Timing/Power/MPG

-
1973Barracuda

1973Barracuda

Well-Known Member
Joined
Dec 11, 2009
Messages
2,020
Reaction score
2,425
OK, I have a pretty fresh 318 .030 over stock heads and cam, 727 and 2.76 gears, dual exhaust. It runs great(at idle and in neutral or park stationary), sounds strong, 10* initial, about 34 around 2500.500cmf Edie, 340 intake(came with the car, I know its a slight mismatch), stock manifolds. It seems real weak to me, sluggish accelleration, new tune up components. This part may sound funny, At tdc, my rotor is pointing at the front of the car, I 180ed it(pointed straight at the rear of the car), and it wouldn't run. I put it back, all was well. I read in a previous post, some guys were saying to time the engine, keep advancing till it stops gaining RPM while reducing the RPM, it was a mech advance dist(I have vac), does this sound right? I know stock 318s are a bit weak, but I think a Neon could take me. I am also getting about 10MPG, I feel I should be getting 16-18. Any ideas are greatly appreciated. I bought this car while in Afghanistan and am working the issues now that I am back. Thanks
Jason
 
1973Barracuda said:
OK, I have a pretty fresh 318 .030 over stock heads and cam, 727 and 2.76 gears, dual exhaust. It runs great(at idle and in neutral or park stationary), sounds strong, 10* initial, about 34 around 2500.500cmf Edie, 340 intake(came with the car, I know its a slight mismatch), stock manifolds. It seems real weak to me, sluggish accelleration, new tune up components. This part may sound funny, At tdc, my rotor is pointing at the front of the car, I 180ed it(pointed straight at the rear of the car), and it wouldn't run. I put it back, all was well. I read in a previous post, some guys were saying to time the engine, keep advancing till it stops gaining RPM while reducing the RPM, it was a mech advance dist(I have vac), does this sound right? I know stock 318s are a bit weak, but I think a Neon could take me. I am also getting about 10MPG, I feel I should be getting 16-18. Any ideas are greatly appreciated. I bought this car while in Afghanistan and am working the issues now that I am back. Thanks
Jason
Click to expand...


First off you have to realize that the Dist and Cam turn at half Speed to the crank......or crank turns 2 times to the dist turning one.

When you pulled the cap and the rotor seem to be 180* out..........it was NOT as you found out by putting it back.

Try this Method and you will find that the rotor is now pointing back to the fire wall were its sapost to be............ Remove #1 spark plug, cover the spark plug hole with the butt end off a screw driver. Now while holding screwdriver, have a buddy keep bumping the starter until you here air escape from around the Screw driver. NOW, bring eng back up to Top Dead center(tdc) remove dist cap and you will find that the rotor is at the back of the fire wall.

Now Just to validate this method above............leave the dist cap off and turn the eng one more revolution...........rotor turn half a turn, Right.......... one more turn of the crank and the rotors back at the fire wall aka 2 crank rev= 1cam/dist rotations.


Next,
2.76 gears 500 cfm carb on top of a 318 and 10 m.p.g.............. there is something Wrong!

does it idle smooth? Drive OK?
 
Cudafever said:
First off you have to realize that the Dist and Cam turn at half Speed to the crank......or crank turns 2 times to the dist turning one.

When you pulled the cap and the rotor seem to be 180* out..........it was NOT as you found out by putting it back.

Try this Method and you will find that the rotor is now pointing back to the fire wall were its sapost to be............ Remove #1 spark plug, cover the spark plug hole with the butt end off a screw driver. Now while holding screwdriver, have a buddy keep bumping the starter until you here air escape from around the Screw driver. NOW, bring eng back up to Top Dead center(tdc) remove dist cap and you will find that the rotor is at the back of the fire wall.

Now Just to validate this method above............leave the dist cap off and turn the eng one more revolution...........rotor turn half a turn, Right.......... one more turn of the crank and the rotors back at the fire wall aka 2 crank rev= 1cam/dist rotations.


Next,
2.76 gears 500 cfm carb on top of a 318 and 10 m.p.g.............. there is something Wrong!

does it idle smooth? Drive OK?
Click to expand...

