Dad9904

Recently purchased an 85 camaro z28. I was dumb and took the guy at his word it was a 350, suprise it's not. That doesnt bother me because the car is solid no under carriage rust no accidents and suspension and steering is sharp as a tack. I never owned a camaro in the past but good lord this car turns in like a go cart. Im replacing the engine in the spring with a 383 I'm having built. The 305 quadrajet 4 barrel carb is wearing me down and im having one heck of time figuring out what exactly the old owner did with this car. My biggest headache is the timing or atleast figuring the timing out. I have the motor sitting at tdc it has a 12 o'clock timing tab BUT the balancer is sitting at 10 o'clock. The balancer appears to be freshly installed so I don't think it slipped/spun. I know of the 12 o'clock and 2 o'clock timing tabs but not familiar with a 10 o'clock tab or if it exist. I measured the balancer across the center and it's a 8 inch balancer. I have a knock and it's not rod knock I took plugs wires off one by one and it gets a touch louder by doesn't go away. Also I cant get a tach to work. I bought two different equus tach and both didn't read rpms. It's a hei but no vaccum advance option. I just want this 305 to get me behind the wheel long enough to hate the motor .I'm investing every dime into the 383 and getting the trans beefed up to hold what I hope is a 550hp motor. I would greatly appreciate any help with the timing woes and after market tach not reading. I did a ton of reading and can't really find what I'm looking for, this was my last resort. I hate asking for help with what should have been something very simple.

sofakingdom

iTrader: (1)

There's no 10 o'clock crank damper. Either it's slipped or it's otherwise fubar.

The engine doesn't whup out "light" and use it on "mark" and "tab" to get a reading, and then open "book" and look up "spec", and THEN decide how it's gonna run. All it cares, is when the spark occurs, relative to piston motion.

Put down "light". Close "book". Forget "spec". Ignore "mark" and "tab".

Advance it. Enough to be REALLY significant. (seems like, ALMOST ALWAYS, wherever somebody's "timing" is, it's "not enough")

Does it run better? (you get to decide ON YOUR OWN what "better" consists of... more HP, crisper throttle response, lower fuel consumption, cooler running on the freeway, ... use your imagination to imagine "better") Yes / No

Yes: advance it some more.

No: set it back to where it was, then a bit more.

Better? Yes / No

Yes: Whatever you just did, do it some more.

No: Go back a little bit.

Better? Yes / No

...

Are we getting the hint yet?

EFFFF abuncha "mark", "tab", "light", "book", "spec", ... EFFFFFF EVERY BIT OF THAT. Instead, give the engine WHAT IT WANTS. Keeping in mind at all times, THE ENGINE knows FAR BETTER than you EVER will, what will make it run better. And the coolest eeeeeezyest thing of all is, if you GIVE THE ENGINE WHAT IT WANTS, it RUNS BETTER. Give it something else, ... YOU do the math.

Allow me to paraphrase one of the GOATs in a completely unrelated field, who, had he been working on a car instead of what he was doing (among the best there ever was) for a living, would have answered:

If it RUNS good, it IS good.

Keep adjusting as described above until ANY adjustment you make, in EITHER direction, makes YOUR engine run NOT better, according to YOUR preferences, with the fuel YOU have available, in the place YOU drive it, with the conditions (temp, humidity, altitude, etc.) that YOU are in, on the roads YOU drive on, the way YOU drive the car, and what's important to YOU. YOU get to be the ultimate arbiter of all this, not "book", not "us", not "consensus", not "the Internet". YOU. Once you get to that point, then THIS particular adjustment is as "good" as it can get.

You may well find that OTHER adjustments such as mixture or idle speed or whatever, need to be reset. Do the same with each of those. "If it RUNS good, it IS good". Every one.

THEN AND ONLY THEN, pick back up "light" and look at "mark" and "tab"; and make a note of where it is. Then, if Skillet comes along later and decides THEY "know" better somehow where your engine wants the "timing" to be, better than THE ENGINE knows, you can un-screw-up whatever they did, and put it back to optimum. Assuming of course that your crank damper's inertia ring (blob of SPOOGE) hasn't wandered some more some way somehow, as they all inevitably and inexorably do. Notoriously inaccurate, inconsistent, and unreliable.

Any number we can give you is only as "accurate" as your "mark" and "tab". None of which is in any manner way shape form or fashion, "reliable".

For all the half-century or so that I've been in this hobby, THAT'S how we got a car to run right. Measured interval on the Earth whether pavement or not (this culvert to that, this stoplight to the next, lap times on the track, how hard it comes up off the corners on a tacky/sticky/loose/dry oval, ET and MPH, etc.), and a stopwatch. Modern conveniences like WB O2 sen-sores and cell phones and GPS and things like that, are a MAJOR help, but by no means indispensable. We have always called this process "TUNING". Learn it, live it, practice it, LOVE it, it works EVERY TIME. If the car goes faster, your change was good; if the car slows down, not so much. Tweeeek whatever handles your setup has (static timing, dist curve, carb parameters, etc.) until it's as good as it can be. Once you get to that point, it's ... as good as it can be.

Questions?

Dad9904

I'm confused do you think I'm a teenager who just got his first car and asking dumb questions? I'm a 41 yr old man who has built and raced fords since I was 16. Im not sure where the anger and hostility came from perhaps drinking, i can't say because I don't know you and your advice is about as useful as a screen door on a submarine. If.i wanted seat of the pants, putting my ear to the motor I would have just gone and done that but actually wanted so clarity on timing tabs for the sbc and a possible fix for a after market tach issue. I'm glad you've done this for 3 or 4 decades but your response os exactly what a 20 yr old without a clue would tell somebody. I hope people just don't blindly follow your science because that would spell disaster for many engines. There is a right way to do things and then whatever non sense you effffffing blabbering about in your post. I'm sorry I ever posted on this site because after reading your post I think I actually lost knowledge not gained it. Thank God I wasn't asking how to setup initial timing on a new motor because your logic of just feel for it maaaannn would cost me a motor. God people on the internet are just so full of themselves and arrogant, get back to your budlight and ill simply find somebody who actually knows what their talking about far away from this trash website.





