Distributor curve

barryr · 02-21-2010, 05:38 PM

I have been reading and reading this forum looking for information on one of my distributors and can't seem to find it. Does anybody have a graph of the curve for a 0231 184 004?
Also, when people send their distributors out to "x" to get re-curved what do they re-curve it to?
My engine is a 2.4T with 2.2 S pistons and sleeves, GE40 cams, heads ported to match manifolds and SDS EFI.
It just seams to be missing that "snap" that I expect.
Thank You
Barry

RoninLB · 02-21-2010, 10:15 PM

I have that dizzy listed as a 2.7 RS and 2.7 Euro in my notes

it's the one I use

Flieger · Flieger's Garage

barryr · 02-22-2010, 05:24 PM

Thank You for the information gentlemen.

I also have a 2.4 T 0231 169 008 dizzy in good shape. Needs cleaning but no end shaft play.

In looking at the graphs it would seem that Porsche had the 2.4 distributor advance sooner to try to retain some of the performance of the 2.2 over that of the 2.4 with it's lower compression engine?

I noticed that the 2.7 also has less total advance 26 deg at the crank versus 36 for the 2.4.

Which would be the better choice for my engine?

My engine is a 2.4T with 2.2 S pistons (10 ish compression?) and sleeves, GE40 cams, heads ported to match manifolds and SDS EFI

Any opinions?

Barry

RoninLB · 02-22-2010, 10:42 PM

I can't really offer advice beyond my engine except that all the compression ratios from the 1972,73 P Spec Manual reads 7.5:1 - 8.5:1

the 10 BTDC initial / 35 max from the RS 004 works great with carbs and 8.5:1

your comment "(10 ish compression?) " means your dealing with a max advance around 28deg, probably

you need more advice than I can offer

barryr · 02-23-2010, 04:40 PM

Thanks RoninLB
Yes the "(10 ish compression?) "comment refers to, if you use 2.2 S pistons in a 2.4 the compression ratio gets a .5 bump over the 9.8 of the 2.2S, or so. The GE 40 cams that I have are supposed to be between an "E" and "S" in performance.
Anybody else care to weigh in on the distributor choice and total advance at 6,000 RPM?
Thanks
Barry

barryr · 02-25-2010, 04:54 PM

any thoughts? anybody?
Barry

Steve@Rennsport · 02-25-2010, 05:59 PM

Barry,

One of THE most aspects of determining one's maximum advance at any given RPM is the fuel octane.

If one has 93-94 or better, you can pretty much do whatever you want. OTOH, if you have nothing but 91, that truly limits the advance, especially at 10:1 CR.

One needs to know your exact CR and what fuel you will use before making specific recommendations,........

hpmad · 02-25-2010, 06:34 PM

hello,

since I need to check my own car timing, does anyone has the advance curve for a 911 SC 1980?

thanks, cyrille

barryr · 02-25-2010, 08:27 PM

Quote:

Originally Posted by Steve@Rennsport

Barry,

One of THE most aspects of determining one's maximum advance at any given RPM is the fuel octane.

If one has 93-94 or better, you can pretty much do whatever you want. OTOH, if you have nothing but 91, that truly limits the advance, especially at 10:1 CR.

One needs to know your exact CR and what fuel you will use before making specific recommendations,........

Hi Steve
I would say the exact CR is 10.3:1 and the best fuel that is readily available would be 91 octane
Thank You
Barry

Gunter · Gunter's Garage

Barry,

Don't you get Chevron 94 octane in Regina? We do in BC.

10.3 CR on single plug with 91 octane calls for very careful timing.

Even if you clean/oil your distributor, you don't know what the curve is in situ.
Also, any curve posted for any given distributor doesn't mean that it is the same for yours; only testing it will show the actual curve.

In short, you need to have yours re-curved to the specs of your engine by an expert like Steve. It requires manipulating/tweeking weights and springs and is not cheap.

However, it's a lot less $$ than a damaged engine due to detonation.

barryr · 02-26-2010, 12:13 PM

Hi Gunter
Nope, no Chevron station. I wish we did. Years ago we took a trip out to the coast in a Maxima and filled up with 94 on the way back. The engine electronics would continually adjust the mixture and timing to get the most performance out of the fuel/engine. I would typically get about 800K out of a tank. Using the 94 I got just about 1000k out of the tank on the way back.

OK. I guess once I get the car back together and it warms up a bit I will try both in the engine and plot the curve. Just to see what is what.

I have a long list of things I want to do to my car by May. We are planing to go on one of the WRR drives near the end of May

Barry

356robo · 02-27-2010, 08:31 AM

My 2.2 T was rebuilt with S pistons, cylinders, and E cams. I replaced a T (008) distributor with an S (007). The difference was significant. You can replace your T distributor with an E (006) or an S (007) because the E and S curves are the same for the 2.2. An option for you would be to send yours out to be recurved to S specs. It will be worth the money. Contact "vintagewerks.com". I was very happy with his work.

Rob