By now, most of you have checked out our 4.2L build thread with the orange GT3-RS owned by "Ranger" here:

https://www.6speedonline.com/forums/...ne-ranger.html

Many people have asked for some details about the engine build, so I thought I'd start a new thread to share some info about what went into that engine. The primary goal of the engine was obviously to make additional power without any compromise to longevity or reliability. This engine is not your standard bore/stroke upgrade. It was truly built to a full race spec with a real focus on dedicated track use. We get a lot of calls from folks looking for the crank, or the pistons, or just pieces of the package. We have no intentions of offering any of the parts as "cherry-picked" upgrades. We'll only be offering the entire engine packages. Of course, each one is slightly different, and cost will vary depending on some specific details of the build.

Here are many of the details of what we did, followed by some studio pictures we took before re-assembly started. Feel free to ask questions, I'll do my best to answer.

• Custom built Mahle pistons with specially tailored valve reliefs. Pistons also have a hard anodized coating on the crowns for heat rejection, as well as an anti-friction coating on the skirts. The bore is 105.9mm, and we've used specially made iron liners for this application.
• The cylinder water jackets have been CNC machined to not only accept the 105.9mm liners, but also to keep the distance between the water jacket and the liner consistent with the OEM Porsche clearance in order to keep water flow in this area optimal.
• The crankshaft was built with a stroke of 79mm. This combination yields a final displacement of about 4.145cc. We've got a future build planned with an 81mm stroke, but this particular engine uses the 79mm stroke. (Before anyone asks....the answer is no. We will not be giving out any details about our crankshaft other then what I just mentioned. It took an UNBELIEVABLE amount of work to develop this crankshaft, and to be perfectly honest, it's not information we want to share with every other engine builder out there. All of the details are documented and explained to customers who have a build done by us.)
• Compression ratio of this engine was set at 13:1. Since it will primarily see only track usage, the benefit of using race fuel at this higher compression will result in higher output. The customized GIAC programming will also have a safe pump gas mode.
• Connecting rods are very custom built Carrillo rods, using proprietary rod bearing diameters. The bearing is a tri-metal construction and is individually sized to each crankshaft journal after an anti-friction coating is applied. In a situation of a missed shift, over-rev, or improper oil fill, this coating may just save the engine in the unlikely event of contact between the bearing and the crankshaft.
• Each engine case is also custom machined to optimized case windage. All of the areas around the webbing and crankshaft are all relieved by machining to maximize air flow and minimize restriction. This is a VERY tedious process, but makes for a much smoother running engine and a few extra HP too.
• The oiling system has also been internally modified. Cross drillings in the crankshaft and engine cases are modified to redirect the flow of pressurized oil most for sustained high RPM use.
• Cylinder heads received a full race treatment. In addition to a multi-angle competition valve job, we also use slightly oversized valves on this engine. We used hi-rev valve springs, as well as super lightweight titanium spring retainers. We also did a complete port, polish, and flow bench port balance on the cylinder ports.
• Keeping the heads in place are some serious head studs. We use an aerospace quality head stud that takes the thread engagement from 10mm in diameter and 25mm in depth, up to 12mm in diameter and 40mm in depth. We then choose an appropriate thickness for the head gasket and rather then use a standard sealing ring, we use a gas-filled ring is used between the head and the cylinder bore. This seal is basically impenetrable.
• Lastly any engine we build like this will receive a full balance as well as documentation of measurement ("blueprinting"). All of internal components of the engine are "zero balanced" which allows the customer to change a flywheel or pulley at a later date.

There are dozens of other details, but for now, this is what we're comfortable putting out there. Some things have to stay a secret I'm afraid. Here's some pics of this engine in various stages. Enjoy.

 

Thanks for posting Tom.

Porsche spent a lot time adding durability to the valvetrain (tensioners, adjusters) and modifying the intake manifold and airbox. How are you handling these areas in your build?

 

Thanks for some more info. I like the smoothed out crank case internals, did you shot peen stress relief/ surface harden after.

Why did you move from Ti for the rods, custom units are available if lengh or bearing sizes needed to specced specially for the build?

I can't imagin cost would have held Ranger back.

Cheers
Jay

 

excellent info.

how high can this motor rev?

 

Rep points to Tom @ CMS. More pics and hope this beast fires up soon!

 

Its already a runner, see Rangers thread. Its being bedded-in and base lines set before changes to the tune and exhaust are made

 

I am relatively local and I checked this out. This RS is the real deal.
Also this guy ranger is insane. I believe he left a few screws back in the battlefield that they didn't put back.

 

Mr Soze,

Please do find out more. And I agree about rangers missing screws but aren't we all inflicted for one reason or another... just check out what we spend on cars!

 

I think Ranger is quite normal, at least by my standards!

 

Sir, your assertion is definitely spot on correct. The passion for motorsports can be quite compelling.
One does need an understanding wife.
Regarding more info, well I'm working on it.

 

I think this build will be a little expensive James, even though I do spend a lot of my hard earned on my two "children"

Looking forward to more details also and can't wait to see the final figures for this beast.

 

Dave, what's the second 'child'?

 

The entire valvetrain was upgraded and rebuilt. As for the intake manifold, we left the stock parts in place, but port matched them for optimal flow. We're also testing a few different airbox configurations right now.

Yup...everything was hardened and re-coated before re-assembly. As for the rods, in a race engine like this one, titanium rods have a useful life cycle, which is typically pretty short. Since we don't want to have to replace them, we went with a good steel alloy Carrillo rod instead.

It can rev up to 9500 rpm's. So far we've gone up to 8900 on the dyno. When tuning is complete we'll probably stop at 9000.

Yup, it's running like a champ. So far with only some very minor tuning, we're up about 80hp and 110 lb/ft of tq over our baseline numbers. You can follow the progress of the total project here:

https://www.6speedonline.com/forums/...ne-ranger.html

 

Wow, I bet it will sound awesome at 9000 rpm with the catless system
I'm hoping we see way over the 500 mark with the final race tune.

James, my other baby is a 85 3.2 Carrera. It's also white, so they are basically twins, although separated by 22 years

 

Dave,

I would like either race spec 930 or 993 as a second, if I was in the UK still it would have happened but costs here make it impossible so its just a dream... for now...