Yes. I see .030 on all out race engines with forged pistons and wider piston to wall clearances = more rock. Aluminum rod motors need more for expansion but your talking a whole different animal.

EDIT: I seen a sprint car build that was under .030 quench that, when we tore it down you could just make out the marks from the cut on the heads on a couple of the piston tops. Think he was @ .028 but loose pistons, large clearances, real high RPM and a full season on it.

 

your compression tation might not be right the zz4 has a 58 cc chamber witha 0.051 head gasket to get 10 to 1 the zz430 has a 9.8 to 1 with a 62 cc chamber .
I had my AFRs milled down to 62 cc and a 0.039 gasket to get to 10 to 1ish

 

All this chaos for the OP who made his first mistake by not ordering a complete ZZ4 , Now he is trying to be Joe the engine builder on top of a ZZ4 short block so he can bolt up ram horns because even though he has never had headers he knows that headers are junk , have issues and really do nothing for performance.

GO BUY A ZZ4 .. Bolt on your ram horns and smile , mission accomplished.

 

[QUOTE=iwasmenowhesgone;1585793047]Are you going to have to modify the exhaust... That kit is for a big block and not sure the manifold outlets are in same spot as the small block

 

Look dude, you are starting to get irritating .

As for the chaos you are talking about, its called a FORUM! If you don't like it, don't read it. The Tech and Performance section is for the purpose of discussing this type of thing.

While you may think a stock ZZ4 is the engine I want, it isn't. I was quite aware of the existence of the engine, as well as the numerous reviews of how weak the engine is, and how little it takes to make it better with a better set of heads and cam, not to mention the things I already told you about like centerbolt covers. That's why I didn't buy it. A ZZ4 shortblock is a good base for a better engine build, and that was my conscious well researched choice.

While headers obviously produce a stronger engine, its a question of what sacrifices I want to make for that increase. After listening to some of the smarter people on this thread, I am considering it now, and I thank them for the honest and respectful advice. I will spend the money to buy the headers that will work properly, and only hope I don't have the problems that others have had with headers.

Lastly, I am an amateur engine assembler. But after 30 years in aircraft maintenance, including many years of reciprocating engine maintenance, multiple engine builds on Harleys, and just being smart, I think doing what I have done on my engine takes a little more talent than just buying a ZZ4 long block. And you are calling me Joe Engine Builder!

 

You're doing fine; any post that starts with "what do you think" is going to generate some...spirited...discussion Take from the discussion what you want, ignore what you don't. In the end, it's all your decision

Hey...will you rebuild my Continental E-185 for me? ;-)

 

[QUOTE=Tjf2000;1585800068]Sorry, I went to the Magnaflow site, punched in the search criteria, and that was what came out. I believe they do make a setup that will work, and maybe best thing to do is call them. There are plenty of C3 Corvettes running this system.

 

Thanks Billa! Do you have an old Bonanza or Navion?

With your advice, and further thought, I am going to go with the 65cc AFR 180 Eliminators and probably Hedman Elite Headers. I was thinking about Hookers, but I am trying to stick with made in USA parts, as much as possible. It sucks the ZZ4 shortblock was made in Mexico, but at least it was GM.

I really did not think headers would add the torque levels that you suggested, and torque is what matters to me. I will never race this car, but I love torque.....that's why I ride Harleys insteads of rice rockets. And good low and mid range torque is what I want in the Vette.

 

I have one of the 246 military Navions - a 1948 Ryan L-17B. Served with the USAF, U.S. Army and the CAP. It has an E-225 conversion on it, but I'm trying to go back to original. I scored a complete E-185 in pieces for $600...which may be good, or bad

You just can't go wrong with AFR heads - there may be a lot of debate on the runner size, but I think you're making a great pick. I'd just add that since you're buying rockers, consider 1.6 ratio. I haven't looked at the cam, but I'm sure 63Mako's guidance is good.

Most of the major header brands are decent - just get some feedback on fitting. They're a little bit of a PITA, but very well worth the money. I'd expect you'll be knocking on 425-450 HP at the flywheel.

