SBC 383 build Advice shooting for 550hp to 600hp

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Desmosis10
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

wyrmrider wrote:couple of questions just saw your latest post after I typed this so some revisions
3/8 rocker studs??
what's your deck height with your chosen pistons, please say 0.0 (and adjust piston to get compression)
your "quench" would be your gasket thickness- the closer the better
on your cam choice
did Comp say to squeeze the lobe centers-comp recommends for 9:1 and 3000 stall and use 110 LC and 106 ICL
but no mention of 383
my take is that is a conservative (but not very conservative) cam
236 @50 can be done with 280 @.006 not needing 288 still with .360 lobe lift and mid 150's @200
or
same seat timing @.006 288 can have more "intensity" to get you over 240@.050 and over 160 @200 and over .360 lobe lift
you could have .620 at the valve with 1.7 rockers
If you already have the comp cam 1.7 rockers would get you around .600 lift on the intake
so what converter??? OK I see you said 3500 that really helps (and tranny cooler)
If daily driver I'd go with the shorter duration higher lift solution no matter what seat duration you can live with
8 degrees is a lot to leave on the table
I may comment on Orr 89's post above
7/16 rocker studs Yes my engine builder decking it to o.o so I can get 11.1.1 compression heads are AFR210cc and are 65cc not really sure on the Quench what would u recommend? I'm not using a comp cam I'm using a Howards Hyd Roller Cam. 3500stall converter 1.6 rocker or intake and 1.5 on exhaust which make it to a 636/600 I believe i'm not really sure i'm new to this... :wink: But this is the cam i'm going with right below ....


Cam Style:Hydraulic roller tappet
Basic Operating RPM Range:3,000-6,600
Intake Duration at 050 inch Lift:247
Exhaust Duration at 050 inch Lift:255
Duration at 050 inch Lift:247 int./255 exh.
Advertised Intake Duration:300
Advertised Exhaust Duration:308
Advertised Duration:300 int./308 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.600 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.600 in.
Valve Lift with Factory Rocker Arm Ratio:0.600 int./0.600 exh.
Lobe Separation (degrees):110
Camshaft Gear Attachment:3-bolt
Computer-Controlled Compatible:No
Valve Springs Required:Yes
Camshaft Manufacturers Description:Small base circle. Hot Street/bracket. Requires aftermarket heads, 3,500+ stall.
Desmosis10
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

wyrmrider wrote:Orr
I don't see a 228 duration with 360 cam lift on Mike's site
but I do see
220 @50 142 @ 200 and .375 lift with only 272 on the seat @.006 should work good with power brakes and AT .637 w/ 1.7 rockers
142 @200 would give plenty of flow
he also show
227@.050 148@.200 .375 lift and 280 on the seat which would be closer to the one you mention
as I said above 8 degrees on the seat makes a big difference
the comp cam suggestion is bigger- 288 on the seat but I do not know how big at 200 and does not have the lift
for those still suggesting a 240 @.050 cam are you thinking of over 160 @200? and around 288 on the seat?
Mike would be much better at discussing his lobes than me finding his catalog
narrowing down the choice to maximize across the intersection power- 60 ft time- with a 3500 stall converter and 4.11s and still make the brakes work
what powerband are you looking for Des?
What do u mean by power band, i'm new to this so i'm trying to catch on as I go and get advice and tips from u guys... :)
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

wyrmrider wrote:comment to af2
OP is in between that rock and a hard place
in order to fully use the heads he needs more lift into the area where they flow best than he can get with seat durations he can use with a 3500 rpm stall heavy car and 4:11s and power brakes
A race car would be easy, lower gears and spin the motor and run optimum duration for high horsepower
a light car he could use more stall and gears
If he wanted a race type narrow power band he could get more top end horsepower
HP at high rpm looks good but if he looses torque at stall the car will be a pita to drive unless he is very hard core
(been there- done that- built a Chevele SS turbo 400 car for a customer too big a cam and ended up changing it, it was great out on the road when you hit passing gear but till then... )

another comment
who was using 97 octane and where do you get it? (or was that the other 383 thread)?
I believe I was said something about 97 octane gasoline, they sell 97 octane which is premium Gas at Shell, its only at shell gas stations well at least over in my area where I live Griffith,In and Chicago,IL.....
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by swatson454 »

