Anyone have a GM zz454? I have many questions - Nova Tech
Nova Tech  
Find Nova Parts at SS396.com     
GROUND UP & SS396.com         
Official Sponsor of Team Nova
   

Auto Insurance



Nova Tech For best results please choose from the forums below.

Novas.net is the premier Chevrolet Nova Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old Apr 2nd, 19, 04:41 AM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Anyone have a GM zz454? I have many questions

My first and foremost question is what replacement head bolts can we use for our headers to fit? I got some heavy duty headers with a nice thick flange and the lower head bolts are too tall and very wide for my headers to fit down into place. I hear replacement ARP bolts fix this issue, but I contacted ARP and they said its a myth and weren't very helpful and seemed like I was bugging him.



How did you guys fix this issue and what bolts will work?


What headers did you go with to fit your 68-72 Nova without it also hitting the steering box?


What oil pan did you go with to clear the steering linkage and cross member?


What frame and motor mounts did you use? I went with factory stock big block frame mounts and poly big block engine mounts with a thin shim spacer that the kit came with.
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old Apr 2nd, 19, 09:54 AM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 17,281
Big Dave has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

In a '70 Nova you use Camaro first gen headers since you have a rear steer Camaro sub frame under your body. The body bushings also have to be in good shape or you will have issues with clearance between the header collector and the floor boards. You need BBC frame stands of the correct dimensions as many aftermarket stands are made to the wrong dimensions (close only counts in hand grenades). You will need a BBC Radiator, a BBC transmission cross-member for a Muncie or a TH400 as both differ from the SBC cross-member. Your radiator needs a BBC fan shroud to reflect the frame stand offset and wider radiator, and a seven blade clutch driven fan blade for a long water pump (The ZZ454 comes with the short pump: if you keep the short pump you use 1968 BBC pulleys and brackets). You will have to cut out the radiator core support to allow air flow and redrill the radiator mounting holes if yours bolts to the radiator core support (as well as a wider top and bottom support if not bolted to the core but sitting in rubber mounts).

Finally you need a one piece rear main oil seal oil pan for a BBC in car body! They are sold by Moroso, Milidon, Hams and others. Your motor shipped with a light truck oil pan and oil pump pick up which has to be replaced; as it won't fit a car body.

Heater Core (and the external heater core cover) has to change as well as the Power Steering pump reservoir as the heads get in the way of the SBC parts, PS pump brackets differ from the SBC and they are different from short water pump pump to the long pump.

As to you headers the flange will have to be ground for clearance as the bolts are all the same in head cap size no matter if made by Rockwell or ARP. Studs just make the problem worse.

Big Dave
Reply With Quote
  #3  
Old Apr 2nd, 19, 05:59 PM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by Big Dave View Post
In a '70 Nova you use Camaro first gen headers since you have a rear steer Camaro sub frame under your body. The body bushings also have to be in good shape or you will have issues with clearance between the header collector and the floor boards. You need BBC frame stands of the correct dimensions as many aftermarket stands are made to the wrong dimensions (close only counts in hand grenades). You will need a BBC Radiator, a BBC transmission cross-member for a Muncie or a TH400 as both differ from the SBC cross-member. Your radiator needs a BBC fan shroud to reflect the frame stand offset and wider radiator, and a seven blade clutch driven fan blade for a long water pump (The ZZ454 comes with the short pump: if you keep the short pump you use 1968 BBC pulleys and brackets). You will have to cut out the radiator core support to allow air flow and redrill the radiator mounting holes if yours bolts to the radiator core support (as well as a wider top and bottom support if not bolted to the core but sitting in rubber mounts).

Finally you need a one piece rear main oil seal oil pan for a BBC in car body! They are sold by Moroso, Milidon, Hams and others. Your motor shipped with a light truck oil pan and oil pump pick up which has to be replaced; as it won't fit a car body.

Heater Core (and the external heater core cover) has to change as well as the Power Steering pump reservoir as the heads get in the way of the SBC parts, PS pump brackets differ from the SBC and they are different from short water pump pump to the long pump.

