Just looking at the specs on the ZZ4 GM Crate engine, and it looks to be a little over-engineered for something producing 355hp. It seems to be begging for a larger cam. Has anyone modified one of these engines - and what were the results?

 

I think you clould go bigger. My question would be the heads at 58cc, could they except larger valves? May have to machine heads for different valve springs.

 

i have the zz4 crate motor. i was doing some reading i think car craft or something and they were saying how it lacks in the intake and cam department. other then that i like it

plans for summer on my zz4 are afr heads victir jr and comp cam not sure what kind of hp the combo will make i was hoping somewhere between 450 480

 

I have the ZZ4 Creat motor with little over 7,000 miles on it. I have the MuthaThumpr cam in it and the aluminum fast burn heads. At that time when the motor was purchased (A few years ago) you could get the 64hp drivetrain upgrade witch came with the cam and a couple other things that boosted it from 355 to probably some where in the range of 425. Its a Nice motor I love it

 

The 113 heads on the ZZ4 are based on the alum L98 vette heads .Guys commonly run the LPE 219 ( 219 .560 ) on those with suitable intake

 

What do you guys think of your ZZ4 engines? 355hp is not bad for a street car - does anyone have any strip times or anything for a 3rd Gen with a ZZ4?

I think that running something like a 218/224 cam with around .520 lift on 110LSA could be interesting. How would this cam go in an otherwise stock ZZ4? Would the springs, lifters, rockers etc be up to the job? It isn't a massive change but should free up a few more horses.

 

ZZ4/LT4 Springs good for .525 lift

 

Subscribing, I'm tossing up a ZZ4 swap come tax time. This could be interesting

 

Your limitation is the flow of the 113 heads. Once you reach a certain point ,more lift has no benefit

 

What sort of power can those heads sustain? The ZZ4 cam has something .500" lift on the exhaust side anyway, so going for mor duration and keeping similar lift should not pose any problems I would think.

 

I decided to go with a long block crate ZZ4
I couldn't pass on a recent offer for one. I did have to pick up a few things to go with it such as a new rev flow water pump, mini starter and full MSD 6AL system,

a TPIS intake manifold, ASM runners, ported plenum and 52mm BBK TB complete my TPI with New 22lb Bosch 3 injectors and a TPIS AFPR

I know the ZZ4 is rated @ 355 with a carb but with my TPIS I hope to achieve similiar #s , if not closer to 400 - I hope

larger injectors or a TB or a possible future project but enough for now

my car is only for street and I like to do 200 + miles in a day without problems

 

the 52 mm TB will be plenty big for your ZZ4. The 355 HP the ZZ4 is rated for is at the flywheel. You'll be losing around 17% by the time you dyno it at the wheel. So figure around 295HP to the ground with is very respectable. These engines tend to make a little more HP with a carb then it would even with after market TPI. Both it sounds like a killer setup good luck with it! I'll have to get to one of those NYTG meets next year and check it out

 

The stock ZZ4 heads are well matched to the ZZ4 cam. You can get more out of it, but expect no miracles from a cam swap alone. The GMPP catalog from a couple years ago had some power graphs for different cams stuffed into the ZZ4 (like the common LT4 HotCam)- they were none too impressive.

Knew somebody who ditched the ZZ4 heads and put on Vortecs modified for added lift (otherwise stock), still retaining the ZZ4 cam. I should also mention the intake manifold was changed as well from a standard Performer on the old heads to a Performer RPM Vortec on the new ones (necessitated by the different bolt pattern and the desire to try out a slightly higher performance intake). Car went noticably quicker. Not sure if it made any more peak power (we suspect it did by maybe 20-30HP) but the torque curve was quite a bit beefier all the way up the rev range.

The ports and chambers on the ZZ4 heads are still of the "old school" design and can't hold a candle to the more modern Vortecs.

 

Has anyone ever run 1.6 rockers on the intake side of a ZZ4 cam to get to .500 lift?

 

I think this is the article your talkin about zz4 crate motor 338hp 296tq,,,,zz4 crate motor with a lt4hot cam and 1.6RRs 391hp 324tq http://www.cis.udel.edu/~davis/z28/buildup/cam/ .I'm building a similar motor to the zz4.

 

With FastBurn heads and all else the same, you get 30 more HP.

With Fast Burn heads and LT4 Hot Cam kit, at least another 30 more on top of that.