CRG Discussion Forum

Camaro Research Group Discussion => Mild Modifications => Topic started by: doomer on October 14, 2013, 05:11:18 PM

Title: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: doomer on October 14, 2013, 05:11:18 PM
I respect the fact that there are opinions regarding the use of rev limiters. However, there is one on my DZ 302 now, so I am seeking some sage advice on what it should be set to?

I recently had the engine rebuilt (original numbers). I am now at .060 over. I tried very hard to stay original on everything. However, the distributor needs work, so I replaced it with a petronics setup that looks rather stock, but includes the electronic setup and rev limiter.

What would be the ideal set point for the rev limiter?


Shane
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 14, 2013, 05:48:34 PM
Relative question ,what are you doing with it ? Racing ,cruising with an occasional bang through the gears ? On the race car we run a 2 step 1st to flash the convertor at launch, 2nd a few hundred past point were power curve starts coming down/shift point.  On the street I plan on 6800 to keep it safe with the 4 gear, plus according to my cam sheet power begins to fall off. They may be able to take a 8 grand spin ,but do you really want to push it ? Don't make a habit of "stuttering the engine " Even on the 1st stage I leave on the tac just under the chip. Very hard on the engine otherwise.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: 69Z28 on October 14, 2013, 06:40:05 PM
I'm curious about this topic as well. At some point I'll be putting my 302 back in my Z. It will be all stock except .030 overbore. Distributor is all rebuilt and ready to install, carb is all done. I want to use a rev limiter and haven't the slightest idea what I should purchase that isn't gonna stick out like a sore thumb. I like the all in one set up for the distributor like Shane has but I have money tied up in the stock 480 rebuild and set up as well as a Dave's Smallbody HEI set up to specs per JohnZ's articles.

To answer Shanes question...on where to set the limit...I was going to stick between 6500 and 7200 RPM on mine. I have been up to 75-7600RPM before but don't want to go that far anymore.


So if anybody has any idea on a stand alone type rev limiter post it here. I had an older Mallory unit years ago that had a dial mounted under the dash that was wired to a small box in the engine compartment, but I'll be damned if I can't find it now.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 14, 2013, 06:42:31 PM
Adding to I ran a Mallory Rev limiting Tac for years in the Z, still have it. Worked great and would dial down to 0 when I left the car. 1 setting for limit ,one  for shift light.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 14, 2013, 06:45:59 PM
We run a MSD box in the Anglia, 500 increment chips, soft touch. You can hide the box under passenger seat. Check their website for specs ,works with points.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: 69Z28 on October 14, 2013, 06:51:51 PM
Adding to I ran a Mallory Rev limiting Tac for years in the Z, still have it. Worked great and would dial down to 0 when I left the car. 1 setting for limit ,one  for shift light.


I've seen those too. What if you have the in dash tach?  I might hit ebay to see what is available in vintage form for Mallory.

The piece I have was once in a friends car and when a bunch of us would go out with him in his car we were always screwing with the dial. He would start up the road normal and then dump it and the engine would break up at 2500 RPM or even lower and he would come unglued wondering what the heck just happened. He finally caught on it was us f'n with him. It was funny to see him get bent out of shape thinking there was something terribly wrong with his fresh engine.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: 69Z28 on October 14, 2013, 06:53:20 PM
We run a MSD box in the Anglia, 500 increment chips, soft touch. You can hide the box under passenger seat. Check their website for specs ,works with points.

Which unit are you using? I have some time to look on line right now. Might as well check into it.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: cook_dw on October 14, 2013, 07:59:04 PM
Like others have already said.  It really depends on what you are gonna do with the car.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 14, 2013, 08:49:03 PM

Which unit are you using? I have some time to look on line right now. Might as well check into it.



6a, which I plan on robbing for the Z . They have a new unit out where you can control everything including different ramps for timing via laptop ,around $500-600.  Very affordable tech for bracket racers. My buddy has a 8.9 72 Camaro his daughter races at mid 9's. We both run locked out distributors and hard starts when at operating temps have been cured. He's sold.
I'm giving it a try next spring. I need to take some more hit out at the line.

My Sun Tac is mounted in dash ( fuel gauge spot) has been 44 years. I had the Mallory, oil/water temp gauges mounted on the cowl. With the glass snorkel hood really had that old super stock look. I did have issues with the MSD dial accessory to control rev and went back to the chips.(Anglia ,I'm bouncing between cars)

These 302's can take a ton of abuse with only high REV issues I'm aware of being in the valve train. Also heavy pistons . Strong crank and rods.(Relieved of course now) My dad shifted at 8200 ,other than some ignition and traction issues she lived to see another day, that was in the 70's and hasn't seen that kind of abuse since. That being said ,today It's staying under 7 grand----you can pickup a dressed 383 crate motor for what one of these blocks are worth.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: 69Z28 on October 14, 2013, 10:23:31 PM

Which unit are you using? I have some time to look on line right now. Might as well check into it.



6a, which I plan on robbing for the Z . They have a new unit out where you can control everything including different ramps for timing via laptop ,around $500-600.  Very affordable tech for bracket racers. My buddy has a 8.9 72 Camaro his daughter races at mid 9's. We both run locked out distributors and hard starts when at operating temps have been cured. He's sold.
I'm giving it a try next spring. I need to take some more hit out at the line.