I turned the motor over with my finger plugging #1, to make sure I was on the comp stroke. My damper was at TDC, but my dist(rotor) was pointed at the front bumper(should be toward the driver's seat-correct?)! I know this sounds crazy. I rotated the dist 180, because I am pretty sure it should point toward 1 o'clock. It wouldn't start after I did that. Put it back, it started. My damper does not appear to be loose. The engine sounds great stationary, but once underway, its a dog. Itdoesn't smell rich, the plugs look decent. I read in a previous thread, about someone timing the engine by advancing till it drops off RPMs, never heard of that, but I'm wondering if my timing marks are jacked. All advice is appreciated.
Jason
 
1973Barracuda said:
I turned the motor over with my finger plugging #1, to make sure I was on the comp stroke. My damper was at TDC, but my dist(rotor) was pointed at the front bumper(should be toward the driver's seat-correct?)! I know this sounds crazy. I rotated the dist 180, because I am pretty sure it should point toward 1 o'clock. It wouldn't start after I did that. Put it back, it started. My damper does not appear to be loose. The engine sounds great stationary, but once underway, its a dog. Itdoesn't smell rich, the plugs look decent. I read in a previous thread, about someone timing the engine by advancing till it drops off RPMs, never heard of that, but I'm wondering if my timing marks are jacked. All advice is appreciated.
Jason
Click to expand...

You would think it would run great by listening to it at idle. I think I see what you are saying about the position of the dist. I am reasonably competent mechanically and this is a little frustrating when everything appears correct and you are intimidated by a Smartcar at a stoplight.
 
You will not have a monster puller with that combo. Should do better then it is but it is not going to be a tire roaster.

First off disconnect the vacuum advance and cap it off at the carb. Get a timing light that has the knob on the back so you can see the timing. 8 to 10 initial should be fine.

The way I set mine is by having somebody run the car up to 5k rpms and set the total timing to 34 - 36 depending on what gas you want to run. 34 for low octane and 36 for Hi test. Leave the vacuum advanced disconnected for the moment.

2nd I suspect that the AFB carb is dumping too much fuel and is causing the car to bog. An easy test for this is to find or borrow a Holley 1850 Vacuum Secondary and put it on. If the bogging higher up goes away you are getting too much fuel. If you can't get an 1850 then disconnect the arm that actuates the secondaries on the AFB and wire them shut. So you run it as a 2 barrel and see if the sluggish/bog goes away.

A cheaper thing that might help. MSD 6a spark box. Much better spark, you can open the spark plug gap to .45 - .50.

A set of 3.55 or more rear end would be the biggest help followed by a mild cam shaft.

What are you running for an air cleaner? An open element 14" would help it breath. Are you running stock exhaust? A Y pipe to a single? This could also cause some issues as you want to gain performance.

HTH,
Dan...
 
Remow2112 said:
You will not have a monster puller with that combo. Should do better then it is but it is not going to be a tire roaster.

First off disconnect the vacuum advance and cap it off at the carb. Get a timing light that has the knob on the back so you can see the timing. 8 to 10 initial should be fine.

The way I set mine is by having somebody run the car up to 5k rpms and set the total timing to 34 - 36 depending on what gas you want to run. 34 for low octane and 36 for Hi test. Leave the vacuum advanced disconnected for the moment.

2nd I suspect that the AFB carb is dumping too much fuel and is causing the car to bog. An easy test for this is to find or borrow a Holley 1850 Vacuum Secondary and put it on. If the bogging higher up goes away you are getting too much fuel. If you can't get an 1850 then disconnect the arm that actuates the secondaries on the AFB and wire them shut. So you run it as a 2 barrel and see if the sluggish/bog goes away.

A cheaper thing that might help. MSD 6a spark box. Much better spark, you can open the spark plug gap to .45 - .50.

A set of 3.55 or more rear end would be the biggest help followed by a mild cam shaft.

What are you running for an air cleaner? An open element 14" would help it breath. Are you running stock exhaust? A Y pipe to a single? This could also cause some issues as you want to gain performance.

HTH,
Dan...
Click to expand...

