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Discussion Starter #1 (Edited)
Just picked up a k20a engine. Should be one from a JDM DC5R, but everything looks like a EP3R engine.. the seller told me this engine is from a scraped car from either Japan or Hong Kong. Appreciate all inputs.

Just by power figures, the DC5R is slightly better than EP3R, so I feel kinda scammed... Anyways could you expert car guys take a look and tell me what's going on here. Even if it's a genuine EP3R engine I'll still take it. If there's any major issue then I think I'll have to talk to the seller....

too many images it could be a formatting nightmare so I uploaded it into a Imgur album
https://imgur.com/a/JfQvz6o

information about this engine for those TLDR:
-block marked 'K20A' and 'PNC'
-cylinder head marked 'PRB-1' above exhaust manifold
-Intake manifold 'PRC HF-1'
-ECU is 37820-PRD-J02
-bottom of timing chain cover marked 'RTA'
-transmission is 'NPR3'

I've researched around a bit, and the information out there are not very accurate or people have conflicting beliefs... I've heard that PRB-1 head is from a USDM RSX type-s... But maybe JDM R engine also uses this? Also that a PNC block is not a type-R one?

It's going into a mid engine kit car I'm designing. Been doing a lot of research and learning, not an engine expert so I appreciate all the help:):)
 

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when buying a jdm motor, k20a does not mean type-r.

If it did not explicitly say "DC5 K20A Type-R", then you should not assume that it is. The other question is how much did you pay for it? A type-r motor is typically $4-5k.

Here is an example from a reliable vendor:

https://www.hmotorsonline.com/shop/k-series/k20a-longblock-02-06/

vs.

https://www.hmotorsonline.com/shop/k-series/k20a-type-r-motor-tranny-ecu/


Since you mention the PNC block, I'm inclined to think you got an EP3 k20a which in the US would be the k20a3. Big differences between these blocks are the oil pump, windage tray, crank, oil squirters, etc. Biggest difference is the crank. All other pieces could be upgraded to PRB/PRC components.
 

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Discussion Starter #4
when buying a jdm motor, k20a does not mean type-r.

If it did not explicitly say "DC5 K20A Type-R", then you should not assume that it is. The other question is how much did you pay for it? A type-r motor is typically $4-5k.

Here is an example from a reliable vendor:

https://www.hmotorsonline.com/shop/k-series/k20a-longblock-02-06/

vs.

https://www.hmotorsonline.com/shop/k-series/k20a-type-r-motor-tranny-ecu/


Since you mention the PNC block, I'm inclined to think you got an EP3 k20a which in the US would be the k20a3. Big differences between these blocks are the oil pump, windage tray, crank, oil squirters, etc. Biggest difference is the crank. All other pieces could be upgraded to PRB/PRC components.
Hey man - thanks for replying:) Yes I am aware that k20a is the code for both base model and type R in JDM world. There's no 'reliable vendor' in the part of world where I live lol. Like you said, the PNC block is dubious, but everything else looks OK.

Going to test start the motor before I take apart the engine and see what's inside the block. I'll post here if I find something new.
 

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Get a boroscope, any cheapo USB will do, and look into the bores for the piston.
The K20a should have a PRC stamp on them:


From:
https://98luder.wordpress.com/2011/07/05/kseries-piston-comparison/

“So i have a few pistons in my possession for comparison
K20a2 prb typeS 11:1cr
k20a prc typeR 11.5:1cr
k20a rrc typeR 11.7:1cr
These are all oem cast pistons

prb on the top
prc middle
rrc bottom”



The engine block of a K20a3 is marked with “K20A3”.
The block of a K20a is marked with “K20A”
The block of a K20a2 is marked with “K20A2”

It could be a rare case of a eco version K20a which is JDM only with 160HP.
In this case the piston code will tell you. PRC is what you want to see on the piston.

Do a google image search and you’ll find examples of all three engine markings above the engine number.

The JDM EP3 also got “the” K20a with the same spec as the DC5R. That it is rated with 5HP less.
I’d expect this to be a result of the intake and exhaust differences. I’d not lose my sleep over it as after a KPro treatment, a more modern intake manifold such as a RBC or RRC and mapping, it will make more anyhow.
It seems all other features are also right.
 

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Nerd mode ON.

Based on your photos its definitely a JDM K20R engine with what seems to be some mixed parts from DC5R+EP3R.

Factory power differences between EP3R & DC5R motor is negligible due to exhaust manifold + exhaust system differences which all are nothing to be concerned about if you're swapping this into a non K-series era car and you'd be running whole different header and unrestricted exhaust system anyways.

Strip those factory exhaust components + slight factory ecu programming differences away and the EP3R & DC5R engine + trans are exactly the same spec.

Regarding your photos...
- Engine has a power steering pump which means the engine most likely came from a DC5R since EP3R's have electronic power steering pumps and an idler pulley
- Tranny code is from an EP3R
- Timing cover p/n doesn't matter, just a typical K20 timing cover
- PNC block number is normal for a k20 block casting, can't really rely on this p/n designating Type-R or not
- PRB-1 is typical RSX Type-S/Type-R head p/n. What matters is if it has dual valvespring valvetrain which I'm pretty sure it has. Non-R PRB heads from early or mid 03 run single spring valvetrain. None of the PRB 'R' heads are ported either. Only the 06-10 RSP Type-R head is ported, well has an NSX like finish in the bowls.
- the camshafts are definitely Type-R. The groove on the outer rings are a dead giveaway of this. Also R cams share the same cam profile as the USDM K20Z1 Type-S. Any other K cams do not have these engraved rings.
- PRC intake manifold is only found on DC5R/EP3R's
- The ECU is from an EP3R (RSXR would be a 'PRC' ecu)
- red valve cover
- it has a factory oil cooler, these only come on K20R or Type-S engines
additionally...
- crank pulley should measure out to 5.5" diameter
- it should have an aluminum PRB oil pan
- vtec solenoid should have the vtec pressure switch sensor plugged
- If you pull the trans off there should be a factory lightened 10lb flywheel. It has visible swiss cheese holes whereas non-R and type-s fwheels have no swiss cheese holes.
- if you peek down the spark plug hole with a scope, the top of the piston should have an embossed 'PRC' part number (11.5cr pistons)
- If you can measure the axles end to end whilst fully compressed I can tell you what chassis those axles come from:
If driver side measures out to 25-1/4" / pass side is 23-3/8" = DC5R axles (DC5-R have the longest driver side factory axle)

Lastly, if it was the weaker JDM K20A (K20A3 equivalent) it would NOT have a PRB head but have a PNL head (2 lobe int cam / 1 lobe exh cam), it wouldn't have a factory oil cooler, silver valve cover, crank pulley would be larger diameter than a Type-R's, may or may not have a black plastic intake manifold, steel oil pan, and would most likely have an auto trans flywheel plate on it
 

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Discussion Starter #7
wow, you are the best! a million thanks for going all the way to help a newbie. these details are invaluable to me

the pistons are PRC indeed, also aluminum oil pan checks out. pretty confident that this is a legit type-R engine now.:)
 
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