As to you headers the flange will have to be ground for clearance as the bolts are all the same in head cap size no matter if made by Rockwell or ARP. Studs just make the problem worse.

Big Dave

Thank you, that is a lot of good information. A lot of what you said has already been resolved since I bought the car with a 454 already in it. I am simply dropping in a new zz454. I will respond to each thing you said below.



The body bushings are brand new, so we're good there.


I bought brand new OER Factory Big Block frame stands which are these ones. https://www.jegs.com/i/OER/691/K701/10002/-1


And these motor mounts. https://www.jegs.com/i/JEGS/555/61801/10002/-1


For the radiator I think I am going to go with a 2 Row with electric pull fan and not use my clutch engine fan.

Here is the oil pan that I am buying https://www.summitracing.com/parts/mor-20413

Here are the headers I bought. They have a pretty thick 3/8" flange. I am wondering if a thinner flange might solve the issue. https://www.jegs.com/i/JEGS/555/300101/10002/-1


I am potentially having many issues with the headers though. I have seen that ARP does have a smaller dimension bolt, but I need to measure what are currently on the zz454. ARP gave me several options once I finally got in touch with someone willing to help and I am hoping the smallest dimension bolt could potentially help. Here are the dimensions.


ARP Bolt HAP2.180-5:
Total length under head = 2.180"
Head & collar height = .400"
Head width = .5"
Washer height = .120"
Bolt & Washer total height = .52"


So these ARP Bolts will be sitting about half an inch out. I am wondering what the zz454 bolt specs are and if these just might help the header flange clearance.


Is there any way you can measure the height of your head bolt sticking out that are below the header flange?

Last edited by 70Nova454; Apr 2nd, 19 at 06:19 PM.
Reply With Quote
 
  #4  
Old Apr 2nd, 19, 06:43 PM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 17,281
Big Dave has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Those headers probably won't ever work. You can not grind on them, or ding them, because they are coated. Marring of the surface finish in any way makes them non-returnable if they do not fit (which I suspect they will not).

I would recommend something like this header:

https://www.hedman.com/product-detail/61618

Check the footnote page to see if your transmission is allowed (some headers are auto only) and if P/S is listed. Few, if any, headers allow A/C (because of the mounting brackets which is why not all allow you to have Power Steering).

If you have a BBC sitting in it now pull it and reuse what you can to get your ZZ motor to fit.

I use Stage Eight Header bolts to keep them from falling off later.

Big Dave
Reply With Quote
  #5  
Old Apr 2nd, 19, 09:04 PM
62 NovaWagon 62 NovaWagon is online now
Site Moderator
Art
 
Join Date: Jul 2009
Location: Big River, Ca
Posts: 7,082
62 NovaWagon has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Hedman headers for sure!.. Use ARP-135-3701 12 point head bolts and you should have minimum grinding on the header flange.
__________________
62 Nova wagon
75 Nova Custom
75 Nova Base
Reply With Quote
  #6  
Old Apr 2nd, 19, 11:15 PM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by Big Dave View Post
Those headers probably won't ever work. You can not grind on them, or ding them, because they are coated. Marring of the surface finish in any way makes them non-returnable if they do not fit (which I suspect they will not).

I would recommend something like this header:

https://www.hedman.com/product-detail/61618

Check the footnote page to see if your transmission is allowed (some headers are auto only) and if P/S is listed. Few, if any, headers allow A/C (because of the mounting brackets which is why not all allow you to have Power Steering).

If you have a BBC sitting in it now pull it and reuse what you can to get your ZZ motor to fit.

I use Stage Eight Header bolts to keep them from falling off later.

Big Dave

Thank you for suggesting those. I am now looking for mid length unfortunately. I did not plan on this and now will need to get my exhaust all redone. But, I would rather do it right. Those still have the same very thick 3/8" flange as the ones I currently have. I think I might still need a new head bolt that is shorter or thinner.