First off, thanks for the responses. I set the timing like you stated, except have never went that high with my RPM-will try it tomorrow. I will also try the carb trick-did not think about that. I am going to the Nashville car show this weekend and am looking for a better rearend as the combo I will run eventually will destroy the 7 1/4. I am running a 340 cleaner, stock manifolds and a dual exhaust. Also looking for Doug's or TTIs this weekend. I will try the recommendations tomorrow as Uncle Sam wants me up in the morning. Again thanks and I will post my results in the next day or so.
Jason
 
Get a coat hanger and straighten it out. Put it in #1 spark plug hole and turn the eng over manually(Key off) until the piston has push the rod or hanger out of the spark plug hole as much as it can. look at you timing mark.

This method could show it being off several * and really its not!.......But if its something like 10* off! Replace you Harmonic Balancer.
 
Where is your #1 plug wire located on the distributor cap? is the rotor pointed near it at TDC? probably or it would not run, perhaps someone has moved the wires on the cap to allow the vacuum canister to clear the non stock intake manifold and still allow timing adjustment. Check the mechanical advance weights in the distributor make sure they move freely and return fully.
 
At TDC your rotor should be facing towards the #1 cylinder and with the cap on should be lined up with the #1 plug terminal not straight forward. Sounds like your distributer drive gear is off a tooth.

This is WRONG

100_1122.jpg


100_1123.jpg


This is RIGHT

100_1124.jpg

100_1125.jpg

100_1121.jpg

100_1126.jpg

(no the valvecovers are not for sale so no one PM me ad ask)
100_1115.jpg

100_1127.jpg
 
Where did you get the timing chain tensioner? I have never seen one of those before.


Dan...
 
Remow2112 said:
Where did you get the timing chain tensioner? I have never seen one of those before.
Click to expand...
As 360scamp said, you should be able to kick one up on ebay. I got mine here: http://chucker54.stores.yahoo.net/timchainten.html
Either way, same result.

Also, I may be mistaken (my memory is crap and grabbing the book would involve leaving the recliner) but it seems that the crankshaft should be turned 360° (which turns the camshaft 180°) from what's represented in the picture above before dropping the distributor in on the #1 firing position. The dots on the sprockets are aligned at 6 & 12 to make it easier to see that the cam and crank will play nice together.
 
Remow2112 said:
Where did you get the timing chain tensioner? I have never seen one of those before.


Dan...
Click to expand...

You can get it from MPP. it's actually a stock piece on a magnum eng but is a grate addition to the non mag (LA) eng.
 
360scamp said:
At TDC your rotor should be facing towards the #1 cylinder and with the cap on should be lined up with the #1 plug terminal not straight forward. Sounds like your distributer drive gear is off a tooth.

This is WRONG

100_1122.jpg


100_1123.jpg


This is RIGHT

100_1124.jpg

100_1125.jpg

100_1121.jpg

100_1126.jpg

(no the valvecovers are not for sale so no one PM me ad ask)
100_1115.jpg

100_1127.jpg
Click to expand...

Thanks for all the advice, everyone. Today I disconnected the secondaries, I also checked my mixture screws, they were about 4 turns out. I screwed them in to 2 1/2 turns(final adjustment 1 3/4 out) and disconnected the secondaries and went for a drive. The car responded much quicker, but was flat at WOT. I also tried the adjust the timing till it stops gaining RPM, the engine didn't like it, so I put it back to 10* initial. I also reconnected the secondaries. Overall the car seems to run better, not sure yet how the MPG will be. I think the car is just a pig with the low compression stock 318 and the 2.76 rear. Going to the car show this weekend, on the lookout for a better smallblock. Again, thanks for all the help.
Jason
 
Try bumping up the initial timing by 2* or so and see if it runs better. I have a feeling your timing marks are off. Also, the fact that you're running a 727 instead of a 904 behind that engine and it's a stock 318 pushing a ~3600 lb. car with 2.76 gears it's not going to be quick. You need compression, a more 'efficient' transmission, a mild cam, and better gears to make a 318 move a '73 E-body well. The car in my sig does OK but it sure takes a while for it to wind out, heck I can hit 65 MPH in first gear! Really needs gearing and compression to be "quick".
 
You must log in or register to reply here.
-

Back
Top