OZ head Running rich, timing problems HELP??

[Anonymous]

OK so we fired up the car w/ oz head today. Running holley 350cfm carb. Running very rich and can not seem to lean it out anywhere near enough? We can not seem to be able to turn the screws enough to be where it is supposed to be. Not sure if i got ahold of a bad carb or what? than as we do try to lean it out it begins to stall. This brings me to my second problem. I am running dizzy 2 w/ msd 6a box and my timing is completely screwed up. When we have the car ideling and put a timing light to it we get readings up into the 50's!! I have never seen anything like it. Also seem to be having some problems w/ vacuum. highest reading we got was about 15 and it was as low as 10. Anyone gone threw this or have any advice would be greatly appreciated. We stopped for now as we are stumped and I was really hoping someone out there might have some advice/ideas. Also temp gauge is reading hot more often than not. Never drove it at all. Tough the heater hoses and one seems only warm and the other is cold. Any ideas on this?
Thanks in advance for the help, Mark

 

[Mustangaroo]

First off sounds like the low vacumn is do to a vacumn leak, very common with these Aussie 2v intakes, I have been making my own from gasket material. You must first fix the vacumn leak and fix your timing problems before tuning the carb. A good starting point for the jets is about 64-66 jet size. You can use starting fluid spray can to shoot along the intake where it joins the head both on top and below as best you can, when you find the leaking spot the engine will smooth out or increase in RPM if the vacum leak is in the intake, check you carb for un-pluged vacumn ports and check all vacumn hoses for cracks.

 

[65coupei6]

What Mustangaroo said. Plus, did you change the cam? A higher performance cam will give you a lower vacuum reading.

Check for vacuum leaks, then adjust your timing.

As, for the carb you say it is a 350 cfm. There are alot of 350's out there even Holley 2300 models. What is the model number? Some of the newer carbs were supposed to be on smog equipped cars.
So, on a non-smog carb you turn the screws in the lean it out but on a smog carb you turn it in the richen it.

 

[addo]

I always use Permatex #3 on the 2V intake gaskets. From the stains I have found on some original units, I believe MoFoCo used a very similar - if not the same - product. Best of all, when the stuff is fairly new and warm, you can easily peel the intake off the head and reuse the gasket.

Are you sure you're timing off the right lead? There are 6 leads out the dizzy; that's 50° (distributor degrees) between each. If the plugs are hooked up "one off" you could be 50 crank degrees early or late. Either would screw your idle. I suspect there is a notch or mark on the D-II where the #1 triggers. Look for it and work your way through the sitcheration.

Regards, Adam.

 

[Anonymous]

and also make sure that the mark on your balancer is in sync with the actual piston

 

[Anonymous]

Thanks guys, I will use your advice tomorrow and see if we can get everything straight. Mustangaroo, how do you make your gaskets? Do you cut one big gasket or do you make it in sections? Also what do you use to make them? Thanks again guys for all the help, Mark

 

[CobraSix]

When putting my gaskets on...after hearing a lot of problems here, I put a lot of gasket sealer on the intake. No leaks what so ever. Definitely sounds like you have a vacuum leak, unless you are running like a 320* cam. With a 260 and Aus head, I'm running at 16"hg at 600 RPM idle.

I had a vacuum leak on my car...but it was caused by a vacuum port I didn't see. Make sure they are all unplugged...and search the carb good. I had 3 ports on mine that needed hookups, ported, unported, and PCV. I had to plug the unported...I forgot about that one.

Once that is settled, then look to your jetting.

Slade

 

[Anonymous]

Six, thanks. I am only running a mild cam a 260. I figure that should not cause any problems. Thanks for the info. Mark

 

[MustangSix]

Your vacuum is probably low because the ignition has the engine running like poo. It is acting like it is running rich because it is firing at the wrong time and you're getting an incomplete burn. You cannot fix either problem until you get the ignition sorted out.

You must fix the timing before you do anything else. I can't imagine that an engine would even start, much less idle, with 50 degrees advance. You must have an indicator out of whack (slipped balancer or wrong mark) or possibly are reading the wrong plug (hooked to #5 by mistake?). Another less likely possibility is that the MSD is very powerful and is bridging the gap inside the cap allowing some WAY out of spec timing that still lets the engine run (badly). Another unlikely possibility is a badly made distributor cap that is way out of phase.

Check to make sure ignition is absolutely correct before tinkering with the carb or chasing vacuum leaks that may not be there. 95% of all "carburetor problems" are in the ignition.

Pull the #1 plug, remove the coil wire, and crank the engine to determine TDC. Set the timing mark to the desired ignition advance. With the cap off, the rotor should be pointed to the #1 terminal. If your advance were 50 degrees, it would be pointed closer to #4, and I don't think that's likely.

 

[addo]

The engine wouldn't run with 50° advance - well, not once the carb had sailed past your nose after an almighty backfire. But 50 retard - that's actually firing 100° ATDC, so it will run really lame.

 

[Anonymous]

Thanks guys! You have given me a lot of really good info. I will go out tonight and see what more we can do w/ this new info. Thanks again and I will keep you posted!!
Mark