wavslav

Hi,
I just built this 375 and was wondering what the desk top dyno puts it at.
I don't know exactly what info the program needs, but heres a start.

GM 400 block, bored .020 over
Eagle forged 3.48 crank
Eagle 3d H beam, forged 6.2 rods
JE 12:1 pistons
Crower Solid lifter, Flat tappet Cam, PN 00350, grind 268 FPD
Adv: intake duration 268* lift .497 clearence hot .022
Exhaust Duration 274* lift .504 learance .024
@ .050 intake 238* exhaust 244* lift: intake .331, ex, .336
valve spring info: 105/115 closed, 320/330 open:

currently running World SR torquer heads Port and polished to run 240 cfm, 64 cc, 2.02/1.60 valves

(plan on Dart Pro 1, 230 w 64 cc chambers) and large valves

Intake: Weiand Team G, power ram, pn wei 7530

Holley 750 Double Pumper #4779

Hooker super comp long tubes, 1.75" primaries

9.5 lb flywheel, 10.4" centerforce dual friction clutch, world class T5 tranny, underdrive crank pully

K&N extreme lid w 1.75" hi K&N regular air cleaner

Canton baffled road race pan, external oil cooler, Redline 20-50.

That's about all I can think of.
How does that come out on the desktop dyno?
With each set of heads? the ones I have now and the Dart Al.s

Thanks

wavslav

It also runs an MSD HEI w 6AL, and MSD wires
redline is 7500 rpm

wavslav

Cmon help a brother out.
it'll be 3 months till I get to a chassis dyno.

johnsjj2

This is all I could do. I used AFR 210 heads b/c I don't have a flow file for Pro 1's. I also couldn't account for the 6.2" rods. THat usually helps torque. I can't attatch the list so here is 1k rpm increments

RPM-----------HP-----TQ
2000............147.....386
3000............249.....436
4000............361.....473
5000............465.....488
6000............524.....458
6500............538.....434
7000............529.....397

6500 was the peak for HP, 5000 was peak for torque. DOn't swear by this dyno. It is an estimate at best. Just get an idea of the neighborhood you are looking at.

Your welcome!!

Hype

My ***, if you get those Dart Pro 1's on there, this sucker is going to be a screamer.

This thing is gonna rev to the moon!

Those world heads are gonna hold you back some, save the port and polish and go for the Darts.

wavslav

[Hey Joshua, thank you very much for taking the time to input my data and to post the graph.
I'm very happy with those numbers.
I might even add them to my sig file, just for the heck of it. =)

Hype, the World heads got P&P last winter when I had them off the 355.
I know they will make someone here on the board really happy for a 355, I'll turn a great deal on them when the time comes.

My buddy on the vettenet has me pretty convinced as of today to go with the 64cc Victor Jr heads.

I left the 1.5 rockers off the info I gave, but that probably doesnt matter

Thanks
Evan

RedFirebird

That motor is nice but i think it would be better served with a beefier cam. Looking at the rest of that motor, that cam is definately on the mild side IMO.

wavslav

Hey Red,
Thanks for your post.
I already had selected that cam and put it in my 355 prior to cracking the block with less then 500 miles on the cam.

The reason I kept that cam is very specific.

This car is a dedicated road race car.
I run it at tight tracks like Laguna Seca, and fast tracks like Tunder Hill.
I specifically kept the cam because the range is 2000 - 7000 RPM.
Most of the roller cams I have seen, and my buddy who built the motor has the same 377 in his Nova drag car with a roller that turns 9000 rpm and 9 sec 1320s, is that I didn't want to move the power band up too high.

My previous Crane power max power band started at 3 grand.
A lot of racers work with that, but for me, I find that coming out of the Andretti Hairpin (turn 2 ) at Laguna Seca, or turn 11, the super tight Hairpin leading to the front straight, My RPMs drop down quite a bit, even in second and I dog till I hit the power band again.
That lag costs me 1/2 sec or more per turn.
The short version of this explaination is:
I want the powerband low and wide so I have lots of bite coming off the corners, but still plenty of power up to 7 grand.

