For Christmas , I got myself a newer version of Desktop Dyno from Comp Cams, Ver 4.20
I plugged in the generic 383 long rod SRP 11:1 pistons and my current AFR 195 heads along with my current Comp 282/288 Hydra roller, .510/.520 .
Using Pat's program that gives me all valve opening of 35btc,67 abdc, on intake and 78bbdc /30Atdc on intake. Ls 110 @ 106 CL., Small tube headers and mufflers and 750 dual plane.

Numbers are some type of stand up comic compared to my 355 mule motor with just being 20 -35 hp higher, IMO. Some went like this
4000 Fly wheel Hp
358, 4500 - 398, 5000-431, 5500-448, 6000-419
Flywheel Tq went like this
470, '''''''''''''' 464, '''''''''''''452,""""""" 428, '''''''''' 393

My 355 mule hp is just under 30 to 50 hp under .

I know , I still have lots of paperwork to do but this is disappointing but then again, these programs are just estimatesl. What do you guys think?

I don't think it is disappointing at all, Don. You're adding nothing but 33 more cubes (since the top end and cam aren't changing) and getting 30-50 HP. Don't know that you should expect more, 383's ain't magic, just a little bigger small block. plug in some 215cc heads and 10 more degree's of cam and see what she says.

Why did you start your sim at 4000, or is that just the lowest number you posted? I bet if you compared numbers from both motors from 2000 rpm up, you would see the difference more.

DD is showing your peak tq at 4000 or less, which seems odd. My 383 (with less cam and head than you have) gives peak torque (on a chassis dyno) at 4200, and doesn't fall off near as fast.

The number you gave for the 355, is that from a real dyno, or from this version of DD? Apples to oranges if your not using the same method to figure power.

How different would your life be if Desktop Dyno had shown 25 more horses than it does now? Would your car be faster? Do you have Desktop Dyno envy?

Thanks for input,

I started with 4000 rpm as a standard measure for me, they were on the mule vs 383
355 fly hp / fly tq vs 383 hp x tq
2000'''''''''''''136 358 155 x 406
2500 ''''''''''''184 387 196 x 411
3000'''''''''''''''225 395 235 x 415
3500'''''''''''''''279 419 300 x 435

All of this is paper numbers, no actual dyno... I will put the newer motor on dyno and try to get car on chassis dyno or run it on dyno after I pull it depending on fees....

I will change cams etc later on today , its a little early and I am on my way to work. I guess what this is still telling me ,, I need BBC power back or larger sb.

I have found the DD's to be quite accurate with the right info.

I only have the old version of DD. It is very dependant on "accurate" cam files and head flow numbers. You can fudge 1 number and get outstanding results. :) Usually DD, if anything, will post higher numbers then what you really have.

I only have the old version of DD. It is very dependant on "accurate" cam files and head flow numbers. You can fudge 1 number and get outstanding results. :) Usually DD, if anything, will post higher numbers then what you really have.
My experience as well.

I have a similar long rod 383, more like 10.3:1 compression, 234/242 @ 0.050, 0.539/0.558 hydraulic roller cam, same heads, made 465hp at 5,700 and 464tq at 4,700 on an engine dyno; engine was carefully assembled but with no port matching or real tuning on the dyno. DD predicted over 500 hp.

Thats not much lift for a hyd roller?

Thats not much lift for a hyd roller?

510/520 lift is actual, I did try 530/530.. I do have room to go 600 but if it does no good, why do it. I have the 1.55 springs so I am ok there too. Remember , this is a long distance hi speed cruiser. I am still juggling numbers.
Will do as JimM mentioned. Try some larger head flows and 10* more cam. I even put in the Bullet cam that was recommended. It runs parallel with my current. Will try more compression with this cam. I have both the older Motion DDyno and this newer Comp Dynosimulator. The older DD does give higher numbers, maybe thats what spoiled me?

