Author Topic: 69 z28 rods  (Read 16191 times)

69er

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69 z28 rods
« on: March 23, 2007, 07:47:17 PM »
I'm not sure if I did this right.

did the 69 z28 come with 'O' rods that were pressed pins?

I'm getting to ready to buy some and the seller showed me the manual
that gives the pressed specifications. I'm not sure if he is right or not.

69er

69er

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Re: 69 z28 rods
« Reply #1 on: March 23, 2007, 07:48:17 PM »
footnote pic

69er

69er

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Re: 69 z28 rods
« Reply #2 on: March 23, 2007, 07:49:32 PM »
these pics from a chevrolet manual indicates that the 302 for 1969
came with interference fit pins for the connecting rod. I'm
confused.

69er

william

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Re: 69 z28 rods
« Reply #3 on: March 23, 2007, 09:28:13 PM »
Nope; 69 302 had full-floating pins with 'pink' rods.

JohnZ

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Re: 69 z28 rods
« Reply #4 on: March 24, 2007, 03:45:33 PM »
The "clearance" note is in the wrong column - typo in the manual; many of the 302 specs in the Service Manual are either wrong or not shown at all.
'69 Z/28
Fathom Green
CRG

69er

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Re: 69 z28 rods
« Reply #5 on: March 24, 2007, 05:48:24 PM »
I talked to the machine shop owner from tennesse who has the set of pink rods
for sale about the misprint in the chevrolet manual. He had no comments about the
misprint. He seems to recall that in 1969 the z28 could be ordered with the optional
offroad camshaft. And with this option came the full floating pins and stronger valve
springs. He sent me some additional pics of the large journal part of a pink rod.
He explains that in the picture you will see a relief notch in the rod cap next to
the bearing tang slot. He said that this was consistent with pink rods used in 302's,
he also says that he has never seen this notch in other small block connecting rods.

The rods he is selling have a pressed fit pin and have this notch where the bearing
tang lock is located, and have the cast letter 'O' on the bottom of the rod cap.

I have attached the pic for your review.

69er

sam

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Re: 69 z28 rods
« Reply #6 on: March 24, 2007, 06:21:23 PM »
The rods in the 69 302 were full floating rods. Means the wrist pin floats in the rod and the piston. Floaters  had the clips on the ends of the wrist pin to hold it in. The other rods had the wrist pins pressed in. Also I don't think you could order the off road camshaft from the factory. I believe it was over the counter.
« Last Edit: March 24, 2007, 06:23:14 PM by sam »

Jerry@CHP

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Re: 69 z28 rods
« Reply #7 on: March 24, 2007, 06:49:07 PM »
All 69 Z28s had floating rods.  We have rebuilt more than anyone in our years of experience.  There is also traces of bronze babbot coating in the small end of the rod when you find originals, and paint on the side beams of the rods.

Jerry

Jerry@CHP

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Re: 69 z28 rods
« Reply #8 on: March 24, 2007, 06:54:42 PM »
And the factory only installed the "346 camshaft,

JM

1968RSZ28

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Re: 69 z28 rods
« Reply #9 on: March 24, 2007, 09:41:23 PM »
Jerry -

If you were going to rebuild a 1968 302 engine, would you go with floating or pressed fit pins?

Paul  

Jerry@CHP

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Re: 69 z28 rods
« Reply #10 on: March 25, 2007, 02:32:15 AM »
pressed,

1968RSZ28

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Re: 69 z28 rods
« Reply #11 on: March 25, 2007, 04:42:25 AM »
Why?  Originality?  Performance?  Other...?

Paul

sam

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Re: 69 z28 rods
« Reply #12 on: March 25, 2007, 01:40:33 PM »
I personally believe they are safer. No clips can come loose to score your wall up. I think the floating pins were more designed for racing to be able to take apart easier when you are  changing  piston/rod  combinations more frequently. But that is just my opinion.

69er

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Re: 69 z28 rods
« Reply #13 on: March 25, 2007, 03:39:12 PM »
Is it true that only pink rods had the notches located in the rod cap?

Maybe someone can look at a set of pink rods that have'nt been installed
yet to see if they have the notch, or just an ordinary set of connecting
rods to see if they have the notch.

Jerry would pressed pins be advised on a 1969 z28 302 rebuild?

69er

Jerry@CHP

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Re: 69 z28 rods
« Reply #14 on: March 25, 2007, 04:15:33 PM »
I would do pressed, it's one less thing to worry about.  Those sprial locks have broken before and when that happens, you have a wrist pin in the cylinder wall.  Not a good thing.  Like Sam said, it's a safety thing.

There will be no difference in performance.  We have several Z28s in the field that can drive to the track and run in the 13 second zone all day with street tires and closed exhaust.  Open headers and tires, look out! 

Jerry