mg62

OK, here are a few questions/issues I've got about my new ZZ4, after spending some time rummaging through the CF archives.

Headers

I've seen conflicting opinions about whether headers are a good idea, a necessity, or more trouble than they're worth (leaks, excessive heat in the engine compartment, melting wires, etc.).

If I get headers, I'm going to get a good name brand, ceramic coated. (Hooker Super Comp or Dynomax seem to get good reviews? What about Flowtech?) I also understand that I need to get proper gaskets.

Anything else I need to know about headers? I think I want to get them, but I don't want to buy hassles.

Water pump

The ZZ4 comes with a water pump, but I've read some posts here in the Forum to the effect that I have to remove that shiny new water pump and replace it with something else. Why is that necessary?

Fuel pump

How can I tell whether I need a new fuel pump?

Radiator

How can I tell whether I need a new radiator?

Distributor

The ZZ4 comes with an HEI distributor. I understand that my mechanical tach won't work with that distributor. Fortunately, I have a freshly rebuilt distributor on my current engine. Am I correct that it's a pretty simple matter to switch these two distributors?

Side story: When I was talking to a parts shop yesterday about carbs and headers, I mentioned this distributor issue, and the guy at the parts store said he'd help me out by taking it off my hands for $100 (cdn). I called the GM dealer where I'm buying the ZZ4, and I'm told that it's a $729 part! I think I'll hold onto it for awhile .... Anyone want to buy a shiny new Goodwrench HEI distributor?

Carb

I ran another thread on the carb subject when I was still shopping for the ZZ4, and got some good input. I think I'm going to go with the Holley Street Avenger 670 cfm.

More questions to follow, I suspect ....

Under the current plan, the engine will be installed into my '74 by the end of next week, depending upon when I can get the car out to the mechanic.

Any thoughts on the above points would be appreciated.

Mack

I like my Hookers O.K.


The original water pump's too long to fit. You'll have to get a short nose pump.

I bought the one that GM recommends.

If it doesn't leak, it oughta be O.K.

I can't comment... Didn't have this problem.

I used a Quadrajet...



[Modified by Mack76, 1:15 PM 5/16/2002]

MotorHead

You should get headers for that setup and 2.5 in. pipes right to the back. Can't comment on the water pump but fuel pump should be OK along with the rad.

Might be interested in the distributor tho. :D

Sigforty

I am getting my motor today. I plan on dropping it in the 71 with in the next two weeks as parts arrive. You need to replace the water pump with the short style. I chose a stewart stage 2 aluminum pump. I plan on reusing my dynomax headers with the zz4. The distributor is another story in order to run an original distributor you will have to change the gear on the bottom to a melonized gear. If not you will shred a gear and mess up the motor. This has to do with the steel roller cams. I personally am going to run the HEI and do without a tach until I can afford the MSD setup. I plan on reusing my fuel pump and radiator there should be no problem with these. I also plan on reusing my road demon carb on this engine. If you have an questions message me I will be glad to help. I also addressed some of the issues in old post if you search for zz4 you should find them.

Mark B.

kgraumann

I had to use the short neck water pump on mine, so my belts and pulleys would line up.

mg62

Thanks. I took a quick look in Google, and I found this link, which seems to suggest that the melonized gear is already part and parcel of the HEI that comes with the ZZ4. Can't I just use that gear?

http://flatlanderracing.com/distgmbb.html

robzr

Headers - you have a few choices here, the $209 1 5/8" Dynomax Jet Hot coated from Jegs, $320 ceramic coated Hooker Comp 1 5/8" headers, or some 1 3/4" headers which will run you about $275 for Hooker Super Comps and another $275 for Jet Hot coating if you desire to do that. Obviously the best deal is the Dynomax 1 5/8". 1 5/8" will give you a bit more torque and gas mileage due to the fact that they will be more efficient at low RPMs, while the 1 3/4" will give you a little more high end and would probably ET your car slightly faster.

Like the folks are saying unless you want to change all your pulleys, you need a short water pump, and a Corvette style one (3/4" shaft) if you want to keep your stock pump pulley. I just so happen to be selling a used Stewart Stage 1 corvette pump if you are interested, other wise you probably want to buy a performance pump for that motor from Stewart or Summit or Jegs.

If your fuel pump is in good condition it is probably fine for 350 horses, if you want some insurance or run into lean problems, then you can upgrade down the road, you could, for example, buy the new Holley Zinc 110 gph pump I'm selling for the mere price of $35, it costs $55 new in Summit and would be a great match for your motor ;)

Radiator you will be just fine with your stock radiator unless it's in bad condition. I ran my 450 hp 388 with a stock '76 L48 radiator, the Stewart pump, a Shaw 180 stat and a mechanical clutch fan (stock replacement clutch, stock fan. Also for sale). Temperature was not an issue, I don't think it ever saw over 200 and I ran it in Chicago traffic on some hot days!

As for the distributor you can reuse your old one or buy a new tach, or buy something like the MSD mechanical tach drive distributor. You can also rebuild your old one (if it even needs it), and upgrade it for better idle, performance, and gas mileage (it's points, right?).

Carb I think you should consider a Road Demon 625! It's a well known fact that Demon under rates their carbs, they are probably at least 650 cfm. You cannot beat that carb for $299 it comes with an electric choke, four corner idle, and top notch quality (and looks).

As far as the gear I would be suprised if you need that, that is for steel cam shafts, but a call to GM would answer that question for sure. If you do then you can buy just the gear and put it on your distrib, or swap it with the new distrib you have. And you can sell that new one for a bit more than $100 cdn on eBay.

