L20AET ENGINE BUILD UP component selection

[Yokohama]

I am thinking about building a L20AET with L20A and L28ET parts I have (for the sake of off boost MPG and being different).

 

I have 3 L20A blocks with the following markings:

1= 2 M3 E30 9524X

2= 2 M3 E30 7003B

3= E30 7330A

 

As for pistons:

I also know that I have flat and domed pistons from NA L20A engines (I am unsure if I have dished or if the L20A was fitted with dished pistons).

What should I use? I don't want to have to order custom pistons. Is there a source for L20A/L20AET pistons (besides Nissan Japan)?

 

RODS:

I have NA L20A rods, Would I need to consider rod preparation like shot-penning? Or should I find L20AET rods?

 

The cylinder head, manifolds, etc.:

I have the 05L Skyline head, the P65 head, and the E31.

However, I would like to get better flow and thought about using the P90 and all the manifolds and such from the L28ET, as I was reading a post that Tony D made (on zcar.com) that stated:

"Everything you bolt on a 2.4 2.6 or 2.8 bolts onto an L20A--this includes, but is not restricted to head, intake manifold and turbo charger."

 

EFI:

I want to get it working on stock l28ET ECCS with an adjusted AFM.

 

As it depends on the pistons, heads, manifolds, etc. used, it is not possible to really speculate on power outputs.

 

Last, I would like to know what the rated MPG or KPL is for a S130J or GS130J with the stock L20(A)ET and with the stock L28ET.

My understanding is that I could maybe get around 24 MPG from a L28ET, is this correct?

 

Thank you for your assistance.

[Challenger]

Note Tony D is on HybridZ. Hopefully he will chime in again...

[1 fast z]

Your P30 block is a 240z block, the E30s are L20A's.

[OlderThanMe]

I say build it with a standard USDM spec block to get a better rod/stroke ratio.

 

Here is the satup I'd like to see:

L28 block bored to 89mm, L20A crank, LD28 connecting rods, KA24 pistons, and your E31 head or P90.

Pistons will protrude 1mm out of the deck.

With the E31 you get a SCR of almost 10.3:1

With the P90 the SCR is just below 8.5:1

It ends up being a 2.6 liter that can rev and last.

The rod/stroke ratio is 2:1 with a maximum rod angle of 14.414 degrees.

 

A L28ET should get close to 30MPG with a good tune. I knew a guy that got 29MPG with SU carburetors!!!

 

BTW I have a set of those 140mm rods sitting around...

 

If I had an L20A crank I'd build that motor up there^. It could rev to the moon and back a few times...

[stagefumer11]

Ive got two l20et's as part motors. If people need bits. Shipping will be a killer tho

[Tony D]

While the heads bolt on, the valves clearing the bores is a big issue.

 

Unless by tax class or racing class you are restricted to 2.0L, I would not waste time on building the engine. "To be different" isn't enough justification for me with the costs involved. We run an L20A in the Bonneville car because we have to by engine displacement class.

 

I think the MPG is a moot point. The L28ET should easily get as good if not better MPG due to far better torque and being able to run with a lower rpm, amongst other things. Just because an engine is smaller doesn't mean it automatically will return better MPG. In many cases (especially with domestic trucks in the USA) the larger engine will give superior fuel economy due to better torque production moving the same weight. GM's 3.8L GENIII will run in the mid 30's highway with a full bodied LeSabre Body hung on it full of passengers.... That is nothing short of amazing considering the load an L28 has to push around!

 

There is much more than simply smaller displacement to fuel economy.

 

Heck, I've made 28MPG with Triple Mikuinis on an L24 running a 4.11 rear end, on a car with a three-speed _automatic_!