Don you need to upgrade from those AFR heads , I tried a set stock and they plain sucked till We ported them . I then went with the Kieth craft heads track1s 227cc yes I know they are too large for what you want but they do have smaller runners also . Put MPFI systen on and you can a buch larger and still drive . But like jim said bump that cam up a bunch and try it , I still like the way the solid roller works over the Hyd . We did just over 5 thousand miles this past summer and the spring pressure is still Ok and I had one broken not bad for 640 lift .
Mark .

If you look at the low numbers you posted, that's what the long rod stroker gave you. Over 50 ft-lbs more at 2000. your whole powerband is shifted down in rpm compared to the 355 with the same airflow.

And you're right, if you want a BUNCH more power, you need more cubes, 406, or a 427 like Mark's got.

And if you are going bigger cubes you need larger heads than what you have , or get out the die grinder in your spare time .
Mark .

I know, I know, to the bank I go. Well , I will not argue with you Mark or Jim. Your mightymouse is a pure display of nothing but brute force. Your combo is what tells me , why spend say $3k or so and 33 ci's and a few more hp , when "for a few dollars more" I can get the block and go larger ci. The heads were the ones that was keeping my on the porch. I was trying to build around them. I agree the heads are not the best in stock form and an I was gonna let Tony at AFR work them over , but with the issue of larger block, it blows the the idea of 383. I don't have many miles on these AFR's and should be able to turn them .
As for the MPFI,, I had the Edelbrock proflow and it worked well with my 57 cruiser . I would not use it for the camaro. Too many others to choose from and the one I want , would be the one I can adjust , on the fly. Its something I would have to do more home work on . And with my daughters wedding coming up,, I may have to table this for more planning and its a good excuse.

Fear not,, I got you in sight , when I come back to detail. Ah ain't skeered .

you would have no problem with the 383 , you just need flow and a bunch more cam , I think mines a bit much but its still drivable and it gets 21 to the gallon . I just purchased the kit for My holley setup for the wideband O2 Boy now I can see if I can get 25 to the gal without wearing Sandra's finger out .
Mark .

you would have no problem with the 383 , you just need flow and a bunch more cam , I think mines a bit much but its still drivable and it gets 21 to the gallon . I just purchased the kit for My holley setup for the wideband O2 Boy now I can see if I can get 25 to the gal without wearing Sandra's finger out .
Mark .

So , Sandra is adjusting via laptop on the fly? That may work, but it was more conveniant with this little 4 x 6 panel that the proflow had. Well , its on paper too. The heads will get some treatment and I have some other cams in the spotlight. Thanks.

Don with the wideband it should be better , I'm running open loop right now and with the widedand we can let the computer do some of the work closed loop . Having the laptop is nice you can watch movies ours has that streets and trips software with the GPS so I don't get lost its great .
Mark .

I think you care about the hp #s a bit too much, which look about right for a 383 with decent heads and a cam in the 230duration as around 450hp is what you'll ussually see. What you need to figure out is how fast you wanna go? 450hp will put a heavy car (3500lbs+) in the high to mid 11s pretty easy. Now if you wanna go faster then better heads and more car will get you there.

I think you care about the hp #s a bit too much, which look about right for a 383 with decent heads and a cam in the 230duration as around 450hp is what you'll ussually see. What you need to figure out is how fast you wanna go? 450hp will put a heavy car (3500lbs+) in the high to mid 11s pretty easy. Now if you wanna go faster then better heads and more car will get you there.

Well numbers are important, it will give me a benchmark on where I should be . And from what you guys are telling me, I am in the 383 ballpark with a 355. I also feel , like Mark said, these heads may need to be opened up or exchanged and that is part of my plan, then go from there. Cam, well , a phone call to Harold should cure this, with the head factor in mind. I dont want to get back into all out racing , but will be on the edge. Hey, its got ps and Ac. Gotta cut some slack. If I lived in those north western states where air is dry and clean, like Mark, those accessories may not exist but I would have wipers and side door glasses.