Author Topic: 1969 302 DZ Heads  (Read 8024 times)

Southerner

  • Newbie
  • *
  • Posts: 11
    • View Profile
1969 302 DZ Heads
« on: March 09, 2007, 05:28:00 AM »
Hi, this is my first post on this forum. I am restoring a 69 Camaro. The heads are 3927186 castings witha date code of J 11 8 and J 28 8. They are the big valve 2.02 and 1.6. Untouched and unported.What I want to know is, did the Z28 motors heads come with guideplates or without in stock form ? As these heads have no guideplates and the (I presume) press in studs.

The cylinder block that these heads came of is  casting 3932386 4 bolt block date code I 25 8 The build date of the 69 body is 12B.

So is it possible the early 69 camaro Z's came out with the non guideplate heads and the later model 69 Z's as the production progressed come out with the guideplate heads.

Gambitt

  • Member
  • ***
  • Posts: 95
    • View Profile
    • My car
Re: 1969 302 DZ Heads
« Reply #1 on: March 09, 2007, 01:18:40 PM »
No 69 Z's came with guideplates.  There were also no screw in studs. 

Southerner

  • Newbie
  • *
  • Posts: 11
    • View Profile
Re: 1969 302 DZ Heads
« Reply #2 on: March 09, 2007, 06:49:42 PM »
So what I have got here is some stock standard Z heads that came off that block then. Thats another question the block was cast on I 25 8 .....  25th Sept 1968 and the build date on the car is 12B.... 2nd week Dec 1968

firstgenaddict

  • Hero Member
  • *****
  • Posts: 1414
    • View Profile
    • Groome Family Automobiles
Re: 1969 302 DZ Heads
« Reply #3 on: March 09, 2007, 09:02:18 PM »
I had mone machined for Screw-in studs (7/16) and guid plates... the 7/16 studs keep the valve train more stable.
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

Southerner

  • Newbie
  • *
  • Posts: 11
    • View Profile
Re: 1969 302 DZ Heads
« Reply #4 on: March 09, 2007, 10:41:48 PM »
i would probably like to keep mine original. the body of the car is going to be the fun.....Oh boy. It has been in CA most of its life, But I have and will be replacing most outside panels.

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: 1969 302 DZ Heads
« Reply #5 on: March 09, 2007, 11:16:04 PM »
FYI,

Original 2.02 heads have an unshrouded polished area around the intake valve in the combustion chamber.  If that is not there, this could mean they were opened up at a local machine shop.  Most shops who open 1.94s to 202s do not have the proper eq to finish the job right.

Jerry

68Zproject

  • Hero Member
  • *****
  • Posts: 1634
    • View Profile
Re: 1969 302 DZ Heads
« Reply #6 on: March 10, 2007, 12:40:49 AM »
FYI,

Original 2.02 heads have an unshrouded polished area around the intake valve in the combustion chamber.  If that is not there, this could mean they were opened up at a local machine shop.  Most shops who open 1.94s to 202s do not have the proper eq to finish the job right.

Jerry

Jerry,

Do you do this service and/or have this equipment?
68Z28

Southerner

  • Newbie
  • *
  • Posts: 11
    • View Profile
Re: 1969 302 DZ Heads
« Reply #7 on: March 10, 2007, 12:45:59 AM »
Thanks Jerry, I will go have a look and send a pic. Mike

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: 1969 302 DZ Heads
« Reply #8 on: March 10, 2007, 03:09:21 AM »
My machine shop does.  They use a certi machine to do these conversions.  And you are better off starting with a 194 head.  The valves are always sunk too far in original 202 heads when you find them, building a new 202 head from a 194 valve head gives you a fresh factory type valve job.  DO NOT INSTALL HARDERED SEATS!!!!!

Jerry

1968RSZ28

  • Hero Member
  • *****
  • Posts: 5214
    • View Profile
Re: 1969 302 DZ Heads
« Reply #9 on: March 11, 2007, 04:01:17 AM »
DO NOT INSTALL HARDERED SEATS!!!!!

Jerry

Why Jerry?   ???

Paul

JohnZ

  • CRG Member
  • *****
  • Posts: 4267
    • View Profile
Re: 1969 302 DZ Heads
« Reply #10 on: March 11, 2007, 02:28:25 PM »
Because there's VERY little metal left between the valve seats on 2.02" heads as it is, and it's very easy for a shop not intimately familiar with these castings to go through into the water jacket when cutting the recess for the seat, at which point the heads are scrap. The seats are NOT necessary unless you're towing a trailer at 100mph all day long or the engine's going in a boat.
'69 Z/28
Fathom Green
CRG

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: 1969 302 DZ Heads
« Reply #11 on: March 11, 2007, 08:20:53 PM »
Thanks for posting that John.  I couldn't have said it any better.

I am suppose to be getting a pair of heads later this month where a seat fell out and did a lot of damage to the valve and combustion chamber.  Another reason why not to install them.

Jerry

68Zproject

  • Hero Member
  • *****
  • Posts: 1634
    • View Profile
Re: 1969 302 DZ Heads
« Reply #12 on: March 12, 2007, 12:21:22 AM »
Thanks for posting that John.  I couldn't have said it any better.

I am suppose to be getting a pair of heads later this month where a seat fell out and did a lot of damage to the valve and combustion chamber.  Another reason why not to install them.

