VETMANIAC

I have been planning to post the details of the evolution of my 540 for many moons now. I have finally gathered almost all of the info together and am ready to start describing the changes I have made and the results I have seen over the past several years.

My original goal for the engine and car was to make as much power as possible, but still have a reliable naturally aspirated daily driver. I define "daily driver" as having the ability to drive in stop and go traffic for a minimum of 50 miles, 5 days per week, year round.

Before I talk about the baseline and dyno results, I would like to mention that I originally had a Demon 850 Vac Secondary carb and had made a few dyno runs. Unfortunately, the results of that dyno have been called into question and I don't have an electronic copy of the results anyway. After less than a year of driving with the Demon I switched to an old Holley 850 DP that Jim Moore let me borrow. I saw an improvement in driveability, fuel mileage, and seat of the pants performance with the Holley. All of the results that I will be showing over the next several posts are from the same Dyno in Richardson Texas and not the dyno that I orginally tested with the Demon.

Here is the baseline that I started with:
Carb - Holley 850 DP (ancient)
Intake - GM LS6 Dual Plane (From an old Mark IV LS6 crate motor, very mildly ported)
Heads - GM Signature Series Aluminum Rectangular Port 2.25 In. 1.88 Ex. (Part # 12363400)
Block - Merlin II 9.8 Deck Height, 4.5" Bore
Rockers - Crower Steel Roller Enduros
Pistons - SRP Flat Top, 4.5" bore, 3cc valve relief
Rods - 6.385 Scat H-Beams
Crank - Bill Mitchell 4.25 stroke Forged
Camshaft - Schneider 232/244 @.050, .585/.595, 110 H.R.
Distributor - Summit HEI
Headers - Hooker 1-7/8 Super Comps (under car)
Static Compression Ratio - 9.1:1

Here are the Baseline dyno results:
RPM HP FT-LBS.
2200 180 429
2300 190 433
2400 197 431
2500 209 440
2600 223 450
2700 238 464
2800 254 477
2900 270 488
3000 284 496
3100 296 502
3200 307 504
3300 316 502
3400 324 501
3500 334 501
3600 341 498
3700 348 494
3800 353 488
3900 360 484
4000 367 482
4100 371 475
4200 371 464
4300 371 453
4400 374 446
4500 378 441
4600 384 438
4700 388 434
4800 391 428
4900 398 427
5000 400 420
5100 400 412
5200 399 403
5300 401 397
5400 399 388
5500 392 375
5600 382 359
5700 374 345
5800 348 315
5900 339 302
6000 336 294
6100 315 271

MAX 401 504

Here are the results after replacing the GM dual plane Intake with a Holley Strip Dominator single plane intake:

RPM HP FT-LBS.
2200 185 443
2300 195 445
2400 203 444
2500 213 447
2600 222 449
2700 233 453
2800 248 465
2900 263 477
3000 279 488
3100 292 495
3200 304 498
3300 313 499
3400 323 498
3500 330 495
3600 340 496
3700 348 493
3800 354 489
3900 361 486
4000 368 483
4100 375 481
4200 378 473
4300 384 469
4400 392 468
4500 399 466
4600 405 463
4700 410 458
4800 416 455
4900 421 451
5000 422 444
5100 425 438
5200 425 429
5300 422 418
5400 420 408
5500 414 396
5600 405 380
5700 390 360
5800 368 333
5900 356 317
6000 349 305
6100
+24 -5
MAX 425 499

Note, the Strip Dominator intake was very heavily ported by yours truly. I managed to eat through where the #2 runner meets the flange. I had it not repaired with a Mig welder and then properly repaired with a Tig welder.

All testing was done on a Dynojet Chassis dyno.

I apologize for this being such a long post, but there is a lot to share here. I will break this up into multiple parts. If you are interested, you can read and discuss this post for a while (feel free to ask questions) and then I will post a part 2.

norvalwilhelm

I would love to see more on this. I would like to build a short block like this but use my blower on top of it.

pef427

It's not nice to tease your friends!
Give us the rest of the story.

427Hotrod

It's about time!! This is going to be fun guys! Just sit back and get some . folks

For those of you who don't know Nick..he's an analytical electrical engineer type who is a strong believer in A-B-A testing and quantifying everything. He has spent an inordinate amount of time and $$$ testing all his changes. While most of us will make a bunch of changes at the same time because ".....we just know they should work", and not really knowing which ones did and which ones didn't, Nick will hold off on stuff until he can actually test it.

