my camaro was running a little badly lately, a lot of backfiring, almost stalls when i floor it from a standstill etc.
so i decided to have a look at my timing (something i've never done before) and it turns out it's over the scale of my timing light (over 50 degrees).
i tried getting it down but it doesn't go much lower before the engine stalls. after lot's of thinking (& looking at a girl's @ss who was painting something on her car a few cars over) i decided to give up on the timing light and set the timing just by listening to engine and then testdriving it around. that took sometime to get it to run properly without pinging & backfiring & stalling etc but it runs as sweet as i could it this way.
then i put i put the timining light on again and i've got 44 degrees of initial timing. how can that be?

next week (if my HEI tune up kit, wires & plugs have arrived) i'll pull the distributor and reinstall that, anything else i could check for?
in some other post here someone suggested to

Pull out the dist, use your jack handle, the end that looks like a flat screwdriver, and stick it down the dist hole, turn until it ingages the oil pump shaft and rotate it a little counterclockwise. Then put the dist back in.

how far is a little counterwise? or should i just reinstall the distributor first and see what happens?

thanks,
Charlie

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"Son, a woman is like a beer. They smell good, they look good, you'd step over your own mother just to get one! But you can't stop at one. You wanna drink another woman!" - Homer J. Simpson

1977 Camaro Sports Coupe (http://home.zonnet.nl/ksstone)

[This message has been edited by Charlie Brengun (edited April 03, 2005).]

Chevy made a couple of different timing tabs and dampers for the Chevy small block. It is possible you have a mismatched set that don't line up. Later cars use a different one than the early engines.
Also, did you disconnect the vacuum advance to take your readings? You need to have the vacuum advance hose disconnected and plugged to prevent a vacuum leak. Then idle the engine as low as possible to check timing so the mechanical advance isn't starting up and messing up your reading. If the springs for the mechanical advance are too soft, they can start to add advance with a high idle.

i had the vacuum advance disconnected & plugged. it could be a mismatched timing tab & damper.. but how i would go about recognising that?

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"Son, a woman is like a beer. They smell good, they look good, you'd step over your own mother just to get one! But you can't stop at one. You wanna drink another woman!" - Homer J. Simpson

1977 Camaro Sports Coupe (http://home.zonnet.nl/ksstone)

take the drivers side valve cover off turn the motor over until the intake rocker arm on the #1 cyclinder closes it should be close to lined up if its 1/4 way around id say miss matched timing tab

You may also have a slipping dampner. Is it the stock one?

i double checked the timing and it came out the same both times. if the dampner is slipping will the read out differ everytime?

i'll go check the intake rocker arm on #1 cyl this week and see what that tells me.

thanks for the help so far,
charlie

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"Son, a woman is like a beer. They smell good, they look good, you'd step over your own mother just to get one! But you can't stop at one. You wanna drink another woman!" - Homer J. Simpson

1977 Camaro Sports Coupe (http://home.zonnet.nl/ksstone)

Charlie, I was wondering if you found any solutions to your timing issue mentioned. I ask because believe it or not I have the exact same dilemma! I have checked everything on my engine, chain is installed properly, I have verified TDC with a piston stop and the distributor is in the proper location. After trial and error I have found my car runs best at 44 degrees advance just as you mention ( I came up with this setting before reading your post and I thought the 44 was a scary coincidence). I have run out of things to check. Besides the reading itself everything runs perfectly. The car pulls strong until about 6200 and has no hesitation or lack of power at any RPM and no detonation.

I'm going to guess the both of you have a mismatched balancer & pointer issue... Do either of you have an aftermarket timing cover/pointer or replaced balancer?

I am running a 6.75" Fluidampr Balancer with a summit adjustable billet aluminum pointer. When I verified TDC with the piston stop everything seemed to line up with the pointer and TDC mark on the balancer. I even found TDC twice by setting the piston stop at two different lengths, both times the mid point between the marks showed TDC to be true.

I know it's a long shot but just an idea (& sorry if you already know this) ....

Is the pointer you have for a 6.75 balancer? Even adjustable pointers have to be made for the diameter of the balancer.

