High RPM heads

Printable View

08-13-2007, 11:59 PM
dhemi1

High RPM heads

Hello all,

I am new to the engine building world (still reading the books) and I have some questions for a engine I want to build someday. (being 18yrs old, I dont have the kind of money right now haha!) my dream engine would be a streetable 7000RPM redline small block 350 running on 93 octane pump gas. Would I need a rediculously long duration cam for that kind of engine speed? and what type of heads do you guys recomend for this application? I will be running a manual transmission in the 5-6 speed range. I want nothing but the best parts in my engine, I am not one to cut corners, when it comes to engines. haha.

Thanks all so much, looking forward to your replies,

-Chris

P.S. sorry for the long post but I thought ill give you all the info you might need.
08-14-2007, 07:28 AM
rumrumm

Hi, Chris. Since you are still in the learning process, let me comment on some of your ideas here. First, your goal should be to design an engine that will best suit the vehicle it will go into and the purpose of said vehicle. How much horsepower and torque will you require to meet your goal? For instance, there is no need to build an engine that will rev to 7000 rpm if you want to drive it on the street. Now, if it is going to be strictly a drag racer, then that is another story. It will take a good sized solid lifter cam or solid roller cam to reach a redline of 7000 rpm, and it will not be much fun to drive on the street because you will be fighting it at low speeds and at stop lights. Keep in mind that you are a lot more vulnerable to breaking engine parts when you rev it to 7000 rpm. Secondly, while the cam may be the heart of the engine, the heads are its lungs, and you would want the best flowing heads on the market so the engine will breathe efficiently. Right now, those are made by Air Flow Research. Check out their website at www.airflowresearch.com and you will see that you can make 500 hp and still not rev it much over 6000 rpm, and it would still be a good driver. Check out the books that Grumpy has posted on this website, read them, and you will learn a lot about building engines. Hang around this website, and you will learn a lot that you will never learn in books--the personal experience of other knowledgeable people can be one of the best ways to educate yourself.
08-14-2007, 09:05 AM
pat mccarthy

what rumrumm posted is right on the money . i will add is the ls1-6 is a very good engine and can take alot with not to much done to them . any 7000 rpm engine on the street will kill valve springs .you will have to stay on top of it checking them all the time all valve train has to be top notch as well as the bottom end. build the engine for low rpm TQ you will be much more happy
08-14-2007, 05:34 PM
dhemi1

Thanks for the great advice! i did some research the other night and i came across 2 heads that seem good. they compromise between low end torque and mid to somewhat high power. here are the specs on them.

Brodix Pro Street:
Port Vol. (cc) 185/80
Intake (CFM) 228
Exhaust (CFM) 153
E-I (%) 67%

TFS Twisted Wedge
Port Vol. (cc) 185/73
Intake (CFM) 216
Exhaust (CFM) 160
E-I (%) 74%

I plan to run a solid roller cam.
yea low end torque would be a deffinate. but i just think a engine that is capable of 7k rpm would be great, the high redline is not something not on my 100% must have list, but the sound would be incredible!
So what do you think of these heads? or should i go with a Edelbrock Perf. RPM to assist the low end grunt more? or is 185cc too big for a street engine?

Rumrumm, ill definetly check out AFR's website.

-Thanks again,
Chris.
08-14-2007, 05:55 PM
500caddy

just my 2 cents. but those heads with a roller cam just don't add up..both those heads crap out around .500-.550 lift hardly enough to make a 350 run good... the track 1 or dart 210 cc runners would be more like it.. the track one port speed is very good down low and they flow better up top then the two heads your looking at... i have built many pump gas 350 that make 450-475 hp that have good street manners..
08-14-2007, 08:33 PM
erik erikson

Quote:

Originally Posted by rumrumm

Hi, Chris. Since you are still in the learning process, let me comment on some of your ideas here. First, your goal should be to design an engine that will best suit the vehicle it will go into and the purpose of said vehicle. How much horsepower and torque will you require to meet your goal? For instance, there is no need to build an engine that will rev to 7000 rpm if you want to drive it on the street. Now, if it is going to be strictly a drag racer, then that is another story. It will take a good sized solid lifter cam or solid roller cam to reach a redline of 7000 rpm, and it will not be much fun to drive on the street because you will be fighting it at low speeds and at stop lights. Keep in mind that you are a lot more vulnerable to breaking engine parts when you rev it to 7000 rpm. Secondly, while the cam may be the heart of the engine, the heads are its lungs, and you would want the best flowing heads on the market so the engine will breathe efficiently. Right now, those are made by Air Flow Research. Check out their website at www.airflowresearch.com and you will see that you can make 500 hp and still not rev it much over 6000 rpm, and it would still be a good driver. Check out the books that Grumpy has posted on this website, read them, and you will learn a lot about building engines. Hang around this website, and you will learn a lot that you will never learn in books--the personal experience of other knowledgeable people can be one of the best ways to educate yourself.

Like rumrumm says check out AFR's heads.
The AFR heads would be my number one choice for a street engine that needs to make 500 hp.
Why not build a 383?
The 383 is almost always worth 25-35 lbs. of torque and this is what you need to get a heavy street car to move.
08-14-2007, 10:34 PM
Sidedraft Deuce

I would agree with all of the above post, very sound advice.

The only thing I would add is stay away from the Trick Flow heads there junk.
08-14-2007, 11:03 PM
gassersrule_196

trick flow junk? are you serious?????
08-15-2007, 08:09 AM
erik erikson

Quote:

Originally Posted by gassersrule_196

trick flow junk? are you serious?????

They are made for Summit racing.
I have seen them and if I had to guess I would say they are made "overseas" some where.
08-15-2007, 01:10 PM
dhemi1

I checked out AFR. GREAT STUFF!! I think this might be a good one. AFR 195cc SBC Eliminator Street Cylinder Head. Yes or no? see i dont want a peaky engine. u know having to rev her up to get any grunt out of her. that would be annyoing. lol. its ok for little 4 bangers but not for a big ol V8. haha!

Thanks for making my search eaiser,
-Chris.
08-15-2007, 01:24 PM
gassersrule_196

i must have been hiding in a shed somewhere i was not aware thanks for letting me in on that tidbit! man am i sheltered!:LOL:

Quote:

Originally Posted by erik erikson

They are made for Summit racing.
I have seen them and if I had to guess I would say they are made "overseas" some where.
08-15-2007, 02:24 PM
rumrumm

Quote:

Originally Posted by dhemi1

I checked out AFR. GREAT STUFF!! I think this might be a good one. AFR 195cc SBC Eliminator Street Cylinder Head. Yes or no? see i dont want a peaky engine. u know having to rev her up to get any grunt out of her. that would be annyoing. lol. its ok for little 4 bangers but not for a big ol V8. haha!

Thanks for making my search eaiser,
-Chris.

Build a light-weight car like I did, stick a good streetable 383 in it, and then go out and have fun! 450 hp in a 2600 lb. car is a real kick in the pants to drive! The power-to-weight ratio is better than a Dodge Viper.