help on knowledge for fitment of 3.0 cis engine in my 914
 

Hello fellow porsche lovers. I am in the process of installing a 3.0 cis engine in my 914. I want to keep the cis for its reliability as I want to have a reliable driver. I have all fo the conversion pieces in place and the engine installed but it looks like I have to remove all of the frequency valve parts to make it fit. Removing all of these parts as I was told is ok?? I would love to know the pros and cons. Also the other abstacol in my way is that the cis is to tall. I have heard of a stainless steel air box that is shorter? Any feed back would be greatly appreciated !l

You might try asking on the 911 forums about the frequency valve in the CIS. I'd be inclined to leave it in if possible, since there usually aren't many extra parts on these motors.

The height can be dealt with in a number of ways. Several of the mounting systems allow the engine to be installed slightly lower, which helps.

Some conversions will cut the rear bulkhead where it fouls the fuel distributor, and either make a cover plate or weld in a fabricated metal "bump out" for clearance. Either way the engine lid latch gets removed, so it either gets relocated or hood pins are used to secure the lid.

Another option is supposedly to flip the entire system by 180 degrees on the engine, which apparently gets it out of the way of the bulkhead. Fuel lines have to be re-made at this point, but that is fairly simple fabrication.

--DD

914/3 liter
 

Had one
Here is picture of engine lid notch. A notch was also cut in bullhead per Dave D. When they cut grill it was “folded” flat so as not to have sharp edge.
Good luck


http://forums.pelicanparts.com/uploa...1646399549.jpg

Thank you for the input!

Issue for 3 liter
 

I forgot to mention another issue but not related to fitment.
Stock 4 cylinder CV joints are insufficient in my experience.
While all failures were at the track, I changed to Renegade axles with heavy CVs and have eliminated the problem. If you are just a cruiser stock may be fine…….just my experience.

be gentle with it and CV will survive

the CIS version that uses a frequency valve, i believe, requires the frequency valve to be present and at least running in open loop mode.

if you wanted to go with a CIS version such pre-lamda (aka K-lambda) you would not need the frequency valve or the computer part of the CIS system. I have both, 1978 911SC and a 1981 911SC. the intake runners are larger for the pre-lambda system so you would need to get your heads bored to match, or perhaps you could just use the everything from the air-box up. All of this adds up to some cash along the way and at some point you might consider going to carbs or perhaps Electronic Fuel Injection. I have been eyeballing the X-Faktory EFI system for just a tad over 5K and it looks like a really good package.

Or an relatively inexpensive Bitz EFI conversion for the CIS.