Distributor timing question

[gereed75]

Just started my 2.4 after a complete rebuild. I have the distributor turned as far counterclockwise as possible and can only get about 20 degrees advance (checking with timing light). It appears that I have to re-time the distributor one gear tooth.

In which direction should it be turned to get more advance?? Thanks

[OsoMoore]

I don't know 2.4s, but my 3.0 SC has a factory spec of 5 degrees advance. 20 sounds way too high. Be sure to check the factory spec for the 2.4.

[gereed75]

The 20 degrees is at 4000 rpm. I am trying to get 30 degree at full advance. 2.4, 9.5:1 single plug mod solex cams

[911pcars]

Remove distributor and re-engage the dist. gear one tooth in the opposite direction of rotation. That should provide enough "swing" space to rotate the housing further.

Sherwood

[E Sully]

The distributor does not reach full advance at 4000 rpm. You need to take it to 6000 rpm.
You also need to make sure the advance weights are moving freely. If they are sticking they will not give you enough advance.
See if the vacuum pod is working. If it is frozen or not holding vacuum it will affect your timing at idle. Recommended method to set timing is 5" ATDC with vacuum line connected, 900 rpm.
If you need more advance from the distributor, and the housing is fully counter clockwise, I would think you need to move the gear one tooth clockwise.

[gereed75]

Thanks This is a 008 distributor from an MFI T. The 20 degrees I am seeing is at 4000 RPM. It may not be fully advanced at that point but every advance curve I can find shows more advance at 4000 Than 20 degrees. Most show 30.

Advice from Bruce on the re-build board is one gear tooth CCW that will make 30 degrees more advance available.

I will give that a try.

[Jonny H]

I don't know the spec for your T but I do know that the curves published by Porsche can sometimes be misleading. Some show crank advance, some show distributor advance (half the amount). Some show the complete engine timing, some show just the distributor timing.

For example, the SC graph shows the graph for the distributor advance and RPM so both axes values need to be doubled to get to engine advance and RPM. It also doesn't take into account the static advance of 5 degrees which needs to be added.

Post up the graph you are referring to.

[gereed75]

You are correct in that there seems to be a lot of confusion (for me anyway) regarding the various timing curves. I believe that The 008 was from a 73 T MFI. It features the vacuum retard and even with that yields less than 30 degrees of total advance (vacuum + mechanical).

from everything that I read, I should try for about 32 degrees total advance on my engine set up (2.4, 9.5:1 single plug mod solex cams). The linked graph is still somewhat misleading as the graph only shows 20 degrees of total advance but the text calls for 32 degrees.

https://www.google.com/search?q=bosch+008+advance+curve&tbm=isch&imgil=JSag4h0gvbgkXM%253A%253BrygMUEkVvm5VAM%253Bh ttp%25253A%25252F%25252Fforums.pelicanparts.com%25 252Fporsche-911-technical-forum%25252F75648-anyone-have-advance-curve-70-911-s-bosch.html&source=iu&pf=m&fir=JSag4h0gvbgkXM%253A%252CrygMUEkVvm5VAM%252C_&biw=1280&bih=913&usg=__XMp9NBe2zylCV1BJ2CMijcL30NU%3D&ved=0CFcQyjdqFQoTCMOIiJjGhccCFQKpHgodrEcHyQ&ei=6IG7VcP0LoLSeqyPncgM#imgrc=JSag4h0gvbgkXM%3A&usg=__XMp9NBe2zylCV1BJ2CMijcL30NU%3D

Any further help would be appreciated,

[Walter_Middie]

Gereed75,

The graph you have a link for shows advance at the distributor. In other words, that is only the centrifugal advance that the dist adds due to engine RPM. It doesn't include the initial advance that most people set at idle.

Total advance includes both the initial advance at idle and centrifugal advance due to engine RPM. This is why it is important to set both. Just setting idle or initial advance does not check that the dist advance weights are working correctly.

Set the initial advance at idle according to your engine specs, then rev to 6,000 RPM to check total advance. If both are within spec, your advance systems are probably working correctly. If both cannot be set, one or the other advance systems needs work.

[E Sully]

What is the full number on your distributor? I believe the 0231 159 008 is originaly for a 2.2 liter. An 0231 169 008 is from a late '73 2.4T cis. Yours originaly should be of the 0231 169 00x type.

[gereed75]

Hmmmmm good question. Did not know there were two versions of the 008.

The motor was installed in my 914-6 by a PO. It is a bit of a bastard child .... 2.4 with Mahle Birals with 901/51 engine number with carbs. I thought that was MFI T.

Could be CIS??? Of course could be any distributor slapped in there. It has the vacuum retard feature. I will check the number again tonight.