I was looking through all the different small block Chevy crate engines from Chevrolet the other day and noticed there’s now a ZZ5. I know there have been a whole slew of different versions and obviously this is the fifth one. What makes this one different than the rest? Wasn’t the original ZZ engine rated at 345 horsepower?
Jeff Smith: The line of Chevy small block crate engines dates back to 1989 when Chevy first introduced the ZZZ small block. It employed a one-piece rear main seal, four-bolt main block with a forged crank, 9.8:1 compression hypereutectic pistons, and L98 Corvette heads. The engine also ran a somewhat long duration 235 degree at 0.050 hydraulic roller cam with 0.480-inch lift and a 114-degree lobe separation angle (LSA) and topped off with an aluminum high-rise dual-plane intake manifold. These engines were rated at 345 horsepower. These engines were the first of the factory crate engines that were popular but suffered from a noticeable cold start piston slap due to use of non-offset wrist pin pistons. Subsequent ZZ1 and ZZ2 engines replaced these pistons with offset wrist pins that eliminated the noise.
The ZZ3 and ZZ4 engines replaced the aggressive 235-degree single pattern camshaft with a more subtle 208/221 degrees at 0.050 hydraulic roller with 0.474/0.510-inch lift for the intake and exhaust with a 112-degree LSA. This combination retained the Corvette heads and 9.8:1 compression while the ZZ4 converted to better ovate wire valve springs to better handle the increased lift and valve acceleration rate of this latest camshaft. Engine power for the ZZ4 increased to 355 horsepower at 5,400 rpm with torque at 405 ft.-lbs. at 3,600 rpm. The ZZ4 is still around as a short block, what Chevy calls a partial engine, under PN 12561723.
You are correct that the latest version from Chevrolet Performance is the ZZ5 with some significant changes. The most important is the switch from the old L98 aluminum Corvette heads, which really didn’t flow all that well, to the newer aluminum Fast Burn cylinder heads that were used on the Fast Burn 385, 350-cubic-inch engine rated at 385 horsepower at 5,600 rpm. This engine also used the 208/221-degree hydraulic roller cam. The Fast Burn 385 is no longer available but the head, with its 2.00-inch intake and 1.55-inch exhaust valves and 62cc chambers, found its way onto the ZZ5 shortblock. Combined with a 9.7:1 compression and the same 208/221- degree at 0.050 hydraulic roller, the ZZ5 is now rated at 400 horsepower at 5,600 rpm with 400 ft.-lbs. of torque at 4,000 rpm. The ZZ5 base engine falls under part number 19301293 and comes with an intake, HEI distributor, polished aluminum valve covers, water pump, spark plugs, and a balancer. There’s also a ZZ5 Turn-Key package complete with all the aforementioned goodies, plus a serpentine accessory drive, carburetor, wires, flexplate, and air cleaner under part number 19301294. Plus these engines come with an outstanding 24-month, or 50,000-mile limited warranty. They can offer such a great warranty because from what we hear, the return rate is incredibly low because of their great build quality. For what it costs to rebuild a hydraulic roller-cammed small block, these crate engines are a great deal.
Hey Jeff- I just took delivery of a ZZ5 and I’m wondering about the intake they use. I have looked around and there doesn’t seem to be much info on it. Mine came “undressed” so I need a carb too. The full monte version comes with a 750 Holley and searching for other choices has not revealed a definite winner. I guess my question should include what CFM would be good for a street driven application. Thanks-Dave
Hello Dave. I have ZZ5 in a 1992 C1500, installed it last summer. I bought the turn-key with the 770 cfm Holley Street Avenger with vacuum secondary. Don’t strangle it. It needs a large carb.
what type of spark plugs do I use on my zz3 motor ??
I use a r44t send yo do well for me. I have the SP383 deluxe. About once a year I changed mine whether I need them or not.
I know that theres a lot of different plugs ,, but what type of plugs do I use in mine ?? I have some that have a lot of threads , and I have a set that have short threads on them ?? so whitch ones do I use ??
I use NGK TR5 in mine
I am getting “not available” responses all over. Has GM pulled the ZZ5 for some kind of trouble?
engine was pulled from service for overstatement of horsepower. additional bulletins coming from GM with emphasis on some a partial refund claim for consumers.
Is there a hint of intent in the bulletins; is this the lead up to a ZZ6; or the end of the ZZ sequence; or just a fix to the 5?
For my project I can’t wait anyhow, and have already ordered a ZZ383, but still interested.
do you know how much horses the ZZ5 really has?
Does your comment mean consumers who bought a ZZ5 will get a refund?
I was gone on vacation, and when I came back I was ready to order one, but I thought it was rated 420 hp. Did they change it?
That was a different motor. I found the print out I had, it was 400 hp.
