Blueboost

QR25DE engine destroked with a SR20DET crank. custom internals, largest cams ever used in a QR to date. Travis who is engineering this engine is stating this engine will produce some pretty big #'s. (+500hp)

This could be one of the first peeks into the future of 4cyl Nissan engine performance. Here's the spy vid.

SQR25DET Video

Epstein

SR20DET crank? Why can't you just use the QR20DE crank? ....of course I have no idea what the stroke is on a QR20.... hmmm

*edit* yeah, those sounds like some nasty cams! I hear a lot about that guy. Is he like the FWD god or something?

EludeR

It does have a shorter stroke then the QR25DE , (the QR20DE) , a friend of mines with a spec-v was preaching tome about how awesome the QR blocks are , and how superior the QR is to the SR (b.s.). I just don't see how the QR block can handle any respectable amount of boost , from a decently sized turbo, the sleeves being the biggest reason.

RubberBerner

Wow...really cool, and ingenuitive. Finally maybe the QR will produce some decent reliable HP #'s...all it needed was a little bit of SR in it. that intake manifold looks pretty squished up against the firewall. I wish he would have let it Idle at like 750...it kept dropping and sounding like it was gonna stall. Once it Idles, i think it will sound amazing.

Blueboost

Yeah it lopes like crazy.

He's done a lot of pioneering w/ the B15 SE-R chassis, and the QR25DE.

The QR's stroke and rod length yields a 1.43 rod to stroke ratio, possibly the lowest of any engine on the market, definately the lowest of all Nissan engines. the high piston speed and short dwell time at TDC leave little time and room to fill the cylinder. (why the QR25 hyperventilates on the top end) The QR20DE crank is a direct fit in the QR25. The bore is the same as the QR25DE (89mm) but it uses an 80.3mm stroke producing a slower piston speed. Comparitively, the SR20 crank would produce a QR that is able to utilize it's high flow head efficiently and also yeild about 2150cc displacement. The shorter stroke and longer rod would be better for high rpm power, and take advantage of the tall deck height on the QR engine (no more hyperventilation) Basically you can get more displacement out of the SR crank, or more RPM's out of the QR crank.

schoellnasty

Really cool stuff. Ill be keeping my eye on this thread.

Jordan Y.

Very uncommon for people to do an engine build looking to reduce displacement.

Epstein

Where can we read about the build process, parts, and specs? The details seem vague.

qr25de-t

i think u got that backwards there buckshot. the sr crank will allow travis to reach a rpm range of around 8k with the destroked and smaller bore qr block. now the qr's crank will reach about 7200 rpm before it starts puting out a horendous amount of vibration much like a ka crank.

has anyone else asked themselves yet, wouldn't just be better to build a badass sr?