I wonder if its theoretically possible to make UCE hydraulic roller lifters work.
No, we have no oil pressure feed to the tappet guides. And even if we could route some special lines to them, our oil pressure is too low to work them properly.
However, there are some solid roller tappets which might be able to work, and I'm doing further investigation about them
Our current tappets are solids that look almost exactly like a valve. Narrow shaft and a big round head. Pretty large face mushroom tappets. And mushroom tappets can get very close to the performance of rollers, in terms of aggressive lift potential. And with our limited lift situation, we may be served just as well by the mushroom solid lifters like we have.
But, there is at least room for improvement on the friction on the faces, which could be improved by a suitable roller tappet, or by using a modern ultra-hard friction-reducing coating such as a "Diamond-Like Coating"(DLC). And there are some other ceramic type coatings with can do similar purpose.
Basically, if we can get a good roller in there, I'll do it. If we are forced to use our existing style mushroom tappets, we aren't far off the performance of a roller tappet with those, and we can get them coated to do the friction reduction. And that may be the lesser cost option, with as much gain as we need to get.
The mushroom tappet is the next best thing, aside from a roller so it's a good performance system if you make a cam that utilizes the mushroom head diameter capacity to the fullest.
And our mushroom heads are much larger than the racing solid mushroom tappets that are still used by modern racers today. Bigger than the racing mushroom tappets sold for GM, Ford, Mopar, or even AMC. And the larger the head, the more like a roller it is, and the more you can get from it..
Our tappets really aren't bad. They just need optimization.
I'll use make them as optimally as possible, and grind the cams to make the most of them, if a roller isn't viable.