AC Delco 41-993 spark plug issues

[TSALI137]

Has anyone had issues apart from the one post of no start on new plugs? It's a couple years old now. So I put new engine in a year ago and fast forward 12,000miles or 18months, and I'm fixing to have to install a new set of plugs wires and distributor cap. Mainly plugs, but here's the kicker, this is set 3 of the spark plugs in 12,000 miles! These things are fowled out shot! So were the others. Granted the specs say 36 degrees on timing advance and I'm currently at about 34 with the cmp at negative 1.8. which is ±2 of dead on the 36 degrees advance. I'll try to correct that when I change the plugs to the Accel shorty plug due to headers. I've had the 0411 PCM tuned by 4 different places and I feel like it's not tuned right based on how it runs and the continuous fowled out plugs. However it could be tuned right but the plugs aren't the best option for the crate engine. Anyone else have any thoughts or anything? There's very limited tuning options in my area and being disabled limits the funds. I'm beyond frustrated and keep kicking myself for not changing the intake and putting a holly carb on the motor. I took the Internets advice and did the 0411pcm swap. Unfortunately I can't tune that. I could tune a carburetor though. I've helped several kids change their trucks out to carburetor on the TBI engine with vortec heads. And for the record all you need is a throttle position sensor for the 4l60e.
So back to the question of any issues with the acdelco 41-993 now that we've had a few years with them?
Also anyone live within an hour or so of Saluda NC that could help with tuning that doesn't require 500-1000+ for a dyno tune. I just need and want a street tune for my daily driver and only vehicle. I understand it takes $100 for the credits and maybe another $200 for time. Thanks in advance to any insight on the plugs or anyone who can tune.

 

[Schurkey]

I put new engine in a year ago

WHAT ENGINE? WHAT VEHICLE? STOCK REPLACEMENT? MODIFIED?

and fast forward 12,000miles or 18months, and I'm fixing to have to install a new set of plugs wires and distributor cap. Mainly plugs, but here's the kicker, this is set 3 of the spark plugs in 12,000 miles!

Something is SERIOUSLY wrong.

These things are fowled out shot! So were the others.

Chickens and turkeys are fowl.

OIl fouled? Gasoline fouled? Glazed from overheating fouled?

Granted the specs say 36 degrees on timing advance and I'm currently at about 34 with the cmp at negative 1.8. which is ±2 of dead on the 36 degrees advance.

Vortec engine? CMP being off does not change the timing. Timing is controlled by the crank sensor and the ECM, NOT the position of the distributor.

I've had the 0411 PCM tuned by 4 different places and I feel like it's not tuned right based on how it runs and the continuous fowled out plugs. However it could be tuned right but the plugs aren't the best option for the crate engine.

I guess either--or both are possible.

any issues with the acdelco 41-993 now that we've had a few years with them?

ACDelco deliberately screwed the pooch with the new plug-numbering "system". The whole point is to make it difficult (impossible) to select a different heat-range within the ACDelco range, than whatever GM specifies.

One wonders what a 41-993 is, in a numbering system that actually makes sense.
41 = Spark plug
9xx = Platinum, I think. Maybe double-Platinum, which would be crazy in a vehicle with a distributor.

 

[TSALI137]

Hp74 crate engine from ATk. https://atkhp.com/product/atk-hp74-chevy-350-vortec-1996-2000-truck-base-engine-315hp/

Stupid phone changed fouled to fowled, I guess because I'm always typing about birds. Anyway, 41-993 supposed to be iridium. I'm also replacing with Accel p526s shorty plugs because I found one wire cracked at the boot due to pacesetter can't make a good set of headers to fit. I haven't pulled plugs yet but more than likely gas fouled due to burning extremely rich.

 

[210Tumbleweed]

Sub'd...

 

[HotWheelsBurban]

41-993 is an iridium plug. That's what my crew cab was born with, and what I replaced those original plugs with in March. The truck runs better with the new ones(though it wasn't running badly with the originals, I just figured after 126K they needed changing).
Dammit now you've got me thinking I should pull them out and see what they look like....

 

[Yeetsmyfeets]

41-993s are the completely wrong plugs for a vortec head! The spec'd plug for the 5.7 Vortec is an AC Delco 14, which has a reach of ish 0.70", and the ones you're using have a reach of 0.98" WAY too long.

Those Accel p526s should work, but goddamn $25 apiece?? I'd pull the headers to replace the plugs every time if they wanted to charge me that kinda ********.

 

[TSALI137]

41-993s are the completely wrong plugs for a vortec head! The spec'd plug for the 5.7 Vortec is an AC Delco 14, which has a reach of ish 0.70", and the ones you're using have a reach of 0.98" WAY too long.

Those Accel p526s should work, but goddamn $25 apiece?? I'd pull the headers to replace the plugs every time if they wanted to charge me that kinda ********.

Bad thing is the tube is bent so far over that it melted the MSD plug wire and then it cracked causing it to arc on the header. if they weren't ceramic coated I'd give them a good hammer tap for space.

 

[Schurkey]

Hp74 crate engine from ATk. https://atkhp.com/product/atk-hp74-chevy-350-vortec-1996-2000-truck-base-engine-315hp/

• Spark Plugs: Autolite #605




I looked-up spark plugs for a '97 C1500 with 5.7L Vortec.
The 41-993s are listed on the Summit web site as compatible...but most of the selections were in the .700 reach range, not the .900 range like the '993s.

Summit also lists the R44LTS6 as compatible. Which means I'd be buying R44LTS which has a more-reasonable gap at .045-ish than the .060 gap of the recommended plug.

Anyone have a Vortec small-block head off an engine, that could measure the plug reach, or take pictures with a .700-ish plug and a .900-ish plug installed? I've got heads, but they're still bolted-on.

I looked-up the Accel P526S plugs, and they're indeed $25 apiece. I figured it was $25 for a set of four. Nope. I sure as hell would not drop that much money on spark plugs for an engine with a repeated fouling problem. I'd put cheap plugs in until the fouling issue was solved. Who does Accel buy their plugs from? NGK? Maybe you can get short NGK plugs at a better price than the Accels.