• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!

    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A TR3A Plug Gap?

karls59tr

Obi Wan
Bronze
Country flag
Offline
What is the prefered spark plug gap .025 or .032 ? I'm going to run the NGK BPR5HS (a little hotter than the BPR6 to see if it will cut down on the carbon fouling). I have 87 mm pistons,Pertronix ignition,mild street cam and a header. Doing the Spring tune up today. :smile:
 
If it's really carbon rather than oil, then IMO you have a mixture problem rather than a heat range problem.

I run .025" as per the book. Tried .032" (along with a MSD 6) but it didn't seem to help at all; and IMO the higher voltage allowed by the larger gap makes the cap & rotor more likely to fail.
 
Get the mixture straightened out. The fives are a cover up, in a worst case, potentially a costly one.
 
Well actually I rebuilt a set of SU's over the winter that I will be installing soon so I appreciate what your saying about the carbs and mixture. I think what was actually happening was the mixtrue nut was stuck to the lower jet bearing on one or possibly both carbs so I wasn't able to do proper adjustments. The rebuilt SU's should take care of that problem. I'll probably leave the NGK 6's in untill I have the carbs installed. I was just wondering what other "3" owners were running for plug gap?
 
Back
Top