FE390 stroked to 445cui -which Timing ?

[Stephan427SC]

Hi Guss,
My FE390 Engine ist stroked to 445 cui and I want to Set timing . What is the right Timing @ Idle and Full Advance for this Engine ? Cam has 110 lobe and the Engine has 4 IDA Webers on top....

Thanks, Stephan

[DanEC]

Who built your motor - this is a good question for them as they would know all of the particulars. Your compression, head type, distributor set up are all factors in your question. The Webbers may or may not also be a factor. In a general sense - 36 degrees total timing (initial and centrifugal) is a pretty safe setting (vacuum advance plugged). Do you have a dial back timing light and know the specs on centrifugal advance for your distributor?

[Stephan427SC]

Hi DanEC,
thanks for your reply. The engine has a edelbrock Performer rpm head and a MSD-8594 Pro Billet Distributor with mechanical advance.....

[DanEC]

From your response I'm going to assume you don't know how much centrifugal advance your distributor is set up for and I don't know enough about MSD stuff to know what it takes to determine this. The best think you can do is get a dial-back timing light. With a dial back TL you can rev the engine to about 3000 rpm (that should bring in all of the centrifugal advance) and adjust the dial on the TL until the timing marks are reading 0 deg TDC. By reading the dial setting you will know what your total timing is - probably 30+ degrees. Then let the motor idle and adjust the timing dial until you again are reading 0 deg TDC and read the dial again. This will tell you what your current inital advance setting is (probably somewhere around 10 - 16 degrees). The difference in the two is the amount of centrifugal or mechanical advance the distributor is set for. With this information you can determine what adjustments, if any, you need to make for good performance.

Without knowing if you have aluminum heads or your compression it's a shot in the dark as to what total timing you should be running. My 459 FE has hi perf steel heads with 9:1 compression and Keith Craft recommended running as much as 40 degrees total timing - but I currently have it set for 38 degrees. Aluminum heads will usually allow a bit more timing but the builder may have increased compression due to the aluminum heads - in which case you may have to pull the timing back a little.

The simplist approach is to set your initial timing at 16 degrees and see how it runs. If you don't notice any pinging then you might try a couple more degrees and see how it does. If 16 degrees produces pinging then pull out 2 degrees and re-check. Of course with side pipes and a light car, trying to detect pinging or detonation is pretty iffy.

[lippy]

Dial back timing lights don't normally work with MSDs. Get an old school Sears light or something like it. I started with using the black distributor bushing (18 degrees) and then I set total timing at 36. This way I could get more initial advance and set my butterfly transfer slots properly.