spark plug gap too close?

[tonyk72]

My 'vette has been blowing smoke out of the exhaust since I changed the oil (Quaker State 10W-30 for higher mileage engines) and installed ned plugs (AC Delco R44T). I first thought it might be the oil that is causing the problems...but the more research I do, I'm beginning to suspect the plugs & that I gapped them too close. I believe they are supposed to be pre-gapped at 0.035 which is correct for my application. I sent AC Delco an email to verify if the are pre-gapped at 0.035. I used one of the dial type gappers and all the new plugs seemed to be gapped at 0.045. So I got them down to 0.035...I'm thinking I might have done this wrong...or didn't need to do this.

Maybe the smoke coming out of the exhaust is caused by too narrow a gap? It's not exactly bluish (I've seen blue smoke coming out of other cars before), it smokes ALL the time, hot & cold, it doesn't smell sweet...

 

[TWINRAY]

First off, I wouldn't use any of this Hokus Pokus Higher mileage oil especially from Quaker State.
? #1. What oil did you use previously?
#2. Forgetting the smoke, does the motor run smooth?
#3. Maybe a hose got disconnected - check the vacumn advance and other vacumn hoses.

 

[tonyk72]

#1.This was the 1st time I changed the oil since I had the car, uncertain of what oil was in there before...
#2.Motor runs very well...
#3.I'll double-check the hoses at lunch, but I'm pretty sure they are all hooked up...

I figure I will increase the gap in the plugs 1st to see if that will fix the problem...If that doesn't, I'll dump the oil and go with plain old Castrol 10W-30...

 

[TWINRAY]

Now I'm confused. You say you may have gapped them too tight?
.035 (which appears to be your setting), is tighter than .045.
How can .035 be too tight if that is the correct setting.

If motor is running Ok than apparently no hoses got disconnected and all the spark plug wires are attached correctly?

 

[Ron Miller]

Haven't used Quaker State since 17 or 18 years ago when I had to have the rocker arm covers on my '83 Olds removed in order to remove enough sludge to let oil drain back to the pan. Also thought I had something broken in the valve train, as it was clattering also. Turned out it was so plugged up enough oil couldn't get to the lifters to prime them. After cleaning it up, ran fine again (on Castrol or Valvoline, I might add).

A month or two later I was at a car club meeting held in one of the member's body shop and saw a Ford engine in the corner of the shop with the rocker covers removed. A thick black gel about like jelly covered the rockers, filled full. I asked about it, he said "Yeah, that's what Quaker State will do in some of these big block Ford engines". To which I replied that it will also do the same in some Oldsmobile engines.

My experience and my $0.02 worth.

rlm :cool

 

[tonyk72]

I say I think I might have them gapped too tight because I assumed the AC Delco's were pre-gapped to 0.035. I had to tighten the gap on all the new plugs. I was thinking that the gap was already correct and I made the gap even smaller...anyways, this is what I got from AC Delco when I emailed them:

This is the question I sent to AC Delco:

Are AC Delco R44T spark plugs pre-gapped? If so, what is the gap?

This is their response:

Thank you for writing ACDelco.

You should always check the gap of a plug before you place it in your application and make sure that it is correct for your application.

Thank you for your interest in ACDelco.
ACDelco Customer Assistance

I've never gapped plugs beforeI used a dial meter to measure the gap. It doesn't look like rocket science...but since this was my 1st time, maybe I messed something up? I made sure the gap on the plug was not able to slide by 0.040. I heard that you need a little bit of play between the electrodes and gap meter when measuring. Is this right?

All hoses are hooked up OK.

The old plugs I pulled were black and covered with soot. I'll check the new plugs to see what they look like tonight.

One more thing, I had my carb rebuilt before I changed the oil & plugs...I'm pretty sure it wasn't smokeing after the rebuild (It was about a week between the rebuild and the oil/plug change). I'm still having some issues with the carb "leaking"gas onto the intake after a long ride... so I'm going to bring it back to get looked at...

 

[TWINRAY]

If I were a betting man, I'd say your trouble has nothing to do with the spark plug or its gap. If the carb rebuild was done wrong, a few things could happen. The car may not start - this is not the case. If it is running rich, you would have black smoke and the engine would probably load up - you would probably have to rev it up to clean it out. Blue smoke is not good. Blue smoke just at start up usually means valve seals. This is a common occurance in older Chevrolets and as long as it's not severe, is "OK." By OK , I mean the initial start up will burn away the oil that is leaking past the value guides. Of course, if it's real bad, the spark firing cannot keep up with the oil flow. You'll get continual oil burning (blue smoke) at this point and you will probably have bad rings. Motor rebuild time:bang
Pull the plugs tonight and see if they are oil fouled. Are your spark plug wires good? How old are they?

 

[tonyk72]

I pulled 2 plugs and they were covered with black soot...so I imagine my fuel mixture is too rich...The carb was supposed to be rebuilt back to factory specs/settings...and it's also STILL seeping fuel...I'm yanking it off tonight and bringing it to get looked at again. Could this be the cause of ALL my problems...a maladjusted/leaky carb?

 

[TWINRAY]

Either get the carb done right or get a replacement. If you paid for a carb rebuild and it wasn't done correctly, you should either get a refund for what you paid or he should guarantee his work and repair it for free. Once that is done, see if you still have problems.

 

[tonyk72]

and end to this thread...

It looks like the problem was all carb related. I brought it back to the shop, but they found nothing physically wrong with the it. All they did was set the float levels to where they were supposed to be...Everything else was to spec...

Sparks, I'll check again and clean up as I'm sure they are black and sooty...I might as well check my compression while I'm at it.

The QS oil has been dumped and I put in Castrol 10W-30.

Also, I sent QS an email a few days ago asking a few questions about their oil...never did hear back from them...I guess if they don't want to answer my questions, I won't use their oil...