Rev limiter?

[Joe R.]

Anyone have any advice on using a rev limiter with a L-72 (427 / 425)? I'm thinking I may want to protect my newly rebuilt engine although it isn't strictly NCRS correct by any stretch.

Joe

[Jim T.]

Re: Rev limiter?

Using an aftermarket tach that illuminates a light when a rpm is reached could be helpful if you have a heavy foot, might help keep it on the road during shifting so you do not have to focus on the tack.

[Dick W.]

Re: Rev limiter?

MSD 6AL with the chip of your choice to limit the rpm's

[Joe R.]

Re: Rev limiter?

Dick,

Thanks for your help, I think I will go with your suggestion. Do you have personal experience with it? Does it replace the distributor? Where would it mount? Can I keep the wiring stock? What should I set the rev limit to?

Joe

[Ken A.]

Re: Rev limiter?

Personally, I would get my tach rebuilt/calibrated and forget the May Suddenly Die ignition. If properly rebuilt, your engine should hit 7500 rpm with no problem, and it should be easy to shift @ 6500.

[Dick W.]

Re: Rev limiter?

Joe, I have an older version of that on our '72, and has been there for over 15 years. No problems. No modifications to the wiring harness. We mounted it on the RH lower splash shield and painted it black. We ran the harness in with the original harness therefore it is not very visible.

[Joe R.]

Re: Rev limiter?

Dick,

Would you be able to supply some photos? That sounds like a pretty clean installation.

Thanks,
Joe

[Dick W.]

Re: Rev limiter?

I do not think that a '72 with 454 and AC you are going to see anything but a large red hunk of cast iron in a photo.. Note.. If you are not going to have the car judged use the MSD or comparable plug wires and their Blaster coil. It is unbelieveable the difference. When I did our car, the addition of the coil, MSD box, and wires added 350 rpm's to the idle speed. The coil on the car was good, the wires new. You can just about forget plug replacement, and the minimal load on the ignition points make the contacts last forever

[Joe R.]

Re: Rev limiter?

I don't plan on having the car judged in the foreseeable future. It does not have points, transistor ignition came along for the ride with the L-72. Would you still recommend the blaster coil and wires? What is the significance of the 350 rpm higher idle speed? Also, I believe the redline is 6500 rpm, should I set the limit to 6000 or 7000 rpm?

Joe

[Tom L.]

Re: Rev limiter?

I don't deny that the insallation of MSD components would make any engine run better. However, a 350RPM increase as a result of parts seems a bit weird. The described tune-up most likely corrected any defficencies in the stock set-up or improper tuning settings. A major increse in RPM suggests an increase in efficiency/power in an engine. Think about it...2/3 increase in RPM as a result of ignition changres would proportionately show a huge increase in HP.
I hope we have not fallen into the trap of unreasonable HP gains as a result of good advrtizing. Really, No harm ment.

[Dick W.]

Re: Rev limiter?

Lynn, the increased output of the coil and the premium wires (the OEM and repro wires are junk) I am sure made most of the difference. Nothing else was changed on the engine. Typical fouling of the spark plugs is non existant. Seven of the plugs have been in the engine for over 10 years. The eighth fouled due to a damaged plug wire. We had the bowl gasket go bad in the carb, engine was flooding so bad that it would only run with the throttle wide open, and had to drive it several miles before we found someone to repair it (ever hunted a garage in WV on Labor Day?). Repaired the carb, started the car and it ran like a new set of plugs.

Every car that I put through PV had the hidden MSD setup. There is a rule in the Judging Reference Manual that is the result of my adding the system. It reads "no performance enhancing modifications" or something similar.

[Clem Z.]

Re: Rev limiter?

if you have the GM TI system on the car now just replace the TI "black box" with a MSD box with the RPM chip in it

[John M.]

Re: Rev limiter?

One of my Pet peeves is a Big Clunky MSD Box bolted on a firewall or inner fender. It ruins an engine bay in my opinion.

I ran a Stealth set up on my 70 SS Chevelle that worked out very nicely.

I had my stock distributor set up as a Magnetic signalling device and ran an MSD Box.

However, I mounted the MSD underneath the dash Pad, and spliced the wires directly into the stock Wiring harness so that all of the connections to the coil and distributor, were 100% stock appearing.

The Power wire was run to the Starter following the existing harness and re-wrapped using the correct wire harness wrap tape for a 100% stock appearing set-up with the benifit of better spark and Rev limitation.

Although I'm not sure if all of that effort is any better than a bolt on Petronix modification to your distributor which is the route I'm taking on the Vette this time.

I also will likely never have my cars point judged on a National type level, but want them as bone stock correct appearing as possible.

Drivers detailed to the extreme.

Here's the stealth MSD installation on the Chevelle.