Calling all ZZ4 Converts! Advice needed.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Here' my tech tip I wrote a few years ago.
https://www.corvetteforum.com/techti...=167&TopicID=3
I pull my engine and transmission as one. I recommend an engine leveler and remove your hood. As added insurance I put a piece of plywood on my radiator "just in case". I can tell you that my ZZ4 is not a DOG and I know that it is not losing approximately 30% of it's power as suggested above.
It is probably putting down around 290 to 300 to the road.
https://www.corvetteforum.com/techti...=167&TopicID=3
I pull my engine and transmission as one. I recommend an engine leveler and remove your hood. As added insurance I put a piece of plywood on my radiator "just in case". I can tell you that my ZZ4 is not a DOG and I know that it is not losing approximately 30% of it's power as suggested above.
It is probably putting down around 290 to 300 to the road.
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
When I swapped out the engine in my '69 convert., I left the 4-speed Muncie in the car, and supported it with a floor jack. I did the entire job by myself in my home garage with a rented cherry picker. With just the engine to be concerned about, it was easy as it came straight up and out. I was somewhat concerned about lining up the trans input shaft to the clutch, but when I got to that part, it went smoothly. I made sure the engine and the trans were level and aligned. After jiggling the engine and rocking the car back and forth a bit with the trans in 4th gear, it went right home. Here's a photo of it coming out. http://www.myruffhouse.com/Out%20with%20the%20old.JPG
This is how it goes best for me too..especially with a Muncie..its light and 1 guy can muscle the trans snout right into the Pilot bushing ..usually without much problem.Heres a Pic..
Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
It's an easy swap ...... your making it sound A LOT harder than it is
You don't even have to worry about hood alignment when your done
I've lost a few lbs since then..... I did my motor swap not long after breaking BOTH arms!!!
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
From GM
Also included with the ZZ4 is an HEI distributor with an ignition timing advance curve developed for performance, a dual plane aluminum intake manifold that accepts your spread bore or square bore carburetor, an 8" high-RPM torsional damper, 12.75" auto trans flex plate and cast iron water pump.
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
I already had a Centerforce 2 pressure plate, disk , and Flywheel(for early 2 piece seal engine) on my old engine..the only thing I couldnt use with the new engine was the Flywheel I switched to Centerforce external balanced steel Flywheel for GMPP late zz engines. Got it at summit..it was expensive. Search summit for Late bolt pattern(1piece seal) Flywheels . But I can tell you not all Fit, Like the Hays..doesnt fit..its not for ZZ engines. The Centerforce advertises as "for ZZ engines". Got to be careful , I had to send the Hays Back.
Melting Slicks
Joined: Jan 2004
Posts: 2,527
Likes: 1
From: St. Petersburg, Fl///Columbus, Ohio
I missed that..... I thought you hd an automatic
i bought a lightweight flyweel for a 99 silverado for under $100.00
You will need to drill a hole & tap it for the "Z" bar ball ..... it took me less than 1/2 hour to complete with the right drill bits & tap
i bought a lightweight flyweel for a 99 silverado for under $100.00
You will need to drill a hole & tap it for the "Z" bar ball ..... it took me less than 1/2 hour to complete with the right drill bits & tap
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Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I've installed a couple of ZZ4s, not in Corvettes. It's a good engine, and a solid performer for a reasonable price. It's not a screamer; the heads aren't all that great - they run out of flow about .450 in stock form and the cam...although the specs seem crazy for those of used to hydraulic flat lifters...is pretty mild. Using the published specs, you should expect about 280HP or so (if you have headers) at the road and a really nice, flat torque curve.
Another option to consider if you don't mind doing some assembly work is to buy the shortblock and put on some better heads (read: AFR
) and a bigger cam. I expect you'd come in around $5,500 or so.
If you're going crate shopping, I just suggest that you shop around a bit.