I've had this problem about 5 years ago and am having the same thing right now. I have a buddie that lives in Orlando, and I boult him a flat top, Dart headed , gear drive?, 406. I did all the work myself here in Mo., took it down to him, installed it, and got it running. I
I would go down every Jan. and stay till after the Daytona 500. Anyway, I went back the next year, and the car was turning to many cruising rpm's, so I told him we had to change the rear gear. He said it was to sluggish out of the hole with 3:73. I drove it, and it had a bad stumble-hesitation off the line but pulled super hard from 3500 up. I thought maybe It was the Victor Jr., but it ran great last year. I rebuilt the carb, changed pumps, squiters, etc. but still did it.
I checked the timing, and had to set it at like 44° to act right. Well, I knew that wasn't right. I was going to change intakes, or theck cam timing.
Well, there it was..Pin broke in the front of the cam, and retarted the heck out of it. Bolts where tight, but PJ gear drive.???
Now I have a dirt car I built the engine for. Ran great at the start of the season. Been slowing down. Runs great in the shop at 45° total, but I know that isn't right.
I've checked Positive TDC, and am scared to send him to the track with that much total advance. Any ideas? No gear drive in this one, but does it sound like another broken cam pin? I'm about lost..
Any help greatly app..Thanks, Rich

If you shear the pin off the cam then you're really doing something. The dowel pin is really only there to line it up properly with the top timing gear upon assembly. After that you've got the torque of the 3 cam bolts holding the cam tight against the gear. If you sheared the pin you'd have sheared all 3 bolts, too. Unlikely to say the least. Besides, if it happened AFTER the motor had been assembled, run and timed it would be obvious- one day the timing would just be way off (retarded) from where it had been the day before (the cam and the distributor would have their timing changed by the same amount if something went wrong up by the timing chain). It would be like throwing a switch- running fine one minute, stalled or barely running the next.

Are you putting the timing light's inductive pickup on the right plug wire? Sorry, had to ask. Are you sure you're looking at the correct timing mark on the balancer (some have more than one line scribed on them)? Have you done a compression test to make sure it's within the realm of sanity (slipped/retarded timing chain will drop cranking compression considerably)?

I double check my TDC mark alignment at the same time I degree the cam. I also put a little paint in the scribed line on the balancer to make it easy to read (and make sure I'm reading off the right line). I don't recall ever having a problem with "insane" timing readings to make the engine run properly.

In my case I have verified TDC twice. My balancer is marked correctly and with timing tape so the marks are very distinct. Cranking compression is right at 185 psi. I am putting the inductive pickup on the right wire. The only possibility that I have come up with is that the distributor may be off by one tooth. This can make sense if you consider the distributor has 13 teeth (360/13) is about 27.7 degrees. If you assume you are running 16 degrees initial that would put the timing reading out at about 44 degrees when in actuality it is 16. I mentioned this before and was told the distributor would not affect timing readings and I am sure that is the case but is the only thing I can come up with at this point.

Damon, Thanks for your reply's, but when the pin broke in the 406(first one), like I said, i didn't drive the Camaro for a year. I couldn't notice a night-day difference. As far as breaking the bolts, They where Loc-Tited, grade 8 bolts, with a locplate. I have good dampners on both of these engines, ATI, and on this 355, its local, I have checked for Positive TDC several ways. Seems good. The 406 is internally balanced, so good balancer there. My MAIN problem-worry is sending this guy out to a 1/2 mile track with 44-46° total advance. I have a wedding to go to, and trying to explain to a electictricion with minimal experience how to do a full throttle plug check is quit the task. Itold him to keep an eye on the water, oil temp., and I figured if he at least pulls a plug when he comes in from a heat race after weighing, waving to his buddies, blipping the throttle, etc..Any Grey, or bad spots, retart the time or fattin it up or load it up. Why burn a piston, head gasket, or hurt the block..I know there is some extra room in the cam bolt holes incase you want to use degree bushings..If it don't work tomorrow night, I'll have to take it apart next week..I'll let you know what I find..Thanks for your replys..Rich

<font face="Arial,Verdana" size="2">Originally posted by Wicked 79 Z28:
In my case I have verified TDC twice. My balancer is marked correctly and with timing tape so the marks are very distinct. Cranking compression is right at 185 psi. I am putting the inductive pickup on the right wire. The only possibility that I have come up with is that the distributor may be off by one tooth. This can make sense if you consider the distributor has 13 teeth (360/13) is about 27.7 degrees. If you assume you are running 16 degrees initial that would put the timing reading out at about 44 degrees when in actuality it is 16. I mentioned this before and was told the distributor would not affect timing readings and I am sure that is the case but is the only thing I can come up with at this point.</font>

Ohhh boy here we go with the 'one tooth off' again. Please take no offense but being one tooth or 7 teeth off make NO DIFFERENCE if the distributor body is oriented so the rotor tip is under the #1 plug tower at TDC.
And just to remind you,,, the cam and rotor turn at 1/2 the speed of the crank. There are 720° crank degrees in one complete distributor rotation. There is a plug tower every 45 degrees around the distributor cap, being every 90 crank degrees. 13 teeth on the distributor would be 55 crank degrees per tooth,, Like Damon I'd SURE suspect ssomeone is using #2 plug wire to set the timing,,, but if yuour sure that's not the case, and your sure there are not two scribes on your balancer, and your sure TDC on the balancer matches the timing tab,,,, well you got some wierd stuff going on there!!!

