Car stumbling and dying

[DRJDVM's '69]

Big problems now....****..

Did the vaccum guage and it peaked around 1-1.5 turns out.... car seems to run better too..... did it a couple of times and messed with the idle.

Took the car out for a ride and it seemed to run better. Went on the freeway, got on it alittle to pass someone, then started to cruise at about 70 MPH and 2000 RPMs in 5th gear....went about 3/4 mile just cruising and ....bamm, some black smoke.... car just started to die and I had to pull over on the side of the freeway.... car cranks but no oil pressure....WTF....

called AAA and the car is home....

WTF did I do ??? How could I have broken something cruising at 70 MPH..... I did get on it alittle before but it seemed fine and nothing went wrong for almost a mile..... the motor is all forged, Dart block etc etc, so....

Could I have leaned it out too much and got into detonation ??

Not good....

[camcojb]

Originally Posted by DRJDVM's '69

Big problems now....****..

Did the vaccum guage and it peaked around 1-1.5 turns out.... car seems to run better too..... did it a couple of times and messed with the idle.

Took the car out for a ride and it seemed to run better. Went on the freeway, got on it alittle to pass someone, then started to cruise at about 70 MPH and 2000 RPMs in 5th gear....went about 3/4 mile just cruising and ....bamm, some black smoke.... car just started to die and I had to pull over on the side of the freeway.... car cranks but no oil pressure....WTF....

called AAA and the car is home....

WTF did I do ??? How could I have broken something cruising at 70 MPH..... I did get on it alittle before but it seemed fine and nothing went wrong for almost a mile..... the motor is all forged, Dart block etc etc, so....

Could I have leaned it out too much and got into detonation ??

Not good....

I doubt it, at least as far as doing damage. You'd have plenty of warning; pinging sound, etc. and even then you'd have to do a lot of it before breaking a ring or piston. You'd still have oil pressure.

Black smoke is usually super rich a/f, like a float stuck, dirt in the needle and seat, etc. I'd pull the air cleaner off and first check if gas is pouring down the carb when you turn the pump on (if electric; if manual you'd have to crank the engine over). Also, what is your fuel pressure? If it's too high, or right at the limit it will cause numerous flooding issues, erratic idle, etc. Also, do you have access to another oil pressure gauge? Is this one electric or manual? If electric, make sure the wire is still connected, didn't burn on the headers, etc. I always start on oil pressure issues with trying another gauge, and the vast majority of the time the gauge or sender is bad, and there is no real oil pressure issue.

Jody

[DRJDVM's '69]

Pulled the valve covers.... things look okay, no milkshake or obvious spring broken etc...

Pull the spark plugs... they all look decent with a light coat of black soot....

Pulled the distributor cap off... nothing there......

Turn it over by hand..... distributor turns, and the valves move.....

So my biggest troubleshoot.... no oil pressure when cranking......

My friend that built the motor is coming over to troubleshoot but any suggestions would be welcome.....

[Vegas69]

How long are you turning it over? It takes quite a while to register pressure while cranking. Does it have an oil safety switch? If so maybe your sender went out and cut your fuel pump or spark. I agree with Jody...always check an oil pressure problem with another gauge if possible.

[DRJDVM's '69]

Well we found the problem... the distributor gear went bye-bye.......

Its was pretty trashed and broken apart on one side....... I'll try and post pix later......

When I turned the motor over by hand more the rotor turned but got to a point that it seemed like it lagged some. The timing marks were pretty close, so at first we didnt think it was that. But I couldnt come up with a different scenario to have the car die and have the oil pressure disappear ( I can understand the guage thing, but it would have to be one hella of a coincidence to have the car die like that and have the guage/sender die too..)

Its and MSD distributor and Comp Cam said we didnt need to run a bronze gear with this cam, so we left the stock gear.....

So I think the safest thing to do is pull the motor and check it all out.... I have too much $$ into this to risk it.....

We drained the oil and cut the filter and there is some fine metal in the filter.... the motor was set up with no oil bypass so 100% of the oil goes through the filter and I was using a K&N, so hopefully there isnt much metal floating anywhere....

PITA but the safest thing......

[ohcbird]

So what's the verdict on why the cam gear went? Are you using an 8620 cam? If your using an iron hydro cam w/ stock gear, I'd look further into why that gear busted.

The black smoke was probably from when the gear went & it went fat, real quick (434Ci is alot of unburnt fuel).

Good luck on the refresh- sounds like a nice combo.

[camcojb]

if this is a roller cam with iron gear compatible dist gear on it, get the melonized gear from GM and have it honed to fit the MSD distributor. You won't have another issue. I get my gears honed to fit from Mike at http://www.lewisracingengines.com/

Jody

[68protouring454]

i will second the quality of mike's work....

[DRJDVM's '69]

The cam is a "standard" (i.e not billet etc) Comp Cam and the distributor gear was the stock MSD piece....

I dont know what the cam gear looks like but I assume its trashed too....... I kinda want a diff cam anyway since this one didnt lope or sound as mean as I was hoping.... the 434 ate it up and it sounded too mellow to me anyway....

I did an internet search and found out alot about the melonized gears....seems to be a common choice...... but not everyone agrees.... seems like a billet cam with pressed on cast gear with the meolinized dist gear seems to work for alot of guys..

I went onto the MSD site and there were quite a few posts about gear failure....mostly Fords..... some "possible causes" were excessive endplay, high volume oil pumps and some other crap....no real specific casues... the scary thing is that there were posts with mulitple failures.... I really dont want to keep doing this.....

One of the theories is about high volume or high pressure oil pumps.... my engine builder put in a custom built oil pump that he swears by.... he runs on in his car and so does my friend with no problems......the oil pressure is around 20 at idle and often in the 70's at highway.... I've never had oil pressure that high....

I just dont want to do this again .....

[camcojb]

Originally Posted by DRJDVM's '69

The cam is a "standard" (i.e not billet etc) Comp Cam and the distributor gear was the stock MSD piece....

I dont know what the cam gear looks like but I assume its trashed too....... I kinda want a diff cam anyway since this one didnt lope or sound as mean as I was hoping.... the 434 ate it up and it sounded too mellow to me anyway....

I did an internet search and found out alot about the melonized gears....seems to be a common choice...... but not everyone agrees.... seems like a billet cam with pressed on cast gear with the meolinized dist gear seems to work for alot of guys..

I went onto the MSD site and there were quite a few posts about gear failure....mostly Fords..... some "possible causes" were excessive endplay, high volume oil pumps and some other crap....no real specific casues... the scary thing is that there were posts with mulitple failures.... I really dont want to keep doing this.....

One of the theories is about high volume or high pressure oil pumps.... my engine builder put in a custom built oil pump that he swears by.... he runs on in his car and so does my friend with no problems......the oil pressure is around 20 at idle and often in the 70's at highway.... I've never had oil pressure that high....

I just dont want to do this again .....

trust me Ned. If the cam has the iron gear for a standard dist gear, use Mikes melonized gear. The MSD has had many problems with failures on Chevy's too, been through it myself.

The cam gear is likely okay, but now's the time to change if you want to. I prefer the billet cams with the iron gear pressed on, especially if you're running a higher rpm and more spring pressure. The standard hydraulic roller blanks are soft in my opinion, seen several that the roller lifter actually dents the lobes.

Jody