Engine - RB25det

The RB25det that is being used for Project Leopard is the original engine from Project Car Magazine. The engine was blown (#6 piston ringland failure) when it was received. 

Initially when the engine was installed, there were very few upgrades (Greddy intake manifold), but the internals were left stock. 

Over the course of various ownerships, internals were never upgraded, but turbochargers got larger and with drifting, the engine was pushed until failure.


#6 Piston Ringland

Crossroad - Replace or Rebuild?

My overall approach to older cars is to rebuild. Since I have never dealt with an RB engine on a personal level, I didn’t know if I wanted to commit to a rebuild. Once I saw the price for an RB25det on a crate (None are new engines), I decided to commit to a rebuild. This being an RB25det, I had to commit to building it from the ground up, address any of the common issues such as oil problems and update/upgrade to good parts and most importantly, use good parts. When Marco (original builder) and I were planning the RB25det rebuild, he said one stipulation, “No cheap parts, No ebay/cheap junk, quality parts only”. I agreed. 

This is when I decided I wanted to build something interesting and amazing. A bit of old school, but also newer technology to make the engine great. While on this process, I needed to learn all the issues and address/solve them as much as I could. I also had to be good with my goals. This is going to be a street car rather than a drift or high horsepower car (even though tempting). 

In retrospect, when I got the whole car and engine (which was in pieces), I should have taken inventory. I didn’t realize it until I started to get some of the bigger components. I learned I was missing the exhaust manifold and a year later, I started to learn that I was missing a lot of small stuff. 


I knew that the RB25DET had to be looked at. Since the #6 ringland blew, I knew that the #6 cylinder had to be checked and honed. At this piont, the whole engine had to be checked at the machine shop. Additionally, crank and head done as well. Afterwards, new pistons, rings and rods with bearings all done. 

Also put on a Nitto extended crank collar.

I did have an idea what I needed to get, so I started on that mission. I knew that I didn’t have the intake and exhaust manifold. I knew I didn’t have a turbo. Those pieces were the main parts that I was missing. 

I did go through a period of trying to get a bigger turbo and thought about a top mount manifold. During this time it was either too expensive or avoid the cheap junk. I knew the stock cast iron manifold would be good too. I would also settle on a Tomei MX8265 (stock upgrade).

Marco ordered the parts he needed to start off and was SLOWLY and SPORADICALLY putting the engine together. That is an issue on it’s own, but let’s get back to engine assembly. 

Greddy intake manifold’s water inlet was damaged, so I got one from Boost Doc in Australia (needs to be pressed or welded on).

With the exhaust manifold looking rough, Hung cleaned it up and had it dropped off for Cerakote. I got the exhaust manifold, heat and turbo shield done as well. 

The engine didn’t get worked on for MONTHS at a time. While it wasn’t something I didn’t enjoy, it did give me time to get upgrades. 


The engine started to come together finally. 

When I would be present at the SR20store, I would always try to get something done. This at times failed because I would be missing small pieces or parts. 

There would be delays as (not my builder) would be in charge of getting these pieces. 

With the SR20store making my engine low priority, allowing it to sit around for 2.5 years, I decided in July 2022 to move on. I grabbed all my stuff and found Jason (Rival Auto Works/A’Pexi) and had him go through my engine to an extent. 

He found some issues and torqued everything to spec. Ordered the stuff that the the SR20store slacked on and put them on the engine.

After waiting to get this engine done (at least for it to be assembled), the final months of 2022 brought Project Leopard closer to being done!

There are somethings that need to be addressed, but for the most part, it’s all there!