What are the members thoughts & experience on the use of either iron or bronze valve guides for a road engine?
I’ve had good luck with the bronze ones in mine!
Keith
The orginal cast iron guides seemed to last around 60,000 miles orginally in the cars. With modern synthetic oils I would expect them to last longer and given the limited use most Elans get their life should be OK.
However a good quality Bronze guide should last longer again and also allow the exhaust valve to run cooler extending its life also.
I use the Cu-Si-Ni guides from the Elan Factory as these are superior again to the standard bronze guides people normally supply but honing them to size needs special tools and an experienced machine shop due to their hardness and toughness. Probably not really needed in a road engine but they will keep the critical guide to valve stem tolerances tight for the longest possible duration
regards
Rohan