Messages

1

Mild Modifications / Re: Engine too high on Z/28

« on: November 21, 2010, 12:51:13 AM »

I checked the frame mounts before I replaced the motor mounts - they are original.

2

Mild Modifications / Engine too high on Z/28

« on: November 13, 2010, 02:43:21 AM »

I have a 69 Z/28 with a 327 out of a 67 camaro, and am having trouble closing the hood.  Thanks to your great web site, I learned that Z28's have special motor mounts that I installed recently.  I have the cowl induction hood and cowl air cleaner set up like original, but the hood has never closed correctly, even after installing the correct motor mounts.  The motor actually sets up a little higher with new mounts.  I would say that the engine is now about an inch too high.  Any ideas why the hood won't close correctly?

Thanks

3

Maintenance / Re: Idle problems under load

« on: April 28, 2010, 11:27:13 PM »

Yes, since this is a RS car, I actually plugged the entire outlet off of the manifold to make sure there weren't any leaks in that area.

Thanks

4

Maintenance / Re: Idle problems under load

« on: April 28, 2010, 02:53:29 AM »

OK - I finally get.  Since the original timing called for 4*, and the weights were designed to add 28* to get the desired 32*.  Since I'm running so much initial, I'm beyond what I need.  I'll find some weights to match the intial timing of 13*.

The damper is one of those that is not marked right, so I found TDC, and marked the damper in the correct location.

The Comp Cam part# is 12-238-2, Grind# CS XE262H-10
Heads are stock Dart Iron Eagle S/S 165
Carb is 1406 Edelbrock
Intake is Edelbrock Air Gap Performer
Hooker Ceramic coated headers
Standard torque converter

I've looked for vacuum leaks, and can't seem to find any. 

Thanks

5

Maintenance / Re: Idle problems under load

« on: April 27, 2010, 12:16:52 AM »

L22K19 -  I degreed the cam when I put it in, and it appeared to be as advertised.  The cam specs are:

                        intake         exhaust
Gross valve lift     .462             .469
Duration at .05    218              224
Lobe lift              .308            .313
Rocker ratio         0                 0
Lobe separation     110
I wouldn't know a mild cam from an extreme one by looking at those numbers.  It's a Comp Cam.

JohnZ - the vacuum when idling and in Drive is around 6", so I see what you mean about needing a different vacuum can.  Is there a can you would recommend? Is there something in the distributor that is supposed to stop the amount of centrifugal adavance?

Thanks

6

Maintenance / Re: Idle problems under load

« on: April 25, 2010, 04:18:52 PM »

Ok, I finally had some time to look under the hood again, and here is what I found out:

Initial timing is 13*  BTDC
Vacuum at idle (850 rpm in Park) 13-14"

Vacuum can: 
8" to start, and 15* max at 15.5"

Centrifugal advance: (with vacuum disconnected)
Motors says:  Starts @900 rpm, and 28* max @ 4200 rpm
Actual:
1000 rpm  13*
1200 rpm  17*
1400 rpm  19*
1600 rpm  21*
1800 rpm  22*
2000 rpm  24*
3500 rpm  28*
4000 rpm  45* (maxed out at 4000)

This car runs GREAT once it get's past the stumble when the throttle plate is opened, and the rpm is around 2000 rpm and beyond.

Do you think I need to change the vacuum can?  Thanks
 

7

Maintenance / Re: Idle problems under load

« on: April 10, 2010, 07:14:59 PM »

Update to my last post.  When I disconnect the vacuum off the distributor, and increase the engine rpm, the max total timing I get is 45 degrees.  Where is the extra 10 degrees coming from?

Thanks

8

Maintenance / Re: Idle problems under load

« on: April 10, 2010, 05:24:30 PM »

Thank you for all of that great information.  I learned more about timing from that article than anything I've ever read.  I've already shared that with other folks.  I finally had some time to put the info to use, and this is what I found out:
The distributor was connected to ported, so I moved that to full vacuum on the carb.
My vacuum at idle with the distributor disconnected from the carb is 12", and 14" connected.
My initial timing is 14 deg (with the distributor disconnected) as it will barely run with anything less.
The timing is 34 degrees when the distributor is connected, which is strange because this is an original distributor, and my Motors manual is states that the vacuum can should only add 7.5 degrees at 12" vacuum.
With everything connected, and I rev it up to 3000+ rpm, I'm way off the the scale on my damper, which goes to 60 degrees.
It's still rough at idle when it's in gear, and now spits and sputters when I try to accelerate, but smooths out after I let up.  I've obviously still got something wrong.  Any ideas would be greatly appreciated.  One other thing that may or may not be related, is the fuel pressure is about 11.5 psi when I first start it up, and then after it gets warmed up, it drops off to 3.5 psi.

Thanks in advance

9

Maintenance / Idle problems under load

« on: April 06, 2010, 12:19:07 AM »

I have a 68 RS with original 327/powerglide, and recently rebuilt the engine.  I put in a mild cam, edelbrock manifold and 1406 carb.  The ignition is the original distributor with a MSD 6AL box.  I re-jetted the carb for my elevation (3000 feet). The engine is slow to warm up, and then finally idles ok.  Then when I put it in gear, it idles very rough, and stumbles when I try to accelerate.  Once I get it in motion, it runs fine, and cruises down the road very nice.  It's running about 12 degrees advanced, and I put in the lighter springs and weights in the distributor to try to get as quick as advance as I could.  Any ideas with this problem would be greatly appreciated.

10

Originality / Burgundy Z/28

« on: June 07, 2009, 12:48:53 PM »

I've been told by other owners of 69 Burgundy Z/28's, that there were only 50 of these cars made, as it was a special order for dealers.  Is this true?