In addition to upgrading my known-good 3.8L N/A engine that's in my lemons car with a splitport intake/heads, I've decided to cobble together a spare engine using the 3.8L engine I acquired from my 89 supercoupe donor car (I bought it for the manual transmission).
My plan is to do this as cheaply as possible so I will take the single port intake manifold from my "known good engine" and throw it onto this SC block.
The goal is to put together something I can quickly drop into the lemons car should something bad happen mid-race.
Right now, I'm hoping to learn more about the differences between the two engines. Please correct me if I'm wrong/misguided here on any of these statements/plans
* I understand that the 89SC has forged Crankshaft and Connecting rods. That's nice but not particularly relevant for me.
* However, the SC has a lower compression ratio (8.2:1) compared to the NA engine (8.8:1). This is a backup engine for me so I don't care about the slightly lower HP (some HP is better than nothing).
Allegedly, the SC compression ratio is lower than the 3.8 because the pistons use a larger dish. (confirmed by SCTbird1994)
* I plan to do a mild polishing/gasket matching for the single port intake manifold and heads. Nothing drastic. It might be labor intensive, but hey, it's a project.
* 89sc engine turns over when you spin the crank but I'm not sure if the head gaskets are good. Since I will have the top of the engine off anyway (and i want to take a look inside the block so I plan on swapping out headgaskets anway)
* SC vs NA Heads: valve sizes are the same but casting is slightly larger for a thicker deck surface and therefore less prone to warpage (see below)
I will go with re-using the SC heads.
* Crank Sensor: TBD
* Timing Belt Cover: different shape and different crank sensor mount position on the early SC vs NA.
* Water pump: the water pumps are different from the SC and the N/A engine so I will need a new water pump if I'm going to convert this engine to N/A.
* I plan to have a 95 return style fuel rail and injectors pre-installed on the 89SC block and ready to rock since I already have a spare fuel rail and that stuff is easier to install with the upper intake manifold off.
* Accessories: I don't plan on buying a spare alternator, PS pump, A/C delete bracket, distributor/ignition system, and tensioner so all of that stuff will be carried over from the N/A splitport engine should something bad happen.
Q: For this 89SC engine converted to N/A, should I just re-use the heads from the 89SC or should I use the heads from my 95 Tbird N/A?
Q: Are there any other differences I should be aware of that I will need to buy in advance or carry over during a race-day swap? Example: oil pan?
Q: While I'm swapping out injectors, I probably should swap out injector seals as well. I see a bunch of different options for seals and the packaging is different.
Is the best option just buying qty six of SK Products #SK57 (includes cap,2 o-rings, and washer)? Or, can I just buy 12 o-rings (2 per injector).