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347 with 205 11R Heads how much Horsepower and torque

9.3K views 41 replies 13 participants last post by  Nitrous SSC  
#1 ·
I was wondering if anybody could help me out? I’m trying to figure out how much horsepower my 347 will make naturally aspirated. I’m just trying to get a close HP and torque range so I can figure out if my fuel system will handle it or if I will need to upgrade somethings. I appreciate any help.

This is what I’m running.
cam trickflow track Max hyd roller duration286/294 lift .542/563, lobe sep 112
Heads 11R 205 cc cnc competition ported 56 cnc chambers
head gaskets are cometic 4.030 in. Bore .066in compressed thickness
Rockers 1.6 ratio 7/16 stud full roller
Trick flow true forge pistons .030 flat top
H beam 4340 forged rods 5.400 length
4340 steal crank along with a girdle
 
#7 ·
I was wondering if anybody could help me out? I’m trying to figure out how much horsepower my 347 will make naturally aspirated. I’m just trying to get a close HP and torque range so I can figure out if my fuel system will handle it or if I will need to upgrade somethings. I appreciate any help.

This is what I’m running.
cam trickflow track Max hyd roller duration286/294 lift .542/563, lobe sep 112
Heads 11R 205 cc cnc competition ported 56 cnc chambers
head gaskets are cometic 4.030 in. Bore .066in compressed thickness
Rockers 1.6 ratio 7/16 stud full roller
Trick flow true forge pistons .030 flat top
H beam 4340 forged rods 5.400 length
4340 steal crank along with a girdle
Roundabout 475 to 500 FWHP. Why did you use a 4.030 bore Cometic?
 
#13 ·
Stock lines are fine with a 255lph pump. Don’t put a 340 in. It’ll just recirculate a **** ton of fuel. Put some LU47 injectors into it. They’re cheap, easy to tune, and have a much better spray pattern.
 
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#16 ·
I was wondering if anybody could help me out? I’m trying to figure out how much horsepower my 347 will make naturally aspirated. I’m just trying to get a close HP and torque range so I can figure out if my fuel system will handle it or if I will need to upgrade somethings. I appreciate any help.

This is what I’m running.
cam trickflow track Max hyd roller
 
#17 · (Edited)
I ain't going to go out and say what are your exact numbers are going to be. One there are a few questions that have to me known. Like comression ratio. And if your running a stick or auto transmission. The stock fuel lines answer a little. Good set of heads great choice. What RPM are you reving too. But i can see you running 425 HP or in 475 HP range to the rear tires. You can get more with a good set of number 8 or 10 feed and a 8 or 9 return line with some nice Fuel rails if your EFI. And again if your stick it is going to make more power then what i am saying. Because auto makes less or can make more. Depends on if your converter is too tight it will makes less. Or if it is loose it will make more HP. Again i ain't no pound my chest expert. But it can be in that neighbood more or less to the rear tires. Also a real good big out of the tank fuel pump like a Weldon race fuel pump. Is a bit too loud. But they flow way better then the intank fuel pumps. That work great. But when you want to make as much power as you can. There the way to go. Oh also if your running AC Power Steering and on and on. That lower your HP numbers. To the rear tires. But hey i gave you what i think is a real ballpark figure. Good Luck !
 
#19 ·
Anything over about 500whp you should be looking at replacing the fuel rails. Ive pushed it to 560whp on the dyno but I wouldnt recommend it. If youre not expecting to see over 500whp the stock rails are fine. If you havent bought injectors yet, look into siemens 80s from PowerAdderSolutions. $380 and they will support up to about 800hp NA. There is no disadvantage of getting large injectors and if you decide to add a blower or turbo, you wont need to buy injectors again even if you do e85.
 
#28 · (Edited)
Yes. "Because you don't listen"

Having said that...this forum is not a revenue source for me. I come here and open only threads that I might be able to add to. Before I do that I look to see who's participating, because there is a cadre of people that I just refuse to interact with if I can avoid it. So I duck the cool kids.

Following that train of thought, since I'm not doing it for me, I must be doing it for another reason.......but I can do that everywhere.

Chasing knowledgeable people, Like Indy, Ed, me, and a few others off the forum will leave the mostly blind to lead the completely blind....and it will not affect our lives in the least. After all, there is even more bad advice on Facebook than there is here....and that's a reasonably high bar to leap.
 
#27 ·
Pretty sure Mark was banned because he told a moderator to STFU after being asked to keep politics in the politics forum. As far as Indy, nobody i know is in contact with him but i think it's pretty obvious why he was banned
 
#32 ·
Taking what personally? If you're insinuating I'm upset about something i suggest you reread what I've posted. I posted my first hand experience with him on these boards after you said he was banned for being a jerk to the wrong person when in fact he was a jerk to people on an almost weekly basis for years. As far as Indy being Indy, nobody including me stopped him from doing him and now hes banned. I'll keep on doing me and not pretending he wasn't a jerk to a lot of people.