Timing help!!

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clutch

clutch

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I need to put a good tune on my broken in 360.I have been searching the tech section and i have seen more good tune up tip's on here than anywhere else! I have never been able to quite get my timing right on. I took off my dist cap and bumped the motor until the rotor line's up with the no.1 exhaust manifold bolt.With that being done it make's my timing mark on the balancer line up with the zero mark on the atdc.Is that where it should be?I have the in dash vac gauge and it read's 3or 4 at idle with the vac advance disconnected and plugged off.My motor does'nt ping or run bad it's just hard to start and will backfire once when warming it up when it has'nt been run for a week or more.Once it warms up it runs pretty good no pinging or popping at all and it has lot's of power.It just smells rich and idles crummy. The motor is a machine shop rebuilt 1971 360 with ported out j-heads 202/160,9.5.1 hypertecic pistons bored 30 over,4-speed, ,489 sure grip with 276 gears (soon to be 323,355) 68/70 340 manifolds, eddy 750,mopar dual plane intake.MP elec dist.8mm wires blaster2 coil. Any suggestions?
 
advance the timing and tune the carburetor.

Set it [for now] at 34* total @3000'ish rpm, drive it then look at the plugs and report with pics.

Try playing with the pump shot adjustment on the front and see if it likes more or less, 3 settings before shooter changes are necessary.

But really need to see the plugs to tell if it's fat or lean, though backfiring out the pipes sounds like retarded timing and or way too rich.

what cam?
 
You need to pull #1 plug and make sure TDC lines up with your mark on the balancer. Then, find a dial back timing light, and then follow the post above.....
 
Oh my cam is comp cams pp284/484 which i think is a 340 grind .So i should confirm where my mark on the balancer is by using the put my finger over the no 1 hole and bump the motor until the compression pushes it off method?Then i guess i will have at least confirmed tdc?
 
Nnnnno.........

Like, use a coat hanger, or some kinda soft wire, put it in the plug hole, and find the piston (careful) turn the engine SLOWLY over by hand, until you feel the piston come to the top, when it stops, that little spot there, is TDC. If your makr on the balancer isn't spot on, make a new mark.
 
dodgetkboy78 said:
Nnnnno.........

Like, use a coat hanger, or some kinda soft wire, put it in the plug hole, and find the piston (careful) turn the engine SLOWLY over by hand, until you feel the piston come to the top, when it stops, that little spot there, is TDC. If your makr on the balancer isn't spot on, make a new mark.
Click to expand...

yep
 
OK so when the piston is at the top of the stroke ,that is where i put my mark on that will line up with the line on my balancer?Sorry about all the ??s
 
I'm not a fan of the total timing deal on street cars with mechanical advance. As 1wild suggested, it's cool to get a baseline to begin from. There are too many variables that can throw you for a loop. One distributor may have 28* in it, another may have 20* and each will cause your engine to react very different at idle. As an example - If your engine want 18* initial, and you have a distributor with 28* mechanical in it, timing it at 34* total gives you 6* initial (34-28 = 6), not near enough and you'll likely never get it to run properly.

Here's my suggestion to get it running better.
Whatever the timing is set at idle now, verify the setting and turn the distributor a bit to advance it and see if it picks up RPM from your base rpm. If it does, reset/lower the idle back to desired rpm. Keep doing that until it stops picking up rpm. Once you reach that point, tighten it, turn it off and see if it starts or kicks back on the starter. If it starts OK when hot, that's where you should leave it. Put the timing light on it to verify the amount of initial.

Now you can tailor the mechanical advance to reach the desired total, usually anywhere from 32-38* depending on engine. Different distributors require their own method.

IMHO, Timing is the root cause of probably 90-95% of carb issues at idle.
 
Is this the mopar performance adjustable distributor?
Then you can do like crackedback says and taylor the curve, and without a welder.

The cam is gonna require a higher initial to get the transfer slots lined up, other wise you're already into the main jets @ idle.

BtW if it isn't adjustable like I think, you can just stretch [carefully] the advance springs, so that it will be how ever much advanced you stretch it, at idle, leaving you with the rest of the mechanical and not have it bounce around and lower on you, like happens sometimes when you just take out the heavy spring and leave the light 1 in, this method nets you around 18* @ idle and around 13-14* advance.
so like if you have 28* advance..stretch'em to use up 18*-22*[thats initial] then you'll have 6* advance from there.
 
