Has anyone seen a build thread on a forum or web page where a late model 4 cyl DOHC (EJ255 or EJ257) was built as a naturally aspirated engine, or do any you have experience with one?

Please don't reply with "why would you do that, just slap a turbo on it!" type answers. I'm trying to figure out how much power a DOHC could make as a NA engine, if it would be enough to make a 818R competitive in NASA ST3. (10lbs/hp).

I've read every thread I can find on NASIOC and Legacy GT about NA engines, but they always start with the 2.5i NA SOHC engine. SOHC doesn't get to the 200-210 RWHP on a dyno reliably. A couple of guys have made it there, at least they claim, but I don't see many, if at all, dyno sheets on them. So that got me thinking what if I started with a DOHC?

I have one professional engine builder specing it out. He's built several SOHC engines that get close, but not quite, to the power level required. It involves all the usual hot rod mods you would do to any NA engine: high compression pistons/cams/porting/headers. When I get his final spec I'll share it here.

And the ultimate why? I think an 818R with a 4cyl NA engine would the lightest possible configuration, no turbo heat issues, no waste-gate issues, no IC airflow issues. I'm trying to reduce the complexity, failure points, and weight. I can think of several races that I DNF'd in my LGT wagon that were all related to something in the turbo system not working as it should.

And I ruled out the 3.0 -3.6 NA because trying to dry sump them would be a long project. Particularly the 3.6 looks dang near impossible to dry sump in an 818. I didn't realize until I dug deep into the specs on those engines that the 3.6 oil system is VERY different from the 3.0 and any of the EJ engines. I know how to dry sump an EJ and it's also lighter than a 3.0/3.6.

2016 NASA ST3 calculation: 2000 lbs with driver (I weigh 220 with helmet/racing suit/nomex) + 200 HP + Non Production Vehicle - 245 tires. = exactly 10lb/Hp.

I guess the other question is can a 818R be built to 1780lbs wet? If not the NA engine would need to come in slightly higher at 205-210-220 Hp.

As Colin Chapman said, "Simplify, then add lightness".

Thanks,
Gator