spin the turbine. Takes up a lot of space and is a pain. Second is keeping the turbine bearing lubed so it doesn't get to hot from the exhaust gasses passing through. I understand you can ad an oil pump to circ the bearing oil after shutdown, until it cools and some say that helped a lot.
Overall, unless you need super high HP (which I would use a supercharger), it's hard to beat fuel injection. Just my $.02

567chevys
06-19-2013, 06:15 PM
what's wrong with NOS:D

Rick_L
06-19-2013, 06:30 PM
Seems like some like to use more cubic inches.

There's no silver bullet.

55mike
06-21-2013, 04:16 PM
We've all heard "there's no replacement for displacement.." This said, my 355 with AFR heads, 292 Comp Cam, 10 to 1 compression, Edelbrock RPM intake, and Demon carb (I want FI!!) and Hooker Super Comp headers is a decent combo. On the other hand, a more modern roller cam'd stroker would even be better!

sleeper55
07-04-2013, 10:51 AM
I am running an old B&M 144 blower on my small block. I just got it back from Super Charger USA in California. It really does wonders for the 350. Pulls hard, sounds cool and the response is perfect. All fits nicly under the hood too. But if your going to go with a blower just remember that blowers need low compression. Mine is 8 to 1. Just sticking a blower on any 350 may not work so well.

the_dawg
07-29-2013, 07:46 PM
Tell us more about your set up.. Heads intake andy other mods.. Heads cam and carb are where you need to look, headers and exhaust too