CDaniel525

I am considering swapping out my stock ZZ4 heads for some AFRs and the HOTcam that I already installed for a Compcam...
I posted this setup a few years back, but no one ever seemed interested in it... its basically a stock zz4 bottom end with the AFRs and Compcam... I already have the single plane intake, 750 carb, and good exhaust...
I can see doing this setup for under $2500 myself. Doesnt seem bad to achieve 500+Hp IMO.
I have some questions tho as im no expert on building up a motor.

The stock ZZ4 heads are 58cc chambers, but the smallest you can get in a AFR is 65cc. I am presuming I would need to have the heads milled to retain my 10:1 compression ration? or how close would the ratio be running the 65cc and how much HP/TQ would i lose by not matching the 58cc? If I decide to mill the heads, is this something AFR can do from the factory and tack on the price? Or am I better off buying them from summit and having a shop mill them down?

This setup makes some serious power above 6000RPM and AFR recommends their higher rating springs and a "Hydra Rev Kit" IS this something I should definitely get? if so there are 2 different types, ones for factory lifters and one for aftermarket... im guessing the zz4s would be factory??

Here are the cam specs...
Part Number 08-444-8
Engine -Present Chevrolet
305ci-350ci
8cyl.
Grind Number CS XR300HR-10
Description
Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.562 0.58
Duration At 0.006 Tappet Lift 300 306
Valve Timing At 0.006
Open Close
Intake 44 76
Exhaust 87 39

These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 248 254
Lobe Lift 0.375 0.387

Lobe Separation 110


Lastly, is this somethign that I would be able to do on my own? Or have to have a shop do... I am definitely mechanically advanced... already did the HOTCAM, but with help of my father. Changed the intake a few times, but like I said am capable of working on things... if I do it, whats involved in doing the heads? im guessing its fairly simple bolting and unbolting them, and dropping in the other parts?? Also, when I did the cam last time, I dont remember using cam timing wheel... is it completely necessary.. if not, how should I approach that install??

Thanks in advance with all the questions!
Chris



Parts list
1 - Heads $~1400-1500 + milling?
2 - Springs - $108
3 - Hydra Rev Kit - $240
4 - Cam - $256

Little Mouse

Max torque at 5500 rpm what does it do at 2500-3000 rpm??
Cam companies recomend more comp. ratio then you will have
for cams with that much duration. What do you have for trans
and rear gears?? with that big of a cam and heads on a 350
you are building nothing but an upper rpm engine. if you have
street gearing and going to run it on the street go
for good lower end torque numbers

CDaniel525

Im running 3.55 rear gears, but a Tremec TKO with a 3.27:1 first gear, which is pretty steep. Most of my driving is hard on the street, and racing.... definitely not a daily driver. Id like to get it into the 11s N.A. and figured about 500HP would get me there if not really close.

Rdavis

ZZ4's are fitted with a thick (.051") head gasket I believe. Chev. offers a .028" composition gasket just like the ZZ4 gasket. Using this or even some of the thinner ones will probobly get most of your compression back.
The hot cam only in a ZZ4 dynos about 390. The heads in stock form are weak, lot of power to be had with this engine & better heads.

Heres a link to gm gaskets.
http://www.sdpc2000.com/catalog/526/...ad-Gaskets.htm
I really think that if you run a thinner gasket that you will be close enough to your 10-1 target w/o having the expence of milling the heads.

Stumpdeisel

I'm running a rebuilt LT1 with shaved heads and a hotcam. What headers are you using?

CDaniel525

Rdavis... Thanks for the info.. that can definitely save some money and frustration. I found this calculator for compression, but cant seem to match up the original compression ratio... dunno if this is cause of how much the "piston is in the hole" cause im presuming it is right even with the top. Anyone know?? Either way, messing with the calculator and some intuition, I could presume with the .28 gaskets, i would only be down to 9.75:1 I cant imagine losing much power due to .25:1...
Is there any risk running such a small gasket?

Stumpdeisel.. using the Hooker 1 7/8" headers that come with the whole hooker side pipe setup...

Can anyone fill me in on how difficult it is to install a set of heads for someone that is mechanically capable. Any special tools needed other than a torque wrench>?

Rdavis

Heres what I think.
Say you gain 50hp with the new heads & you loose 5 because of the .25 diffrence in comp. You are still 45 ahead. I really do not think that 1/4 point is going to make a lot of diffrence.

dgruenke

I think you are going to be pretty disappointed with an engine that has 9.75 CR and a 300 ADV duration cam. You car will be about as quick as a Civic until you reach upper RPMs.

jerome1979

go here!!!!
you will find good upgrade idea for a ZZ4

http://gilbertautoparts.com/ChevySma...s/safrzz4.html

gkull

I get very skeptical when people start talking about 500 hp with 350 ci and insisting upon H-rollers. With the new AFR eliminator 195 cc heads and a cam of 248/254 your max hp might not occur till over 7000 rpm. Well beyond the limitations of a hydr-rev kitted HR cam.

For what it is worth i use a cam of simular duration in my 434 ci small block.

I once owned a 355 ci with 10.7 C/R and a solid roller - it self destructed. I taught me that smaller ci motors just don't have the TQ to push our heavy vettes very fast. It was a consistant 12.30's machine with slicks.

I have a set of AFR 210 heads that were flat milled to 64 cc. I think that was near the limit. I would research some other manufactures to see who might have 58cc

CDaniel525

Thats pretty much the same thing im going for... the 195cc AFR heads, the "Rev Kit" and a bigger cam.... this cam seems a bit more streetable tho I suppose. They say using Fel-Pro #1003 head gasket that they get 10.1:1 comp ratio with 58cc combustion chamber... Im guessing this is with the healds being milled. I might call Gilbert and see if they just sell these heads.

I wonder what kind of power I could make with just adding the AFR heads, and keping as close as possible to 10:1... and just keeping my "HOTCAM" for now...
My cam specs are duration at .050” tappet lift (intake/exhaust) is 218/228; and maximum lift with 1.6 rocker ratio (intake/exhaust) is 525/525
The one in the Super AFR ZZ4 are duration at .050” tappet lift (intake/exhaust) is 222/230; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 509/528

Im not expert on cams, but they seem very close to me, considering i have the 1.6 rockers already.

ANy thoughts on what kinda power I could make with just those AFR heads?

jerome1979

do a search on their forum!

http://www.sallee-chevrolet.com/Disc...pts/discus.cgi

CDaniel525

$1818 + ship for the heads already milled to 58cc and the Hydra Rev Kit....
might go along the route. Gonna call AFR for a price direct with the milling, unless there are some AFR distributors on the site!?

Any clues if I can make over 450-460HP with just adding these heads and leaving my HOTCAM with 1.6 rockers in there?? if so thatd be a good idea, knowing that I would then have some heads that could make over 500HP if i find a cam good enough for that or if i decide to stroke or SCer it in the future.

Little Mouse

If your going to stroke the engine in the future don't go with the
58cc chamber.