Author Topic: Does engine internals affect originality? Specifically cam...  (Read 4513 times)

dale_z28

  • Member
  • ***
  • Posts: 251
    • View Profile
Does engine internals affect originality? Specifically cam...
« on: January 09, 2016, 04:21:02 AM »
A couple years ago at a small local car show I talked with the proud owner of a '69 Z. His car was sharp, looked correct to my not-so-amateur eyes. The more we talked the more I learned. It was on eBay when he spotted it, had been certified by the famous "Jerry" and his Camaro Association (I honestly can't remember his last name or the clubs and I'm too lazy to find the picture I took of the framed cert.
I told him about my car and that I hadn't heard a 302 run in almost 25 years. I asked if he'd mind starting it for me, which he did. It purred like an everyday modern small block. Not a hint of cam. Is it normal for guys to swap internals for a more driveable car? I was extremely surprised and at the same time disappointed. My wife had never heard one, either, and as far as I'm concerned she still hasn't!
'69 X33 02D   Since 11-29-'77

Details are trifles, but trifles make perfection. And perfection is no trifle.
~Ben Franklin

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #1 on: January 09, 2016, 04:38:53 AM »
If he is/was driving his car daily, he could have installed 350 ci internals and even a hydraulic cam for easy driveability...??  I would not say that's common, but it's probably something a lot of us have thought about..
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bcmiller

  • CRG Member
  • *****
  • Posts: 4012
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #2 on: January 09, 2016, 06:20:49 AM »
Everyone needs to read what those certification reports say, not just look at the certificate. The reports are normally a few pages.

Might not have had the original 302 in it. To me they sound best with the off road cam, but even the stock cam has some "lope" to it and should be recognizable. :)
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

ZLP955

  • Hero Member
  • *****
  • Posts: 2186
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #3 on: January 09, 2016, 09:10:06 AM »
Many seem to go for a similar grind to the factory specs but in a hydraulic cam, where's the fun in not having to adjust lash regularly?
To answer your question though, if it's the cars original block, it's an easy swap to replace the cam and lifters back to stock specs so I wouldn't see that as affecting originality (unless you're talking about show judging?) except the sound enjoyment! If it's a replacement block, well the originality has already taken a serious hit so engine internals matter not.
Many original DZ blocks have newer replacement internals (rods, pistons etc) but the cam is an obvious one as soon as you hear it running.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA.
AHRA Formula Stock at Lions Dragstrip, NHRA E/MP at Pomona Raceway

X33RS

  • Hero Member
  • *****
  • Posts: 1092
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #4 on: January 09, 2016, 03:09:45 PM »
I'm rebuilding mine as we speak.  I had to take a few liberties on the build namely for reliability and longevity.  Rods for instance was one area I wasn't willing to reuse.  After 46 years of use they could be fine, or maybe not.  Even after machining and good bolts, I still didn't want to take the chance of one coming apart and taking out a numbers matching block.  So we went with a nice aftermarket rod, much stronger and slightly lighter as well.  The lighter weight is much easier on the rotating assembly.

Another liberty I decided to take, rather than use my NOS pistons for the build, we decided to go with an aftermarket forging.  Lighter weight piston which again is easier on the rotating assembly when you spin these things up, but it also has other advantages like shorter skirt design and a smaller ring package for less drag. 

I'm staying true to the nature of the engine however, compression will still be 11:1.

Heads are getting hardened seats, a good set of valves that are designed to flow a little better, and a good valve job, as well as cutting for positive seals for better oil control.