Have you already bought all of the parts?
Live in such a way that those who know you but don't know God will come to know God because they know you.
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by wyrmrider »

wish I could get 97 octane...
Recap
AFR 210 comp heads- 65cc 0.0 deck 11:1
Talking about non twist cast crank which does not compute
(non twist cranks are all fordged) short rods

you need to cram more lift on that stick
What do u mean by that???
your aiming for 550- 600, why would you only use .6 lift
Do you have duration @ .200" lift figures for that cam?
No I don't have the duration for the cam @.200 lift, why u ask that?????
That number gives you some idea of how much power the cam will make in upper rpm's.
thats funny, more dwell in the right area of the lobe will net much more than a measley 2hp
On the Howards cam
Mike posted
A 247/255 Hydraulic roller would have about 8 more degrees of seat duration (than a solid roller).
I calculate it'll make 517hp @ 6,500rpm.
IMHO Cam holds past 6500 due to exra long exhaust
flow 296 @ 500
flow 310 @ 550
flow 318 intake and 235 exhaust at a 600 lift
flow 322 intake and 237 on exhaust on a 650lift...
IMHO not a lot of difference- exhaust is flat- almost any lift will work
get the intake over 500 as quick as possible and for as long as possible
reread 66vette's post pg 3 IMHO shoot for a 6500 rpm motor not a 7000 rpm every time you run it motor

af2 weighs in – spot on IMHO
With an engine that needs maybe 260 on the flow to make the speed get there why do you think the heads flowing 318/
forget the exhaust . It is what it is/ heads?
Time to think and understand what is needed.
Squish/ quench is also part of what you need when building the short block...
IMHO gasket thickness, .035 piston to head,

The over .200 inch degree duration is what gives you the power
The seat timing is what gives you bottom end and driveability
300 degree seat timing is going to suck big time
That cam reminds me of a first gen HR 80's grind
for example Crane's 298-306 HR
there are other ways to get your lift up to better utilize those fine heads without going to a long intake duration
you can build a valve lift curve to give you .630 plus lift with as little as 270's seat duration
do some digging
what is the 200?
“more area over the nose with less overlap, resulting in more horsepower and torque without sacrificing idle-smoothness and reliability “
with the short rod the piston accelerates rapidly
to have the cam keep up with the piston (air flow requirements) one way is to start opening the valve earlier (more duration = more overlap)(less power brake and street friendly)
or open it later and quicker
both solutions can have the valve open the right amount where the piston is at maximum velocity
15 or 20 degrees extra intake seat duration makes a huge difference
Try graphing a valve lift curve
for the same valve lift curve you can use a smaller cam lift curve with higher ratio rockers
inverse radius grind will save you 10+ seat degrees
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by kirkwoodken »

OP,
If you want a GOOD build, listen to what wyrmrider is telling you about cam timing. 300 degrees seat duration and 150 degrees at .200" lift is not a good cam choice, no matter what kind of lifter is used. Almost any cam will rev to the point of engine blowup and engines will blow up from mechanical failures due to extreme revs. Although revs are part of the horsepower formula, they are not as important as cylinder filling. I am not trying to pass judgement on Howards cams. I am saying you can get a cam that will fill your cylinders better than the one you seem to have your mind set on.

AFR makes very good out-of-the-box heads. The builders on this site are telling you what cam timings will work best with your heads to give you a good performing engine. Just as an example, my old Comp Cams catalog lists a solid roller RT280-1 as having 280 seat duration, 250*@.050" lift, and 173 degrees at .200" lift. Lobe lift is .416". I'm not saying this is the cam you need, just pointing out it has 20 degrees less seat duration and 23 more degrees duration at .200 lift. Comp also makes a 300 degree hydraulic roller with 171 degrees duration at .200" lift.

Joe Sherman, Cam King, and the rest of the gurus are trying to steer you away from the Howards cam you have picked. I'm not a cam expert, but picking a cam similar to the RT280 will gave you more power and a broader torque band.

A lot of us grew up with cams like the Howards. There is better stuff to be had now. Take advantage of advances in cam timing. If you have to throw the Howards cam in the trash can, so be it. Get something that will work as well as it can.
"Life is too short to not run a solid roller cam."
"Anything is possible, if you don't know what you're talking about."
I am NOT an Expert, and DEFINITELY NOT a GURU.
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

swatson454 wrote:Have you already bought all of the parts?
Yes the only thing I bought are the rocker arms , why
U ask?
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by A Atwood »

Have you not caught on to the fact that EVERYONE is trying to steer you away from the Howard's cam??!!
Gees!
What does it take, an anvil?
www.atwoodperformance.com
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by A Atwood »

And trade those rockers back in for 1.6:1s.
www.atwoodperformance.com
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by wyrmrider »

