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hp on my new build

  
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hp on my new build

 
sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
10:06 AM

I have just built my first engine and was wondering what you guys think I might have for power.  Its a 67 Pontiac 400 lower end is stock accept ARP bolts.  I have e heads ported to 316 by Butler with torker 2 intake ported to match. Doug 2 inch headers holley 850 dp and 3 inch exhaust.  I have a xe268 cam and 2500 stall with a tci th400 with trans brake.  Think I listed the info you guys would need to make a guess. Thanks for any info.  I plan I doing the bottom end next year if I have the money. Oh I have 1.65 roller rockers. I hope to make over 400 HP and really good torque.  

Pontiacman8 Pontiacman8
Moderator | Posts: 5779 | Joined: 02/08
Posted: 07/30/13
12:18 PM

What is your Compression ratio?  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
12:24 PM

10.3 to 10.5 I have 72 cc heads  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/30/13
12:39 PM

Hello


First I see you are a new member so welcome!

The budget Comp computer dyno estimates 457 hp  5500, 480 tq  4000. Might be a bit optimistic.

Your carb seems like a bit of overkill.

Your cam seems like a bit of underkill. If you want a tire burner I'd switch it to an XE274H or comparable Lunati but if you have stock cast pistons I might not.  

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
12:47 PM

Thanks for the help and I have been thinking of going to the 274.  When I put a new rear end in I only have a 10 bolt with 256 gears for now.  I want to build a drag car this year I built the engine and got the trans. Oh also I got a aftermarket front subframe from speed tech.  Hope to drive it some and do more work next year.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/30/13
12:48 PM

What's your gear ratio?

Unless you are a fwy flier I would run around 343 with around a 2200 rpm stall on the 268 or 2400 on the 274 if you want to roast some tires with either of those cams.


As i mentioned, i might not run the 274 with cast pistons.  

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
01:06 PM

No high way driving at all just drag racing and I sometimes drive it around my small town  

Pontiacman8 Pontiacman8
Moderator | Posts: 5779 | Joined: 02/08
Posted: 07/30/13
03:05 PM

I would estimate 400-420HP.

Good luck with those comp products as many others have had problems with there products.

I would have looked for a cam with a little more duration to take advantage of those ported eddy heads.  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
03:11 PM

If I get some gear in my car what would you recommend for a cam?  

Pontiacman8 Pontiacman8
Moderator | Posts: 5779 | Joined: 02/08
Posted: 07/30/13
03:26 PM

http://www.lunatipower.com/Product.aspx?id=1763&gid=279  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
03:40 PM

Thanks for the info I will look more into there cam's I have heard good things about them.  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/30/13
04:08 PM

"No high way driving at all just drag racing and I sometimes drive it around my small town."

Well the gears should be matched to cam and tires. If you rent tall slicks at the track things change but in general:

350 = street and slow fwy driving not great for strip.

373 = better street/strip, 60-65 mph fwy driving at best but high engine rpm's, max gear for 268 and 374 cam.

391, street/strip 50 mph fwy, needs bigger cam than 374

411 on up strip.



"If I get some gear in my car what would you recommend for a cam?"


As I mentioned, I think if you go to a 274 with gears your stock cast pistons may hurl. Any bigger and your rods may follow.



"Good luck with those comp products as many others have had problems with there products."

As I mentioned, definitely don't buy their lifters, I have run many of their cams as well as many of my friends with 0 problems.

It is also possible that comp owns lunati anyway now so if in fact that is the case then do the comp lifters get better or do the lunati ones get worse, lol?  

sunnerville sunnerville
New User | Posts: 9 | Joined: 07/13
Posted: 07/30/13
05:45 PM

Like I said earlier I am just starting on this car hope to make it to the bottom end of the engine next year and plan on back halfing the car if I went with the 274 it would be after I bore and stroke the  engine and have forged parts.  

jjrush jjrush
New User | Posts: 2 | Joined: 07/13
Posted: 07/31/13
08:28 PM

Hello,

I am new to this forum myself too. I believe I am in the same boat as you. I just recently did my first build of a motor. It was quite the experience for me. I am a little curious on how much HP, I will be getting myself. I used a 73 Pontiac 400 block with flat top pistons, stock crank, I did upgrade the came I bought a COMP Cam high energy with a Duration 274/286, Lift .488/.491, I have a torker 2 intake, 1969 428 heads #62; that I had ported and polished with seats put in; along with getting the valves tripled angle, I have 3 inch headers, to a 3 inch Pypes racing exhaust and it is topped off with a Holley 750. I currently have a 2500 stalls with .355 gears. I did upgrade the water pump to a flow kooler. Is there anything else I should do minus the pistons and crank?

I am hoping next year if I have the money to; is maybe actually upgrading the pistons and crank in the motor. Currently I just plan on using it for just on short cruises and shows. I was going to take it to the strip and see how it would do. Any suggestions, I am new to this endeavor. Thanks  

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/31/13
10:56 PM

Hello

Welcome to the forum

For the moment I would say the same thing to. If you have cast pistons, especially old used ones you are tempting fate. 1 short burst is all it might take to break one or more. I would limit the throttle travel to eliminate the possibility of "overbursting" it until i installed a stronger pistons and rod bolts at the least.

Is your engine running?

Do you have Comp lifters?

Do they make a ticking sound like a slightly loose lifter?  

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