The devil is in the details in this engine stuff, so measure twice, cut once

 

I have a ZZ4 short block with some AFR 180s with a lt4 hot cam with 1.6 rockers Hooker 1 5/8 headers your really going to like this engine

 

Your making good choices. with the 1.6 rockers if you haven't bought them yet. Call AFR, tell them your cam and rocker ratio and get your heads set up with the correct springs for your cam. They have 8-10 options where the others heads out their usually have 2. The right springs might be available through most vendors but if not AFR will fix you up.

 

Why did u limit yourself to a 350ci shortblock?? Could have went with a Dart SHP 400ci block with forged internals.Dart SHP block has some great features,that a stock block doesn't have...CNC Motorsports looks like a good builder for a stout shortblock...400ci would have loads of low end torque....Have those headers coated inside and out and you should have no heat issues...May keep the engine bay cooler than with stock ram horns....

 

Verify with both the header manufacturer and afr about plug fitment and plug angle. I believe headman elite have thicker flange and a better collector connection. I can't attest to their fitment as I run hookers.

 

Since you run Hookers, can you tell me what PN you used, and did you use these on a raised exhaust port head? I hear that is one of the items that make a difference. The AFR exhaust ports are only 0.100 inch higher than stock, so I can't imagine that being an issue. Also, did you use stock idler arm or Moog heavy duty. And how about the steering box, any issues there. Pictures would be awesome!

 

This is where we lose control, a Dart SHP block alone is more than half the price of the ZZ4 short block....and if I go there, why not build a 383 (which is actually I started with, long story, not here), or maybe a 427...or 454, why stop there,...go 502!

Really, as I have said all along, I will never race this car, on a track or on the street. When some punk in a Honda Civic pulls up beside me with his silly boom can exhaust and four cylinder, and starts the game, I intend to just smile and wave. It doesn't matter to me if he could beat my by a million miles, he is not sitting in a C3 Corvette. I win....he loses!

I wanted a healthy, well built reliable motor, built with as many Made in USA parts as I could. Not interested in buying a ZZ4, I wanted to make it my own, with great parts. I think I have done that.

 

Youre on the right track, what youre putting together will easily overpower the tires and live.
Sometimes the mildest combos are the funnest to drive, least maintenance also
.100 or more wont give you a fitment issue at all.

 

Most heads are weak on the ex side. We make up for that w/dual pattern cam.
The GM Hot Cam is about 10* extra on ex. I believe the QB heads are still a little weak on the ex side?

My question is: When upgrading to AFR heads, that already flow 80% on the ex side, wouldn't a single pattern cam be better?

I run 218-224 w/TFS heads. I'm thinking a 224-224 w/AFRs, would give me more across the curve. Am I wrong?

I'm sure someone here knows. lol

R

 

Depends on the rest of the exhaust system. You have only 6 degrees difference. Stock exhaust with stock heads might want 12-14 degrees difference. AFR with 1 3/4 primary long tubes, 2 1/2 mandrel bent, true dual exhaust with really good free flowing mufflers might like a single duration cam. That said a 4-6 degree split will not show a lot of difference. A lot of guys see a difference on the dyno with dyno headers and virtually non existant exhaust backpressure that will be negated with street exhaust. Having appropriate lift for your head capabilities and correct intake closing point to optimize DCR and cylinder pressures has much more impact. 1.6 rockers on the intake is another option to get closer. Your Trick Flow heads have about the same I/E ratio as AFR. Check here:
http://www.users.interport.net/s/r/s...ehdc.htm#Chevy

 

They are a little on the pricey side, but check out the 109Y headers from Stan's:

http://www.stans-headers.com/gm_headers.htm

They are a tri-Y header, good for low-end torque, I believe, and Stan's has a stellar reputation. Made in the USA, too. I've never used a set (yet!) so I can't speak from personal experience. Just throwing it out there as an option.

Scott

 

I'm not home to see my receipts so I believe this is it Part # 2456-1hkr 1 5/8" ceramic coated. I wish at this point I'd went with 1 3/4" instead but when I bought them they were for my l48. I use them now on my 400" with afr 195cc and if I recall there ports are .100'' raised. I warped or bent the flange as I use a double gasket which is why I made the comment about thicker flanges. Fit ment was good though I didn't have to change any thing on the steering to fit.