Proper spark plug gap?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
1980 350 V8. Standard plugs, cap and rotor.

What should I set them to?

Sent from my SM-T720 using Tapatalk
 

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
5,989
Reaction score
7,495
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
Stock head, ignition, etc I want to say .035

I’m at .060 with my current setup, but I’m pretty sure I’m remembering that correctly.
 

Chevyguy

Full Access Member
Joined
Sep 10, 2012
Posts
185
Reaction score
60
Location
Eugene,OR
First Name
Clayton
Truck Year
1987
Truck Model
V20
Engine Size
5.7 Litre
1980 350 V8. Standard plugs, cap and rotor.

What should I set them to?

Sent from my SM-T720 using Tapatalk
Should be listed on the emission sticker that's either on the air cleaner housing, or the top radiator mounting plate. My 87's by the radiator.

Clayton

Sent from my LM-V350 using Tapatalk
 

hunters628

Full Access Member
Joined
Sep 10, 2019
Posts
237
Reaction score
203
Location
Ellensburg Washington
First Name
Hunter
Truck Year
1982
Truck Model
K10
Engine Size
305
I just make sure there is actually a gap on the plug and I call it good. Lol. No noticeable performance difference in properly gapped plugs so what’s the point. That’s how I do it on all my rigs. Learned that trick from a vw engine builder of 40+ years.
 

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
5,989
Reaction score
7,495
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
There’s absolutely a difference in plug gaps. Try running my gap on a turbocharged engine. Compression, flame front, timing, ignition strength...there are a ton of variables. I guess on a 160hp 8:1cr v8 it may be a wider window, but at least you’ll get longer plug life and more complete combustion.
 

Dan Miller

K15SG
Joined
Sep 11, 2019
Posts
385
Reaction score
577
Location
Indiana
First Name
Daniel
Truck Year
1978
Truck Model
K15
Engine Size
350
Ive had alot of mine come preset at .045 . I use AC - R45TS in my stock 350 2bbl ,, seems to do fine for me
 

Chevyguy

Full Access Member
Joined
Sep 10, 2012
Posts
185
Reaction score
60
Location
Eugene,OR
First Name
Clayton
Truck Year
1987
Truck Model
V20
Engine Size
5.7 Litre
Looking online .045 seems to be the recomended gap for your 1980 HEI motor.

Clayton

Sent from my LM-V350 using Tapatalk
 

Dysco

Full Access Member
Joined
Apr 12, 2019
Posts
393
Reaction score
174
Location
Wisconsin
First Name
Rick
Truck Year
1979
Truck Model
K10
Engine Size
400
Gap certainly does make a difference. The wrong gap means you aren't burning all the fuel, and/or at the right time, which means you are giving away horsepower, torque, and spending more at the pump. It's a factor in the timing and performance of any engine.
Generally with a stock 350sbc,h and carb, .35 is reccommended. An aftermarket hei and/or injection is often 45.
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
Gap certainly does make a difference. The wrong gap means you aren't burning all the fuel, and/or at the right time, which means you are giving away horsepower, torque, and spending more at the pump. It's a factor in the timing and performance of any engine.
Generally with a stock 350sbc,h and carb, .35 is reccommended. An aftermarket hei and/or injection is often 45.
I would agree. If an engine doesn't care about the spark plug gap, it must be running really poorly in other areas.

Sent from my SM-N975U1 using Tapatalk
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,629
Reaction score
24,146
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
I have pre gapped E3 in my tired ol dog so idk.... lol
 

1973c10

Full Access Member
Joined
Sep 25, 2015
Posts
6,376
Reaction score
24,013
Location
Oregon
First Name
Don
Truck Year
1973
Truck Model
C10
Engine Size
454
.045 on HEI
X3
 

Latest posts

Forum statistics

Threads
42,390
Posts
915,101
Members
33,904
Latest member
joshs74nova
Top