Do I need to have my distributor recurved? I am using a stock 2.7 distributor on my carburetor 2.7 L engine I understand that to have a optimal performance a recurve is needed however is it really worth $500? My car is not set up for racing?

In other words will icy $500 worth of improvement from the modification ? My distributor is otherwise in excellent condition.

It will run for now but, if you have cams/performance work it will not be optimum.

The other option, if you want to keep the dizzy, is to lock out the advance mechanism and buy a MSD AL6-2 Programmable. Then you can hook up a laptop and change the curve any way you like.
Still almost 400 bones, but at least you know exactly what the curve is and if you don't like it, or in the future you change something like your cams you can re-curve it.


https://www.msdperformance.com/products/ign...trip/parts/6530

Interesting, how do you know how to program the correct curve with the A6-2?

If programing curves, wouldn't just going with a distributorless system make more sense?

FWIW: I'm in the same boat, trying to see what is the best option for my 2.7 that will be running carbs (if the internals check out OK).

How do you know what to program into a distributorless system?

Really the curve itself isn't rocket science. You can look up on the net what other peeps have used for curves. It usually starts at 10 degrees BTDC up to 1000 rpm and steps up to full advance at around 2600-3000rpm. Full advance is somewhere between 28-32 degrees. As long as you don't go over 32 degrees you're golden.

Phasing is a concern, basically its the point the rotor is in contact with say the #1 pin, throughout the advance curve you must have contact.
The 2.0-2.7 cap and rotor has a smaller contact area, so you might not be able to get much more the 28 degrees (actually 18 degrees advance, 28-10=18) total advance.
You don't have to fool with retard, you can, but that's more for turbos.

As with any tuning I highly recommend a wideband O2 meter, it will tell you instantly if you are running too lean. Rich makes it run like shit, but in the short term it doesn't hurt much. Lean on the other hand can burn a hole in a piston PDQ.

After that your curve will be a combo of research and playing with the program.

BTW I have a Patrick MS/Jarvis twin plug dizzy and a regular AL6, if I don't like the curve I will be buying a MSD AL6-2 Programmable.
I do know my dizzy only has 18 degrees in its curve, so 28 degrees total advance.

Yes!

Me and a friend of mine compared our two 3.0l webber 914's. They were almost identical, except mine had the dizzy re-curved and just a little more cam lift. Mine had significant more low end punch. It seemed to really help bring the motor alive. I would recommend it, but it's not required. maybe save it as a possible future upgrade but much easier to do now.

There is a lot of potential left on the table when the ignition curve isn't optimized; both power and economy.

If your engine still is configured as it left the factory, then the factory ignition curve will be close but not optimal for your operating conditions. Remember that the factory has to use a conservative curve to ensure that it will not suffer detonation and self destruct if it gets low octane gas, if its run hot, if the intake air is hot, when it is put under full load at low rpm, etc, etc. Likely you can get more advance and increase the performance of the engine if you change the curve. You can do this iteratively on the road, but you can do it easier and safer using a dyno and sensors to monitor the engine.

Don't see you would want more advance,34-35 degrees is plenty,surely it's more about how it comes in during the rev range.
The carbs will wake up the 2.7 as the CIS is a fairy tame system power wise,maybe it won't matter...
500 notes to recurve ?,seems expensive changing the auction of the advance weights and a few tests on a distributor tester ??.

I would agree.. I can't believe its $500 Shoot I sell my tanks for $600 and they atke about 6-7 hours to complete start to finish

So.... do you have a distributor tester you can lend me?
And then can you come over and show my how to adjust my weights, because you know that's all there is to it...and give me all your knowledge on what makes the best /6 advance curve...and maybe throw in new bushings while your at it.....
I'll buy you a beer...


And VW guys wonder why I don't work on their engines much anymore ....



.

Always so positive.. .. I actually find dizzy machines for sale locally from time to time.. Always think about buying them but just never felt it was worth it.. I think the last dizzy I had done was about $200 at burnbros.. (Aaron)) maybe when he worked for Henry but that was a long time ago.. Just surprised the job is so expensive now.

Four years ago I was told $600 on Pelican so it's come down a bit.
Just razzing you guys, yeh it's a tad spendy, but you have to pay the Porsche tax.

That's why for my money I'd get the MSD, then I'm not stuck with someone else's idea of a good curve.

That's true..

I have enough local drag racers in the area that discard the last year's model for the newest model so used options are out there as well.

It is absolutely wroth $500 of your money.

--DD

How about the 123ignition setups?

A brand new distributor that you can set different curves to find one you like.

http://www.123ignition.nl/products.php

I switched from CIS to Webers on my 3.0L and sent the dizzy to one of the best (Barry Hershon) to get rebuilt and recurved. Expensive but worth it and I don't have to worry about dizzy problems for a very long time. Running the 6AL and the engine has been perfect for ~2 years with no maintenance (aside from dirt getting in the Webers).

~$800


Disassemble, clean, inspect all parts, polish, replace upper shaft bushing, replace external hardware, paint small parts
Weld and CNC machine scored underside surface of weight carrier plate attached to distributor shaft
Remove Vacuum can, weld vacuum hub and install cover for vacuum can hole
Replace badly worn lower shaft bushing, which had begun creeping up inside the housing
Assemble unit for calibration mock-up
Replace shims and washers, set end play
Install High Performance components
Calibrate unit for carburetors and hot climate
Construct MSD Direct Cable without Green Trigger Wire

I've installed one of these distributorless ignition systems: Megajolt. The car is only kind of on the road so far due to other tuning issues, but so far I've been really happy with the Megajolt system.

Its a crankfired system, allows for a 3D (ie load based) ignition map, has a programmable rev limiter, and has other RPM based programmable channels. I'm looking into how to use these to replace the rpm transducer that controls the fuel shutoff solenoid on my MFI pump.

That looks interesting. They have a model where you can adjust the curve using your cell phone. That's pretty crazy. If a recurve is $590 or so- the price doesn't really sound that bad. Does anyone have experience with these? I have read several good reviews online. If it works as described then the big issue would simply be finding the right curve numbers from someone. Does anyone know of a place to get different curve numbers for different setups?

I think McMark just installed a bluetooth version a few weeks ago. (not sure if on a /4 or /6)

I will try one out and let everyone know how it goes. I just ordered one. Any idea where to get curve data?

Lock current distributor spend $200 get cb black box. Works great on my 4 cylinders. Has option 4-6-8 cylinders

http://www.cbperformance.com/CB-s-Black-Bo...dule-p/2013.htm

i will start out by saying please flame me. this question is some what stupid. recurve the distributor. sure heavier springs, lighter springs, heavier weights, lighter weights, all affect the rate of advance. whatevr the set up, timing is done at fully advanced. that can be 27 degrees or 34 degrees. achieved by rpms, weight of advance cams and springs. the dist. will only advance to the point it is set at max. idle is set at no advance. recurving is not really an option on a mechanical advance. only a rate of advance from idle to fully advanced. so, unless you are going to a distributorless ignition, your "curve" options are limited to spring rates and weights on the advance unit in the dist. i hope this answers your question.