Does anyone have a still factory stock zz454 that can measure their head bolt for me?
Reply With Quote
  #7  
Old Apr 2nd, 19, 11:27 PM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by 62 NovaWagon View Post
Hedman headers for sure!.. Use ARP-135-3701 12 point head bolts and you should have minimum grinding on the header flange.

Thank you for recommending these. You wouldn't happen to have the specs and dimensions of the shorter bolts would ya?



I found these that I can buy individually. I believe they said these are their lowest profile smallest bolts. I don't have any way of measuring the stock zz454 bolts and if anyone had one, this would answer so much.




ARP Bolt HAP2.180-5:
Total length under head = 2.180"
Head & collar height = .400"
Head width = .5"
Washer height = .120"
Bolt & Washer total height = .52"
Reply With Quote
  #8  
Old Apr 3rd, 19, 12:00 AM
62 NovaWagon 62 NovaWagon is online now
Site Moderator
Art
 
Join Date: Jul 2009
Location: Big River, Ca
Posts: 7,082
62 NovaWagon has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by 70Nova454 View Post
Thank you for recommending these. You wouldn't happen to have the specs and dimensions of the shorter bolts would ya?
Not sure if I have any of those left, I'll have to take a look in the morning.
__________________
62 Nova wagon
75 Nova Custom
75 Nova Base
Reply With Quote
  #9  
Old Apr 3rd, 19, 12:13 AM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by 62 NovaWagon View Post
Not sure if I have any of those left, I'll have to take a look in the morning.

Okay thank you. I can't believe that how uncommon my setup is 70 Nova with a GM Performance zz454. Go figure. I am having to reinvent the wheel.


I found maybe 3 other guys with Novas and my setup on youtube and trying to get in touch with them.
Reply With Quote
  #10  
Old Apr 3rd, 19, 12:39 PM
Big Dave Big Dave is online now
Site Moderator
Dave
 
Join Date: Mar 2006
Location: Tampa FL
Posts: 17,281
Big Dave has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

I have built about 60 Novas with a BBC power plant. Never experienced an issue as you describe it.

The question I have is what exactly is interfering?

Here is a picture of a BBC head bolt kit for cast iron stock heads:

https://www.summitracing.com/ga/part...waAn-VEALw_wcB

You have four short bolts for the outer edge of the head. The other four long and eight medium length bolts secure the head under the valve cover. These bolts are longer than the stock bolt so that you can place a hardened washer beneath the head bolt, but they are not as long as the head bolts required for an aluminum head. The stock BBC head bolt measures (for the four long bolts) 5.375" length, for the eight medium bolts 3.850", and the four short outside bolts 2.00". These measurements are made from under the hex cap to the bottom of the bolt. The lengths get longer for aftermarket heads and the head manufacture will tell you how long a bolt to use (Chevy uses the Edelbrock RPM head for it's aluminum signature series sold with aluminum headed ZZ engines, so you can check their web site for recommended head bolts).

Aluminum heads use longer head bolts, not because the heads are cast out of aluminum, but because aftermarket heads (the usual source of aluminum heads) have a thicker deck than a stock head. That added material requires a longer head bolt. It also changes the length of the push rod (in case your problem was caused by someone replacing a set of aluminum heads he wanted to keep with some stock cast iron pea nut port heads when he sold you the car)

Gen IV blocks had the head bolts open to the coolant so you could run them down to the bottom of the threaded portion of the bolt if you wanted to. Gen V and GEN VI blocks and all aftermarket blocks have blind head bolt holes. There is a lug cast in the block that is drilled and tapped to accept the head bolt, but it isn't open to engine coolant. As such if you try and bottom out the threads you will hit the bottom of the casting. Any over tightening from that point of bottoming out will either rip out the threads or break off that cast lug under the bolt (good luck getting the head off after that happens).

Because I do not know if a head bolt has been over torqued in the past, or has been mixed up with a bolt off a stock cast iron head or one from an aftermarket aluminum head I always buy new fasteners whenever I put a motor together. I buy them in the length required to secure the head I am using. I also clean all threaded holes before I put a bolt or stud in the hole to verify the threads are in good shape.

