Engine timing mechanical

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tooslow

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Location
lockport, Il
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Al heads-ported
10.5 Compression
Mopar mechanical purpleshaft 557 Cam aprox Dur 243 @ .050 112 centerline
1.6 lift comp roller rockers
Single Plane intake-M1
900 CFM carb
MSD ignition with MSD distributor
Using mechanical advance ,Springs set so timing all in at 3000RPM
727 transmission
323 rear gear

I have been trying to set the timing to 12 deg initial , idle and 36-38 deg at 3000 RPM
RUNS LIKE **** a stock fiero could beat me and tends to run hot , sounds shity when I get on it like its running 6 cylinders . Chevy neighbor has been making fun! :( I tried diff combinations 32-34 , shity
I put the timing light away and set the timing by ear . I reved the motor to 3000RPM and turned the distributor till the engine sounded good and locked it down
IT runs Like an a Gorrilla on fire . I Can light the tires up and go sideways in second gear.
The temp is staying below 210 above 3000 RPM, would climb passed 220 before but only when above 3000 rpm
Question
I put the timing light back on and I have the following
3000 RPM 52 deg before top dead center ????
idle 800 rpm I have 17 deg
>Isnt 52 way to advanced ??
>Is my timing tab in the wrong place?
>
 
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#1- Verify the location of your timing marks. Bring #1 piston up to TDC on intake stroke measured at the piston. Then look at timing marks - are they perfectly lined up? If not, then something may be wrong with your pulley. #2- was your distributor set up on a machine? When does advance start? You may have too much advance at idle or vacuum advance plugged into wrong carb port.
 
#1- Verify the location of your timing marks. Bring #1 piston up to TDC on intake stroke measured at the piston. Then look at timing marks - are they perfectly lined up? If not, then something may be wrong with your pulley. #2- was your distributor set up on a machine? When does advance start? You may have too much advance at idle or vacuum advance plugged into wrong carb port.
thx
No Vacuum advance ,its mechanical
I will check #1 again with the timing tab
 
Sounds like above, marks slipped on the balancer. have you tried "timing with a vacuum guage?" thats a quick fix, best to find TDC and make new timing marks on pulley or get new harmonic balancer. P.S. cant have Chevy guy ribbing you :)
 
1. Verify timing marks on balancer with piston stop.
2. Verify the polarity of the two wires to the pickup of the MSD are correct.
3. Use a timing light KNOWN to work with the MSD box
4. Set timing.
5. Smile when doing 100 yard burnouts
 
If above all check out correctly you may need to look in to rotor phasing on the MSD cap.
 
I agree with TT5.9mag. If it's not detonating bad at 52°, that probably isn't really where your timing is at. Especially with a 3.23 gear. And I have also had a balancer that the timing mark was off. Mine was 6° retarded from tdc, so when I thought I had 38, I had 32.
The info I have, admittedly uncofirmed, says that cam has 252° at .050, and should be in at 108 centerline. If yours is six retarded, maybe that's why it needs timing.
I have basically the same combo, same compression and cam, and I've done exactly what you did, gave it timing till it runs right.
 
Help me eliminate stuff
Its an ATI harmonic balancer with timing marks engraved , keyed so it cannot be off , correct ?
Timing chain cover tab could be off , right ?
I am going to bring #1 piston up to TDC , Timing tab on distributor should be at plug #1
0 on the ATI damper should line up with 0 on the timing chain cover tab at #1 top dead center , correct ?
Runs really good now by ear but I dont want hammer the engine to death or break a piston , ring if its to far advanced
I HAVE TO FIGURE THIS OUT< THX FOR HELPING
 
You are thinking right, we need to start at confirming the simple stuff. Ignore the timing marks- get the piston to true TDC, then look at timing marks. I think we may find a mis-match and this could lead us to the problem. No matter what balancer or pointer you have, we need to confirm their accuracy so we can move on.
 
It can be off if the balancer ring has slipped, but I don't believe that's the case. 12* initial is way too low. That's why it's running hot. The mixture is still burning exiting the exhaust ports, because the ignition is firing too late and that's putting a lot of heat in the engine bay. Try jacking the initial up to around 18-20 and then limit total back down to 32-34. Big blocks generally like a little less total than small blocks. Whereas small blocks take around 36 give or take, big blocks like a little less. I believe it's the low initial timing that's your problem.

That said, I also agree with everyone that you need to verify TDC first.
 
once you verify TDC like previously posted, limit the advance to get more initial timing. I have had good luck with the 32-34 as rrr recommended.
most of my big blocks I locked out the advance and ran 32-34, would start fine for me there.
 
once you verify TDC like previously posted, limit the advance to get more initial timing. I have had good luck with the 32-34 as rrr recommended.
most of my big blocks I locked out the advance and ran 32-34, would start fine for me there.
 
