I look for a new engine for my 1970 TTOP 4 speed.
Does a ZZ4 turn key (19201330) fit a the car with no body modification and with the standard hood ?
Thank you
Stephane

 

Yes, Its a Very popular engine for your Car

 

I dropped one in a '79. No hood clearance issues.

I think you may have some issues with serpentine belt system if you keep your stock fan shroud. With my '79 I went with an aluminum radiator and dual electric fans, so the fan shroud was deleted, and no longer an issue for me. Hopefully someone with experience with a '70 will chime in if this will be an issue.

The only clearance issue I had was with a pulley on the serpentine belt system that would not clear the control arm shaft on the upper control arm on the passenger's side, so you may run into that problem. I had a new bracket machined to relocate the pulley about two inches from the control arm shaft, and everything fits fine. Others have solved this problem by turning the stock bracket upside down, and grinding down the bracket that holds the compressor. Others have deleted the pulley. Either way, it is not a tough problem to work around.

 

I put a ZZ4 in my 70 (was a L46) with the supplied intake. Got a Holley Street Avenger 670 carb and it would not clear the hood. I had a L88 hood scoop put on by Body Shop with a 3" air cleaner and clears by a good inch or two. I put it in myself and there were no other clearance issues.

 

I think it comes with a long neck water pump. I bought mine with the ZZ4 already in it and one aweful looking short neck pump. I have always assumed it came off the engine that was removed since the ZZ4 came with the long pump. This is what it looked like when i got it:


I don't have a pic handy of what it looks like now, but among many others it's got a new endurashine pump and new pulleys, and I got rid of the red heater hoses to clean it up also and I'm running dual electric fans.

 

Here is a picture of a ZZ4 in a 1980. Prior to installing the fuel injection, I used the stock Q-Jet carb and the intake that came with the ZZ4. No hood clearance issues. I did need to swap out the long nose water pump, and the flywheel for a manual tranny.




BTW... the serpentine belt system is not included in the ZZ4 long block.

 

Summit racing tells me to use a Performer manifold (http://www.summitracing.com/parts/EDL-2101/) and a small air cleaner (flat) in order to reduce the total height of the engine.
With that, they think it could be ok with the standerd hood.
Do you agree ?!
Thanks !

 

Summit will not swap the manifold so you will end up with an extra one. Also, Summit ZZ4 , and I assume any ZZ4, comes with an HEI electric tach connection and your 70 has a mechanical one. Summit would not swap it so I ended up buying a mechanical HEI and am stuck with the electric one. Above post is correct in that the ZZ4 long water pump must be replaced with a short one.

 

I put a zz4 in in a 1971 used a 770 holley hood would not close.
You need to try the stock fan with the fan shroud with the water pump that comes with the zz4 it work on the 71.
Also read the warranty very closely if you install the engine yourself you only get parts.

 

FKING1, Summit told me the same think after verification :
----------------------------------------------------------------------
More complications,
The pulley assembly with the Air Conditioning compressor will probably not work due to the width of it. The compressor will hit the hood, besides that the water pump is the LONG style ands rotates in the opposite direction. Your original engine has a SHORT water pump and the clearance with the radiator is also critical. Next problem, the distributor that comes with this engine is the HEI electronic, it is larger in diameter will not clear your firewall. It's not a tach drive model so your tach will not work. These new engines use a one piece rear main seal and the crankshaft flange is different. You will have to buy a new flywheel. I got all this information from an associate that has a strong Corvette background.
Now, depending on the condition of your existing parts you might have to consider the long block below and bolt on all your old components.
http://www.summitracing.com/parts/NAL-12499529/ This long block is the older one-piece rear main seal, like your original.
-----------------------------------------------------

I'm a little bit disappointed...
I don't know what to do !
My car have an old engine wich is not standard, so I don't want to re use part from the actual engine.

 

The long block from Summit is 290HP where the ZZ4 is 355.
Considering all of the above and having to buy a short WP, HEI mech tach and L88 hood scoop I am very happy with the result. With the Holly 670 the car runs like a bomb and Autocrosses better than my driving ability. Also, put on a new flywheel and Summit racing clutch.
One more tidbit, if getting a ZZ4 make sure to take off the flexplate that comes on the motor if you have a manual tranny.
Summit's price was $1000 less than the local Chevy Dealer.

 

FWIW, the ZZ4 is available both as a base engine, a fully dressed longblock with no intake under P/N 24502609 and a "partial" engine which is just the shortblock under P/N 12561723. There are better head choices out there, but the 58cc chamber volume is a bit of a challenge.

I don't know why Summit would suggest a 350/290 long block as a replacement for a ZZ4 when a flywheel swap is relatively simple and cheap.