My experience with Howards was 60 years ago, racing Jack Chrisman in the Twin Bear, two 3/8 stroker 283's with chain drive 471 blowers
hopefully new masters cus then were not especially easy on the valve train- Chet Herberts were easier on the valve train typically due to gentler ramps and longer durations - they replaced more rocker arms than we did
I looked at the Howards and Bullet catalogues and no way could I navigate all those masters, and no idea what vintage they are.
The only way to do it is not to look at cams but look at the cylinders air flow demand caused by piston movement (crank rotation- rod angle)
This is tougher with a short rod motor as there is less dwell at tdc
one way is to start to open the intake earlier (and close the exhaust later)
this, of course, increases the overlap which has well known consequences reversion, lack of vaccuum but not usually mentioned is the pull of the exhaust on the intake which gets the intake flowing even at tdc when the piston is not moving down yet
you can squeeze the lobe centers together...
open the intake too early gets the flow going the wrong way... more so at low speeds, so crank up the idle
the big cam will bleed off some compression pressure from too high a c.r. which also bleeds off torque
no free lunch
the final mechanical c.r needs to be determined with the camshaft ane rocker selection, not separately
http://rehermorrison.com/tech-talk-81-t ... e-streets/
note the compression recommendation
cheers
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by rfoll »

Many of the best engine builders around have offered advice on how to achieve your goal of 550+ horsepower, but in the end it is just a number. You state this is your "first engine build", or something to that effect. I suspect it might not be advisable to push the build too hard if you are not experienced. You might end up with expensive scrap metal, and someone else could be hurt in the process. If this is a street car, neither you, your friends, or the ridiculously spinning tires will know the difference between 500 and 550 horsepower.
So much to do, so little time...
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by wyrmrider »

you are not alone


Re: seat duration, intensity

postby Enigma » Sat Jun 29, 2013 10:31 am
from this thread
seat duration, intensity
viewtopic.php?f=1&t=36317#
You should pm Mike Jones (camking). He doesn't put a lot of stock in the theory of lobe intensity, but unless I'm mistaken he has a 5 inch wheel and grinds a lot of IR lobes.
Most of what your asking boils down to what your engine wants in the way of piston cfm demand.....and when it wants it. Order pipe max and play with it.
The important thing with shortening seat timing while increasing @.050 and .200 is to have enough flank so as to slow the acceleration and velocity while remaining dynamically stable. You can introduce some nasty harmonics if you aren't very careful in your curve.
In general.....reducing seat timing will increase vacuum, but your engine may or may not want that. pipemax will give you a very close approximation of what your engine actually wants. Talk with Larry meaux (spelling?) and see what he thinks. Sounds like you guys have a good idea of what you're doing, but just creating masters and changing lift curves and ramp rates to see if a change works can get quite expensive and time consuming.
Port velocity is good, to a point.
But can be over-done.
Pressure differentials between port and cylinder come into play here and it's a good idea to have some type of program to give you an idea of where to start.
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

A Atwood wrote:Have you not caught on to the fact that EVERYONE is trying to steer you away from the Howard's cam??!!
Gees!
What does it take, an anvil?

LOL yeah I see that, I wonder why? Whats wrong with Howards cams????
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

swatson454 wrote:Have you already bought all of the parts?
Yes I have everything. The only thing I haven't bought are the Rocker Arms, But I wonder why everyone is trying to lead me away from Howards cams I know they been around for years, is there something about Howards cams I should know????
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Re: SBC 383 build Advice shooting for 550hp to 600hp

Post by Desmosis10 »

kirkwoodken wrote:OP,
If you want a GOOD build, listen to what wyrmrider is telling you about cam timing. 300 degrees seat duration and 150 degrees at .200" lift is not a good cam choice, no matter what kind of lifter is used. Almost any cam will rev to the point of engine blowup and engines will blow up from mechanical failures due to extreme revs. Although revs are part of the horsepower formula, they are not as important as cylinder filling. I am not trying to pass judgement on Howards cams. I am saying you can get a cam that will fill your cylinders better than the one you seem to have your mind set on.

AFR makes very good out-of-the-box heads. The builders on this site are telling you what cam timings will work best with your heads to give you a good performing engine. Just as an example, my old Comp Cams catalog lists a solid roller RT280-1 as having 280 seat duration, 250*@.050" lift, and 173 degrees at .200" lift. Lobe lift is .416". I'm not saying this is the cam you need, just pointing out it has 20 degrees less seat duration and 23 more degrees duration at .200 lift. Comp also makes a 300 degree hydraulic roller with 171 degrees duration at .200" lift.

Joe Sherman, Cam King, and the rest of the gurus are trying to steer you away from the Howards cam you have picked. I'm not a cam expert, but picking a cam similar to the RT280 will gave you more power and a broader torque band.

A lot of us grew up with cams like the Howards. There is better stuff to be had now. Take advantage of advances in cam timing. If you have to throw the Howards cam in the trash can, so be it. Get something that will work as well as it can.
Yeah I see everyone is leading me away from howards cam they been around for years, are they not good cams is there something I don't know about Howards cams? I'm trying to figure out and understand what you guys are saying about seat duration and lift at .200, to tell the truth i'm kinda of lost, But are u saying the cam I have bought is to much on advertise duration which is 300, which will not give a good power curve and wouldn't be good on the street? Im trying to take everything In and learn from everyone just a kinda lost at times....LBS
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