I had a 1975 L82 model - including the '962 cam - so this was an easy tweak. The flow numbers I used were for the 195cc SBC Super Street heads from Patriot's web site as they appeared to be pretty close to what you were spec'ing and the web had values from .100 through .700.

Clearly not getting much from the heads with that cam, and I suspect that's showing up in the weird torque curve. I swapped in a .550 lift roller hydraulic and saw about 460HP :-D

 

63mako, my experience has been that changing the cam timing 4 degrees moves the peaks about 500 RPM.

I'd be happy to DD this engine if you can give me more specs - take a look at the first post in the thread and if you can post all of that I'd LOVE to DD the engine considering that you're heading to the dyno!!

 

I could not find this cam at CompCams - do you have a grind number or link to the cam card?

 

I think I'm caught up - if I missed ya, shout out

 

Thanks Billa! Here you go!

SBC
[*]Displacement, bore, stroke, rod length.383, 4.030 bore,3.75 stroke, 6" rods

[*]Cylinder heads, valve sizes - flow numbers are a big help here and a link to the web site (AFR, etc.) for your aftermarket head is great!AFR 195 Competition ported 2.05 valve
http://airflowresearch.com/195sbc_sh.php

[*]Compression ratio, or the information to calculate (piston compression height, etc.)10.4 to 1

[*]Induction - carb CFM, manifold type Split single plane tripower 816 adjusted CFM

[*]Header tube size and system 1 7/8 primary hooker side pipes W/ Maxflows

[*]Camshaft and rocker ratio - this is the tough one and the one that has the single biggest impact. You must have the cam card to make this happen. Most cam vendors have these online and a LINK to the cam card is great. If you don't have the specs, I'll have to pass as there just won't be any useful results

.Special Grind
GRIND # CS 3316S /3317S HR114.0

ARM RATIO INTAKE 1.50 EXHAUST 1.50
DURATION @ .050 INTAKE 236
DURATION @ .050 EXHAUST 242
LOBE LIFT INTAKE .3470
LOBE LIFT EXHAUST .3600
VALVE LIFT INTAKE .520
VALVE LIFT EXHAUST .540
LOBE SEPARATION 114.0
INTAKE C/L 110.0

DURATION .006
TAPPET LIFT INTAKE 287
TAPPET LIFT EXHAUST 293

VALVE TIMING .050
VALVE OPEN INTAKE 8
VALVE OPEN EXHAUST 59
VALVE CLOSED INTAKE 48
VALVE CLOSED EXHAUST 3
ADD 150 shot Nitrous! With and without would be great.

 

OK, here's my shot. I used 6lb/min for the NOS flow which should be about right. NOS, then NA.

 

Glad to see you're back Billa. It's fun watching this thread and scoping out all the different engines and cams. My engine builder is suggesting the Comp Cam XR264HR:
HYDRAULIC ROLLER-
264 270 Adv. Dur.
212 218 Dur. @ .050
.510 .510 lift
110° lobe seperation

My engine specs are as follows:

LS5 454 BBC
bored .030 over. Stock stroke, and stock rod length.
Forged pistons
Cylinder heads… Chev… 3964290 101cc chamber oval closed. (shaved 12 thous)
Intake Valve: 2.19 undercut
Exhaust Valve 1.72 undercut
Rocker ration 1.72 ratio
Compression: 10.3:1
Carb: Holley Street Avenger 770
Aluminum Edelbrock Performer RPM Intake manifold (# 7161 12105)
Exhaust: 2 ½” Headman headers

I know you are going to have difficult with the flow numbers and guess at the impact of the larger valves but do what you can please. Thanx

shmoky

 

IM SLOWLY PUTTING MINE BACK TOGETHER. WOULD LOVE TO SEE WHAT HAPPENS.

STOCK L48 BOTTOM

EQ 200 CC HEADS 202 160 64CC
FLOW NUMBERS http://www.lightningcylinderheads.com/flow.html

9.5/1 COMPRESSION

670 STREET AVENGER

PERFORMER EPS DUAL PLANE PORT MATCHED

1 5/8 HEADERS DUEL EX FLOWS

LUNATI VOODOO HYD
IN DUR 262
EX DUR 268
LOBE SEP 112
LIFT IN 468
LIFT EX 489

THANKS

ANY SUGGESTIONS WOULD BE TAKEN POSITIVE.

