That 805 hp 87 octane street 572 - again!

[blykins]

That post was removed so I guess that was just too much like an ad for the ST powers that be.

I probably shouldn't say this but sorry folks just calling it as I see it.............You guess DV???? IMHO nearly every one of your thread is an ad of "look at me everyone and what I've done, you sheep should run out and buy my books. If DV was hanging out here without an agenda he would answer questions freely about his BS 572, let his rep speak for itself and not post threads like this one which is just another ad. *Note to mods. feel free to delete this but it needed to be said as I feel this forum is for professional engine builders and machinist like myself to help each other, trade ideas and occasionally help the novice.

THIS WAS FROM THE OPENING POST - So got questions ? Go for it.
WHATS NOT FREE ABOUT THAT! and let's not overlook the fact that i spent about $5000 doing this 572 stuff. Can I respectfully ask when it's your turn to spend that much and give it away for free?

With all due respect, David, all of your posts are an ad of some sort, so I can see why the moderators would nix one or more of them. Obviously, you make a living by performing tests and offering the results as a seminar, book, etc. If you're going to start a thread with, "This test engine is for sale.", or "The results will be in book number x", etc., it comes across as a promotion or advertisement.

With all of that being said, congratulations on your retirement.

[wyrmrider]

I'm looking for the collaboration on the SBF projects- stay well

[RevTheory]

Did you have to get deep enough into it to offset bore the block in both directions (forward and thrust)? I'm guessing bore notching and piston porting was a given.

[David Vizard]

Did you have to get deep enough into it to offset bore the block in both directions (forward and thrust)? I'm guessing bore notching and piston porting was a given.

Shawn, actually no - part of the brief was to hold cost increases to a minimum. Fortunately some things we could upgrade as GM had already put parts from the company we wished to deal with into their inventory. So no offsets and no reliefs (not so important on a 4.47 bore)

Here is a basic rundown on what parts we changed and tested in one form or another.

#1 Camshaft - no tests here just went right into a cam that we knew upfront would be just a whole lot better.

# 2 Cam timing engine was equipped with a Jesel belt drive so every test had optimal cam advance.

# 3 CR had to remain at 9.4 so everything was configured around that.

#4 we could use any intake for evauation purposes but whatever we deliverd to GM would have to be with the original height intake.

#5 we could look at power with a fully streetable 850 with choke etc and an alternative such as a Dominator.

#6 Cylinder heads - from past experience it was known that too much port volume not only killed torque but in many cases impeded the generation of HP. This being the case head intake port sizes were limited to a nominal 320 cc. Heads, in as cast form, from Edelbrock, Brodix, Dart, TFS, RHS, BMP, and Profiler were tested. Many of these heads were also tested in ported form.

# 7 We had to come up with a stronger piston to survive the 50 hour test. We had some made up and tried several different ring packages including skinny Total Seals.

#8 Worked on quench patterns and introduced what, in house, we are calling 'Late Phase Chamber Hyper Scavenge'. Not sure where we stand on this patent wise but in addition to that found some interesting quench fir and clearance results.

#9 Got a good tale to relate as to why you cannot just change rocker ratios and expect it to work as hoped for every time.

#10 tested a bunch of rockers.

# 11 Piston Flat top down bore and dished with quench ring.

This is already a big list and will take pages to cover even in just enough detail to put you on track. I have got a bunch of this already written up in great detail originally intended for book 3 of the BBC series but now that's not to be so I may post that in full form on my website.

Anyway there is enough there for plenty of questions so fire away.

DV
PS There is more but I need to get out in the shop as of now.

[F-BIRD'88]

So did GMPP 's bite on this? (Buy In?) Will this be adopted ( in whole or in part(s) ) as available stuff you can buy, from GMPP? If not, Y Not?


Nice Job

[David Vizard]

So did GMPP 's bite on this? (Buy In?) Will this be adopted ( in whole or in part(s) ) as available stuff you can buy, from GMPP? If not, Y Not?

F-Bird sir - tech questions only - business is private.
DV

[F-BIRD'88]

You'd think GM and or Mercury Marine Racing might be interested.. With just 9.4:1cr and peak power at some 5600rpm this motor could run all day in a Off shore boat.
Especially with your durability work/testing.

I'll most likely never build a 572 but the tech probably can be applied to other builds.

[Racerrick]

That being the case I will spill the beans on the tricks that make this 572 a real killer of a street motor

Questions are..... heads used. did you roll them, valve seat angles and cutter numbers, Port volume, flow, velocity over the turn, Valve specs with neck radius, back cut, valve springs PART# and open and closed pressures, rockers and ratios, lifter # and preload, Cam spec with lobe number and sep, intake used.... I could go on if you like.

[prairiehotrodder]

I'd like to know the cam specs. I have a 10 -1 CR 540 and am always trying to learn how to go faster with it. I can definitely learn from your 572. I basically asked this same question before the other post was removed. I've even considered buy a COS-CAM from your website but i'm happy with my Straub cam for my current build. I'm gonna guess that you put higher ratio rockers on the intake valves then retarded the cam to compensate. I've been thinkng of doing this after reading your book. Also going to a tunnel ram.. My motor is probably 100 hp less than your 572 but i'd like to get where it is.
thanks for being willing to share.
Brian

[Race Engines]

Did you have to get deep enough into it to offset bore the block in both directions (forward and thrust)? I'm guessing bore notching and piston porting was a given.

#9 Got a good tale to relate as to why you cannot just change rocker ratios and expect it to work as hoped for every time.

Anyway there is enough there for plenty of questions so fire away.

DV
PS There is more but I need to get out in the shop as of now.

David, tell is about the rocker ratios and LSA used. Thanks

[DaveMcLain]

With only 9.4:1 compression what do the EGT's look like on the engine light load vs WOT?

[MadBill]

That being the case I will spill the beans on the tricks that make this 572 a real killer of a street motor

Questions are..... heads used. did you roll them, valve seat angles and cutter numbers, Port volume, flow, velocity over the turn, Valve specs with neck radius, back cut, valve springs PART# and open and closed pressures, rockers and ratios, lifter # and preload, Cam spec with lobe number and sep, intake used.... I could go on if you like.

You may have to limit it to three questions per customer, David!

[RevTheory]

That being the case I will spill the beans on the tricks that make this 572 a real killer of a street motor

Questions are..... heads used. did you roll them, valve seat angles and cutter numbers, Port volume, flow, velocity over the turn, Valve specs with neck radius, back cut, valve springs PART# and open and closed pressures, rockers and ratios, lifter # and preload, Cam spec with lobe number and sep, intake used.... I could go on if you like.

You may have to limit it to three questions per customer, David!

And know the difference between honest questions and bait

[Kevin Johnson]

David,
What changes needed to be made to the pistons in order to survive the 50 hour test?

[blykins]

And know the difference between honest questions and bait

Who's baiting? This isn't sanfordandson that we're talking about here...

Seriously though, I don't see anyone baiting. Normally when guys get on forums and show off their builds, they come forward with all the information up front and then guys ask questions about details that they didn't see listed. We are seeing the exact opposite here: "I built a nice engine. I'm not giving any details up front, but ask as many questions as you want, so we can perpetuate the focus." I mean honestly, we basically know it's a 9.4:1 compression, 572 inch engine, and that's about it. Are we supposed to guess about which questions he wants us to ask???

Again, no disrespect intended toward Mr. V., but I have to wonder about the motives involved.