90mm sleeves in different flavors

http://www.larryspower.com/engine/NissanQR25.html

http://www.larryspower.com/engine/QR25.html

Sorry my bad forgot to put YD22DDTi and YD25DDTi engines, which are diesel and share most
of the design with the QR, except the inlet valve mechanism.

This super sturdy diesel engine is the same engine as the qr and pr but cast iron to run
the higher diesel compression and stresses of added boost.

Allows a 2.5L turbo version using the PR25DD head to easily outflow the 4g63 and VW 16v
For a budget build use the YD25De block with QR25DE crank, yd22 rods, QR25DE pistons
Stock pistons are capable of 500hp with quality tuning as proven by altima owners.
Over that 500hp will need forged rods and pistons which are available off the shelf.


As a comparison to Toyota 1ar-fe 2.7L beast


This is the Toyota 1ar-fe 1000hp pappadakis world drift championship winning engine

https://www.motortrend.com/how-to/1809-inside-papadakis-racings-1000hp-4-cylinder-drift-engine?galleryimageid=caaf6702-02e6-4d96-a154-34afd97ff2ad

https://www.motortrend.com/uploads/f/172096648.jpg?fit=around%7C1000:625

One can see the head is much taller using Honda borrowed design than direct cam actuating
like Nissan keeps using on the PR25 and the Pappakis billet set is over 2k usd where the
Nissan PR head can remain untouched in this areas saving $$$ for cams.

The beauty of the toyota engine is the 105mm stroke and 90mm bores all alloy 2.7 L4
its a proven bottom end that can easily handle whatever is thrown at it
https://www.motortrend.com/uploads/f/172096669.jpg?fit=around%7C1000:625

vs
Nissan PR25DD 100mm stroke and 89mm bores
https://www.motortrend.com/uploads/f/172096669.jpg?fit=around%7C1000:625

PR25DD heads on the Toy 1AR is tempting!
but the 1ar brand new from china is a steal as it is
https://cgauto.en.made-in-china.com/pr ... esa-Senna-Highlander.html

So ... basically the PR25DD is a cast-iron version of the QR25DE cylinder block, together with a new, much improved! cylinder head?

2021 Mitsubishi Outlander
2021 Nissan Altima
2021 Nissan Rogue

Mitsubishi



Nissan T33 Rogue/X-Trail



Nissan L34 Altima built in Mississippi USA

well the plot thickens and my lips are still savoring the QR as my daily
but now seen the PR head, by chance found a bottom end that is based on
the QR engine yet is stronger cast iron with the usual 89mm bores.

"The engine shares much of its architecture with the QR petrol engine. "

This is likely where the fully counterweight post 2007 QR crankshaft and supercharged QR rods
were sourced from the same engine to save in costs.







BEEF!!!



This is theoretically a better option than sleeving the qr25 for 2500usd as offered in the US
No need for sleeving and likely able to withstand the power levels of 4g63 but with much better
flow than any four cylinder ever made. No complicated mechanism cam over bucket win win.

6 speed manuals also available for FWD, 4WD and RWD presents prob the last Nissan beast L4 ever


Even Nissan 1.2 liter HF has massive ports LOL

the pic on the link is a 1ar-fe and still smaller than pr25dd pictured

I like the idea of a sr20de bottom end with the pr25dd head as the sr
had beefier closed deck bottom end and proven to spin to 10k if oiling
is kept at optimum pressures.

look up frankenstein motorworks channel on yt, he is a legend only
spending 1k usd to get 280hp from the 2ar hybrid engine

Toyota 1AR-FE engine with dual VVT-i made 188PS from 2.7 liters. It was an SUV engine -- use in the Highlander, Sienna, Venza and the Lexus RX

The Nissan PR25DD is 188 HP from 2.5 liters. It is a North America engine, and was only used three years (2018-2020), then replaced during the "great reduction" of 2021 with a 1.5 liter turbo. Can get the PR25DD cheap from used engine places



Toyota AR engine family had 6 variants, the most powerful was 220HP, but most were Atkinson cycle (low torque) versions used in the hybrids

I can't figure out which version used the head from your picture. The hybrids used various port shapes, and the hi-po 2AR-FSE used large oval ports

Toyota AR vs Nissan PR cylinder heads, the Nissan pips it

Toyota AR head
https://tse2.mm.bing.net/th?id=OIP.oDqLwd_hX0XQXL2J2qI5zwHaHc

[img width=600]https://tse2.mm.bing.net/th?id=OIP.oDqLwd_hX0XQXL2J2qI5zwHaHc[/img]

Nissan PR head



The 2.5L Toyota AR engine tuned by Frankestein motorsports for his MR2 race cars are
just simple bolt on cams, manifolds and springs/retainers 270HP atw @ 8000rpm
which is mad and craps all over the Honda K series engines for making that hp

https://www.youtube.com/watch?v=FqNSENu29ak&t=15s

The Boosted AR engine tuned for winning world drift championships makes 1000hp
https://www.youtube.com/watch?v=rw0Vkgasa70

The Nissan PR head seems to have more potential flow
but limited by the block being open deck design

Just noticed the Nissan PR25DD has swapped the inlet and exhaust sides
which makes the PR better than the QR for rear engined setup for an N10
or K11 when I get one for a father and son project.
At least the exhaust will face the back and the inlets the back of the
front seats so no heat on our backs.

Still no closed deck design though




beefier stroke support though on the outer sleeve areas?

Looks like a nice head for boost for a cheap SR20DE bottom end
as the SR crank fits the QR but the SR is still a closed deck
and sand cast block thicker than pressure die cast.
This head would make an SR 10-12kg lighter using boost as no
need for a heavy turbo manifold, no need for porting just take
out those new worlds first resin insert thinga me bobs

Ah, the new Altima engine

Used in Nissan Altima, Nissan Rogue, and Mitsubishi Outlander

Quote:

The world’s first application of a resin intake port improves anti-knock performance. The resin port is inserted into the intake port cast in the cylinder head, thereby forming an air layer between the intake air passageway and the head inner wall so as to suppress the rise in intake air temperature

* mirror bore coating (a la the GT-R engine)
* Direct injection
* variable valve timing control (Nissan VTC) system
* cooled exhaust gas recirculation (Cooled EGR)
* integrated exhaust manifold
* variable displacement oil pump

Attach file:

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  Mechagodzilla cylinder head.jpg (193.38 KB)


  integrated exhaust manifold.jpg (86.06 KB)


  VVT.jpg (144.73 KB)