What distributor curve for RS motor?
 

Recently built a replica 2.7RS motor but with carbs instead of MFI.

Single plug
Early S cams
90mm Mahle RS P+C's
Deck height ended up being 1.1mm

Question:

The distributor I have for it is a 2.4T unit. Bosch #0234 169 003. running Pertronix Ignitors.

Should I re-curve to S-spec considering Cali gas (91 octane)? Should I have the vacuum connected?

I had a motor just like yours but with MFI. I used the stock 2.4 T distributor and it worked fine. I did have the vacuum line hooked up since it was an MFI car just like the 2.4T. I would think you could use it without the vacuum line. Just check for a max of 35 degrees advance at 6000 RPM. The RS curve is different but not by much.

-Andy

Hi Andy,

Thanks for the reply. In talking with Ed Fall at Vintage Werks today he said the distributor curve was the same for T, E and S but that the rev limiter was different. This makes me wonder if the difference, if any, in advance for T, E, and S motors came from the vacuum.

Hopefully Steve Weiner will chime in.

Bobby,

The RS has LESS mechanical advance and more initial and it is the curve I would choose.

24 deg of mechanical advance with about 12 initial for a total of 38deg. You don't have much compression so you have alot of room to play around with an aggressive curve. If you run into pinging with the RS curve, simply lower your initial untill it goes away.

http://forums.pelicanparts.com/uploa...1227664389.jpg

Thanks Aaron.

I just did a search on the Tech forum and came up with these charts which back up what you are saying. It also shows that the T, E, and S did have the same mechanical curve.

I guess the extra initial advance for the RS is due to the 90mm pistons diameter. Makes sense I guess.

P.S. This graph shows advance at the crank as opposed to distributor advance.

http://forums.pelicanparts.com/uploa...1224035327.jpg
http://forums.pelicanparts.com/uploa...1224035349.jpg

Notice the advance settings are almost the same at 2k, 4k, and 6k. Only below 2k are things much different. Who cares how much power you get below 2k?

-Andy

I use the 2.7 RS/74-76 Euro Carrera 0.231.184.004 dizzy

My act is initial at 10 deg, total at 35.

It's great with carbs... and doable with stock 2.7 CIS cam and CIS.


Brand new w/cap, rotor an points is about $300

004 distributor
 

Anybody want one?