THANKS BILLLA

 

Thanks for running my 427 sb. I'm still getting the timing worked out on it, but it still isn't putting out that kind of power. Only 382rwhp/410 rwtq on the one full run (hp flatlined at around 4900 rpm), but I think the timing is about 10 degrees too slow. Getting my fans/alternator, and leaks fixed before I start tuning it again. Runs and idles great though, even in alpha N, bank to bank. No surging at low rpm cruising or anything (for example 7-8 mph, don't have to stab the clutch, ever, just keeps chugging along very smooth). Actually easier to drive than my efi 383 I had in it before.

 

Fred,
I would like to jump in and offer a suggestion. You are runing at about 9.9 C/R with the first combo. I would agree with Billla that the quench is not great. The swap to a .015" gasket will raise the C/R to 10.5 and will improve quench.

If you remove the H-278-2 and replace it with the F-278-2 along with the gasket change mentioned above you will pick up 25-30 HP based on my own DD model. That is a sold lifter cam with the same torque/HP curve shape but would give you a significant across the board increase. Same shaped curves but raise them up 27 HP. DCR is still good at around 8.0

Maybe Billla will model those two together for you.

As for the 1.52 rockers - if you were going to use the stamped steel rockers you will be short on lift. The 1.52 rockers are a good piece to use BUT don't look for a big HP increase. The only thing you will gain is the lift you would have lost due to the stamped steel rockers not providing the full 1.5 ratio they are supposed to provide. I hope that makes sense.

-Mark.

 

That's kinda wierd considering the heads and cam; did the dyno guys have any thoughts? I have to think that's not just a timing issue...

 

Billa, Thanks for the DD run. I am not dissapointed with the numbers .....hell Im sitting with 230 HP now. Could you throw up the run with the .550 cam and give me the part number you used. With that said,..... and this is open to any forum members. What specfic change can I make to the cam or other component to get to 400HP/400TQ street car that is drivable using the heads and the 1.6:1 roller rockers I already have. Would like to bump up the TQ numbers to the left into an RPM range I will most likely be driving 1500 - 5500. By drivable I mean no big lopey cam rough idle or need for a high stall speed converter. I might be asking for something that is not attainable with my components if so I am happy with the results in the making. Thanks in advance for any info you can give. Semper Fi Bob

 

The specific cam number and/or pointer to the cam card on the Holley site would be a big help on this one.

 

http://www.holley.com/data/Products/Technical/60102.pdf
THIS IS LINK TO CAM CARD. THANKS

 

Thanks. I appreciate the time and effort!
I was hoping for more. here is some more info from another dyno sim when I was designing the motor and a link to AFR's combination I based it on.
It is the motor built by American Speed. I upped the compression, carb CFM, Went from a dual plane to split single plane, increased header size, and increased LSA to flatten the torque curve and work better with the nitrous. Will post dyno results as soon as he gets to it.
AFR LINK: http://www.airflowresearch.com/chevy_dyno.php


Quote:
Originally Posted by 63mako
Quote:
Originally Posted by King Lear
Quote:
Originally Posted by 63mako
much better your cam ramp rate is 2.8, going by seat to seat timing and .05 timing combined your number at 10:1 are
526hp @ 6500 rpm & 479 ft lbs @ 4500 rpm & 5000 rpm
you also reach 100% volumetric efficiency from 5000 rpm through 6500 rpm then drop below 100 VE.
-4 = 542hp @ 6500 rpm & 484 ft lbs @ 5000 rpm

If you go up to 10.2:1:
530hp @ 6000 rpm & 482 ft lbs @ 4500 rpm
-4 = 547hp @ 6500 rpm & 487 ft lbs @ 5000 rpm

10.4:1 is
535hp @ 6000 rpm & 485 ft lbs @ 4500 rpm
-4 = 551hp @ 6500 rpm & 490 ft lbs @ 5000 rpm

So there you have it, much better numbers when the actual cam seat timing is added to the equation. I flat milled my heads 3cc to 61cc to get a 9.9 CR and really don't see what everyone is so scared of. I definitely would not angle mill cause then you have to mill the intake also to match. Most heads can be flat milled 4cc until you have to worry about getting into the intake valve seating area. That is what I have read anyway. I also called RHS to make sure they could be milled this far safely. If you are going to mill them I would call AFR and see how far they can be milled within tolerances safely before issues could arise.
Enjoy,
Rich

