I'm having some trouble trying to decide what components to use in a carbed 350 that is going to be my daily driver. I am not even sure as to how much power would be too much for a street car. I am hoping to get around 375 hp and 400 ft lbs of torque.
I found a website that is out of hand with engine combos, and lots of other things. Check it out if you want -
URL=http://www.ryanscarpage.50megs.com/combos1.html]http://www.ryanscarpage.50megs.com/combos1.html[/URL]

From what I understand, a broad, flat torque curve would be best. Also, keeping the cam from getting too radical would be a necessity, because I need vacuum for power brakes. I wish I could go with a big cam though, cause I'd love a lopey idle, but I don't want to install a vacuum canister.
Anyway, do any of you guys have any setups that you recommend, or maybe comments on some of the combos on that website? I'm going carbed for sure, and am trying to keep costs under $2700 (I'm building it myself). Oh, one more thing, I don't want to overwhelm the car with power if it can't take it. I'm gonna be using a T56 (I think it'll take 450 ft lbs) and a fourth gen rear. I definitely don't want to make cracks or bend the car (I've heard stories), so my goals are dependant on that.

 

No one? I refuse to believe that no one here has any advice on anything whatsoever.

 

http://www.ryanscarpage.50megs.com/combos1.html

There. Now anyone can reach that website easily.

I'd say you're on the right track. Although none of those combos show a dyno sheet. It's hard to see the 'flat' torque curve without them. But for an overall street car, with the occasional trip to the strip, a flat torque curve is best.

One quesion though. Why do you want to get rid of the TBI?

To avoid any problems with the chassis, use subframe connectors. And I suppose a strut tower brace would help also.

AJ

 

I wanted to get rid of the tbi because of several reasons. I have been planning to get considerably more power than the 305 has, and here were my options. I could stay with the tbi on a 350 (not the most powerful combo), buy a tpi setup which would be restrictive at high rpm, or go carbed. I've always admired the simplicity of old muscle cars, and hated the complexity of computer controlled cars. They are very annoying to work on. As far as the whole idea that fuel injection adapts better to changes in weather, it is probably true, but my experience has been the reverse. My fuel injected camaro runs great on cold windy days, and feels like a pig on hot days. Meanwhile, my dads carbed f150 runs the same no matter when.
Anyways, I decided that I'm gonna go carbed and forget gas mileage. The tbi setup is getting me about 11-12 mpg right now in the city, and carbed can't be much worse. I do plan on getting subframe connectors soon, and the strut tower brace is gonna be there shortly too. I just don't know if they are enough. Also, how much duration / lift is too much cam for a daily driver?

 

If you are going carbed and want the lopey sound, you can always get like a 218 to 224 duration cam which is fine for a street car and turn you idle speed down. My Hotcam can sound like a dragsters duration when the idle is around 500-600.

 

218 - 224 degrees of duration is enough for a lopey idle? Thats great. By the way, how much vacuum is needed for a daily driven vehicle?

 

My engine is the same as combo 83 (on that site) minus the roller rockers.
I used Crane stamped steel 1.5" rockers with the roller tip.
Check my combo out in the Readers Rides on this sight for details.
This setup is very smooth and streetable with reasonable good
gas mileage. It also passed a smog inspection (Ontario) and test.
Goes like stink and is Nitrous ready. It makes the power and torque you are looking for and is within your budget. It doesn't require and expensive hi stall torque converter, but does like a bit o' gear. Anything from 3.23 to 4.10 will work well. Basicly its a "0" decked flat top piston 350 (cast pistons). The Hp and torque
numbers I list are Rear wheel net.

 

F-BIRD '88, I went back to the site to see combo 83, and I am confused. 10.6 to 1 compression ratio for the street? Then I went and saw your car at reader's rides. 10 to 1 compression (I think thats what it said)? I had thought that 9.7 or 9.8 was roughly the limit that you can use with pump gas on cast iron heads. I must be totally wrong.
That setup would be great for my goals, except that I didn't want to limit myself with my head choice. Vortec heads can't make a whole lot more power than they do in that combo, atleast from what I understand. I was thinking that it would be better to go with a decent set of aluminum heads that'll flow a little better, and that way I can have more potential power in case I later decide that i still want more power.
Anyway, if that combo likes some gearing, thats not a problem, I'm gonna be running 3.42s. What mileage are you getting right now?

 

Don't kid your self on the ultimate potential or upgradability of Vortec heads. There is plenty of room to grow. We're seeing big flow numbers and power with easily done porting, even with the stock valves. A huge port is not desireable on a street motor.
170cc to 180cc is about ideal on a 350. Volosity is very important on a street motor (lowend torque, throttle response, gas mileage)
Generaly I would agree with ya about 9.8:1 cr on street motors,but
My motor has a measured cr of 10.03:1 and runs fine on 94 octane Sunoco gas. (.015" deck height). These heads are a little less detonation sensitive than previous designs. I have not actually measured the gas mileage, but so far it seems to be very reasonable.
No you can't bolt these heads on "out o' the box" and make 500hp, but they are hard to beat on a budget.
If you are "confused"and want a combo that performs
on the street, on a budget, this is a great baseline. I'm currently
building a 406 with fully ported, big valve vortecs that will make a lot more power but I am sure mileage will suffer. I'ts almost a shame to take out this 350. It runs that nicely.
P. S. I have less than $2700 in the whole car.

Good Luck

 

I was looking through the scoggin dickey catalog last night, and something doesn't sound right. Check this out-

L31 Vortec Heads

Lift Intake Exhaust
.100" 70 48
.200" 139 101
.300" 190 129
.400" 227 140
.500" 238 147


Fast Burn Heads

Lift Intake Exhaust
.100" 62 45
.200" 129 85
.300" 173 120
.400" 209 143
.500" 230 157
.600" 235 166

The Vortec heads outflow the Fast Burn heads? What the hell? I must be missing something really obvious. I know the vortec heads flow pretty good, but better than the fast burn heads?

Oh, one more thing. A 170 to 180 cc port is ideal for a street motor, right? The fast burn heads have a 210 cc port. What does that mean in terms of streetability?

 

That means lower port air volosity at a given RPM for a given size
motor.
As a general rule this means less low and midrange torque.
Dyno tests between the 2 different size heads (on a 350) show this to be true.

Published airflow specs seem to vary widely on exactly
how much fastburn heads flow out of the box. I have never worked with a set so I don't know too much about them.
The pair I seen (at a GM performance parts display) had rough
cast ports but good contours. Apparently they flow like
no tommorrow with just minor port clean-up.

The popular published specs of 430hp on a 350ZZ4 with
an LT4 hot cam, can easily be reached with a simular combination
with moderately worked vortecs. For a lot less!
The bigger fastburn 210cc ports will get ahead on a larger more radical
motor with a higher lift cam and racing intake.
But then your getting away from a "street motor"

 

So I would pretty much save money and get more low end torque with some ported vortecs? Damn, thats good news.
Roughly how much more do cast iron heads weigh over aluminum heads? If it would significantly help weight distribution, I guess I can justify their cost, but if its not alot, that is just throwing away money.
F-Bird 88, you have really got me interested in vortec heads. I'm gonna go figure what it would cost me to build everything with vortecs and then compare that to other setups.