Engine requires 20 degrees of initial to idle well...

[Cal_gecko]

Still having problems with my 360.. it's got a Comp Cam XE268H cam, Edelbrock Performer Intake and Performer 600cfm carb (model 1405), MSD 6AL with Blaster 2 coil... stock heads, compression, pistons, etc.

The best idle I've been able to get out of it so far is right at 1000 rpm, with 30 degrees of ignition advance.. all vacuum lines disconnected and plugged. Here's a video showing tach and vacuum gauge..


[ame="http://www.youtube.com/watch?v=8PJFZTCcdfo"]Still tweaking and tuning - YouTube[/ame]

I've already checked the timing marks on the timing sprockets, and even replaced them with a Cloyes set, just to eliminate the possibility of mis-marked sprockets. Replaced the spark plugs, adjusted the reluctor gap in the distributor (to .008")... replaced the intake gaskets with Felpro black gaskets with blue rings...

Any other ideas?

 

[Johnny Dart]

30 degrees initial advance ?
Hooo Doggie ! If that's the case you would be around 46-50 at full advance.
Can you say Kaboom !!!
Depending on your distributor,it should be setup around
12-16 initial 34-36 full advance.
Is your balancer marked to true TDC ?
Was the cam degreed, or put in straight up ?
Have you checked for vacuum leaks around the manifold,carb base ?
Do you know how to adjust Ede carbs ? The A/F ratio has to be close to idle right.

 

[OldmanRick]

If i understand correctly, your true static compression ratio is pretty low, maybe as low as 7.8-8.0 to 1. Even though you have a resonably mild cam, it's still gonna bleed of a little cyl. pressure also. Vacuum reading on vid was not extremely low, but that's a 30 deg. initial. I'm gonna think on it a bit, but i'd like to see the results of a compression test?

 

[AdamR]

How nice of an idle are you expecting with that cam ?

 

[crackedback]

How nice of an idle are you expecting with that cam ?

[ame=http://smg.photobucket.com/albums/v655/crackedback/?action=view&current=DemonontheRoad009-1.mp4]

[/ame]

Like that! 360, same cam a bit more compression at 9.3-9.5:1, 16 initial IIRC.

He still hasn't addressed some important issues is my guess. I'll say this, you've had the opportunity to address and verify some important details regarding this deal and my guess have taken the easy way out. Just install stuff and button it up.

Did you degree the cam while having the front ripped apart? Where was it installed with the old chain and the new one? Did you change it from the recommended installed ICL?

I've had some EXPENSIVE chains be 8* retarded when installed dot to dot! Whether it was the chain, cam or combo of both, it was a clusterf*ck.

No way, no how should the idle/vacuum be bouncing/surging like that. I bet if you pull the plugs again, they'll be BLACK and fouling!

 

[OldmanRick]

I agree with Crackedback and JD about the cam timing, this could be a accumulation of several issues at this point causing this result.

I tuned a Chivie years ago with a lg. hyd, 8.5 comp with poor heads....not my combo and had to put 20 degrees in it, but i pulled the total back to 40 to try and stay safe.

As i stated earlier a comp. test will also reveal poor cam timing to a certain extent.

 

[67Dart273]

.................Did you degree the cam while having the front ripped apart? Where was it installed with the old chain and the new one? Did you change it from the recommended installed ICL?

I've had some EXPENSIVE chains be 8* retarded when installed dot to dot! Whether it was the chain, cam or combo of both, it was a clusterf*ck.

No way, no how should the idle/vacuum be bouncing/surging like that. I bet if you pull the plugs again, they'll be BLACK and fouling!

X2 Did you verify the balancer timing marks are actually correct?

Valve adjustment?

Leakdown/ compression check?

What ignition system SPECIFICALLY are you running, dist, box, etc

Any chance the pickup wires are reversed, causing a rotor phasing problem?

 

[72bluNblu]

Something's definitely not right there. My car is set up at like 18* advanced, but it does ok there set up at 36* all in. You've got something else going on.

Did you check TDC? I mean, not just check that the dots line up, but actually that #1 is at true TDC when the marks are lined up?

Was the cam degreed at all?

What's the deal with your carburator? Has it been used before, did the engine run well with it as is? Or is it new?

What has been changed recently? I'm assuming the cam is new, what else?

