350 Spark Plug issues

MelbGMC

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I'm after some information as to what would be causing the plugs to foul so bad and burn the tips of plug 6 & 7.
The motor has only done approximately 2000km's in its life, I have put edelbrock 5073 heads on it, a crane energiser 266 cam, crane roller rockers, Edelbrock EPS manifold and a Edelbrock 600cfm carb with 0.101 jets and 068-052 metering rods.
I have done a compression test and all cylinders are 120psi.
Can the cause be a timing issue?
I have asked the question on a facebook group page and someone mentioned the PCV valve may be stuffed and causing oil directly into the inltet manifold, I have checked the hose and it is dry, so oil is not coming from there.
Could it be valves, seats or seals?
Also the engine used approx 2 litres of oil ofter a 300-400km trip.
The pic without heads & rocker covers on the car is when I put the Edelbrock heads, cam and roller rockers in it

I'm thinking I may need to pull the motor out of the car.......

What are peoples thoughts?
 

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Turbo4whl

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Definitely oil consumption. The compression seams a bit low but may be the variation in test gauges, or engine temp when you did the test.

Since the heads are new, I would hope it isn't valve guide seals. Personally I like Perfect Circle seals, but I'm old school. Other people may disagree.

I would move on to a cylinder leak down test. That will tell you if the rings are bad. Your engine is sucking lots of oil from somewhere. Same as a compression test, the engine should be warm for the test.
 

MelbGMC

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Compression test was done cold, will do a leak down test and see what results I get from that..........
 

Matt69olds

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Did you have the throttle held open, and all the plugs removed? Rule of thumb, the very first pump should be at least half the final reading. In your case, since you had 120psi, the very first needle jump on the gauge should have been at least 60. If not, that’s usually a sign of poor ring seal.
 

fast 99

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Could it be sucking oil from the intake gaskets? Block of the breather and PCV, check for vacuum in the crankcase.
 

MelbGMC

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I have done a wet compression test on the motor today, all cylinders are around 5psi higher than the dry copression test.
I'm thinking head issues, valves, guides, seals etc.
Surely all cylinders wouldnt have bad rings would they........
 

Grit dog

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That’s a really pretty engine!
Wherever the oil fouling is coming from is fairly consistent across all cylinders, it looks like most of the plugs are goobered up.
Does it smoke on startup? If so that would make me think valve guide seals.
If not, rings. Oil can only get in 2 ways, I think.
Doesn’t seem likely a new engine would have a plugged crankcase vent.
 

MelbGMC

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Doesn’t smoke on startup unfortunately
 

AuroraGirl

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I'm after some information as to what would be causing the plugs to foul so bad and burn the tips of plug 6 & 7.
The motor has only done approximately 2000km's in its life, I have put edelbrock 5073 heads on it, a crane energiser 266 cam, crane roller rockers, Edelbrock EPS manifold and a Edelbrock 600cfm carb with 0.101 jets and 068-052 metering rods.
I have done a compression test and all cylinders are 120psi.
Can the cause be a timing issue?
I have asked the question on a facebook group page and someone mentioned the PCV valve may be stuffed and causing oil directly into the inltet manifold, I have checked the hose and it is dry, so oil is not coming from there.
Could it be valves, seats or seals?
Also the engine used approx 2 litres of oil ofter a 300-400km trip.
The pic without heads & rocker covers on the car is when I put the Edelbrock heads, cam and roller rockers in it

I'm thinking I may need to pull the motor out of the car.......

What are peoples thoughts?
That looks to be manual choke? Also is it using the camshaft driven fuel pump, is it a edelbrock brand by chance? (edelbrock says their fuel pump can eliminate needing a regulator, which you have which is a good thing.) also, Manual trans? Auto?

The PCV situation, is your breather the opposite corner of your PCV? the PCV brand is?


Also, I just saw other photos. auto trans and regular mechanical pump. Do you know who made the pump? maybe a poor quality fuel pump, It seems to be an epidemic as of late. I only bring this up because it points to my pump pushing gas into the crankcase so I need a new pump. Does your oil smell gasy or have that "feel" which Im not really able to describe, but anyone whos drained out gasy oil and ever felt it compared to just old oil maybe would understand what Im saying?

