Hello there,
Welcome to my project blog! My name is Vlad, I'm a Mechanical Engineer from Toronto, Canada. Please follow me on this quest to convert a Porsche Boxster S roller into a V8 beast!

Boxster V8 conversion

Valve Lapping

I took the heads apart and as expected the valve faces and seats were pretty gunked up and pitted, not to mention all the crap and leaves that were in the cylinders. Since I didn’t have money to get the valves recut, I decided to lap them. Most people are against this, but this is a budget build, so screw it. I used a hand drill and a little piece of air hose to do the job. Again, most people advise against this, but there was way too much pitting to do it by hand.

There was a fair amount of buildup and pitting on the valve faces

The seats weren’t as bad, but they definitely needed some lapping

Lazy way of lapping the valves using a hand drill and a piece of air line. You have to be really careful when using the drill, its pretty easy to screw up. Make sure to lift off pretty often and switch rotation. Also keep checking the seat width to ensure you stay within the spec. Of course the best way is to get them cut at the shop, but if you must, a hand lapper is the next best thing.

You can see that the valves still have some pitting, but I wanted to stay within the seat width spec.  Lapping the valve more would look nice, but it would cause all kinds of problems in the long run. From what I read, a wide seat allows for too much heat transfer from the valve, which can cause some serious carbon buildup.

Leak-down Test

I decided to check the engine to see what kind of condition its in and if it would need a tear down. We built a leak down tester from some parts my dad had laying around and hollowed out a spark plug to make a fitting (I will do a full write-up on how to build one). Long story short, all the cylinders but one had zero compression. You could pretty much hear the air coming from all the valves, so I decided to take the heads off for a some cleaning.

Home built leak-down tester. Just some simple NPT fitting and gauges. Pretty easy to make, except for hollowing out a spark plug. I will do a writeup on how to put one together in the near future.

Found the car

At this point I had the engine, but I had no car. I posted several wanted posts on Kijiji, and signed up for notifications on eBay and every major city on Craigslist. A few things came up here and there in the States, but nothing really worth the drive and hassle of importing it to Canada. Eventually I made a post on the 986 forum parts classified section and within a few days I had my car. One of the members from Ottawa was in the process of parting it, and essentially was left with exactly what I was looking for: a rolling shell with a 6 speed tranny.

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Rented a RAM 1500 from Enterprise and a trailer from Uhaul. I’m sure glad the gas prices are down!

LM4 Small Block

I found a low mileage (150,000 km) LM4 truck engine at a local scrap yard that was said to have great compression. The guys on the phone were very helpful and had the engine delivered to me in a couple of days. I spent the next week or so disassembling and cleaning every surface to bring it to a respectable condition.


Couple of the bolts snapped on the intake manifold which was a huge pain in the butt. I managed to pull a couple out using an extractor and a screwdriver, but the third one wouldn’t budge. We even tried dry ice to loosen it, but nothing worked. At the end I just decided to abandon it. Its located in the centre of the manifold, so its not crucial when using eBay headers.