I would start by finding true TDC and making sure everything lines up accordingly. A fair number of new dampers are marked incorrectly or inaccurately, and timing gears and chains aren't much better. Ideally you'd check it with a piston stop, but even if you just look down the #1 spark plug hole with a flashlight while a buddy turns the engine by hand you can get fairly close, just have them slowly advance the engine until the piston "hangs" for a second. I usually go past it and then back a few times to make sure I'm in the right spot. Not perfect, I set mine up with a dial indicator when the heads are off, but it sounds like it'll be more accurate than what you've got already...

 

[67Dart273]

if you just look down the #1 spark plug hole with a flashlight while a buddy turns the engine by hand you can get fairly close,.

You and I were doin' OK 'till you posted this. Not accurate. Not even. Piston stop is the "only" practical way. There are others, using fluids and manometers, balloons, and hell, I don't know, a seance, maybe

 

[805moparkid]

im another hand for comp test and cam degreeing... when i did my slant with an JP timing set i had to go 4* retarded on the sprockets to get 4* advance on the cam... lol

 

[67Dart273]

I didn't realize "machine tolerances" had gotten this bad!!!

 

[MRL Performance]

Does it do this "surge" when cold? or only when its warmed up? Does it do it while driving?

 

[Robbie2734]

Subscribed, I'd love to know whats doing that. My vote is the cam timing is off.

 

[OldmanRick]

Just caught this. On the video it says based off a dial back timing light.

Anyone ever see a faulty db timing light? I personally haven't, but i guess crazier things have happened. :scratch:




Guess at this point we just need a little more info. from the OP?

 

[67Dart273]

................... On the video it says based off a dial back timing light.....................Anyone ever see a faulty db timing light?

ABSOLUTELY Back in my parts store days, one service we did was to send customer test gear in to a repair facility. I've personally seen at least 4 different timing lights THAT WERE NOT ACCURATE

I don't know about "nowadays" as it's been awhile.

For me the tests are simple

1 Establish true TDC using a piston stop (for the dampener)

2 Degree the cam, and at least know "where it is"

3 Either degree the wheel, or at least mark the wheel at a couple of important points, like 20 and 40, so you have "ballbark" and or use timing tape

4 Confirm your light with a plain 'ol light. You can find em used at garage sales, Craigslist, or even new ones won't break the bank

5 With things like MSD aftermarket ignitions, delay boxes, ETC, and mating off--brand distributors and modules (My case, Mopar dist, GM module) You MUST check rotor phase.

THEN after the above SIMPLE steps, you can worry about carburetor, check the advance mechanism, distributor wear, valve adjustment, vacuum leaks, etc.

 

[365DUSTER]

I've had this happen before....a dialback timing light and MSD 6AL ignition will show a very high reading a lot of times. Mine did the same thing, except mine showed nearly 40 deg initial. With a standard light it was at 18 deg like it was before. Could be as easy as that!

 

[crackedback]

Dial back light... yuk...

I love my 25-30 year old inductive light! Simple and efficient.

My understanding, is TDC on balancer has been verified with a tdc stop

 

[OldmanRick]

I've personally seen at least 4 different timing lights THAT WERE NOT ACCURATE


[QUOTE= THEN after the above SIMPLE steps, you can worry about......




You spelled out alot of good info. there, post #15. Hopefully he will resond and take the advice.

Good to know there is always a possibility of a bad light. Guess i've been lucky, only faulty light i ever had i ran over by accident...lol.

 

[moper]

It's a pretty well known fact that many dial back lights have major issues with MSD systems. I'd suggest a plain old light and timing tape. I use an old Craftsman one, brcause my digital Snap On light is usually off with MSD systems. Many racersl use the self powered induction lights for that reason.

Also - How far out is the idle speed screw?

 

[Cal_gecko]

Thanks for all the replies.

Yes, TDC has been verified using a piston stop... it aligns perfectly with the mark on the balancer

I did pull the timing cover, and the marks on the sprockets lined up perfectly. I put on a Cloyes double roller set JUST IN CASE the marks on my previous one were off.. and they lined up perfectly as well.. I did NOT degree the cam shaft, for every 1 person who told me I should, I had another that told me it was unnecessary on a street engine. I was going to, until I realized how freaking complicated it was going to be.

I will take the suggestion of marking the HB with a silver sharpie at every 5 degrees, and instead of using my dialback light, I'll use my other one, and see what that's telling me.

I'll have to google "rotor phase" ....

No valve adjustment .. I have stock, non-adjustable 360 valvetrain

The car has not been driven.. not more than in and out of my garage to my driveway and back.

