Looking to swap in a JDM LS B18b long block into my 96 GSR. I currently have all the components from my blown GSR motor. I've tried searching but can only find links swapping in a GSR into an LS.

Firstly, can I use my existing GSR wiring harness with the JDM LS? Both are OBd2 and I'll be getting a USDM LS ecu, so I'll swap over GSR oil pump and crank sensor.

What modifications will I need to make to the wiring harness? My ultimate goal is to swap in a 98 spec ITR motor in the future.

Are there any other modifications I need to make for the LS swap? Also, I'll be mating the engine with my GSR transmission.

Thanks for any help

 

Why bother swapping in an LS when for a couple hundred bucks more you could go with a B20?

 

Really funny you said that because during my research, a lot of B20 suggestions came up. Looks like the B20 is the better bang for the buck. Plus, I'm more of a torque guy and the B20 may be right up my alley.

I assume, my original wiring harness questions would still apply to a B20 swap?

 

Plug and play just don't hook the vtec wiring

 

Since when was a B20 long block more expensive than a B18b?

 

Excellent. What would you recommend for the vtec plugs? I don't feel comfortable letting them dangle around.

 

Tyere are two versions......

Regular B20B low compression with tall intake manifold, torquey, but no super powerful

The 99+ JDM B20B or usdm B20Z high compression. They make a lot more power, but cost a couple hundred more

 

In my area, B20 is always a hundred bucks cheaper than a LS. Even the high comp ones. The low comp ones go for dirt, 300-400


**** for a couple hundred more bucks OP should just sit and save for a GSR longblock that fits his budget.

 

You can either cut them off or zip tie them so they dangle just in case u want to go vtec later. Me I just zip tie mine somewhere on the harness so they don't hang.

 

Really, you can buy the high comp B20 for that cheap. Same as the one in 96 hatch, from an Orthia ?

 

Called a JDM engine shop in my area and they have the high comp B20 for $500. Not too bad.

 

Yeah, but the "version" I showed you man, they are not all the same

 

If it looks like the above picture, I'd be a happy man.

 

Really depends on the shop you go to.
Low Comp b20 can be had for $300.
High comp b20 for $400-$500.

B18a/b engines are usually found at Honda dismantlers and ask anywhere from $700 & up for their longblocks. The b20s are imported engines from overseas while the b18s are locally removed from damaged vehicles within the states.

 

get the high compression, you'll be happy.

 

Ok, so I'm planning out my B20 swap and made a list of what I need and can use off my old GSR motor.

-B20 long block
-GSR trans (donor) resurface flywheel with Stage 1 Exedy clutch
-LS IM w/ throttle body using GSR fuel rail and injectors (donor)
-Reuse GSR exhaust manifold (donor). Or would a stock LS header be better? Length wise
-LS OBD2 manual ecu
-Reuse GSR wiring harness
-Reuse GSR OBD2 distributor (should I replace?)
-Reuse GSR alternator (should I replace?)
-New gaskets, seals, and belts
-New water pump and oil pump

Any opinions or advice on the above list? Thanks

 

You probably won't have to replace the intake manifold, as you can see from the pic's it fits just fine. Just ensure you are purchasing the high comp.

Also add new:
- rear, crank, and cam seals
- tensioner and spring
- oil pan gasket

Get'er done while its out. You'll thank yourself later.

 

LS intake manifold was a decrease in performance. The Low rise b20 definetly gave better performance

 

Will the 96-98 P75 ecu work fine with the low intake with air chamber? I have a 96 obd2 GSR and planning on using my original harness.

I got a price of $550 for the B20 with that funky IM.

 

The P75 will work fine. For me, i tried a few different ecu's.....and the best result was an obd1 conversion, using a pr4 ecu.

 

If you're referring to a GSR intake manifold setup on a b20 with a p75 ecu, it wont work. p75 has nothing to control the gsr intake bypass. Stick with the manifold that comes with the engine.

 

No, I was referring to the picture above with the air chamber. After research, looks like P75 should work ok.

 

Is the head on your blown GSR ok? For a little more money it sounds like a good opportunity to build a B20/VTEC

 

you need to raise the fuel pressure if you plan on using a stock p75 ecu.

you need the nonvtec distributor and either the low rise or b18b intake manifold

definitely replace the main seals as well as the other aforementioned gaskets and timing belt, tensioner and water pump. trust me i didnt replace the rear main on mine and i had to pull the trans and do it a few weeks after the swap.

with the gsr trans it will be fantastic to drive around, torquey and responsive.