Whomever assembled this motor thought that the made in china dress up kit would be cool, only problem is that pointer is nowhere near accurate. Can I use a vaccuum reading to set timing? If so how?

 

Best way is to make new timing marks that are accurate, find top dead center on the compression stroke on #1 cylinder and make some kind of mark you can see well that lines up with the make on the dampener. Computer controlled engines need to be timed correctly, if the engine is not computer controlled the timing can be set by getting the highest vacuum reading and smoothest and highest idle RPM, then if it's idling too high adjust the idle screw to get the correct RPM. Just listen for pinging under heavy throttle and back off the timing if you hear any. Good luck!!

 

Stole It,

The vacuum gauge method will be a good indication if your engine is stock, but more aggressive cam profiles and different cam timings will change the vacuum readings enough so that the method might not be that reliable. If the engine has an ECM, make sure you bypass the EST before setting the timing by this method, or the ECM will just try to compensate and skew your results.

Making up a new pointer (even a temporary one to set the base timing) is probably your best bet. I've seen some of those aftermarket "Chinesium" dress kits that you speak of. At least the timing tab is on the correct side of the engine, but that's about all.

 

Thanks guys, the car isnt computer controlled and is fairly stock, intake carb and mild cam, headers. I used this method (highest vaccuum) to set it, I just didnt know how accurate it would be.

 

Out of curiosity, how do you find tdc if your timing marks are wrong? I know how to tell when you hit the compression stroke, but dont know how you would tell when you were at tdc.

Ben

 

There might be a better way but I have used one of those little plastic coffee straws, take out the plugs, have a buddy turn the engine over by hand and stick the straw in the #1 cylinder just after it has started it's compression stroke, just don't drop it all the way in!!! As the engine is turned the piston will start to push out the straw, when the straw stops being pushed out of the plug hole you should be at TDC. You should repeat this 3 or 4 times to make sure you get the same reading.

 

The most accurate method is with a degree wheel and piston stop, but the "straw" can work to get you close. The main thing is to get a reference mark, set the timing, then make incremental changes based on that mark, Every engine runns a little differently, so the "numbers" are not like gospel - they can change slightly for every engine. Just work to find th eplace where you'r runs best. In doing so, a reference mark of some kind will be helpfule.

What I can tell you is that the keyway in the crank snout is machined at TDC of the #1 crank throw. If you can see the keyway, yo can make a mark or pointer based on the position of that. At least you might be able to see how close the straw method is.

 

It is accurate enough to use, I dont use a light anymore on my cars anyway. Plug in the vacuum guage advance the distributor untill max vacuum is read then back it off 2 inches of vacuum. This will put you far enough out to run well and back enough to keep you out of detonation.