The worst example I can think was my trucks 2nd oil change which was shortly after I started fixing on it and the oil wasnt all that old but the truck ran richer than bezos and it diluted and washed a lot of gunk out and then it had a very strange filmy feel which even overdue oil on my fuel injected truck just felt like old oil but didnt have that slimy.


Anyway, not the point anymore I guess,
bcp5es NGK is a nickel spark plug, I dont have the know how to know what the closest possible cross in ac delco would be, so I am not sure what the heat range or qualities of this plug are. But if you can, I would check all the important things, put a set of copper AC delco of normal variety if you are able(not sure if the heads you put on require a different seat,pitch, etc ) and see what some miles do to them. The reason why, you live in australia, yes? Presumably its hot and your truck is a weekend cruiser, do you get on it? surely you have power and want to use it sometimes lol. How long are your drives, how do you drive during it, and what kind of pedal action do you do? Someone who eases into it or jabs it like youre getting a vaccine from an excited medical worker. Being its the edelbrock, to my understanding, the potential for it to maybe richen more than needed with the accelerator pump may exist.. im grasping for things to maybe affect it lol....

Basically, im wondering if your frequency of using it, driving habit while enjoying it, hot conditions, interactions with available gasoline maybe.. spark plug heat range... you see where Im headed? If a bcp5es NGK is the fine heat range for your driving and conditions, then what kind of gap you running and have you tried iridium,copper, platinum by chance?

Also, edelbrock says if you use a long duration cam to connect to manifold vacuum. No idea if your cam is, the specs go over my young head, but the the port you are using is ported according to edelbrock. How important to any of this is that? Im not sure and its an age old debate. But you arent using emissions setup, so maybe try the other port and see if anything seems better?

I also see a rubber hose running to what I assume is the intake behind the carb which is for your vacuum modulator. Is that hose strong walled to withstand collapse and not kink? I cant see it well but I just noticed that.
there is also a company that makes an add on plate
You must be registered for see images attach

they are called power blast
Googling the website I saw someone on a forum claim that it increased their output 14hp or so, and they were pleased. They crunched the $2.60 or something per hp based on the cost. Take that as you will, I have no experience with it personally, they just didnt seem like they were shilling for the product and thus i hope they wouldnt lie about it either

lastly about that choke, are you diligent about setting it and opening it appropiately? Not forgetting? Just something to think about

whats your valve cover look like? Baffled by the pcv? And you said 2k kilometers on your new engine, sounds.... kinda simple, but did you break the engine in the proper procedure/oil/drive the appropiate way to the directions and then also what kind of oil are you using?

also dry PCV hose? Not even oil vapor that you could see? Unless you were running the cleanest catch can setup vehicle ive ever seen I feel like oil vapor/small amount of oil or atl east wetness should be in the hose, but it depends on how long you were using it. If youre burning that much oil, Id kinda expect oil for sure. Is your PCV caked in oil or dry itself?

Sorry for the mind spit here today but I am optimistic about your engines long term outlook! :)
 

MelbGMC

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Ive been doing some research while waiting for my leakdopwn tester to arrive.
I've put the cam specs below, along with the pushrod length as well.
Edelbrock state to use 100thou longer pushrods for the heads I installed.
So the pushrod information below states they are for high lift cams, my cam is not high lift
I'm just wondering if the pushrods are too long for this application and this is causing my issues with plug fouling and using oil.

What are peoples thughts?


  • Home
  • Hi-Tech 210 Radius 7.900" Long, .080" Wall, 5/16" Diameter Pushrod - Set of 16


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Hi-Tech 210 Radius 7.900" Long, .080" Wall, 5/16" Diameter Pushrod - Set of 16​

AVAILABLE SOON
SKU
7946-16
Available Soon items may take 2-4 weeks for delivery.
$201.95

