[R67chevelle]

Okay... Whats the real story about this engine... Dyno from GM says 620/650 and some magazines say 700/700 or lower. What gives? 572 cubic inch with a 850cfm not a 950hp carb...

I have been thinking of scrapping the whole LS motor thing for now and doing the ZZ572. Just under $ 12,000 turn key and can drop in the engine bay with BB mounts.

Please advise. I want a 10 second car. Will run 3.73's out back with a Art Carr/california performance 200r4.

Is this an idea or not... Advise from the CHEVELLE gearheads are needed and welcomed...:thumbsup:

Blessings,

 

[kw1162]

Sounds great. I am thinking about waiting for a rebuildable one so I can get rid of that 12:1, and throw a blower on it.

 

[Junkyard Dawg]

Did the mags do any work to the engine?

Or did GM under rate them? (don't know why they would)

 

[Harold Sutton]

The 620 H.P. version is the low compression version, not 12-1, and yes they do rate them using a different method of horsepower correction. Their method is supposed to give more average results. The "old" J1349 method used a 0' Density Altitude air correction factor, (59 degrees, 29.92 barometer, & zero humidity) while the "new" J1349 standard is appx. 1000' Density Altitude and uses (77 degrees, 29.32 barometer & zero humidity). On the other hand these motors aren't particularly powerful. If one gets the shortblock and adds a real good set of heads you might really have a barn burner but then again if you just want a good dependable high to mid ten second car then it might be a good way to go. The LSX motors have at least as much if not more potential though and are starting to become available in junk yards. G.M. is coming out with cheap heads and a cast iron LSX block that will easily go out to 454" and should run as fast as the big motor and get much better gas milage. In my neck of the woods a mid ten second car will lose a lot of races these days.

 

[RATtyCamino]

On the other hand these motors aren't particularly powerful. If one gets the shortblock and adds a real good set of heads you might really have a barn burner but then again if you just want a good dependable high to mid ten second car then it might be a good way to go. .

Harold's right on target here. Just to elaborate, Edelbrock is proving this point with their recent "502" combo. With a barely 9:1 502 short block, a streetable cam and their Victor Junior heads/intake....they are cranking out a solid 600 HP. Many folks on this board are making insane numbers with their fairly mild 496/502/540 combos. That being said, I do think it's cool that you can get an all-inclusive 572 crate motor from your Chevy dealership!

 

[Busted Knuckles]

You can save yourself a lot of tall deck headaches and get a short deck crate 540 or 555. I'd go 555, bigger bores unshroud the valves which helps with airflow and horsepower, I know Harold is a big advocate of that as well. Sunset Racecraft builds a pump gas 555 with better parts that will outperform the GM 572 for about the same money. GM's warranty is pretty much like everybody else's for street engines - if you race it once, you void the warranty. Who'd buy a 572 without intending to race it - even stoplight stuff? Not me, that's for sure! By the way, the Crane hydraulic roller cam that GM uses in the 572 is the same as Sunset uses in their 555. It's one mean, no BS sounding critter, sounds tougher than a lot of trailered cars you'll line up against at the strip!

 

[Burnsamatic]

Where can you get a 572/620HP GM crate motor for under 12K?

 

[RATtyCamino]

Where can you get a 572/620HP GM crate motor for under 12K?

The long block is available for $11.5K here:

http://www.sdpc2000.com/catalog/3449/GM-Performance-Parts-ZZ572-Crate-Engines.htm

 

[Bowtie-72]

Where can you get a 572/620HP GM crate motor for under 12K?

Current GM cost is a little over that. There's some dealers who will sell below cost due to volume buying discounts, and hope you buy other stuff from them to help balance it back out.

I can buy a replacement tranny for 12% UNDER cost form a place in town. Too bad he doesn't do perf stuff like that.

 

[SS_Sean]

You might try Sallee Chevrolet (Now Gilbert Chevrolet). They do a lot of mail order, and a lot of volume.

http://www.gilbertchevy.com/frame.html?/Crate_Engines/performance.html

Also on their website is a link to a zz572 install in a 70 Chevelle SS, with some detailed notes and pics on how the install went in, parts used, etc. Hope that Helps.

 

[Burnsamatic]

Wow! They have some really nice 502 low deck combos. I think I'll be buying my crate motor from them! Thanks for the link!

