I believe it’s identical to the k20z3 but with that beautiful beautiful RSP head. Same 11:1 compression as the z3.
The k20a is the only one that got the factory compression bump.

That head is what you care about lol. Wish I could get one.

As for your question, I’d say it’s on par with the k20a2/k20z3/z1. They’re all performance k20’s with 50* vtc and vtec on both sides.

I also believe the z4 has the balance shaft oil pump like the z3 but that I am not sure on

 

I believe it’s identical to the k20z3 but with that beautiful beautiful RSP head. Same 11:1 compression as the z3.
The k20a is the only one that got the factory compression bump.

That head is what you care about lol. Wish I could get one.

As for your question, I’d say it’s on par with the k20a2/k20z3/z1. They’re all performance k20’s with 50* vtc and vtec on both sides.

I also believe the z4 has the balance shaft oil pump like the z3 but that I am not sure on

So in theory it should respond to an intake manifold and cam upgrade even better than my euro r k20a which has the rbc head.

 

I don’t know if it would be a big difference with just oem compression but maybe?

 

I'd treat it like a DBW version of a k20a2 and near identical to the z1/z3 engines.
Cams etc are all compatible.
The ECU might be compatible with the Honda tuning suite. That might save some money if you stay with DBW.
Otherwise convert to the usual 02-04 DBC loom etc.

 

I'd treat it like a DBW version of a k20a2 and near identical to the z1/z3 engines.
Cams etc are all compatible.
The ECU might be compatible with the Honda tuning suite. That might save some money if you stay with DBW.
Otherwise convert to the usual 02-04 DBC loom etc.

I think I'll be doing link g4x either in plugin or wire in. The dbw appeals to me. I plan to supercharge it if I can drive a mid mounted car without killing myself.

 

The RSP head is an upgraded over RBC/PRB from what I’ve found. The casting is much nicer and it flows a bit more

 

Do you know if the k20z4 rsp had the same factory porting/ valve seat geometry as the fd2r? I'm wondering if the fd2r had extra hand finishing done at the factory compared with the fn2r.

Either way, I bought it and it's on its way here hopefully.

 

The RSP has a different casting all together. I believe the port is similar to PRB but with a better finishing. Valve seat I’m not sure about. I read somewhere the casting is done at the factory where the nsx heads and where the bike heads are done. Somewhere different from where all the other k20 heads are done

 

the PRB/RBC heads are already response to modifications as is. The ports are huge and flow extremely well.
The RSP is a nice head, but it is not that you see some mystical 20HP popping out of nowhere.
And with boost, the difference become even smaller as you will be knock limited under power anyhow.

 

I see it had the RSP cylinder head, is this the same as the fd2r RSP head?

There is only one RSP head in 2 casting versions available. The K20Z4 longblock is the best what you can get in AUDM, NZDM, EUDM and eastern hemisphere of the 86x86 sized K-series. Best does not mean with great distance, the intake and exhaust port flow slightly better compared to the K20A2 longblock.

 

That's what my thoughts were. It just seemed strange to me that this one was priced a lot lower than other type r engine/ gearbox swap kits around here.

 

Z4 specs i've learned:

golden rsp head + manifold
11.0cr due to PRB pistons
Equipped with typical R cams
balance shafted pump (read: approx 5whp loss due to parasitic drag) also has a weird oil sensor in the middle of the pan.
5.0fd equipped trans w/lsd (same as FD2r)

Perhaps stock header design maybe even air intake is holding power back on these, and pretty sure an RRC manifold would help bring numbers closer to 220hp. oh and lack of RRC 11.7cr pistons....lot of little things add up!

K20Z4 hell yea its good imo!

Good recent vid showing Z4 potential in its native chassis w/rrc manifold and pump upgrades aside from basic i/h/3"exh (these guys play with fn2's all day long):

apparently the stock FN2 exhaust manifold is I kinda suspected.

RRC pump upgrade 5whp gain dyno proof (but old news):

 

Not all FN2 type R came from factory with LSD, only certain year and model. Yes the k20z4 is good and has the best flowing RSP cylinder head from the k-series family

 

Not all FN2 type R came from factory with LSD

The EUDM FN2 Type R don't have LSD at all. Which year and market did have it?

 

According to this tegiwa blog post, 2010+ FN2's came LSD equipped while pre 2010's varied:

Honda Civic FN2 Buying Guide – Tegiwa Automotive Blog

www.tegiwaimports.com

 

According to this tegiwa blog post, 2010+ FN2's came LSD equipped while pre 2010's varied:

Maybe we had no UKDM CW, M200 and GT special model's here in Germany 😒. My SPWM gearbox from an 2009 Type R has definitely no LSD and end of 2010 the Type R was vanished, as it was only EURO 4 compliant. Only the super rare Championship White Edition July-Dec. 2010 had a LSD here. We had a 30th anniversary model here too, but also no LSD.

 

My good deal is turning into more work than I wanted. It was supposed to be a full engine/ gearbox package ready to bolt in and go.

 

The axle seal on the dummy shaft fell out since it's the wrong size for the gearbox. Lots of bolts are loose or missing. I pulled the head to see if the bores are rusted too but thankfully they look good. A few small vertical marks but no rust or visible wear.

Now I'm wondering if I pull the pistons out while I have the head off to re-gap the rings since i plan to supercharge this motor further down the track.

The guy i bought it off seems willing to help out with the problems we've found so that's positive. He bought the car to part it out but never checked under the valve cover.

 

I could trade you a good RBC head if you like - Ive been wanting to get an RSP to try 😁

 

Lol the head was my main reason for buying.

 

Anyone know if this is normal? I'm fairly certain this is an all original unopened engine and I found the con rods clocked in different orientations.

 

I am fairly certain that the blanc shallow balancing holes are from someone balancing the shaft.

The k20a2 service manual explicitly states the mounting direction of the rod. I know someone who did not follow this and spun a rod bear gin in short order.

Someone rebuild that engine with a high certainty. I can't see a Honda factory worker installing the rod the wrong way around and inspection not catching it.
All k20a2 crank pictures I have scanned indicate that Honda balanced the shafts with the deep drill holes that appear black.
My own PRB crank only has the deep holes. It was balanced checked by a meticulous engine shop and he stated it required zero rebalancing.

Educated guess. You find a 0.5mm undersized journal under the rotated rod cap. The machine of the journal required a rebalancing.
The rod was swapped and mounted the wrong way around, the piston reused.

 

Dont stress mate, I have the same engine here and it is exactly the same as yours. #2 rod backwards and exactly the same balancing machining.
What I am curious about is your oil gallery between 2 and 3 isnt plugged...

 

Mines not plugged because it's still running the balance shaft pump.