How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Anthony Your Own Question
Anthony
Anthony, GMC Technician
Category: GM
Satisfied Customers: 11750
Experience:  GM Certified
15218643
Type Your GM Question Here...
Anthony is online now
A new question is answered every 9 seconds

An HT 502 engine - what is the best spark plug - the gap - the timinig

Resolved Question:

I have an HT 502 engine - what is the best spark plug - the gap - the timinig etc
Submitted: 6 years ago.
Category: GM
Expert:  Anthony replied 6 years ago.

Hello!

 

The timing is 4 degrees BTDC

 

Spark Plugs CR43TS - Gap .035

 

Customer: replied 6 years ago.
thx, what is the "best" plug ( platinum?) & are you sure about the 4 BTDC - the paperwork shows 10?
Expert:  Anthony replied 6 years ago.

The best plug is a #1 Delco Rapid-fire. the GM specs say 4 degrees. Where are you getting your specs?

Customer: replied 6 years ago.
do you have the AC Delco part number - the engine is an HT 502 part # XXXXX - the spec sheet came with the engine.
Expert:  Anthony replied 6 years ago.
Definitely 4 degrees and a #1 rapid fire is the way to go with your engine. I just triple checked. If for some reason it has no power try the 10 degrees your sheet says but try 4 first.
Anthony and 3 other GM Specialists are ready to help you