 

[protouring72]

I agree with the comments about just getting a regular block standard height deck. Easier to "drop right in" The only issues I had were with the headers, had them custom made. Otherwise it does "drop right in"
Shop around on the internet. I got my 572/620 deluxe version shipped to my door for 11,800. I got it from Rydell Chevrolet in Iowa if I remember correctly.

 

[Shawn Gilbert]

any article i have read on the 620 shows it closer to 700 everytime.

 

[Bomber '67]

Dominate67, refer back to Harold's reply: all the magazines and hot rod industry use a more favorable dyno correction factor than GM for the horsepower results.

Really it matters not how much horsepower you want to brag about - hell add 10% more if it makes you feel good. Otherwise all I want to see is your time slips!

Thomas

 

[540Hotrod]

I believe they might make around 700HP also (572/620 version).

But I 've yet to see either the 572/620 or 572/720 run anywhere near the MPH numbers we would all expect 700-800HP to do. Weird......


JIM

 

[Harold Sutton]

Most of these '70-'72 Chevelles weigh in at around 38-3900 lbs. with a roll bar, driver and moderate amount of gas. The 200-300 or so extra pounds over a Nova, late model Malibu or Camaro really shows up in their E.T.s and speeds. They rarely run even close to the lighter cars.

 

[Ron454]

I believe they might make around 700HP also (572/620 version).

But I 've yet to see either the 572/620 or 572/720 run anywhere near the MPH numbers we would all expect 700-800HP to do. Weird......


JIM

I agree with Jim here.
But I think there is a reason.
Hard core guys build their own, and make it how they want with a goal in mind not just for HP but what they want the car to run.

Buying a 572 is an easy way out, plunk down the cash, and bolt it in. These folks might not be as hard core as the rest of us.

Myself, if I was going to do a 572, I'd buy a short block and add my own head and cam choice.
Personally, I'd do a 540.

Tall deck block isn't that much of an issue, but add heads with raised ports and you are into header clearance issues on most if not all chassis.

BTW....yes Chevelles are heavier, but can get to Nova weight pretty easy.

Ron

 

[nutt]

You might try Sallee Chevrolet (Now Gilbert Chevrolet). They do a lot of mail order, and a lot of volume.

http://www.gilbertchevy.com/frame.html?/Crate_Engines/performance.html

Also on their website is a link to a zz572 install in a 70 Chevelle SS, with some detailed notes and pics on how the install went in, parts used, etc. Hope that Helps.

just curious any idea what the price is on the super street prem engine and the ultimate street engines?

anyone know the reliability factor compared to the zz502?

 

[Bob West]

BTW....yes Chevelles are heavier, but can get to Nova weight pretty easy.

Garrets Camaro weighs 3525 fully equipped w/driver, my car weighs 3850+ fully equipped w/driver, Chevelle driver weighs at least 100lbs more than Camaro driver . A Camaro and a Nova are comparable, please explain how to lose 2-300lbs easily? What does your car weigh? I've noticed in some pics you've posted it doesnt have inner fenders up front, and has race buckets too.

 

[Harold Sutton]

Garrets Camaro weighs 3525 fully equipped w/driver, my car weighs 3850+ fully equipped w/driver, Chevelle driver weighs at least 100lbs more than Camaro driver . A Camaro and a Nova are comparable, please explain how to lose 2-300lbs easily? What does your car weigh? I've noticed in some pics you've posted it doesnt have inner fenders up front, and has race buckets too.

I agree with you, Bob. My son's car weighed 3680 when he first put the rat motor in it, without a roll bar. When you add 40 extra pounds for the Dart block you have 3720 plus his 245 lbs. and you can see the weight adds up pretty quickly. Even after stripping out all the unnecessary items like factory seats and adding every lightweight part his class allows and his car's race weight is still 3560 lbs. with him on board. Most of the Novas are right on the 3400 minimum with the driver or even a little lighter. Giving up that much weight means you have to make at least 75-100 extra horsepower to to run the same times. A 1967 Camaro with a rat motor weighes appx. 3200 lbs. + driver and that is a way easier place to start shootout racing. The earlier 1965 - 1967 Chevelles are a little smaller and lighter (appx. 100-150 lbs).