|#9721 Spark Plug Hole Caps. Seal your Spark plug hole openings with these inexpensive tapered fit plastic caps. Prevent debris from accidentally entering ports and creating damage or mischief. Ideal for sealing for winter storage, preventing moisture from corroding internal engine parts. Also can be used to seal ports for leak testing, an important procedure that locates potential air leaks before they cause costly engine damage. Tapered fit provides positive seal for either vacuum or pressure testing, Tapers from 0.482" to 0.526".|
These fit my small block Chevy (after-market heads) spark plug holes perfectly, in preparation for painting of the newly finished engine. My order was filled immediately, and the parts arrived MUCH sooner than I expected. THANK YOU.
These plug hole caps do not fit aircraft engine spark plug holes (18mm)
If you order these, you will receive T-5 Cap Plugs (Stock No. 04-00048), these will probably work on the spark plug holes in a Ford 289, but not on an O-320! T-8 Cap Plugs are O.K. ( Stock Number 04-00050) work with the 5/8-24 spark plug holes, typical of most engines.
Way way too small for the typical 18mm spark plug hole common in aviation. Might work for 14mm, but if youâve got a typical Lycoming or Continental, donât bother with these.
Too small for 18mm spark plug holes.