Another option to consider if you don't mind doing some assembly work is to buy the shortblock and put on some better heads (read: AFR
) and a bigger cam. I expect you'd come in around $5,500 or so. If you're going crate shopping, I just suggest that you shop around a bit.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Thanks Tom
What is the the 6a - 6al Ignition and why do I need one?
I really didnt want to blow $350 on a dist.
I already have 2 tach drive units and a few HEI units but not for a manual tach.
Also, are you saying if the transmission is left in the car its easiest to leave the bell housing with the trans?
-EDIT- Ok, I see, the 6a goes with the MSD (more money)What I really need to know is if I can use my original dist and simply replace the gear.
Thanks again
What is the the 6a - 6al Ignition and why do I need one?
I really didnt want to blow $350 on a dist.
I already have 2 tach drive units and a few HEI units but not for a manual tach.
Also, are you saying if the transmission is left in the car its easiest to leave the bell housing with the trans?
-EDIT- Ok, I see, the 6a goes with the MSD (more money)What I really need to know is if I can use my original dist and simply replace the gear.
Thanks again
a new dist gear on your current dist. is all you will need at the most.
no reason to buy another Dist, unless yours is in bad shape.
new dist. gear is cheap. You can run a CDI box (6AL) on a
points distributor. 6A is the cheaper CDI, 6AL is the same thing
but with a rev limiter.
Last edited by Little Mouse; Aug 25, 2007 at 12:22 AM.
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
If your buying the long block,
a new dist gear on your current dist. is all you will need at the most.
no reason to buy another Dist, unless yours is in bad shape.
new dist. gear is cheap. You can run a CDI box (6AL) on a
points distributor. 6A is the cheaper CDI, 6AL is the same thing
but with a rev limiter.
a new dist gear on your current dist. is all you will need at the most.
no reason to buy another Dist, unless yours is in bad shape.
new dist. gear is cheap. You can run a CDI box (6AL) on a
points distributor. 6A is the cheaper CDI, 6AL is the same thing
but with a rev limiter.
I did buy the long block
Just had Lars bring an old spare tach drive back from the dead for me last winter.
The ZZ takes a melonized distributor gear and I ordered one yesterday
Team Owner
Joined: Jun 2001
Posts: 23,375
Likes: 1,067
From: Virginia USA
Here' my tech tip I wrote a few years ago.
https://www.corvetteforum.com/techti...=167&TopicID=3
I pull my engine and transmission as one. I recommend an engine leveler and remove your hood. As added insurance I put a piece of plywood on my radiator "just in case". I can tell you that my ZZ4 is not a DOG and I know that it is not losing approximately 30% of it's power as suggested above. It is probably putting down around 290 to 300 to the road.
https://www.corvetteforum.com/techti...=167&TopicID=3
I pull my engine and transmission as one. I recommend an engine leveler and remove your hood. As added insurance I put a piece of plywood on my radiator "just in case". I can tell you that my ZZ4 is not a DOG and I know that it is not losing approximately 30% of it's power as suggested above.
It is probably putting down around 290 to 300 to the road.Normal parasitic power loss is between 15 and 20%. Let’s do some math so pay attention:
ZZ4 is rated at 355hp at the crank
355 x.20 = 284hp at the wheels
now what you're saying
355 x .35 = 230hp at the wheels
I put my loss at 15% since I am not running PB, PS, A/C, smog pump. I have headers + 2 1/2 inch exhaust.
Think what you want and I'll do the same.......I'm out
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Can't we all just get along?
Consider is that the 355 flywheel HP is on the engine dyno with dyno headers and typically open exhaust...or at least, no tailpipes. It's also an optimal dyno tune. If you're using stock manifolds, a full exahust and haven't had a dyno tune then I'd agree with around 240HP at the wheels max.
The easy solution is to drop $250 on a dyno tune - you'll get a better performing engine and a slip to show what you've got.
Consider is that the 355 flywheel HP is on the engine dyno with dyno headers and typically open exhaust...or at least, no tailpipes. It's also an optimal dyno tune. If you're using stock manifolds, a full exahust and haven't had a dyno tune then I'd agree with around 240HP at the wheels max.