Tried to order ZZ5 and dealer parts guy has told me that this engine has been discontinued. Maybe that’s a good thing….now researching options.
I have a turn key 385 Fast Burn GM crate engine. I checked the details of the ZZ5 on Jeg’s website, and all of the hp pruducing parts appear to be the same. Where did the 15 hp come from? In fact, it looks to me that the valve covers are the only difference.
Here’s the deal on the ZZ5. I JUST Bought my ZZ5 IN FEBRUARY, I was so HAPPY to buy my first kind of big boy motor. I installed it in a suburban. In July I received a phone call in regard to my ZZ5. ( This really sucks). I now have to go inside the motor to reclaim 20 horse power that I thought I paid for. In order to make the ZZ5 have the 400 horse power, I will need to Add these parts- here are the Part numbers- ( p/n19114384 =160 Degree thermostat). And a (set of  1.5 roller rocker arms- p/n 19210728). In addition, the engine will need to have a 36 degree total spark advance, and use 93 octane. And if that is not enough to piss me off .They discontinued the ZZ5. I am so disappointed. That they are trying to make this my problem!!!!!! .Thanks Chevy performance.
Well I bought a ZZ5…….I call the dealer I got it from..RECALLED.(they were told by GM to contact all zz5 owners that they sold one to) 3 weeks ago…sorry…….motor does need all the above changes to get the 15 or 20HP back…But GM will send me 700 bucks for parts and labor if I sign a waiver and supply them with the original invoice in my name………………….The extra HP is at 5600RPM so I’am keeper the cash. ….My motor going into street rod and I’ll never get it above 4000RPM
Robert – I’m trying to track down this refund, do you have anything official from GM?
You need to contact the GM Dealer you bought your ZZ5 motor from….They will give you all the info ………you must be the original purchaser ,have your original invoice and sign a waiver, send it to GM……..I sent my stuff in today. I also heard from my dealer that they are also recalling the ZZ383……………you can call GM at (888)980-6148….. Or Email ZZ5Engine@acbcoop.com
Unbelievable but the customer service and excellence was non existent in the GM (Government Motors) vocabulary!!!
Robert-Thank you for the info. I just called and got everything printed up and sent in.
I bought mine in December 2014. Printed up my info and sent off to Memphis today, as per instructions on link you posted. I never would have known this if not for this thread. GM has said/emailed nothing to me…..Thanks Robert.
As a follow up, same here, I bought mine through JEGS and had not heard anything from JEGS or GM. Thanks a million (Or at least 700.) to Robert!
I assume we don’t need to upgrade push rods or guide plates?
I did hear from JEGS today ,I sent the paperwork to GM ,.hopefully the fix will work without guide plates or pushrods.
Got my check today…….took only 30 days……Thank you GM
FINALLY got my check. Took over 2 months, but I got it.
Heard it was recalled and still not available
I was told in November that my claim was approved for the rebate. Haven’t rec’d the cheque nearly 3 months later and told that GM has not transferred any $ into the abcoop bank acct. – if others have rec’d their $ something doesn’t sound right.
i bought a zz4 a boat anchor. changed cam carb lifters 355 rear end msd and still a boat anchor, what a waste of money time and sleep 265hp not 400hp. what can i do? just heard gm is doing exchanges.
I had issues with a zz383 the cam timing was off 11 degrees from the factory,ordered an adjustable timing chain now it runs very strong.
I purchased the SP 350 crate engine – originally the zz5. I live in the Imperial valley, California where the temperature can reach 120 degrees. So I purchase a Champion aluminum radiator, 4 core, the call the monster radiator for 800 to 1000 hp. The engine reaches 200 to 210, a temp i’m not really comfortable with. I was wondering what thermostat these come with. I read in one of the previous lines that you recommend part number 19210728 = 160 thermostat. I would appreciate your advice.
My ZZ5 has a 195 stat…..the fast burn heads need the high temp to work right……Make sure you run the water pump to intake short water bypass hose,like a BBC….it saves the heads from overheating during warm-up……..so I had to do my heater return line into my lower rad hose (steel Y). Cooling ….I’am running a walker rad…..cooling concepts 2 speed fan….and a Dakota Digital fan controller. This fan and controller works fantastic never overheats stays below 200. The fan controller also showed me my temp. Gage Was reading 7 to 10 degrees to hot. The controller does everything……set any…on/off temp for 2 speed fan or dual fans……set fan run time after shutoff,(really helps engine temps at short term /gas stops)…………also you can check temp. Thru there 0 to300 degree stat. Hope this can help ya! Robert
Robert again…….I use a 15 lb cap and a overflow tank (puke tank). FYI ……the fast burn head motors like the LS and LT motors Puke up to a Quart ….The standard 350 pukes only a pint. So I used a 50 oz. tank…………keeps the air out of the rad…..Everything helps