Need Cam Timing Specs
 

Okay, I searched but it's the proverbial needle in a haystack. So, here's my plea for help...

I have a 69 911T. The engine was rebuilt with 2.2 "S" pistons, 2.7 "S" crank and rods, and "E" cams. I don't know what year the cams came from but I have never heard of a different range of specs for the "E" cam.

Does anybody out there know what the ideal cam timing for this engine should be?


Thanks!

I would use the cam timing for an E engine 3-3.3mm overlap. Essentially you have a 2.4 L engine. 84 mm bore , 70.4 mm stoke but probably with more compression than the stock 2.4 l engine.. The 69 had a 80 mm bore and 66 mm stroke. the 2.2 had 84 mm bore and 66 mm stroke. Your S pistons have more valve cutout than an E piston would so you may want to experiment with more overlap and see if it gets you anything in the way of hp or torque. The S spec overlap with S cams was 5mm so i would think thatyou have some room to play with if you want. Have fun.

This info is great and makes perfect sense. I knew I could count on someone from the board.

Thanks for the help!

I bet that is a screamer of an engine. Those 2.2S pistons were 9.8:1 with the 66mm crank. you are well above 10.5:1 with that 70.4mm crank. I just hope they opened the heads on that 2.0T motor for you to take advantage of it.

Yeah, it runs pretty good for a 2.4...

0-60 about six seconds flat and 14.5 in the 1/4 mile (car is only 2150 pounds which definitely helps!).

Thanks again for the help!

David

Well ... there were different timing specs used over the years for the 'E' engines, unlike the early 'S' cams!

Here are the '72 - '73 2.4E specs ...

http://forums.pelicanparts.com/uploa...1088021342.jpg

I have this book for 1970-71 but I didn't have the data you gave me. I think they are the same but it's good to confirm. Thanks!

the '70-71 book should show 3.0-3.3 for the E

I timed to 3.1.. the differences may have been due to smog.