Hi Rich. Thanks a lot! I will mill the heads .012 which will put me at 10.2 to 1. I think I will leave the cam straight up for better low end torque. The torque band is probably flatter with it straight up also. I do have the AFR rev kit but hate to push the RPM to get power or I would have went solid roller. My tripower will give me a lot of midrange power as well. I got a 150 nitrous shot too so that will be plenty. The VE helps a lot with nitrous also. That is why I went with the 114 LSA. Less overlap for better efficiency. Might pull close to 700 HP with the NOS. Not bad for 383, 10.2 to 1, hydraulic roller with moderate lift and 195 heads! Kevin

I just put the 150 lbs nitrous shot on you figures at 10.2 straight up and here, WOW!:
693HP @ 6500 Rpm @ 656 ft lbs @ 4500, 679 ft lbs @ 3000 rpm. In the 63, I think that will be plenty. I might actually have too look at that myself, although I will have to get a new TC.

679 FT LBS @ 3000!! WOW!! So much for having to have 434 CI, 220 CC heads, a solid roller and run it to 7500 RPM's to generate big power. Can't wait to get this thing on the dyno for real. Sounds like a Tom's differential is in my future $$$. Thanks for all your help![/quote]

No problem, your welcome, let me know when you get it dyno'd how close it is too what the CC dyno figured,
Rich

 

My DD's are pretty conservative - I typically use tested vs. published flow numbers. There are also real limitations on the DD model that show up in engines beyond about 1.4 HP/CID - it's great for engines below that that are relatively straight-forward configurations, but the further out you go and the higher in the power range the more iffy the results get. Interesting that the effect of the timing change was pretty much what I expected in terms of RPM for the peaks, but I was surprised that you picked up that much power.

To net it out for comparison:
No spray
Other simulator: 530HP@6000 RPM/485TQ@4500 RPM
billla DD: 466HP@5500 RPM/478TQ@4500 RPM
-64HP

150 Shot
Other simulator: 693HP@6500 RPM/656TQ@4500 RPM
billla DD: 615HP@5500 RPM/647TQ@4500 RPM
-78HP

 

Hey billa. Thanks for helping out everyone like this. Here are my specs (hope this is right):

SBC
383, 30 overplate bore, 3.750 stroke, 5.7 H beam rods
Trick flow 23 deg alum heads Heads URL, valves are 2.02 1.60
11:1
Edelbrock #1903 (795 CFM) carb / edelbrock performer intake
Hooker super comp longtubes / 1-3/4" x 25" Primary 3" collector
Comp Cams 230/236
Harlam Sharp roller rockers 1.5


I hope that's everything and is what you need.

Thanks mate!

 

Thanks again. It is good to have the two to compare. I will really be happy with your numbers. Good power for a mild build. Looks like it will pull hard all the way through the rpm range. 300 Ft LBS @ 1000 and over 400 Ft Lbs from 2000 to redline is awesome. Torque curve is pretty flat and the torque #s are real close on both simulations. looks like 3000 RPM is the sweet spot to hit the nitrous which is what I planned. Also was looking for peak HP around 6000 to 6500 with my hydraulic roller. Real objective is a well mannered streetable motor with good power in the working RPM range using a relativly mild low maintainance valvetrain, good port velocity heads, bulletproof bottom end and built big block performance on demand. thumbs:

 

Pretty impressive numbers on the heads - my only suggestion is that given those flow numbers you don't have enough lift If you can afford it, I'd strongly encourage consideration of a hydraulic roller with 1.6 arms to get full use from those great flow numbers. I'd also consider stepping up to larger-tube headers. Bottom line is that the engine isn't a perfect match for the heads in terms of CR and cam choice.

 

Great information - THANK YOU; this really makes the process quick and painless

Nice engine - very sweet torque and HP curve. That "doink" in the torque curve is giving me fits and I'm working with the DD folks.

The carb seems kinda big unless you'll be turning it high; the formula I use is CFM = ((CI x RPM)/3456) x VE...given that you won't need that carb until 7500 RPM or so.