Make sense?
BTW I had originally bought the block to build for a '85 vette road race project car that I aborted and sold as a roller on the corvetteforum (in six hours)

I still have my full resto '74 stroker stingray, but it's up for sale to keep payin for racin'
Thanks

wavslav

Oh yeah, my buddy with the nova has brodix heads and matched intake

ME Leigh

Heres what i get

rpm hp tq
20 139 354
25 182 382
30 228 400
35 286 429
40 345 453
45 400 467
50 447 469
55 478 457
60 493 432
65 499 403
70 488 366
75 474 332
80 438 287
85 406 251

wavslav

Ok, Wait a sec while I change my sig file again.
J/K
Which heads did you use for this comparison?
Thanks
Evan

ME Leigh

I used the Dart Pro 1 230cc heads.

wavslav

Thank you for running my numbers.
If you have a few minutes could you see if they change at all using the 64cc Edelbrock Victor Jr Head?
Thanks
Evan

bbunting

rpm.. hp... tq
2000 159 417
2500 212 446
3000 266 466
3500 321 481
4000 378 496
4500 430 502
5000 478 502
5500 508 485
6000 524 458
6500 520 420
7000 502 377
7500 486 340
8000 448 294
8500 412 255

This is what I get after inputting the cam specs from my Crower catalog, and the flow #'s off the Dart heads. The motor needs more camshaft! Comp cams 12-460-8 makes 600+HP.

ME Leigh

This doesn't make much sense:
With Edelbrock Victor Jr. 68cc
rpm hp tq
20 140 367
25 183 384
30 229 401
35 278 417
40 319 419
45 341 398
50 343 361
55 327 312
60 297 260
65 273 220
70 234 175
75 198 139
80 154 101

With Edelbrock Victor Jr. Aluminum
rpm hp tq
20 142 373
25 187 393
30 237 414
35 292 439
40 348 457
45 399 465
50 440 462
55 466 444
60 472 413
65 470 380
70 453 340
75 434 304
80 394 258
85 358 221
90 312 182

wavslav

Chamber size increases, compression drops, Hp drops?

ME Leigh

No, in DD2000 compression ratio is a different variable, and is not related to the heads. You just set the compression ratio as its own component.

RB83L69

I don't put too much stock in Desktop Dyno and the like anyway... So I'll just tell you what I think you need, from real-world experience.

Your cam is a bit on the smallish side. Although, you didn't post the lobe separation, and I'm too lazy to track it down. That by itself would render most simulators' simulations rather moot. You also don't say if there's any kind of rules on the cam; lift limits, spring limits, or any others like that, that I've had to deal with in building motors for organized racing. So for the moment I'll assume there aren't any restrictions.

I'd suggest getting your new heads cut for 1.56" springs, and using a set of something like Comp 999 springs, or equivalent; and a cam with about 240-244° on the intake and about 12° more on the exhaust than the intake, and around .600" of lift. To keep the torque curve flat, I'd suggest that the lobe separation be around 114°. That will cut the peak torque down some but will flatten the curve toward both the low end and the high end.

89ProchargedROC

You have a good combo but the duration is too small........

you need a cam that has around 250/260 @ .050 and around .600+ lift on a 110-112 (110 would work the best)

Also, to make that motor shine you are going to have a limited RPM band of like 4000-7000

bbunting

Yes-it makes sense to me, being a road race fanatic (mostly in my Z06), but not knowing the car weight, gear ratio, tranny ratios, tire height, etc. we are guessing at best.

In my cars, regardless of track, the power band is 3500+. Keeping the car in the correct gear (heel & toe) can be challenging. I drop about 500 RPM per shift. Is yours different? You could run a solid roller with a higher power band
and come out of the turns in a lower gear and ease into the go pedal. That will save time waiting for the motor. (smooth)

The heads- I have the same 230 CC Pro 1's on my IROC. The reason we are all saying that you need MORE lift is that they really start to shine OVER .600 lift. That will really help the motor breathe, and still give you the push on corner exit, and the pull down the straights. New cam might mean bigger carb too!
All means more HP/TQE! Sorry for the long reply. Good luck.

Your combo with:............HP................TQE
Dart230/Crower 350.....544@6500....506@5000 solid
add Comp 126125.........564@7500....471@5500 solid
add Comp 122215.........553@6500....504@5000 solid
add Comp 124608.........605@7500....508@5500 hydraulic roller
add Comp 129059.........609@7000....506@5500 sld rlr road crse