Rob




[Modified by robzr, 2:52 PM 5/16/2002]

mg62

Robzr, thanks for the detailed and very helpful reply.

Did some calling around on headers, and the two main performance parts guys (Performance Improvements and Karbelt) don't sell Dynomax and can't get Hooker or Hedman brought up here in less than 3 weeks. So, not sure what I'm going to do about that.

Given that the ZZ4 water pump apparently won't fit in the Vette, will my mechanic be able to tell by looking at my pre-existing water pump whether it should be replaced? Any way I can figure that out ahead of time?

Thanks for the offers of the various parts, but I'm prob'ly going to go with new stuff for the parts I need to replace.

On the distributor issue, a little more digging turned up this thread, in which SteveG75 also confirms that I can use the gear from the new distributor that comes with the ZZ4 in my existing distributor:

http://forums.corvetteforum.com/zero...514538#2514538

theandies

ZZ4 Heads have "D" shaped exhaust ports. For best flow, make sure you get "D" shaped headers primaries. Jim Pace http://www.paceparts.com has a set of Headman Headers made for the ZZ4 heads. You can get the coated if you want. That is what I installed and I have no clearance problems what so ever. DO NOT INSTALL YOU OLD DISTRIBUTOR WITHOUT REPLACING THE GEAR WITH A MELONIZED GEAR !!!!!! The ZZ4 comes with a steel roller camshaft and it will chew up your old distributor gear and wreck your brand new engine with metal shavings. The HEI unit that comes with the engine will have the proper gear on it and it can be swapped to you old distributor if you go the route. MSD's tach drive has a melonized gear on it already, it is plug and play. Your radiator should work just fine. Have it flushed just to be on the safe side. I used the stock fuel pump with my old q-jet and have not had any problems. Water pump. You need to get a shortie style. I went with an Edelbrock aluminum water pump. One of the bolts that hold the timing chain cover will have to be ground down a little for the short style pump to fit but its no big deal.
John

mg62

theandies, thanks for that. I am well warned on the melonized gear issue. I will make sure that the gear inside the HEI, which I've already paid for, gets used in the install.

Are there any headers I can safely get that aren't D-port headers? As mentioned above, I can't get any of the D-ports here for a number of weeks, and I'll be damned if I'm going to wait that long.

How can I tell if my existing water pump is suitable, or if I should replace the ZZ4 "long" pump with a brand new "short" pump?

theandies

The water pump off your old engine will work just fine. Just make sure you test fit it and grind down the timing chain cover bolt so you won't have a leak when you install it. Call Jim Pace, I think it only took 3 or 4 days for my headders to arrive.
John

P.S. Your gonna love this engine!! :yesnod: :D :yesnod: :D

Chris Butchart

1. Distributor- Everybody is correct, must use the special gear
2. Water pump- Don't use your old water pump-You have invested a lot of money in an engine and you are going to trust it to an ancient water pump. Buy a high performance water pump. I used edlebrocks. While you are at it buy an aluminum radiator from Be-Cool. Do you want all that junk from an old radiator flowing through your new ZZ4?
3. Headers-I got Dynomax in 3 days from Jegs. And yes-they fit the ports and no clearance or leak issues
4. Fuel Pump-Use a high performance pump
5. Carb-I used edelbrock performer 600cfm $209-Easy to adjust, runs great, much cheaper. Anything over 650cfm is a overhill on a 350 engine
6. ALSO MOST IMPORTANT-DO NOT HAVE TO GRIND YOUR BOLTS-JUST BUY A CHROME TIMING CHAIN COVER FROM GM AND THERE WILL BE NO CLEARANCE ISSUES :D


[Modified by Chris Butchart, 12:01 AM 5/17/2002]

gdh

Mark go to Cdn Tire - you can order the Hedman's from their performance division, about $210 cdn.

mg62

Thanks for the recommendations guys. I'll look into those things.

buds

Hi mark, good choice on the motor. A friend of mine put the ZZ4 in his '88 pick-up last year and loves this motor.

If it were me, I'd stick with the HEI ignition and find yourself a '75-? tach from a vette, as I've heard this is a simple conversion (anyone know for sure?)

There's a guy in Kitchener who parts out vettes, I'm sure he has one. I'll get you his number if your interested.

Please let me know the next time you guys are getting together for a cruise. :cheers:

mike

mg62

Thanks Mike. I'd be interested to know if anyone has any info on converting the tach.

(Mike, I'll let you know. Keep your eye on this page, though, because the rallying cry for a Toronto cruise is usually posted here first.)

Sigforty

You will also need to relocate the temp sender from the head to the intake manifold. I found the info out from John (theandies) earlier this week and put the sender in today. It looks like it is a tight fit with the upper radiator hose, but the only way to do it. I was also wondering if anyone here had pictures of the HEI wire routing. Since my original motor was points style I am not sure how to route the new HEI wires.

Mark B.

theandies

It is a little tight, but on mine the connector dosen't touch the upper radiator hose. There is about an 1/8 in clearance.
John

mg62

Why is this necessary?

theandies

Because I could never find a small diameter sender unit that was calibrated to my gauge and I didn't feel like playing with resistors and stuff like that, so I just used my old sender in the intake. The sender unit port in the head is smaller on the ZZ4 is diameter than the one off the old cast iron heads. you know Chevy :crazy: though, yours may be different.
John