| Author | Message | ||
     Chris Tokarski New User Username: 49bentley Post Number: 30 Registered: 10-2024 |
I'm having a hard time starting my 49 MK VI.What should the static timing be for the car? Thanks | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 746 Registered: 07-2018 |
With modern fuels today, I set mine at 3 degrees before top dead centre. That's a static timing done while the engine isn't running. | ||
| Chris Tokarski New User Username: 49bentley Post Number: 31 Registered: 10-2024 |
Thanks Jeff. How can you tell how many degrees, as there are only 3 rows of o's seen on the flywheel. The center being TDC. | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 747 Registered: 07-2018 |
It's just not that critical on a low compression engine like this for initial set and start-up procedures. TDC is fine an 1/8 of an inch before the TDC line will work well enough. If you want to get it dead accurate, a timing light where you can adjust the degrees on is nice to have. I'm assuming that the rotor is pointing no #1 when the flywheel is at TDC ? The instructions in the manual with the light bulb works very well and is simple. The rotor turns clock wise, so you turn the distributor body counter clockwise until the light goes out, that's when you get your spark. Points are set at 20 thou. Firing order is on the distributor cap. I don't want to talk down to you here, so I won't go any further unless you ask, but many people get confused about ignition timing and forget that the rotor turns half the speed of the engine. Other things; check the spark at the coil once you get the ignition timing set up, then from the wire to the cap. Check the steel spikes on the distributor cap for corrosion, even more so if the car has been stored where it's cold and damp. If it is cold and damp, it will have to be choked to full with the throttle about half open. If you have the built in resistor on the rotor, don't run resistor plugs or wires. I'd be curios what the compression is, but it should still start even if something is wrong there. If it was running, the ignition timing won't need adjusting. | ||
| Chris Tokarski New User Username: 49bentley Post Number: 32 Registered: 10-2024 |
Hi Jeff. Thanks a million for all the help. Finally got the engine to run. Used the light bulb trick to set the timing. Looks like the timing was off. The engine was firing past tdc, but just a bit. That is why I did manage to get it going a couple of times before. Now its running well. Will need to adjust the carbs. I had the engine rebuilt quite a few years ago. My compression tester shows all cylinders between 62 and 72 psi, but the tester might be off. Thanks again. Chris | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 748 Registered: 07-2018 |
That's a low compression number even for that engine, were the butterfly valves on the carbs all the way open, to get full compression atmosphere has to be able to get into the engine ? My engine is at 115 psi after a complete rebuild some 22,000 miles later, but I used aftermarket forged pistons with modern rings and such. The bores were fully sleeved and brought back to it's 3.5 inch bore. Do you know if you're still running the half chimney liners ? | ||
| Chris Tokarski New User Username: 49bentley Post Number: 33 Registered: 10-2024 |
Hi Jeff, The engine was cold and no the butterfly valves were closed. I'll retest the compression again with valve open and engine warm. When engine was rebuilt no liner was put in. | ||
| Chris Tokarski New User Username: 49bentley Post Number: 34 Registered: 10-2024 |
Hi Jeff, Did a engine leak-down test which showed 5-10 % drop. Which is supposed to be excellent. compression is between 68-72 with engine warm. Did a wet test, no change in compression. Checked valve clearances, intake - 0.006", exhaust - 0.012". Had garage check my compression gauge, which looked to be accurate. Played with timing. got engine running with a 16degree advance. Tuned carbs, running pretty well at 925 RPM. Will work on carbs & rpm later. 16 degree advance seems a little high?? Any ideas? Cheers Chris | ||
| Jeff Martin Frequent User Username: jeff_r_1 Post Number: 749 Registered: 07-2018 |
16 degrees seems a bit much, I would go 9, but no more. Book says 3 before TDC with modern fuels, but that info is outdated. When you're cranking and the engine kicks back, then it's advanced too much. Listen for "pinging" when you take it out on the highway and when accelerating hard up long hills when driving at speed down the highway. The advance weights give around 25 to 30 degrees at full advance (with out checking) so adding 16 to that is pushing it. RPM is a bit high too, should be at 600rpm, and others say 400 or even 350, but that's demanding a lot. To get one of these engine to idle that slow and sit there still, all things have to be perfect. One of the main reason's for a lumpy idle are worn exhaust guides, stems, seats, and valves. It creates this "Pfft" in the exhaust at idle The other is a worn distributor shaft and bushing when running duel points. With those two things going on, it's quite difficult to properly set the carbs. | ||
| Chris Tokarski New User Username: 49bentley Post Number: 35 Registered: 10-2024 |
Thanks Jeff. Will look into these items mentioned. Cheers Chris | ||
| ChristopherCarnley Unregistered guest Posted From: 86.148.160.11 |
Chris, See the "Service Hand Book" on this site. The instructions can be a bit confusing and it depends on the timing marks on the flywheel and also have you installed the damper/ cam wheel correctly? The "Service Bulletins" are worth consulting. (Message approved by david_gore) |