Details
Designed for high lift applications where pushrod and seat interference are problems at maximum lift, Hi-Tech 210° Radius Pushrods work well with rocker arms that feature cup type adjusters and applications that demand pushrods with more load bearing surface. Hi-Tech 210° Radius Pushrods have the same features as other Hi-Tech™ Pushrods, with the addition of a 210° radius rather than standard 180° radius. Featuring a one-piece design from .080” wall, seamless chromemoly tubing that ensures exceptional durability, the pushrods are heat-treated for maximum strength, OD ground for consistency and black-oxide finished with length and part number laser etched on for easy identification.
  • Designed for high lift applications where pushrod & seat interference are problems at maximum lift
  • Work well with rocker arms that feature cup type adjusters & applications requiring more load bearing surface from the pushrod
  • Same features as other Hi-Tech™ Pushrods with addition of 210° radius

266 H10 HYDRAULIC FLAT TAPPET CAMSHAFT FOR CHEVROLET 1957-1987 V-8, 262-400​



Good low end torque, smooth idle, daily usage, fuel economy, light towing, off road, 2200- 2700 cruise RPM, 8.5 to 10.0 compression ratio advised. (50 state legal, pre- computer, C.A.R.B. E.O. D- 225- 21).



Part Number:10004Grind Number:266 H10
Engine Identification:
Start Yr.End Yr.MakeCyl
Description​
1957
1987​
CHEVROLET​
8​
Good low end torque, smooth idle, daily usage, fuel economy, light towing, off road, 2200- 2700 cruise RPM, 8.5 to 10.0 compression ratio advised. (50 state legal, pre- computer, C.A.R.B. E.O. D- 225- 21).
Engine SizeConfiguration
262-400 C.I.
V​
Valve Setting:Intake -
.000​
Exhaust -
.000​
Hot/Cold -HOT
Lift:Intake @cam2934@Valve440All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam2934@Valve440
Rocker Arm Ratio1.5
Cam Timing:TAPPET@ .004
Lift: OpensClosesADV Duration
Intake24 BTDC62 ABDC266 °
Exhaust64 BBDC22 ATDC266 °
Spring Requirements:
Part Number99848
LoadsClosed114LBS @1.700or1 45/64
Open297LBS @1.280
Recommended RPM range with matching components
Minimum RPM1400
Maximum RPM5000
Valve Float5600
Cam Timing:TAPPET @.050
Lift: OpensClosesMax LiftDuration
Intake0 BTDC30 ABDC105210
Exhaust40 BBDC(10) BTDC115210
 

Bextreme04

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Ive been doing some research while waiting for my leakdopwn tester to arrive.
I've put the cam specs below, along with the pushrod length as well.
Edelbrock state to use 100thou longer pushrods for the heads I installed.
So the pushrod information below states they are for high lift cams, my cam is not high lift
I'm just wondering if the pushrods are too long for this application and this is causing my issues with plug fouling and using oil.

What are peoples thughts?


  • Home
  • Hi-Tech 210 Radius 7.900" Long, .080" Wall, 5/16" Diameter Pushrod - Set of 16


You must be registered for see images attach


Hi-Tech 210 Radius 7.900" Long, .080" Wall, 5/16" Diameter Pushrod - Set of 16​

AVAILABLE SOON
SKU
7946-16
Available Soon items may take 2-4 weeks for delivery.
$201.95

Details
Designed for high lift applications where pushrod and seat interference are problems at maximum lift, Hi-Tech 210° Radius Pushrods work well with rocker arms that feature cup type adjusters and applications that demand pushrods with more load bearing surface. Hi-Tech 210° Radius Pushrods have the same features as other Hi-Tech™ Pushrods, with the addition of a 210° radius rather than standard 180° radius. Featuring a one-piece design from .080” wall, seamless chromemoly tubing that ensures exceptional durability, the pushrods are heat-treated for maximum strength, OD ground for consistency and black-oxide finished with length and part number laser etched on for easy identification.
  • Designed for high lift applications where pushrod & seat interference are problems at maximum lift
  • Work well with rocker arms that feature cup type adjusters & applications requiring more load bearing surface from the pushrod
  • Same features as other Hi-Tech™ Pushrods with addition of 210° radius

266 H10 HYDRAULIC FLAT TAPPET CAMSHAFT FOR CHEVROLET 1957-1987 V-8, 262-400​



Good low end torque, smooth idle, daily usage, fuel economy, light towing, off road, 2200- 2700 cruise RPM, 8.5 to 10.0 compression ratio advised. (50 state legal, pre- computer, C.A.R.B. E.O. D- 225- 21).