I bought the carb used about 8 yrs ago, and it was in great condition.. I did go through it about 2 years ago and cleaned it out... and it's been started a couple times since then.. nothing major though

Ignition system is an MSD 6AL box with a Blaster 2 coil, and Electronic Ignition distributor. I don't THINK the wires are reversed.. if I cut them and reverse them, will it do any damage?


I was able to get the initial timing back to about 15 this morning, it ran pretty rough though.. again, that's using the dialback light as my reference ... so I'll use a regular light instead to check it.. later.

I have not had time to do another compression test.. I usually don't get home from work until 8pm or so... and try not to work on it after 10pm out of respect to my neighbors.

 

[crackedback]

I did NOT degree the cam shaft, for every 1 person who told me I should, I had another that told me it was unnecessary on a street engine. I was going to, until I realized how freaking complicated it was going to be.

Should have done it if for no other reason than verify it was installed at least close to or on spec. Anyone that told you not to bother doesn't care about doing things correctly. Maybe the cloyes chain is in worse shape from a degreeing aspect than the first one you had. You don't know, therefore, you can't rule out the cam being out a bunch.

 

[4spdragtop]

We had similar issues, but we discovered our TDC on balancer was way off!

 

[805moparkid]

It's a pretty well known fact that many dial back lights have major issues with MSD systems. I'd suggest a plain old light and timing tape. I use an old Craftsman one, brcause my digital Snap On light is usually off with MSD systems. Many racersl use the self powered induction lights for that reason.

Also - How far out is the idle speed screw?

something alot of people forget is you have to check timing above 3 grand with the MSD or it can throw off your reading...

Should have done it if for no other reason than verify it was installed at least close to or on spec. Anyone that told you not to bother doesn't care about doing things correctly. Maybe the cloyes chain is in worse shape from a degreeing aspect than the first one you had. You don't know, therefore, you can't rule out the cam being out a bunch.

i dont think its a machining "issue", just there are so many hands in the pe so to speak... the mopar (or aftermarket crank), and then a cam from one of hundreds of makers, and then the same for the timing set...

 

[67Dart273]

....I'll have to google "rotor phase" .... .

"Rotor phasing" is simply the relationship between when the spark is triggered (points, pickup coil, and the ignition box) and the rotor contact position with the cap. If it's been "off for awhile" you can see "tracks" in the cap, IE the spark will have damaged the cap and tracked the inside up by the contacts.

This can be caused by things like a mis--match in parts in the distributor, some machining eff up, or maybe someone took, say, a stock dist. and eliminated the vacuum advance, getting the advance plate too far out of alignment.

AND IT CAN BE CAUSED by reversed pickup wires on a breakerless system

In a "normal" distributor, the rotor phasing does NOT change with changes in mechanical advance, because the reluctor (star wheel) or breaker points cam does not move in relation to the rotor.

The vacuum advance, however, DOES change rotor phasing, and this is NORMALLY taken care of by design.

You can easily check this, Google around, just cut/ break an old cap so that you can see the no1 (or actually any) plug tower contact through the hole you cut. Hook your timing light to whatever plug wire matches the hole you cut, and run the engine with the light directed at the hole. You can then SEE where the rotor is in relation to the cap. It should AT LEAST be "in contact" (alignment) so that the "corner" of the rotor contact is "mating" with the "corner" of the dist. contact. You should also move the vacuum advance if used, and the rotor should change over to the opposite "corners" of the contact.

Hole drilled in cap:

http://www.binderplanet.com/photopost/data/532/1534phasing_0047.JPG

Checkin' er

http://www.hotrodhotline.com/md/assets/images/Rotor_figure_2.jpg

Effect of der vacummin

http://www.hotrodhotline.com/md/assets/images/rotor_figure_4.jpg

Not all of what he says applies in your case, but this shows the rotor change

[ame="http://www.youtube.com/watch?v=aWMlNwGW0tM"]MSD Tech: Rotor Phasing - YouTube[/ame]

No valve adjustment .. I have stock, non-adjustable 360 valvetrain.

You should still check this out. All you had to do is mill the heads a little, and mill the block a little, and if using factory pushrods, you might not have enough clearance for the lifters

Ignition system is an MSD 6AL box .

Exactly what dist. are you using, IE Mopar breakerless, or MSD made for the 6AL box?