No offense taken, I tried to say that I figured that distributor position didn't matter but it was the only thing that I could even try to make sense of. I know that my level of experience cannot be comparable to most on this board but I have built five engines and know my way around things pretty well. I do know where the number 1 spark plug wire is and I do know how to attach the timing light's inductive pickup to the number 1 wire, I can assure you of this. I do know to disconnect the vacuum advance (and plug the vacuum hose) and I do know how to find TDC. I have been shocked a couple of times while adjusting the timing in the past so maybe some arcing is going on that is affecting the timing readings, the engine has never had a miss though. I am stumped and will just have to do more experimenting on my own. I will probably make myself look like even more of an idiot by asking more questions here.

Thanks for the input!
Chad

This sounds a lot like the 400 I had in a 79 Camaro a few years back. I had the distibutor in right, timing was WAY out to lunch like you describe, engine had a big time stumble off idle. I happened to have the hoods open side by side on my 79 and my 75, and guess what I noticed? I had the plug wires wrong... one terminal out all the way around.

I'm going to reitterate what Marv said a couple of posts above. Being off by a tooth or two or three or nine won't cause your timing to be off. The distributor may end up pointed at a bizarre angle to keep the engine running but when the timing light says, say, 20* BTDC connected to the #1 plug wire it WILL BE 20* BTDC actual. Same thing with having the wires off by one post on top of the distributor. You may have to twist the distributor at a bizarre angle to get the engine running but when the timing light says 20* BTDC connected to the #1 plug wire it WILL AGAIN BE 20* BTDC actual.

Neither of those things is the problem here.

The probblem here is that the engine SEEMS to want to run best with 45* of ACTUAL timing advance. That's a legit head-scratcher. Engines will often idle best with 25-30* of timing advance (much of it supplied by the vacuum advance canister if it's attached to a full vacuum source) but 45* is just too much. It would be popping and bucking if it idled at all.

In Charlie's case I think we still haven't confirmed whether we have a balancer/timing tab mismatch. 45* is about the difference between the typical 1:30 position timing tab (all aftermarket tabs and many factory ones, too) and the oddball 12:00 timing mark position used on some Chevy SBCs with a 6-3/4" balancer. That's a REAL common mismatch. I see at least one a year on various friends engines when they put in a new motor (or a different/aftermarket timing chain cover) but reuse the original balancer.

Wicked 79's case and Breese's case, however, are different. Both cases true TDC on the balancer/timing tab was supposedly verified. That leaves not much that can be wrong other than a slipped balancer, a mistake when checking timing or some bizarre internal engine problem (slipped timing chain, etc.) that would cause the engine to ACTUALLY want that much timing to stay running properly.

Damon, Your right about my problem. Weird man. I have been a auto machinist since 1977. I have checked everything. We ran the car Sat. night, I told him if it started to nose over or get hot, pull in. The total advance ended up being 55°! I pulled a plug after every race, didn't look bad, I have a Spark plug light, but this thing is still LAZY. I'm not the sharpest tool in the shed, but I know which wire is #1, I positively checked TDC, I think the cam pin is broke. I just have to get it apart..I'll let you know what I find..55° T.A. would melt a piston and or head gasket. Crazy

OK guys. Here's something that happened to me last month, and falls into the same category....

I just replaced my power steering pump and took my wife for a drive into Kansas City (50 miles from home). At one point I smoked a late-model mustang from one stop light to the next, but when I stopped, my car just died. I finally get it barely started, limped off to the shoulder, and popped the hood. Barely start the car again, and I see gas shooting out the top of my 650dp holley. $150 later and I'm towed back home.

I take the timing cover off, no timing chain slip on the double roller and it lines up to TDC. Take the valve covers off and no broken springs. Take the distributer cover off, and it's pointing at the #5-6 cylinder!! WTF over?

I took the HEI distributer out and I see no damage. I also don't see any damage to the oil pump drive. Any reason for this?? Anything else I should look for wear or damage? I'm scared to put the distributer back in and reset it to #1, cause it could happen again if I don't find out what happened.

Any thoughts?
(350/268xe/vortech heads/T56)

[This message has been edited by Nutt (edited August 07, 2005).]

Nutt,you were probably just 180 off(meaning you would have to turn it one more revolution to TDC)

So I've been running the car 180 degrees off for the last 4 years? Is that possible? With that kind of advance, would it still let me cruise at 100mph turning 1800rpm with that much power loss? I know I set the timing when I had the engine on the dyno.

I need to check to make sure the camshaft didn't crack in the middle and then catch again. Maybe that 268xe broke on me.

[This message has been edited by Nutt (edited August 08, 2005).]