As to header bolts there are two lengths of 3/8th inch 16 threads per inch bolt used to secure the flange to the head. The SBC uses a five eighth inch length and the BBC uses a three quarter inch length.

Big Dave
Reply With Quote
  #11  
Old Apr 3rd, 19, 02:52 PM
62 NovaWagon 62 NovaWagon is online now
Site Moderator
Art
 
Join Date: Jul 2009
Location: Big River, Ca
Posts: 7,082
62 NovaWagon has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

I'm thinking he's talking about the header flange hitting the head bolts preventing him from bolting up the header???
__________________
62 Nova wagon
75 Nova Custom
75 Nova Base
Reply With Quote
  #12  
Old Apr 3rd, 19, 02:54 PM
62 NovaWagon 62 NovaWagon is online now
Site Moderator
Art
 
Join Date: Jul 2009
Location: Big River, Ca
Posts: 7,082
62 NovaWagon has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Quote:
Originally Posted by 70Nova454 View Post
Okay thank you. I can't believe that how uncommon my setup is 70 Nova with a GM Performance zz454. Go figure. I am having to reinvent the wheel.


I found maybe 3 other guys with Novas and my setup on youtube and trying to get in touch with them.
Well, looked through my stuff and can't find any guess I used them all up, sorry bout that.
__________________
62 Nova wagon
75 Nova Custom
75 Nova Base
Reply With Quote
  #13  
Old Apr 3rd, 19, 04:46 PM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

Yes Big Dave and 62 NovaWagon, I am referring to what NovaWagon mentioned.



These Gen VI big blocks with aluminum heads have tall bolt hole areas and they also use a pretty thick tall bolt. The bolt head and collar are directly under the header hole in some areas which make it impossible to get the header in there since the flange hits the bolt preventing it from sitting flush or even being able to line up.



I have heard a few guys grind down the header flange in the bolt area which works just fine for them. I would prefer having a header flange and/or bolt that would work together.



That is why I am trying to find a guy who has a 68-72 Nova with this zz454 combo. What did he do? Which headers did he go with to not only fit the head and bolt, but also to fit in the engine bay and power steering box?


A few trucks guys have responded that have the zz454 and they found some headers that slip right between the head bolt and attach perfectly, but those headers won't fit my Nova.



I know this is possible and I am not going to give up and with your help and ideas we will get there much faster to a working resolution.
Reply With Quote
  #14  
Old Apr 3rd, 19, 04:48 PM
70Nova454 70Nova454 is offline
Tech Team
 
Join Date: Jul 2017
Location: CA
Posts: 43
70Nova454 has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

I am even starting to look at the mid length shorty headers with potentially a thinner flange. My current one is 3/8" thick. Super heavy duty and nice, but hits the darn head bolt under the exhaust port hole.
Reply With Quote
  #15  
Old Apr 3rd, 19, 08:52 PM
62 NovaWagon 62 NovaWagon is online now
Site Moderator
Art
 
Join Date: Jul 2009
Location: Big River, Ca
Posts: 7,082
62 NovaWagon has a positive reputation
Default Re: Anyone have a GM zz454? I have many questions

If you take your time you can grind the flange and make it look like it came that way, and save on the sanity, lol..
__________________
62 Nova wagon
75 Nova Custom
75 Nova Base
Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
which one of the many tuck bumper questions jerryt 1968-1974 0 Apr 23rd, 18 03:05 AM
CARiD Articles: you have questions, we have answer CARiD CARiD.com 0 May 3rd, 12 06:35 AM
66-67 ZI 327, how many did GM build? ziowner Engine 3 Apr 27th, 12 09:17 PM
New here with many questions rowdy51 New Member Introductions 5 Nov 14th, 11 09:19 AM
carb choice for zz454? nicks70nova Engine 5 May 13th, 10 07:33 PM


All times are GMT -4. The time now is 10:04 PM.


2009 AutoForums
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.