I read the destructions for the 6AL and 6AL-2. They MENTION different wiring for points, breakerless, and (for the 6AL-2) Hall effect, so you want to be CERTAIN that is correct

While this box does not have a selectible spark retard/ advance, IT IS microprocessor controlled. One has to wonder if "somethin' might go AFU" in these boxes?

The answer is, "I don't know" but I CAN tell you this----

Since you are having so much trouble, I'd substitute something else until you eliminate the problem.


If you have an old points dist, hook it up without the MSD

If you have a used/ working Mopar ECU, toss that temporarily on there

IF THIS WAS MINE I would temporarily "rig" a GM HEI module, which you can do in very little time, for very little money

Here's the diagram of mine, using a Mopar / Accell distributor:

You do need to screw it to flat metal for heat sink, and ground the mounting screws. The diagram shows proper polarity for the Mopar dist. connector. You can hook this thing up with 6 bucks worth of Radio Sh## clip leads!!!

 

[Cal_gecko]

"Rotor phasing" is simply the relationship between when the spark is triggered (points, pickup coil, and the ignition box) and the rotor contact position with the cap. If it's been "off for awhile" you can see "tracks" in the cap, IE the spark will have damaged the cap and tracked the inside up by the contacts.

This can be caused by things like a mis--match in parts in the distributor, some machining eff up, or maybe someone took, say, a stock dist. and eliminated the vacuum advance, getting the advance plate too far out of alignment.

AND IT CAN BE CAUSED by reversed pickup wires on a breakerless system

In a "normal" distributor, the rotor phasing does NOT change with changes in mechanical advance, because the reluctor (star wheel) or breaker points cam does not move in relation to the rotor.

The vacuum advance, however, DOES change rotor phasing, and this is NORMALLY taken care of by design.

You can easily check this, Google around, just cut/ break an old cap so that you can see the no1 (or actually any) plug tower contact through the hole you cut. Hook your timing light to whatever plug wire matches the hole you cut, and run the engine with the light directed at the hole. You can then SEE where the rotor is in relation to the cap. It should AT LEAST be "in contact" (alignment) so that the "corner" of the rotor contact is "mating" with the "corner" of the dist. contact. You should also move the vacuum advance if used, and the rotor should change over to the opposite "corners" of the contact.

Hole drilled in cap:

http://www.binderplanet.com/photopost/data/532/1534phasing_0047.JPG

Checkin' er

http://www.hotrodhotline.com/md/assets/images/Rotor_figure_2.jpg

Effect of der vacummin

http://www.hotrodhotline.com/md/assets/images/rotor_figure_4.jpg

Not all of what he says applies in your case, but this shows the rotor change

MSD Tech: Rotor Phasing - YouTube

Hm... OK... I'll have to watch the video for checking it with the vac. advance.. .I'm guessing I just hook up the vacuum advance line from the carb, and wait for the vac. advance to kick in and watch the rotor move...

You should still check this out. All you had to do is mill the heads a little, and mill the block a little, and if using factory pushrods, you might not have enough clearance for the lifters

Sorry, but I don't understand.. wouldn't it just make the valves open a little further if that was the case?

Exactly what dist. are you using, IE Mopar breakerless, or MSD made for the 6AL box?

Standard rebuilt Chrysler electronic ignition distributor:

I read the destructions for the 6AL and 6AL-2. They MENTION different wiring for points, breakerless, and (for the 6AL-2) Hall effect, so you want to be CERTAIN that is correct

While this box does not have a selectible spark retard/ advance, IT IS microprocessor controlled. One has to wonder if "somethin' might go AFU" in these boxes?

The answer is, "I don't know" but I CAN tell you this----

Since you are having so much trouble, I'd substitute something else until you eliminate the problem.


If you have an old points dist, hook it up without the MSD

If you have a used/ working Mopar ECU, toss that temporarily on there

I do have a couple Mopar ECU's (one brand new, I think) and pigtail.. don't have a ballast resister though.. is that only necessary with the stock coil? Can I get away without a ballast if I stick with the MSD Blaster 2 coil?

IF THIS WAS MINE I would temporarily "rig" a GM HEI module, which you can do in very little time, for very little money

Here's the diagram of mine, using a Mopar / Accell distributor:

You do need to screw it to flat metal for heat sink, and ground the mounting screws. The diagram shows proper polarity for the Mopar dist. connector. You can hook this thing up with 6 bucks worth of Radio Sh## clip leads!!!

hmmm.. that looks a little confusing.. thanks though!