My Sun Tac is mounted in dash ( fuel gauge spot) has been 44 years. I had the Mallory, oil/water temp gauges mounted on the cowl. With the glass snorkel hood really had that old super stock look. I did have issues with the MSD dial accessory to control rev and went back to the chips.(Anglia ,I'm bouncing between cars)

These 302's can take a ton of abuse with only high REV issues I'm aware of being in the valve train. Also heavy pistons . Strong crank and rods.(Relieved of course now) My dad shifted at 8200 ,other than some ignition and traction issues she lived to see another day, that was in the 70's and hasn't seen that kind of abuse since. That being said ,today It's staying under 7 grand----you can pickup a dressed 383 crate motor for what one of these blocks are worth.


So a nothing special rev limiter is a 6A? I don't want to do anything different to the engine once I get it were I like it, and I guess a basic keep me out of trouble limiter would work just fine. Nothing high dollar, this is budget time for me.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: cook_dw on October 14, 2013, 10:39:06 PM
Like the OP listed..  Pertronix has been around for a while & this is just making a great product better.

http://www.pertronix.com/support/videos/ignitor/install-i3/default.aspx (http://www.pertronix.com/support/videos/ignitor/install-i3/default.aspx)
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 14, 2013, 11:07:17 PM
6AL is  the control box so to speak, small chips ,which are actually resistors , plug in for quick change on the side. They come in an assortment of numbers ,I'm not getting into a product debate because I'm not on MSD's payroll. Yes Pertronix has a great rep and offers a clean , stock appearing upgrade. Back to your original question, IMO keep it under 7 grand.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: cook_dw on October 14, 2013, 11:13:00 PM
,I'm not getting into a product debate because I'm not on MSD's payroll. Yes Pertronix has a great rep and offers a clean , stock appearing upgrade. Back to your original question, IMO keep it under 7 grand.

That was not my intent..  Just stating that for a stock appearance to go under the cap the pertronix is a nice product.  If I was doing it my way I would use the 6AL box.. ;D
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 15, 2013, 03:35:31 AM
No problem, I tend to rant when talking performance mods, the pen units do seem to offer the best bang for the buck while keeping it looking stock and clean, not firing a 14:1 engine.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: doomer on October 15, 2013, 12:00:47 PM
Relative question ,what are you doing with it ? Racing ,cruising with an occasional bang through the gears ?

You got it! Cruising with an occasional bang through the gears. I may run it up the strip on a drag night with my club just for fun, but not often. I'm after a little insurance against missing a clean shift/gear wherever I may be.

BTW, my bad on the spellun... Pertronix.

So as I understand it, the advice here seems to be between 6800 and 7200? It was set at 7100, although for some reason, it seems to be cutting in at 5100 right now. I am going to take a closer look as soon as I get a chance.

Great info all around, thanks folks!

Shane
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on October 15, 2013, 01:02:11 PM
Have fun ! I think most here operate in that gray area between not wanting to destroy what's irreplaceable but not "clipping" them either. They are Z's ! If I cant take mama out and still scare her in it once in awhile it's hitting the red carpet.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: Stingr69 on October 22, 2013, 07:55:21 PM
I run a Crane CD Multispark box that is triggered by NAPA high RPM points firing a stock coil. The crane box is hidden where the center radio speaker would be.  I have the adjustable rev limiter set at 7200 RPM.  The valve train is pretty stout and with the box set to 7200 RPM max, the fun is there and the springs should last a long time. This setup does not run high voltage through the points so the contacts stay clean.  No need to precisely set dwell and no condenser is needed either.  You can easily crank down the RPM limit with a small screw driver for "Valet Mode" if needed. :~D

-Mark.
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: KERR on December 18, 2013, 02:55:28 PM
maybe i miss read but what parts do you have?

Its takes more than just a set rpm i want to turn it,   You can revve anything as far as you want ONCE! 

My 327 has MSD box set 7800,   but to get the motor live at that many rpms you need good parts,  and to get it to keep making power you need to have heads, cam and intake that will work in that power range.   Like i said you might have typed out all of that and i missed.. 
 I  just dont want you to go  " oh the guys on line said i can spinn them 7200 and then end up with a hand full of parts"
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: janobyte on December 18, 2013, 11:10:48 PM
Original post stated rebuilt 302--came out of the box with "good "parts  ;)
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: 69Z28-RS on December 18, 2013, 11:49:35 PM
The 'factory 302 redline' was 6000 rpm.   I once had a '67 302 that would turn 10,000+.   when I drove my mostly stock build '69 DZ motor on the street, fairly hard, I had no rev limiter but I had my Sun Super Tach redline indicator set to 7000, but would occasionally go beyond that.

What your Rev limiter should be set to is based on how the engine was built, your confidence in the engine builder and the parts, and how much 'risk' you want to take.. :)
Title: Re: New 69 Z28 302 rebuild, dizzy has rev limiter. What is the best RPM limitation?
Post by: KERR on December 19, 2013, 02:13:44 PM
well said 69Z,

on the that 327 ive got its been hurt a few time lol...  the last time they said i could twist it more but if something happens they cant fix it again..  so its at 7800..  still sounds awesome threw side pipes,  well to me the neighborhood isnt impressed.