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Discussion Starter #1
I built a 383 that I thought would make around 580 hp and it seems to be no faster than my 485 hp 355 that I took out.

I built a 383 with eagle crank /rods forged 10.5 to 1 pistons, ported AFR 210 heads, huricane manifold and a sollid roller cam. I ran the specs thru dyno simulator (596 hp) my machine shop( he said it should make the number) and even ran the specs here on the bullit and almost everyone thought it should make 560-600 hp. It runs fine, plugs are colored nice, no stumbles, pops, misses or anything. its just slow!

my question is this. I had a local cam grinding company make this cam. if the specs are right could the cam still be "lazy"? Slow or not aggresive lobe profiles? could it cost 70-80 horses?

Second question. I have a comp cams roller that I originaly wanted to run, but it is not a small base circle cam. Does the 383 always need the small base cam?

thanks for the help.
 

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Post the cam specs.
Also, what is the cranking compression ?
 

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mine is a reg base with eagle rot assy.i think the rods are small enuff to clear?ck for yourself tho.i havent made a full pass yet!!!
 

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Second question. I have a comp cams roller that I originaly wanted to run, but it is not a small base circle cam. Does the 383 always need the small base cam?

thanks for the help.
A 383 should use a regular base cam. I went to a small base when I went to a 3.875 stroke crank.
 

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A 383 should use a regular base cam. I went to a small base when I went to a 3.875 stroke crank.
Depends on the rods used. Some are more cam cut than others.
 

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He's using forged Eagle rods (I'm guessing 6") so they should clear..........BUT I would ck to make sure.
 

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Discussion Starter #9
Times at track , rest of combo (trans ,axle , gear , tire size ) ?
car only ran 11.16 @118 th350, 3.50 because of the 235 drag radials in a 3400 pound nova. ran a a verry poor 10.54 @129 with the nitrous on.

the iron headed 355 ran 10.95 and 10.07 as bests.
 

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Discussion Starter #10
Post the cam specs.
Also, what is the cranking compression ?
cam specs are:

int .674 ex .656 (with 1.6 rockers)
@.050 .256 .262

22 btdc 54 abdc
65 bbdc 17 atdc

I dont have the cranking compression, the day after I ran the car, took the family on vacation. just got back last night. planning on tearing into it this weekend.
 

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Discussion Starter #11
What carb, timing ,cam specs,converter,gear?
using a well worked 750 hp timing locked at 38 on motor and 30 on the bottle. cam and rest of setup are above. the tire are a class spec tire. this is a headsup class, and I need that 80-100 hp to be competative.
 

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He's using forged Eagle rods (I'm guessing 6") so they should clear..........BUT I would ck to make sure.
Def check for sure.
Nephew put together a budget 383 two years ago using a Scat steel crank and their "stroker" rods - 6" length. Still had to clearance four of them as they just kissed the lobes.
 

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cam specs are:

int .674 ex .656 (with 1.6 rockers)
@.050 .256 .262

22 btdc 54 abdc
65 bbdc 17 atdc

I dont have the cranking compression, the day after I ran the car, took the family on vacation. just got back last night. planning on tearing into it this weekend.
Ok.
What is the cam's LSA and where is the intake installed ?
 

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my 383 with 5.7 rod with .630" solid roller crashed with the rods. went to a small base circle with no issues. Had a std .530 lift solid cam that cleared with no issues. Think it depends on lobe lift and event timing.
 

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I run a .900" BC on all the stroker engines up to 4.00" stroke, I then use .875" for the billet roller stuff. I don't use Eagle in the big stroke engines.
As for your camshaft, how muchc ompression is in the engine? The cam you have will be great for 11.1, which is what you get with 62-64cc chambers, .005" in the hole with a small bore gasket and flat tops with -5cc reliefs. The LSA is important as is where it is installed. I grind them on 108's and install them at 104's in these. Your camshaft is VERY close to what I run in my street 383/406 engines, I also use a 950 hp, as the 750hp is too small and drop power on my setups. How fast it will be is determined by the rest of the setup. Gear,tire, weight, converter etc..shift points are important as well. Nothing will be the same for the 383 as it was the 355. Cranking compression with a ported 210, 11.1, and that cam with a 108 in at 104 should be in the 200psi range, give or take a few as it depends on the corrected altitude of where you are. Otherwise as for power, these combinations I do are in the 600hp area so what you have should be right in that range. Let us know what the drivetrain is like, as well as LSA and IC. Also, I would step up to the 950 when you can, as well as a HVH SS spacer, 1". Timing seems to be about right as well, have you tried different timing numbers? Also, where do you shift it at? I run the 215 Dart Pro 1's with mild work and with my cam, a tough bigger than yours, runs to about 7,200..LMK.
 

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Discussion Starter #17
I run a .900" BC on all the stroker engines up to 4.00" stroke, I then use .875" for the billet roller stuff. I don't use Eagle in the big stroke engines.
As for your camshaft, how muchc ompression is in the engine? The cam you have will be great for 11.1, which is what you get with 62-64cc chambers, .005" in the hole with a small bore gasket and flat tops with -5cc reliefs. The LSA is important as is where it is installed. I grind them on 108's and install them at 104's in these. Your camshaft is VERY close to what I run in my street 383/406 engines, I also use a 950 hp, as the 750hp is too small and drop power on my setups. How fast it will be is determined by the rest of the setup. Gear,tire, weight, converter etc..shift points are important as well. Nothing will be the same for the 383 as it was the 355. Cranking compression with a ported 210, 11.1, and that cam with a 108 in at 104 should be in the 200psi range, give or take a few as it depends on the corrected altitude of where you are. Otherwise as for power, these combinations I do are in the 600hp area so what you have should be right in that range. Let us know what the drivetrain is like, as well as LSA and IC. Also, I would step up to the 950 when you can, as well as a HVH SS spacer, 1". Timing seems to be about right as well, have you tried different timing numbers? Also, where do you shift it at? I run the 215 Dart Pro 1's with mild work and with my cam, a tough bigger than yours, runs to about 7,200..LMK.
using the 750 right now because it is a good and known carb to me, I have it on a wilson 2" tapered spacer. I have a 950 hp for when its running right. At 36 degrees car slowed down, at 40 deg same ET but less mph. motor was built to shift at 7-7200 but its all done at 6200. car leaves good but where it is suposed to start making some real steam is where its laying down.
cars 60' is at 1.55 on motor with the small tires. should run a 1.45-1.47 on bottle on good track.
 

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I would run the bigger 950 with the HVH spacer. Next, have you tried different shift points? You are giving an apples to apples comparison using the same drivetrain, so something is off from engine to engine. The carb is the only thing I can see being too small for the 383 as opposed to the 355, as well as where the engines make the power. I know the 383's like every bit of 7-7200 setup like yours..
 

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Discussion Starter #19
best et and mph is shifting at 6300. shift at 6700 and will sloww to the .20's and into the .30' if shifted at 7000. I can put the 950 on but I dont want to be fighting two problems at once. I guess I can take the 950 and the 750 and see what happens. what cam do you run in your 383?
 
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