75 2.7S CIS w/ Webers, cam options?

[jpsurfer]

I would like to know if I can safely run either Solex or E cams in this setup without changing from the stock pistons or modifying them? As title states motor is a 1975 2.7S and currently has stock cams, Weber 40s, headers, and sport muffler. Any help would be greatly appreciated.

[Steve@Rennsport]

Nossir,.....the biggest cam you can run with stock CIS pistons are 964 ones.

Some people machine the domes for Solex or S cams, however I think thats a bad idea considering these are cast pistons. Further, these are really not suitable for 7K RPM operation.

[jpsurfer]

Thanks Steve, that is very useful to know and will help in my decision as to where to go with my car. Is the 964 cam a good improvement over CIS cam or not really worth switching to? Would I see more power or a more useful powerband etc when paired with the carbs?

[tonizzos]

Originally Posted by jpsurfer

Thanks Steve, that is very useful to know and will help in my decision as to where to go with my car. Is the 964 cam a good improvement over CIS cam or not really worth switching to? Would I see more power or a more useful powerband etc when paired with the carbs?

That s a very good question, i have the same setup like you and was wondering too wath cam would be ok to just swap in without any other modification...

Cheers
Steve

[Steve@Rennsport]

JMHO, but I think its well worthwhile installing a 964 grind cam in your engine. You'll get improved mid-range power and thats what this is all about,....

[tonizzos]

Originally Posted by Steve@Rennsport

JMHO, but I think its well worthwhile installing a 964 grind cam in your engine. You'll get improved mid-range power and thats what this is all about,....

Ok so if i understood well.. I take my original cis 2.7s engine with 40 webers and i can put 964 cams in it to get a better mid-range power...
I realy like the engine, but i had a 2.0s before.... This engine is realy nice for driving to work... But i would like a little bit more rev enthusiasm...

[Steve@Rennsport]

Originally Posted by tonizzos

Ok so if i understood well.. I take my original cis 2.7s engine with 40 webers and i can put 964 cams in it to get a better mid-range power...
I realy like the engine, but i had a 2.0s before.... This engine is realy nice for driving to work... But i would like a little bit more rev enthusiasm...

OEM 964 cams will not fit your 3-bearing cam housings, however you can buy new 964-grind cams from companies like Elgin or Webcam.

If you want it to rev, you MUST change pistons to allow anything remotely close to that 2.0S. Further, you really really don't want to run the cast CIS pistons beyond 6600 RPM.

[tonizzos]

Originally Posted by Steve@Rennsport

OEM 964 cams will not fit your 3-bearing cam housings, however you can buy new 964-grind cams from companies like Elgin or Webcam.

If you want it to rev, you MUST change pistons to allow anything remotely close to that 2.0S. Further, you really really don't want to run the cast CIS pistons beyond 6600 RPM.

i know that the best would be to change the CIS pistons , but the engine has been redone before i bought the car ... it has only 2500 miles since the rebuilt and he used new P&C .. unfortunately CIS pistons...
so i wanted to use it a little bit before tinking about RS P&C

i realy enjoy the engine , but as i wrote it could be a little bit more "nervus".. that s why i tought that changing the cams could be a nice idea without spending to much money...

in any case thanks for your infos

cheers
steve