 

billa,
Could you please elaborate a little more on this statement?
Thanks.

 

Sometime this year, I think it was one of the last several months, Hot Rod magazine had an article on how to get more HP out of the stock ZZ4 engine. They changed the cam for one thing, this was an obvious change since the ZZ4 can be bought with a Hot Cam upgrade from GM. This increased HP from the base 355 to 395 HP. Hot Rod then bought new heads for the ZZ4 and that also brought up the HP noticeably. Unfortunately I don't remember the brand name of the heads. If you can search through some of the latest Hot Rod magazines - maybe their website or maybe a reader will have a copy of the magazine. I'll look but I think mine is gone.

 

[QUOTE=Squeed;1571341381]I look for a new engine for my 1970 TTOP 4 speed.
Does a ZZ4 turn key (19201330) fit a the car with no body modification and with the standard hood ?
Thank you
Stephane[/QUOTE

The ZZ4 will fit in your 70 and you can use the stock hood. I don't think you can use the complete stock air cleaner. I used the top part of the stock air clearer (the upper plate or upper pan), but had to use a drop base lower pan (lower plate) from Morosco. This cost $30. Since the top of the air cleaner is stock, almost no one can tell it's not a stock air cleaner.

As stated in an above post, the ZZ4 comes with a long neck water pump. You can remove the long neck, and replace it with the short neck that came with your stock engine. Then I think all the stock accessory braces and brackets will fit the ZZ4. Using these part, the "nose" of the ZZ4 will look stock.

If you want to use the ZZ4 Serpentine kit, you keep the long neck, but I think now you should think about an aluminum radiator and fans. This represents $$$$. Check out DeWitts for a good aluminum radiator. Costly, but the aluminum radiator gives a lot of cooling.


The Serpentine Kit will fit your 70. The Serpentine idler pully bracket has to be installed upside down to clear the passenger's side upper control arm bracket. To install the idler bracket upside down you have to grind a little of the aluminum off. A simple hand tool will work. An electric drill and a sandpaper attachment will work. I used a air powered die grinder.

For a manual transmission you need to replace the flexplate with a flywheel. Get a General Motors Performance Parts catalog. The flywheel to get is an external ballanced one that is designed for a one piece crank seal.

I really like my Hot Cam ZZ4. I have the Serpentine Kit, aluminum radiator and electric fan, a mechanical drive HEI distributor, a mini-starter, and electrical fuel pump.

You can get a lot of assistance on the forum. There's a lot of people that have installed the ZZ4 and the almost identical ZZ383.

 

The ZZ4 uses the "Fast Burn" cylinder heads P/N 12556463. This head has a 163cc intake runner and 1.94/.15 valves with a 58cc combustion chamber. They also have exhaust ports that are raised .100. It's essentially an L98 head from the C4 'Vette with better springs.

This was kind of the "bridge" head between the muscle car heads of the 60's and the more modern Vortec designs. For it's time and price, it was a decent factory head at a decent price - and as a replacement head the small chamber gave a compression bump - about .6 point for a 64cc head (60's) and about 1.8 points for a 76cc head (70s, 80's.). This was a sweet deal as you could "top" a pathetic 8:1 engine and get 9.8...and open up your cam choices a bunch.

Today the flow numbers are kinda pathetic in comparison:
.100: 62/53
.200: 115/101
.300: 159/134
.400: 189/157
.500: 190/171

..and we see that the flow really tops out at around .400...so that the camshaft P/N 10185071 with .474/.510 lift isn't a great match for the head.

The ZZ4 shortblock with a decent set of aftermarket heads with around 180cc intake runners, or if you're on a budget even a set of Vortecs (with better springs) would be a better match. Better heads need a bit better cam, and you've got a stronger engine in every respect. You do lose .6 CR, dropping to 9.4CR, but this is a small price for a significant gain. That .6 can be reclaimed to some extent with a thinner head gasket.

I can give a bit more background, but that's the gist

 

Not sure if this is helpful to you or not but it is full documentary of the ZZ4 in my '77.

ZZ4 Install

 

Billa,

Thanks for the info!

 

This is all very interesting. I've been unsatisfied with the ZZ4 I have for some time. First, it's running way too hot (210F) so I'm putting in the DeWitts with dual Spals as we speak. I should get some gain there with a new 180F t-stat I would think.

68/70, Are you saying that with a simple cam change I can get to 395hp? What does that do to the tq number? Can you advise what the cam is?

Thanks,
Dan

 

I believe this article is the one referenced. My read is that the article finds the heads as the real limiting factor - as previously noted.

http://www.hotrod.com/techarticles/e...ons/index.html

Look at the flow numbers for the TFS heads; the whole story is right there...

http://static.trickflow.com/global/i...23_ss_62cc.pdf