Jerry

I think I'll have you do mine.  I already have a Dz motor that's now worth about $10.00!
68Z28

firstgenaddict

  • Hero Member
  • *****
  • Posts: 1414
    • View Profile
    • Groome Family Automobiles
Re: 1969 302 DZ Heads
« Reply #13 on: March 12, 2007, 12:52:19 AM »
$10... just about anything can be fixed... even if she needs to be sleeved or cracks welded up... if the engine is original to the car you do whatcha gotta do.
 
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

68Zproject

  • Hero Member
  • *****
  • Posts: 1634
    • View Profile
Re: 1969 302 DZ Heads
« Reply #14 on: March 12, 2007, 01:14:37 AM »
Not original to the car, unrepairable crack at main #2. :'(
68Z28

Jerry@CHP

  • CRG Member
  • *****
  • Posts: 1457
    • View Profile
Re: 1969 302 DZ Heads
« Reply #15 on: March 12, 2007, 03:28:53 AM »
Fixing cracked cylinder heads is dicey at best.  Most of the time when it's important, the "cold lacing" process is about the only thing that can be done......and that doesn't work all the time. 

We are trying to save a 1969 Z28 original block now.  One of my clients bought a car and when we got the engine apart, it was cracked in the lifter galley.  Botched repair and the whole nine yards.  It's a mess but we will do our best.

Jerry

firstgenaddict

  • Hero Member
  • *****
  • Posts: 1414
    • View Profile
    • Groome Family Automobiles
Re: 1969 302 DZ Heads
« Reply #16 on: March 12, 2007, 12:55:39 PM »
Sounds like it froze... that happened to my boat when I didn't winterize it one year... made the 454 a nice anchor... live and learn... I was being lazy and it cost me... BIG TIME...
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

1968RSZ28

  • Hero Member
  • *****
  • Posts: 5214
    • View Profile
Re: 1969 302 DZ Heads
« Reply #17 on: March 12, 2007, 05:39:48 PM »
Because there's VERY little metal left between the valve seats on 2.02" heads as it is, and it's very easy for a shop not intimately familiar with these castings to go through into the water jacket when cutting the recess for the seat, at which point the heads are scrap. The seats are NOT necessary unless you're towing a trailer at 100mph all day long or the engine's going in a boat.

Thanks John.  I've never heard that before!  My car has been stored for 26 years and I have not "fired her up" because everybody tells me to install hardened valve seats before I do.  So lets see... I need to change all the fluids and install a new battery...   ;D

Paul

melav8r

  • Member
  • ***
  • Posts: 102
    • View Profile
Re: 1969 302 DZ Heads
« Reply #18 on: April 25, 2007, 02:05:36 AM »
Is using a certi machine all that's required when openong up a set of 1.94's to 2.02's? Is there any additional unshrouding required?

GaryL

  • Hero Member
  • *****
  • Posts: 538
  • Marilyn and me
    • View Profile
Re: 1969 302 DZ Heads
« Reply #19 on: April 25, 2007, 04:17:18 AM »
delete
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

JohnZ

  • CRG Member
  • *****
  • Posts: 4267
    • View Profile
Re: 1969 302 DZ Heads
« Reply #20 on: April 25, 2007, 04:40:30 PM »
Is using a certi machine all that's required when openong up a set of 1.94's to 2.02's? Is there any additional unshrouding required?

The heads built as 2.02's at the factory had an extra unshrouding cut on the chamber wall adjacent to the intake valve; if you convert 1.94's to 2.02's and don't make the unshrouding cut, they'll flow less air than they did with the 1.94's. Photo of a factory 186 2.02" chamber below.
'69 Z/28
Fathom Green
CRG

melav8r

  • Member
  • ***
  • Posts: 102
    • View Profile
Re: 1969 302 DZ Heads
« Reply #21 on: April 25, 2007, 07:57:01 PM »
I understand that but does the certi machine cut that extra material or is additional unshrouding necessary after using a certi machine?

olympic69

  • Member
  • ***
  • Posts: 74
    • View Profile
Re: 1969 302 DZ Heads
« Reply #22 on: April 26, 2007, 05:18:48 AM »
I understand that but does the certi machine cut that extra material or is additional unshrouding necessary after using a certi machine?

I believe it is all about how it is set up- the answer being yes, maybe or no! The Certi machine makes cuts, not grinds so it is just another part ( step) of the operation, but might not be done if not specified ( sorry about the crappy explanation- its late!).The bottom line is it needs to be done if you go to 2.02, so see that your machinist knows that- the Chevy Power book says you need to go for a 2.34" total profile width. Also, David Vizard has an excellent book on working the -186 casting for performance.

Good luck-
Rob
Olympic Gold X33

"Its all crazy..."

68Zproject

  • Hero Member
  • *****
  • Posts: 1634
    • View Profile
Re: 1969 302 DZ Heads
« Reply #23 on: April 27, 2007, 03:55:11 PM »
Would this Vizard book work for the 291 68 Z heads?  Were the chambers the same for 68 and 69 Z heads?
68Z28

olympic69

  • Member
  • ***
  • Posts: 74
    • View Profile
Re: 1969 302 DZ Heads
« Reply #24 on: April 27, 2007, 05:51:02 PM »
It is a very good book, applicable to all of these late '60's- early '70's 64 cc heads which we are speaking of, with flow figures, Mods., a really good book plus has some great stuff on the aftermarket heads as well.

ISBN is   0-87938-547-2

How to build and modify small block Chevy Cylinder heads David Vizard , 1991 MBI Publishing Co
Rob
Olympic Gold X33

"Its all crazy..."