The easy solution is to drop $250 on a dyno tune - you'll get a better performing engine and a slip to show what you've got.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
And therein lies the fallacy.
It's a simple matter to do a search of this forum and if you are thourough, and people haven't pulled them, you will find a wealth of dyno slips for ZZ3s and ZZ4s on this and the C1-2 forum. Just try to find one that shows more than 250 hp. Most show between about 225-240. Many ZZ3s are down around 205-225.
It's a simple matter to do a search of this forum and if you are thourough, and people haven't pulled them, you will find a wealth of dyno slips for ZZ3s and ZZ4s on this and the C1-2 forum. Just try to find one that shows more than 250 hp. Most show between about 225-240. Many ZZ3s are down around 205-225.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
It's a simple matter to do a search of this forum and if you are thourough, and people haven't pulled them, you will find a wealth of dyno slips for ZZ3s and ZZ4s on this and the C1-2 forum. Just try to find one that shows more than 250 hp. Most show between about 225-240. Many ZZ3s are down around 205-225.
I wonder if you're confusing engine dyno and chassis dyno results. Here's one engine dyno example:
http://www.chevyhiperformance.com/te...ild/index.html
Last edited by billla; Aug 25, 2007 at 02:09 PM.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
I'll respectfully disagree;
I wonder if you're confusing engine dyno and chassis dyno results. Here's one engine dyno example:
http://www.chevyhiperformance.com/te...ild/index.html
I wonder if you're confusing engine dyno and chassis dyno results. Here's one engine dyno example:
http://www.chevyhiperformance.com/te...ild/index.html
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Then I don't understand your comment that ZZ4's putting out 350 HP or so at the crank is a "fallacy". It is a dyno rating - as with most crate engines. No crate will make full rated HP in the chassis with a streetable exhaust, and you're not going to get close unless you invest (as previously noted) in a free-flow exhaust and it's properly tuned. ZZ4's aren't any worse in this regard than any other crate engine
If someone's making only 205HP from a ZZ3 then they've made some choices that have limited the ability to make power...and that has nothing to do with the engine itself.
And you've weighed in on this before - do you think your engine would dyno to "only" 365HP?
http://forums.corvetteforum.com/show...ht=ZZ4%2C+dyno
http://forums.corvetteforum.com/show...ht=ZZ4%2C+dyno
If someone's making only 205HP from a ZZ3 then they've made some choices that have limited the ability to make power...and that has nothing to do with the engine itself.
And you've weighed in on this before - do you think your engine would dyno to "only" 365HP?
http://forums.corvetteforum.com/show...ht=ZZ4%2C+dyno
http://forums.corvetteforum.com/show...ht=ZZ4%2C+dyno
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Start your own topics about your C3 engines..if you even Have one..which I doubt.FWIW, I've built over 150 engines...
Last edited by billla; Aug 26, 2007 at 01:21 PM.
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Racer
Joined: Jan 2006
Posts: 395
Likes: 0
From: Orange massachusettes
I wish I had a scanner, so I could post dyno sheet, but I do not. I had my '72 vette on a Mustang chassis dyno on August 2nd . I run a ZZ4 w/ BG 650 mech.sec. carb, full length Flow- Tech ceramic coated headers and 2 1/2 inch Alens chambered 2 exhaust. I run a HEI tach drive dist. and have a M20 Muncie 4spd. PEAK HP is 258.7 at 5125 rpm and PEAK TORQUE is 301.2 at 3810 rpm. BOTH measured at the rear wheels. As you can see, this engine runs out of steam pretty early. Its not a HIGH rpm engine. What you cant see, is the nice flat torque curve from about 1800 rpm all the way to 4750 rpm. Always close to 300 ftlbs of torque to the GROUND. Not a super hi-po engine, but NOT a dog either. Hope this helps clear things up.