For the moment I'm sticking with my tired and true A15 but I've recently been besieged with engine options:

There is the SR20DE that will work with the rules set I run under. Even bone stock it would offer some decent speed and this was my plan for late 2019 or early 2020. The goal with this was 140whp.

While at a vintage race weekend one of the sports racer guys told me he'd make me a reeeally good deal on two E-series race motors and a ton of spares. His car is powered by a bike engine so he hasn't used the an E-series motor in ages. These motors are e15s with modded cranks because the class had a 1300cc limit. If I remember correctly they made 170 flywheel horsepower at 8600 rpm, they may be as much as 185hp. It may be possible to bring the motor back up to 1500cc as well.

I was at my fabricators shop and telling him about Simon's car, he's not a fan of turbos but is a fan of supercharging. In theory we should be able to get 150whp.

The SR20DE makes sense as it would run on pump gas go several seasons and could be done for around $2000 (motor tranny combos with ECU are $1500)

If the E-series is my version of cheap I can slightly detune them for longer life. Most of the issues that one would normally encounter with E15 would be solved as the motors are running dry sumps and crank fire ignitions. Even if I left them in full race trim there are enough parts to run them for 5-6 years.

Supercharging, the basic parts are probably going to run $1500 (supercharger, pistons etc.) this option wouldn't require fabing up new motor & tranny mounts. I can make some of the parts myself. The big bonus is my fabricator pal like this option most and so he'd charge a lot less because the project is fun to him.

So because I'm a flake I can't commit; so what choices might you guys make and why?

If it aint broken dont fix it . Go ol school" Blown A15
You may not have to change Diff , Brakes , Suspension etc
You,ll get 130 rwhp on 10 psi with stock pistons with heaps of torque.
If moneys no option , go the later, either way, they,re all proven combo,s

SR is
* more reliable -- if near bone-stock as you say
* more durable/long-lasting
* more available for parts

.

I have an SR in my Sunny, and very happy with it.

I think that there's plenty of valuable contributions from everyone so far, and I wouldn't argue with any of them. Blown A15 (or any A series) would be cool, and plenty of torque.

In my opinion the real benefit of an SR is that you'll never have gearbox failures again, in fact I expect that you'll not even have wear problems. The transmissions can handle a DET, so on a DE you're all set. Ratios aren't perfect, but the torque from an SR in a 1200 (~1600 lb?) will overcome the sub-optimal ratios

Makes sense all day to keep it simple and run an Sr16ve or sr20ve as
they are 190hp to 204hp stock and rev all day long, simple and powerful.

For me weight is the key and the head on an SR20DE/VE is about 28kg alone
The bottom end is about 32kg fully loaded so bare its a very light engine
but the head is heavy! yet the power could almost make up for it however...

If I had $ to burn Id use an FIA L16 head cleaned up with some 48mm webers,
a BRE camshaft profile, aftermarket roller rockers and stock FIA valves
can make also do 200-210hp ate but weight 12kg lighter up top than a race
L series or SR20 engine. The bore spacings are very close but would need
Darton 90mm sleeves, custom rods, pistons, sr16ve crankshaft for 1800cc.

The FIA head weighs 16kg fully dressed so you get a sound no SR can make
just listen to the sound of the L16 BRE raced at 5.39 onwards pure ecstacy
8.50 blows your every goosebump up into water droplets all over the place
https://www.youtube.com/watch?v=6IOJOwZomUU

In the end the sr20ve is the winner but the sr16ve could be a class destroyer
if you have a 1.6L class, those sr16ve will never die they just keep revving.

D while I love different I'm trying to keep it simple.

To further add to my flakiness is I could bore the A15 out to 1600cc and go with bigger valves which might bring the car up around 125whp. This option is probably $1500.

Then there is the fact that Matt is working his cross flow head project. Dependent on what valves he puts in the head I'd expect bolting a cross flow head on the existing A15 might be worth an additional 30hp.

At the end of the day my brain says the SR20DE putting out 140-150 at the wheels could be done for $2000.

What I've wanted to do for years was use a Cosworth BDA but those are crazy expensive ($10,000 to $20,000)

Honestly , I cant see you getting a Sr20de on the track for $2K

Are you allowed any engine choice or just Nissan?

Are there different classes eg. 1.6 and 2.0L or
is it all under 2Ltr?

The Sr16ve will beat 2ltr cars in your body
The Sr20ve will beat them as well but less rpm more torque
and will need the FCW crank unless theres a model with.

Cant beat an engine made to rev by factory Nissan.
sr16ve cams are making 10-12hp more and itbs also
some more with right pipes so 230hp is possible with bolt ons.

Most do not know that a Cosworth BDA crank will fit into an L series if you use 40 thou under main bearings, that will allow an L16 to run reliably with the right pistons and rods to 10,000 RPM that will be very sweet music indeed.

I ran a 1688 at 9600 RPM for about six months until a Rod Bolt stretched and broke destroying a genuine L 14 block that was with a normal L18 crank and 83mm bores, research into the Cosworth crank came out of that failure a guy I knew did it in an Australian formula 1600 class single seater and it was reliable and quick.

So there is another option out of left field, I also know about FIA heads mine was built on a L20B Japanese block bored to 90.5mm with a non thrust face wall thickness minimum of 6mm after boring the FIA heads make awesome torque but lots of luck finding one these days under 10K, I paid $700 for mine at the time off a speedway guy with pipes and manifold wish I had kept it but I know who has it these days in a 1600 it was in the ex Sheka Mehta Works PB210 I once had which is now getting rebuilt down in the Bega valley in southern NSW.
the original LZ14 went into Geoff Portmans Bluebird project who knows where that engine is now, I got the PB210 off Geoff