Thinking about 3.8 SC for race car swap - got some questions!


Registered User

I am thinking about swapping the Supercharged Essex 3.8 into a datsun enduro race car (chumpcar), have a few questions about these engines.

I can swap in a stock engine with very little "points" and no penalty. However to be competitive I need >230whp but if I do to many modifications I would get penalty laps.

Would CAI, ECU, Exhaust, Intercooler be a good start? Or what modifications would you do?

I have classified the different modifications, I can do 2 cheap mods or 1 medium mod. I would avoid the expensive mod

Free modifications:
  • CAI,
  • ECU,
  • Exhaust

Cheap mods:
  • intercooler (can be very highend)
  • intake manifold
  • header
Medium mods:
  • Cams

Expensive mods:
  • Head
  • aftermarket blower

What about reliability? Can I push a junkyard engine hard?

Looks like these motors can be had for $500-$1000, sounds about right or I have misunderstood that?

Many thanks

(The swap you can make depends on how it was rated from factory, so for instance I can swap in something rated at <200hp without much fuzz but >220hp it gets complicated. So ideally you want something that is rated low but can really be fast with some mods. Good example are SBC, bad example is a Miata engine. )


SCCoA Member
I would try to steer you away from the SC engine for endurance racing. These engines make lots of torque, which makes them great for drag cars or street cars, but they are very sensitive to heat, and tend to blow head gaskets when beat on, so for road racing in a lightweight chassis, a 5.0 is a much better option.

Having said that, if you continue down this path, you should be able to easily get that much power while looking and sounding stock. A ported 94/95 blower, along with a larger throttle body and a big front mount intercooler will make that much power with a good tune. No matter what, you will need a good tune and larger injectors. I would suggest at the very least pulling the engine apart and freshening it up with new bearings and double check all the clearances. Also while you have the heads off, some stiffer valve springs will let you rev a little higher, and at that point some basic port work would make a significant improvement for basically no money.

XR7 Dave

Registered User
I would do the intercooler and a 94/5 supercharger. With a basic short/open exhaust that will get you where you want to go HP wise. Don't bother with headers or anything else. I'd replace the head gaskets with MLS and ARP studs which should be a free maintenance mod. Personally I'd tear the motor apart and replace bearings, deck the block and heads, and go.


Registered User
sound advice from both 'gents

I would highly recommend the 94/95 supercoupe for your donor as the edis ignition is far superior to the older external tfi (DIS) ignition used on the 89-93s which are prone to failure and do not tolerate heat as well.

the 94-95 also has the better s-port blower and the larger 34lb injectors. It was commonplace years ago to swap the earlier 89-93 pulley on the 94-95 blowers to give you a little more boost as well.