Noob resurrecting '66 911

[Moron95M3]

Hi All,

First forum post here, lurking since 2003....


I have a 66 911, sitting since 1985, that I am getting going finally. We worked on this a lot in 2002-2003, then it sat (college happened, adult life happened, etc). Here is the status.

Has a '70 914-6 2.0L (6410214), rebuilt in 2003 (not by me), installed. Has never ran until last week.
*I have not checked valve clearance
*I am struggling with timing.

Running all original electrical panel, except have a new 3ohm flamethrower coil, and bypassing the ballast resistor. New plugs, New wires. New cap/rotor. Points have been cleaned and adjusted to .16" (although I'm seeing .12" in the workshop manuals?). Figured the flamethrower will allow me to do an ignitor CDI in the future. Wiring was cut but has been put back together and all is functional (will clean up later...goal is to make sure things work then tiddy up).

Fuel system, added regulator, gauge, and filter. Pulling new fuel from external tank. Getting 2.5psi of fuel pressure. Original(?) Bendix pump.

Bosch Dizzy.

Carbs are 40 IDAs, also rebuilt in 2003 (not by me). These were supposedly tuned to a 2.4L. Carbs are set for mixture screw at 1.5 turns out.

Fresh oil/filter - 2bar oil pressure cold.

Issues I'm having:
I can get the engine to start and even sort of idle, however:
-Seems very rich (or burning oil?). Lots of white in the air, stinks up the garage, burns my eyes.
-Runs generally rough sounding. Revs ok I'll post a video link below.

I went to time it, and found it close to 30 degrees advanced at idle. I went to bring this down and cap wouldn't turn enough. So I determined the wires were put on the cab one cylinder ahead.

Redid wires, clocked the dizzy/cab back so I have adjustment. Now if I get roughly to 10 degrees or less (around idle) I start to get some backfire out the intake. These should be close to 0 degrees at idle, correct??

Muffler installed as well. Has new (2003) heat exchangers. Muffler is oe(?) but a bit rotted out and patched (poorly) for now.

I'm not sure how to get this thing timed...unless I need to adjust carbs a bit first? My thoughts are things are way to rich, but backfiring out the intake usually means lean?

I've seen mixture adj. to start at either 1.5 turns out or 2 turns out, then tune. I'm at 1.5, maybe that is a hair lean?

Or is my fuel pressure just too low? I thought about taking off the filter (it's small and media, not just a screen, so I imagine it's restrictive). I see webers need 3.5psi to be happy. (I figured 2.5 would be enough to keep the bowls full for idle and base timing, but I can be wrong!).


Thanks in advance. I've learned a ton on these forums already, just struggling now when it's getting more specific.

I owe some research:
-Carb setup (??)
-Check Valve clearance
-Fuel pressure w/o filter and regulator




This is with timing close to 25degrees advance.
https://youtube.com/shorts/sA01PLihOaw

Pics for general reference.

Building base tune for the little one, she loves it.

Overall car - garage sucks, working on outbuilding/storage. M3 is in storage to give this one a spot, and that makes me a sad panda.

Engine/etc in current status.

[Rodsrsr]

Backfiring out of the intake is usually either retarded ignition timing or crossed wires. Check the basics first. Put #1 on TDC, confirm rotor is pointing to #1 on distributor cap, turn distributor slightly to give a little advance and this should get you in the ballpark to where the car should start and idle okay so you can fine tune.

You may also have a valve sticking since its been sitting for so long. Run it for a while to get things moving again and see if there's any improvement, but if the wires are correct and its timed properly you can move on to additional troubleshooting if needed. check valve lash, carbs may have issues from sitting to long as well. 2.5 for fuel pressure is a bit on the low side, it should be 3 to 3.5 with Carbs. Also, expect smoke, stink, and roughness after 30 years sitting. Rings need to reseat and Carbs may have revarnished after all this time.

Welcome to the forum!

[roblav]

A sticking Weber float valve is pretty typical for the 40 IDA after sitting a while. Clogged jets too. Your fuel may be clean now, but you don't know if it always was. At some point, you'll need to adjust the idle air screws so the flow through each venturi is the same. Speaking of that, which venturies are in the carbs? They should be 28 or 30mm to match the lowest power 911 engine built. Welcome to the intracies of an early 911.

[Hi_Fi_Guy]

It may be helpful to confirm systems in this order to avoid chasing phantom issues.
Compression, including valve adjustment
Ignition, including timing
Fuel, including carbs

[Moron95M3]

Thank you all!

Will try to sort things out.

-new FLAP fuel pump, regulator adjusted and getting a solid 3.5psi. This seems to have helped some.

-air mix adjusted to 2 turns from 1.5. Also helped.

-ordered a carb synchrometer

-need to order a valve lash feeler.

-messed with timing a bit, advance is working. Seems happy ish around 5btdc, which is a big improvement. Rev’d to 4K and it seems much happier over 1500rpm. Need to finalize timing a tighten down dizzy.

-still seems loud and clanky, but could be partly that the muffler is rotted. Adding muffler didn’t change sound level much at all. Holding on a $800 muffler till later. And after watching some other videos…these are not the smoothest sounding at idle. (I’m used to 90s bmw I6s).

-also found my original 66 oil temp sensor as this engine had the newer one, saved $230 by locating the old one…and functions well. I was nervous running too long without a working temp gauge (pegged gauge with incorrect sender), pressure is there but nervous the oil tstat functions. Happily every gauge works (!) and I’m beyond happy about that.

Next steps:
-valve lash check, and making sure no sticky valves.
-check carbs out a bit, get data. They were rebuilt and dry, so shouldn’t be clogged up, but I should still inspect.

-next next steps include fuel tank removal, cleaning,etc.

…and welding in a front pan. This one’s going to take some time.

…then brakes, clutch cables and throttle linkages.


If I have enough time, this could move this year…