Hello Vitamindart
What do you mean by lock out the advance ?
Im not using vacuum, plugged, Using springs provided with the MSD distributor
picked 3000RPM , matches my build, and convertor ,
I do not drive it around town , highway and back roads , 323 gear
 
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I'd be concerned about running on the street with 3.23 gears and locked timing...
My 10.3:1 iron head 451 begins to fight the starter at 25 degrees when fully hot.
 
With an msd distributor, the mechanical advance can be locked (no weight or advance action) and then just set the total timing to where you want it.
Sometimes a timing retard, or a on/off switch for ignition power, is necessary to get the engine to crank.
Your msd should have come with bushings that you can change, to get the amount of distributor advance you want.
 
With an msd distributor, the mechanical advance can be locked (no weight or advance action) and then just set the total timing to where you want it.
Sometimes a timing retard, or a on/off switch for ignition power, is necessary to get the engine to crank.
Your msd should have come with bushings that you can change, to get the amount of distributor advance you want.
 
Thx 331
The MSD did come with bushings and now I understand , not a street car in the sense i would ever drive it through town on purpose, not my thing
Going to leave the springs for now but experiment with bushings later, after I fig whats off with my timing
 
Solved
Thank you for all the help and no negativity
I brought #1 up on the comp stroke and got exact TDC with a probe cam
Pulled cap and rotor was on #1 . Damper marks and Timing tab were off
The bolt-on timing tab on the timing chain cover is not accurate , 0 is off by 15 degrees . It bolts on in one position only so I assumed it was correct .
I was setting my initial at aprox 0 and total at 3000 rpm to 20 deg. Ran like a 2 legged dog
Now it is at 14 intial and 34 total with the correct timing marks
Gets up and goes !
Takes care of my other problem , she was running hot on the highway
I just put a 4 core Holley radiator in it , what a beautiful piece. Holley does it right !
Firiing after TDC will make it run hot i believe
 
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33IMP is spot on, with locking out the msd dist. that's how I ran mine.
the bushings can be swapped to limit the mechanical advance. you will probably fine if you swap them and put in one that limits the advance, it will work better.
only reason I can see to even run the advance would be to save the starter and not have to buy a start retard. ( if its not a street car )
 
While I understand this car is not a sit in traffic daily driver, it also doesn’t seem to be a dedicated drag car. Save the locked out timing for the cars with lots of gear, (not 3:23) a lot less weight, a bunch more compression, and a bunch more camshaft. You will benefit from developing an ignition curve for your combination in your car. Take some time and plot your advance at different rpms and do some testing to see what your engine likes with combo it is attached to. Carb tuning will be easier, your starter will last longer, your fuel mileage will increase, and it will make just as much power at WOT. I would even add in the vacuum advance once the initial curve is established and tune that as well.
 
Never assume any timing marks are "correct". Don't forget, for the "LA" smallblocks alone there are 3 different timing cover designs (left-side cast, right-side cast, bolt-on tab) and then the dampeners that are supposed to line up with those. Add to that balanced, and unbalanced dampeners. Some companies make just two dampeners that "fit" all those different engines! Obviously they won't work for a lot of engines. Verify true TDC with a piston-stop, mark the balancer, and install a timing tape if required.
EDIT:
(oh crap, I just realized this in the big block section. Well, almost the same problems crop up with those too.)
 
Thanks again everyone I have been driving it and working on it for a couple days now
I had an Edelbrock vacuum secondary carb 800 cfm on it, running seriously rich and switched to a Holley 950 CFM brawler series mech sec carb
I made a few adjustments and again a shout out to Holley
What a nice carb !! beautiful piece !. My neighber had the same edelbrock 800 CFM on his 427 Chevelle , never ran very good, changed jets ect... so he switched to the 950 CFM Holley, never looked back
I bought one too
Starts easy , doesnt stumble , adjustments, loads more power when i step on it .
I drove 90 miles this am pretty fast, zipped up to 140mph and had gas left in my 10 gal fuel cell
Lifes good , now i need to put a tremac man trans in it
 
Thanks again everyone I have been driving it and working on it for a couple days now
I had an Edelbrock vacuum secondary carb 800 cfm on it, running seriously rich and switched to a Holley 950 CFM brawler series mech sec carb
I made a few adjustments and again a shout out to Holley
What a nice carb !! beautiful piece !. My neighber had the same edelbrock 800 CFM on his 427 Chevelle , never ran very good, changed jets ect... so he switched to the 950 CFM Holley, never looked back
I bought one too
Starts easy , doesnt stumble , adjustments, loads more power when i step on it .
I drove 90 miles this am pretty fast, zipped up to 140mph and had gas left in my 10 gal fuel cell
Lifes good , now i need to put a tremac man trans in it


I’ve done about a half dozen QF Brawlers and they are ALL pig rich.
 
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