Part Number:10004Grind Number:266 H10
Engine Identification:
Start Yr.End Yr.MakeCyl
Description​
1957
1987​
CHEVROLET​
8​
Good low end torque, smooth idle, daily usage, fuel economy, light towing, off road, 2200- 2700 cruise RPM, 8.5 to 10.0 compression ratio advised. (50 state legal, pre- computer, C.A.R.B. E.O. D- 225- 21).
Engine SizeConfiguration
262-400 C.I.
V​
Valve Setting:Intake -
.000​
Exhaust -
.000​
Hot/Cold -HOT
Lift:Intake @cam2934@Valve440All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam2934@Valve440
Rocker Arm Ratio1.5
Cam Timing:TAPPET@ .004
Lift:OpensClosesADV Duration
Intake24 BTDC62 ABDC266 °
Exhaust64 BBDC22 ATDC266 °
Spring Requirements:
Part Number99848
LoadsClosed114LBS @1.700or1 45/64
Open297LBS @1.280
Recommended RPM range with matching components
Minimum RPM1400
Maximum RPM5000
Valve Float5600
Cam Timing:TAPPET@.050
Lift:OpensClosesMax LiftDuration
Intake0 BTDC30 ABDC105210
Exhaust40 BBDC(10) BTDC115210

Pull one of the rockers and see where the mark is on the top of the valve. You should see a mark right in the middle of the valve where the rocker tip has been riding on the valve. If the mark is to the inside of the valve tip, your pushrod is too short. If it is to the outside of the valve step it is too long. If you don't know how long they need to be, buy a pushrod length checker and test springs and measure it by installing the spring and pushrod on one valve, put dykem on the tip of the valve(black sharpie will work too) and rotate the motor over a bit. Adjust the pushrod length until the mark is in the center of the valve.
 

Bextreme04

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Also, 2 liters in a few hundred kilometers is A LOT of oil. My truck has a leaky oil pan gasket and drips oil everywhere... I'm down about a quart every thousand miles or so.

Have you replaced the PCV? A bad PCV can definitely cause this kind of issue. If its dry, that means that the PCV isn't working right and can be causing the crankcase to pressurize and blow oil past the rings. What are you using for ventilation on the other valve cover? Do you have a pic of it all assembled and running?
 

Bextreme04

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K25
Engine Size
350-4bbl
120 psi equals about 8:1 dynamic compression... which is about right for a street motor and that cam. Adding 5 psi with a wet test is a bit more that you'd like to see, but definitely not enough to have that kind of consumption.
 

MelbGMC

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Posts
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Location
Melbourne
First Name
Marcus
Truck Year
1982
Truck Model
1500 Stepside
Engine Size
350
Also, 2 liters in a few hundred kilometers is A LOT of oil. My truck has a leaky oil pan gasket and drips oil everywhere... I'm down about a quart every thousand miles or so.

Have you replaced the PCV? A bad PCV can definitely cause this kind of issue. If its dry, that means that the PCV isn't working right and can be causing the crankcase to pressurize and blow oil past the rings. What are you using for ventilation on the other valve cover? Do you have a pic of it all assembled and running?
This is the motor assembled prior to me putting the new heads and cam in, showing breathers etc.
 

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MelbGMC

Member
Joined
Sep 14, 2021
Posts
47
Reaction score
39
Location
Melbourne
First Name
Marcus
Truck Year
1982
Truck Model
1500 Stepside
Engine Size
350
Also, 2 liters in a few hundred kilometers is A LOT of oil. My truck has a leaky oil pan gasket and drips oil everywhere... I'm down about a quart every thousand miles or so.

Have you replaced the PCV? A bad PCV can definitely cause this kind of issue. If its dry, that means that the PCV isn't working right and can be causing the crankcase to pressurize and blow oil past the rings. What are you using for ventilation on the other valve cover? Do you have a pic of it all assembled and running?
I'm going to replace the PCV this weekend and give it another run.
 

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