A 284/484 cam is going to need at least 16* initial and probably closer to 20*, to run even close to right IMO.
 
OK so when the piston is at the top of the stroke ,that is where i put my mark on that will line up with the line on my balancer?Sorry about all the ??s
Click to expand...

Are you lost yet?

Sometimes the simple answers are hard to come by around here.



When you determine that the piston is at the top, your line on your balancer should be at the 0 mark on your timing case. If it's not, make a new mark on the balancer, I use a red paint marker, unless your motor is red, LOL. :toothy10:

See what your timing is at idle, and say, 3K, and get back to us please.
 
With the modifications already made, forget standard timing peocedures. Warm the engine to normal operating temperature; advane throttle to 2600 RPM (3000+ withMSD); set total timing to 36* lock dist. Return idle to street RPM and read degrees on timing light. start and stop engine to determine easy starting and shutoff without dieseling. This pwocedure will get you close and slight adjustments could be needed.
My personal preferance for mopar small blocks are MSD wires and Autolite 66 plugs. Good luck with any tuning method you use.
 
Spend a few bucks on a TDC piston stop or make one using an old spark plug.

Easy to use and will get you a definite answer whether your balancer mark is in the correct spot.
 
Ok thanks for all the input.I will verify that i am at tdc before i start adjusting anything. I will report back later Thanks again
 
Coming in late here...

But I disagree with the coat hanger method mentioned above regarding finding TDC - it is far too inaccurate because the piston "sits" at TDC for much more than 1 degree as we can accurately measure with our fingers and any sort of wire, at least not with my fingers; so I now use a piston stop

I know this because someone removed their adjustable timing indicator and someone else accidentally moved the adjustable pin while it was off the engine; don't ask who did that please, but apparently it was to clean it better during a cam degreeing operation on my SBC

Piston stops are easy to use, cheap to buy, and comes with instructions too. You rotate your engine, piston stop installed in #1 cyl spark plug hole, bringing the piston up to the stop in both directions and mark the balancer both times at zero on your timing tab, find the middle between the two marks and that is true TDC; if you do your part right. Now get the right timing tab (or an adjustable one) and you're good to go

Handy Hint: pull ALL your spark plugs when using a stop, makes rotating your engine much easier and safer (so your piston won't go flying into the stop while you fight compression to rotate the engine by hand)

I don't mean to come off harshly, but if you are going to go to the effort to do something, take 15 minutes more and do it right

All other advice given sounds good and prudent
 
Thanks octane junkie,i did use a piece of wire it didn't prove to be to accurate for me.I invested in a vac gauge and a digital timing light.I pulled no 1 plug and used the bump the starter method,my rotor lined up right inline with the no 1 cylinder.Started the car and it ran crummy.I set my initial at 19.5 and my timing came in at 36 total.My overall was 52.I set my carb and got 22inch vac (started at 3inch! so that part is good) Idle is 930.Drove the car and it pinged so i put a 3/32 allen wrench into the vac on my M/P dist and turned it 1/2 inch clock wise which was as far as it went ,it stopped at that point ,i drove the car and it still ping a little so i took a break because i am kinda stumped!
 
IMHO, ditch the vacuum advance. It's causing you problems and is really only useful for fuel mileage at cruise.

Keep it disconnected, plug it at the carb and drive it.

You got 22" of vacuum at idle? That's seems WAY too high for a 284/484
 
Hi crackedback,it was all going so well,I had the manifold vac up, i could start off on a hill with little effort it sounded good,then i got out on the road and started going thru the gears and it started pinging!After that i shut the car off and turned the vac adv on the dist. clockwise 1/2 inch (2degrees?) and it bottomed out .What does that mean?Should i adjust it the orther way and try that.
 
clutch said:
I invested in a vac gauge and a digital timing light.
Click to expand...

Please tell me you didn't get one of those over price pieces of crap timing lights from Schucks Auto Supply. I made that mistake before and the thing never read right or even close!
 
A motor runs best with the timing at full advance all the time if you can buy a MSD billet Dist. and get a Digital 6 box.Lock out the timing in the dist and use digital 6 has a built in start retard in it and it wont run rich either.If you need a DIGITAL 6 I have one for sale and you ill just have to buy a Dist.The cam I run in my W8 motor is [email protected] with 15.4 comp on E-85

DSC_3666wtmk.jpg
 
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