Spark plug ground straps burned off

Noticed that the 547 was running rough and thermal gunned the header pipes to find #1, #4, and #5 were low. Removed the plugs to see that the strap was burned off at the bend radius for #1 and #5. The strap was 1/2 better for #4. All of the other plugs look great.
Plugs are Autolite 3924
Motor is 547 with SCJ's, 13.5 comp, E85, roller cam, timing locked at 32, victor 1050 Dom. Runs at 180f

Must be to hot? step to 3923's or colder? Why 1, 4, and 5?


Thanks,
Dave

3924 is 3 hotter. the 3934 is the one you need w/cut back tips.

Dave De wrote:Noticed that the 547 was running rough and thermal gunned the header pipes to find #1, #4, and #5 were low. Removed the plugs to see that the strap was burned off at the bend radius for #1 and #5. The strap was 1/2 better for #4. All of the other plugs look great.
Plugs are Autolite 3924
Motor is 547 with SCJ's, 13.5 comp, E85, roller cam, timing locked at 32, victor 1050 Dom. Runs at 180f

Must be to hot? step to 3923's or colder? Why 1, 4, and 5?



Thanks,
Dave

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jetting just a little off ,and the intake needs port work, and get the temp down

Dave De wrote:Noticed that the 547 was running rough and thermal gunned the header pipes to find #1, #4, and #5 were low. Removed the plugs to see that the strap was burned off at the bend radius for #1 and #5. The strap was 1/2 better for #4. All of the other plugs look great.
Plugs are Autolite 3924
Motor is 547 with SCJ's, 13.5 comp, E85, roller cam, timing locked at 32, victor 1050 Dom. Runs at 180f

Must be to hot? step to 3923's or colder? Why 1, 4, and 5?


Thanks,
Dave

Sounds a little lean to me ...
Is this a Victor intake manifold "end runners"...?

Dave you you need a ar3934the 3924 is way to hot for your setup its hot for my junk. you should be in the 7- 8-9 heat range in a ngk and 3924 is a 5 heat range if you like projected tip 3922 work well and are easy and cheap to get. going down to woodward tonite if the weather is good. got caught in the rain wed nite was that american pie 22 & schoenherr on the way home 32 mile it was pouring truck is a mess

Today I picked up NGK R5671A-8 they say "8" on the plug. Is that good they crossed up with AR3934?

The differences between the plugs from the center cylinders is night and day with the front 2. I always checked 2 or 3, or 6 or 7.

The manifold is a 4150 victor that was re machined for a 4500 and ported. Are these manifolds notorious for uneven distribution?
From now on I'll be looking at #1 and #5.
The 1050's got 90's up front with a PV and may go to 93's or lower the air bleed a touch.
Also the 3924's were a year old and had been down the track about 50 times. The center cylinder plugs looked so good I didnt think there was a problem.

Thanks for your comments,
Dave

quick 52 wrote: Dave you you need a ar3934the 3924 is way to hot for your setup its hot for my junk. you should be in the 7- 8-9 heat range in a ngk and 3924 is a 5 heat range if you like projected tip 3922 work well and are easy and cheap to get. going down to woodward tonite if the weather is good. got caught in the rain wed nite was that american pie 22 & schoenherr on the way home 32 mile it was pouring truck is a mess

Dale,
Next time you are at American Pie let me know. I'm only 4 miles from there.
Cant make Woodward tonite and dont want to take a chance with leaving the stickies on it.
Dave

Dave De wrote:Today I picked up NGK R5671A-8 they say "8" on the plug. Is that good they crossed up with AR3934?

The differences between the plugs from the center cylinders is night and day with the front 2. I always checked 2 or 3, or 6 or 7.

The manifold is a 4150 victor that was re machined for a 4500 and ported. Are these manifolds notorious for uneven distribution?
From now on I'll be looking at #1 and #5.
The 1050's got 90's up front with a PV and may go to 93's or lower the air bleed a touch.
Also the 3924's were a year old and had been down the track about 50 times. The center cylinder plugs looked so good I didnt think there was a problem.

Thanks for your comments,
Dave

4 & 5 run the leanest unless it is ported to alleviate that tendency; 2 & 7 will usually be the fattest.

Cross jet the carb with the driver front and passenger rear about 2 to 4 sizes richer.

rmcomprandy wrote:

Dave De wrote:Today I picked up NGK R5671A-8 they say "8" on the plug. Is that good they crossed up with AR3934?

The differences between the plugs from the center cylinders is night and day with the front 2. I always checked 2 or 3, or 6 or 7.

The manifold is a 4150 victor that was re machined for a 4500 and ported. Are these manifolds notorious for uneven distribution?
From now on I'll be looking at #1 and #5.
The 1050's got 90's up front with a PV and may go to 93's or lower the air bleed a touch.
Also the 3924's were a year old and had been down the track about 50 times. The center cylinder plugs looked so good I didnt think there was a problem.

Thanks for your comments,
Dave

4 & 5 run the leanest unless it is ported to alleviate that tendency; 2 & 7 will usually be the fattest.

Cross jet the carb with the driver front and passenger rear about 2 to 4 sizes richer.

randy does that happen on the ford intake Lem sales the victor style in the 4150 flange

It is the SAME intake manifold with different numbers and letters cast into it.

Dave Who did the E85 carb for you? if not done right it will go lean when cruising or WOT. You said 90 in the from But what in the Back. I'm in Denver and I'm jetted 93-103 using a PV as well and its just slightly on the lean side.

Ace

powerstrokeace wrote:Dave Who did the E85 carb for you? if not done right it will go lean when cruising or WOT. You said 90 in the from But what in the Back. I'm in Denver and I'm jetted 93-103 using a PV as well and its just slightly on the lean side.

Ace

I made the changes and am at 93-103 now. Horsepower Innovations did the carb. I think the carb was close but the difference between the cylinders on the plugs is great. The Victor manifild must be the problem. I will only use the corner cylinders to read the plugs now.
Its time to get a wide band.

Dave De wrote:

powerstrokeace wrote:Dave Who did the E85 carb for you? if not done right it will go lean when cruising or WOT. You said 90 in the from But what in the Back. I'm in Denver and I'm jetted 93-103 using a PV as well and its just slightly on the lean side.

Ace

I made the changes and am at 93-103 now. Horsepower Innovations did the carb. I think the carb was close but the difference between the cylinders on the plugs is great. The Victor manifild must be the problem. I will only use the corner cylinders to read the plugs now.
Its time to get a wide band.

I just sold my LM2 wideband. Eric is a good guy and has hit the nail on the head on my deal. Some carb builds don't know whats really going on on this E85 deal

Ace