As far as the cam goes, I have a stock grind new in the box, but without a cam card, and after talking with the machine shop that is doing the work, he suggested we use a Comp copy of the cam, slightly modernized lobe profile but .050 numbers are the same at 254 and lift is the same, I think the lash is tightened to .024 rather than .030, and the same 114 LSA.   My goal is to have the engine sound exactly like it should sound.  I may play with the install position a tiny bit.
   I find the stock cam very drivable myself, when I'm done tuning, and the way I like to run my timing curve and initial advance, vacuum advance etc....the stock DZ cam idles fairly smooth for me with only a slight hint of a lope when cold, as the engine warms it's hardly there at all.  The biggest giveaway is the noise of the lifters.
  I've heard other 302's run that are rather choppy and others that are smoother like mine.  I chalk that up to either the owner has changed the cam, or the tune on the engine isn't as crisp.  Myself, I can get the stock 30-30 cam to idle fairly smooth with 16 initial on the timing and some vacuum advance thrown in there as well, some carb tweaks, and some people would probably question if it's the right camshaft  ;)
« Last Edit: January 09, 2016, 03:33:00 PM by X33RS »

X33RS

  • Hero Member
  • *****
  • Posts: 1092
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #5 on: January 09, 2016, 03:27:07 PM »
To add to that and try to answer the original question, I think it depends on the individual and what you plan to do with the car.  But as far as how I'm building my engine, my opinion is that it only adds to the value and doesn't hurt value in any way.
  I say that because the engine is still true to form, will still sound the same, yet I'm taking advantage of some modern technologies for more reliability and likely a little more HP so the engine will run better than it did when it was new.

Another trick I'll let out of the bag that I'm taking advantage of is a nitride treatment of the camshaft for hardness to cut down on wear, and I'm using the newer solid lifters with oil feed holes on the face of the lifter for more lubrication on the camshaft.  This simply provides longevity and piece of mind for me but doesn't affect how the engine runs or sounds per say.

Lots of little things inside the engine you can do, (coatings are another one  ;D) it's not cheap at all to build one this way and frankly I'd be willing to pay more for one that has had this attention to detail, which is why I don't feel it hurts overall value in the end, if anything, it increases value in my eyes.

dale_z28

  • Member
  • ***
  • Posts: 251
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #6 on: January 09, 2016, 05:16:54 PM »
I know it was a DZ block but I think it might be a hydraulic cam/lifter combo. I didn't want to bring it up (smooth idle versus choppy lope) since I wasn't sure what he knew about the engine.  I love his car, and he's been great to allow me to come look at it several times - and given me information and measurements when I had questions about stripe placement, etc. (his is also a vinyl top car) I can't wait for him to see my car, and hear it. If it's the setup he wants, I'm ok with that. We all have our opinions and what we want/expect out of our cars. I hope he doesn't feel "cheated" if he learns the engine internals are different than factory-equipped. Thanks for your input, guys.
'69 X33 02D   Since 11-29-'77

Details are trifles, but trifles make perfection. And perfection is no trifle.
~Ben Franklin

z28z11

  • Hero Member
  • *****
  • Posts: 1853
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #7 on: January 09, 2016, 05:34:13 PM »
Dale,

You mentioned "Jerry and his Camaro Association", that should be Jerry MacNeish, author of a set of great reference books that you need to purchase (his Definitive Facts books, available from Amazon, most Camaro parts houses), if you haven't already. Jerry has been a good source for Camaro information for a lot of people in this business over the years - his book references most all of the info and part numbers you'll ever need to look for for '67-68 Z's and the '69 Z and SS396 1st Gens.

No, I don't sell his books or publish them, but I have enjoyed them for years.

Regards,
Steve

1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

dale_z28

  • Member
  • ***
  • Posts: 251
    • View Profile
Re: Does engine internals affect originality? Specifically cam...
« Reply #8 on: January 09, 2016, 06:26:35 PM »
Thanks, z28z11, it was right before bed, and I had known his last name but couldn't think of it at the moment. I have the book, sort-of. My restorer is using it as a reference and I will "inherit" it when the job is finished. Right now he needs it more than I do. Thanks again!
'69 X33 02D   Since 11-29-'77

Details are trifles, but trifles make perfection. And perfection is no trifle.
~Ben Franklin

 

anything