Ok, first I would like to say that this is Midnyte 81. Now back on subject.
I have this, and this is what I'm finally sticking with:
-mildly ported and polished 3986336 x heads 76cc
-1.5 roller tip rockers (Comp Cams) and hardened pushrods (Federal Mogul)
-Assembled 4-bolt main 350 bored 0.060 w/ stock rods
-Old Style Lunati flat top cast pistons 9.5 CR on 76cc head
-Comp Cams XE268 cam and lifters with 477/480 lift
-Holley 750 DP carb, z-28 aluminum manifold, and 110 GPH fuel pump
-MSD 6AL ignition
*Take note that this in no way will be a race engine. This will not see a day above 6000rpm*

Now, can someone put this on engine dyno and help me out with an estimated hp number on this? In the very near future, I'll get 2.02/1.60 valves on the heads and get a 3-angle valve job for $200.00, but I just got back home from a long deployment and don't really feel like doing it at the moment. Also, this will be going into an 84 z28.


Any help is appreciated!

 

Probably around 350 hp. What about the exhaust?

 

I'll be using 1 5/8 hooker comp headers and the infamous y-pipe that nobody seems to carry. I'm going with this setup because it cost me only 200 dollars to clean the heads, buy the gaskets, and check the pistons. (Engine was in a flood) I already have Flowmaster 80 series muffler.

 

Also, is this 350 at the flywheel? I'm looking at a Car Craft article with home ported 993 heads and the same mods I have making 421 hp and 438 ft/lbs of tq. I know it sounds far fetched, but If thet "say" they made that much, I would definately make more with ported and port matched intake runners, bowl blending, and polished exhaust ports. What I really need to know is: What was the stock intake runner and exhaust port volume? That way, I know the increase from the flowbench test. remember that these are the 336 "x" heads that are supposed to have the larger intake port. The last thing I want is an approx hp/tq numbers from info above. I appreciate the help!

 

I had 993 heads but had to get rid of them. I know there are better stock heads out there, but I'm not looking for one. I already had the 336x's from years ago (Now I sound like I'm old) and I'm just trying to get the old Z28 some pep in her step.

 

So did you have them flowed? Port volume cannot be correlated or extropolated into port flow. Porting and polishing can actually make flow worse if done incorrectly.

 

I should say then I have removed those gross and obvious casting flaws and port matched the intake manifold and heads. The intake and exhaust are bowl blended and the exhaust ports are polished. You would never think cast iron would shine like that. I'm not hogging out the ports and they have maintained integrity. The exhaust port is already the size of the headers and gasket ( 1-5/8 in), so there was no need to enlarge there. I also smoothed out the short side radius. I know I could have gone with the XE 274 cam, but it seemed like too much cam for pure street. Besides, I didn't want to get into that "Gray" area where you would need screw-in studs.

 

If you want to stay out of that "gray" area, drill and pin the studs. thats all that is required.

 

I didn't want to get the screw-in studs at the time because I'm getting robbed by the machine shops down here. 200 for it, not including the studs.