QUOTE=sofakingdom;6510279]There's no 10 o'clock crank damper. Either it's slipped or it's otherwise fubar.

The engine doesn't whup out "light" and use it on "mark" and "tab" to get a reading, and then open "book" and look up "spec", and THEN decide how it's gonna run. All it cares, is when the spark occurs, relative to piston motion.

Put down "light". Close "book". Forget "spec". Ignore "mark" and "tab".

Advance it. Enough to be REALLY significant. (seems like, ALMOST ALWAYS, wherever somebody's "timing" is, it's "not enough")

Does it run better? (you get to decide ON YOUR OWN what "better" consists of... more HP, crisper throttle response, lower fuel consumption, cooler running on the freeway, ... use your imagination to imagine "better") Yes / No

Yes: advance it some more.

No: set it back to where it was, then a bit more.

Better? Yes / No

Yes: Whatever you just did, do it some more.

No: Go back a little bit.

Better? Yes / No

...

Are we getting the hint yet?

EFFFF abuncha "mark", "tab", "light", "book", "spec", ... EFFFFFF EVERY BIT OF THAT. Instead, give the engine WHAT IT WANTS. Keeping in mind at all times, THE ENGINE knows FAR BETTER than you EVER will, what will make it run better. And the coolest eeeeeezyest thing of all is, if you GIVE THE ENGINE WHAT IT WANTS, it RUNS BETTER. Give it something else, ... YOU do the math.

Allow me to paraphrase one of the GOATs in a completely unrelated field, who, had he been working on a car instead of what he was doing (among the best there ever was) for a living, would have answered:

If it RUNS good, it IS good.

Keep adjusting as described above until ANY adjustment you make, in EITHER direction, makes YOUR engine run NOT better, according to YOUR preferences, with the fuel YOU have available, in the place YOU drive it, with the conditions (temp, humidity, altitude, etc.) that YOU are in, on the roads YOU drive on, the way YOU drive the car, and what's important to YOU. YOU get to be the ultimate arbiter of all this, not "book", not "us", not "consensus", not "the Internet". YOU. Once you get to that point, then THIS particular adjustment is as "good" as it can get.

You may well find that OTHER adjustments such as mixture or idle speed or whatever, need to be reset. Do the same with each of those. "If it RUNS good, it IS good". Every one.

THEN AND ONLY THEN, pick back up "light" and look at "mark" and "tab"; and make a note of where it is. Then, if Skillet comes along later and decides THEY "know" better somehow where your engine wants the "timing" to be, better than THE ENGINE knows, you can un-screw-up whatever they did, and put it back to optimum. Assuming of course that your crank damper's inertia ring (blob of SPOOGE) hasn't wandered some more some way somehow, as they all inevitably and inexorably do. Notoriously inaccurate, inconsistent, and unreliable.

Any number we can give you is only as "accurate" as your "mark" and "tab". None of which is in any manner way shape form or fashion, "reliable".

For all the half-century or so that I've been in this hobby, THAT'S how we got a car to run right. Measured interval on the Earth whether pavement or not (this culvert to that, this stoplight to the next, lap times on the track, how hard it comes up off the corners on a tacky/sticky/loose/dry oval, ET and MPH, etc.), and a stopwatch. Modern conveniences like WB O2 sen-sores and cell phones and GPS and things like that, are a MAJOR help, but by no means indispensable. We have always called this process "TUNING". Learn it, live it, practice it, LOVE it, it works EVERY TIME. If the car goes faster, your change was good; if the car slows down, not so much. Tweeeek whatever handles your setup has (static timing, dist curve, carb parameters, etc.) until it's as good as it can be. Once you get to that point, it's ... as good as it can be.

Questions?[/QUOTE]

Aaron R.

The internet is full of idiots dispensing car repair advice from their couches. Just ignore the dumb ones and listen to the ones who get their hands dirty.

ironwill

QFT. Fortunately, very few such people post on this particular site.

Let us not forget that the interwebz is also full of other idiots claiming vast experience but then asking 'beginner' questions, leaving those who attempt to advise them having to assume they are actually 'beginners.'

TransamGTA350

iTrader: (2)

Sounds like your timing marks are off and maybe some other stuff going on. There were no 10:00 TDC balancers. 12:00 and 2:00 yes. If you are measuring exactly TDC with a piston stop and timing wheel, then I would just mark the balancer at TDC to the installed timing tab. Stock timing setting on the stock 305 if I recall correctly is 6 BTDC with the 4-pin plug disconnected from the distributor. However, this is assuming that the motor is all stock and you are still running the complete computer controlled carburetor, distributor and all of the sensors and all of that is functioning.

Fast355

iTrader: (2)

The 70s and 80s engines run like garbage on the factory timing advance settings. I had a 305 with a Q-Jet in my 1983 G20. After I played with the timing advance as recomeended, I was at about 12-14° advance rather than the factory 4° spec. My van responded like it had suddenly had a 350 installed. Far more responsive, a lot more torque and better fuel mileage. On the van I was able to mess with the timing from the driver seat. I advanced the timing until it spark knocked at WOT, then backed off a bit, pulled over and locked the hold down bolt down. Then I rechecked the new spec with a timing light back in the drive way. Give the engine what it wants, not what some spec somewhere shows.

Fast355

iTrader: (2)

Real world example of the information provided by a response you did not want to hear.