The first time I met Nick after chatting with him here on the Forum was when I brought him that homebuilt 850 DP to try. I wish I had a picture of his grin the first time he kicked into it with the new carb! His nice little daily driver (literally) Vette had a new penchant for 3rd gear wheelspin!

He has lots of data that will help everyone....he has tested carbs, exhausts, cams, head porting, intakes, new heads, more compression, less compression etc etc etc. Really good stuff....we'll just have to wait for him to give it all up.

But just look at this first one. By giving his motor a little more air with a relatively small single plane..he picked up approx 10-26 RWHP throughout the curve. He also reported driveabilty was still just fine.

All of his data will be RWHP and flowbench data on various heads and mods. When you pick up 20+ RWHP from a simple mod..you're seat of the pants buttometter tests are going to really feel it!! When you get it to "hang on longer"...you'll go faster too!

So have at it Nick......maybe everyone will start to see where we come up with this "...Bigger ain't always bad" angle we use sometimes!

Motors are air pumps...you gotta give 'em what they need!

JIM

VETMANIAC

Norval,
If you are interested in starting with a fresh short block, I would advice you to do the same thing that I am advising a friend to do ... build a 598. In this day and age, you can now build a 598 for exactly the same price that you can build a 540. The only difference is that you must use a tall deck block and you would also need some outstanding cylinder heads to take advantage of 598 cubes. I would recommend going with the Dart Big M block if you are starting fresh.

By the way, I have been emailing you about your roll cage and thank you for the responses. I think you have done an outstanding job with your rollcage design and I will be picking your brain further on rollcage design if that is OK.

Patrick,
I am not teasing. I just didn't want to bore anyone to tears with too long of a post. There is a lot to tell here. I will get to it all. I just want to give everyone to a chance to discuss the fact that a large single plane outperformed a dual plane in every respect (including driveability) on the 540. This hasn't been the case on smaller cube big blocks, but 540's seem to cross a threshold where the old rules for what is "streetable" no longer apply.

Brettmc

And Dep said the LS6 manifold will not hold you back.....sheesh...

Brett

427Hotrod

And this was with the old tall style L-72 type intake..not the flat pancake LS-6 Vette intake.

Wait till you see what a bigger carb does....


Oh yeah...I forgot..this stuff doesn't work on the street!! Love to "kick it" with those guys!!


JIM

VETMANIAC

Jim I am sorry it has taken soooo long to post all of this.

Everybody, as you will see, all of the changes I have made and things I have learned along the way wouldn't have happened without Jim's help.

White 68

I,m back on my 68 project and look forward to the engine mod info ...How much does a 540 or 598 cost to build ? Are the Merlin/and other crate motors good deals price wise ?

Vetmaniac were do you live in Frisco ? I think I may have heard and seen you go by a few times my backyard/drive backs up to Ohio across from the primrose daycare. I,ve spent the last few years playing with a Zr1 which I just sold and have a 68 which got neglected the last very years.

Jim I,ve seen your beast run at Hallsville what a ride
Heres some pics from 2004
http://temp.corvetteforum.net/c3/sog...ille1__17_.jpg

Budman68

Jim, if only he would have performed a slick test at the track. Great info Nick, Looking forward to part two.

VETMANIAC

White 68,
Patrick (PEF427), is pricing 540,572,598 combos right now. I think he found a company in Nevada with excellent pricing. Here is a link to a new 572 I found on RacingJunk.com :
http://www.racingjunk.com/exec/ca/vi...c-all-new.html

I live on just off of Hillcrest and Preston Vinyard. Send me a PM or email and we can exchange phone numbers. There is a Corvette Forum gathering at the new Cruizer's restraunt every Tuesday night on Preston. Do you think you can make it to the next one? I would like to see the 68.

427Hotrod

Wait 'till Nick gets the next version of his car done if you want to see a 'Wild Ride"!!

Hey Nick...you going to give details of the all weekend/no sleep head and cam change?? That was fun!!

JIM

PS- White68...great videos! You were walking that ZR-1 out of the hole pretty darn good! Gotta love stick cars! Please tell me the '68 has 3 pedals in it too. I think you and I chatted at Hallsville...i remember you now. Beautiful ZR-1..hate to hear you sold it...but you got a C-3 so that's even better!

But man...my car looks like a 4x4 sitting there with all those new whiz-bang slick and smooth cars!

VETMANIAC

Jim,
I absolutely plan to give all of the painfull details. That won't be until part 3 though.

427Hotrod

He he he.....another one lured over to the "Dark Side"!!


Man..I'm having major "motor envy" issues!


JIM