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I composed this little table of results:
RPM HP Torque Notes
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4800 180 Nissan claim
2800 202 Nissan claim
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3000 170 Dyno run "before"
4500 130
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3900 192 207 Dyno run "after"
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Conclusions:- peak horsepower increased 13% going from 170 to 192 (+22 hp on 170)
- compared to 19% expected from combined displacement and compression increases
- peak torque increased 60% going from 207 to 130 (+77 ft-lb on 130)
- and the peak torque moved down from 4500 RPM to 3900 RPM
I don't understand why the Nissan claim has peak HP at 4800 while you measured it peaking so much earlier at 3000 RPM on the first dyno run. Maybe HP is really flat, so the RPM is irrelevant, or maybe you miss-typed and meant 4000 RPM?? Anyway, this radically lower RPM for reaching peak torque is why the engine feels so different.
I think the new cams (and maybe the head work) are responsible for allowing the cylinders to fill at lower RPM and get you all that torque earlier. This at the expense of poorer idle performance and perhaps worse low speed emissions performance which might explain why Nissan doesn't build motors that way.
Maybe you can post the dyno plots from before and after so we can better understand these details.
Anyway, congratulations on the build. Seems like you really achieved some impressive real-world drive-ability improvement goals. Nice!
Chris - peak horsepower increased 13% going from 170 to 192 (+22 hp on 170)
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Looks like it reformatted my post to be different from the "preview". Let me try again with my little table:
Nissan claimed 180 HP at 4800 RPM and 202 ft-lbs of torque at 2800 RPM.
According to Matt, he measured 170 HP at 3000 RPM and 130 ft-lbs of torque at 4500 RPM with a stock engine.
That's a lot less torque than Nissan claims.
Then Matt modified the engine and found
192 HP at 3900 RPM and 207 ft-lbs of torque also at 3900 RPM.
That's a huge improvement of peak torque, both absolute amount and reduction of RPM where it was available.
Chris
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In case my prior post was confusing, here's the actual before/after dyno results, taken at the rear wheel…on a Mustang chassis dyno
r9EO.jpg -
Fantastic work. Thanks for sharing.Originally posted by Racinjitter -
Thanks for sharing! Looks like you flipped your HP and torque on your previous post. The HP was 146 and the torque was 182 at the rear wheels.545 RWHP & 540 RWTQOriginally posted by Andrew84zx
tell her your car is so fast it will make her panties fly off
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Is there a specific reason you sought the JDM engine? vs. a junk yard block? -
Just curios, Is there a specific reason you sought the JDM engine vs. a junk yard block?
Is there a difference? -
The reason I went with JDM instead of junk yard is because I've had bad experiences with junk yard blocks, and I haven't with JDM stuff. My experience has been that JDM stuff is generally cleaner and appears (upon close inspection) to have fewer miles/less wear. There are several differences in engine brackets, accessories (AC and alternator), intake castings, and various ancillary devices (vacuum solenoid valves and such). Basically…it was a matter of assurance and convenience. Downside: $800 price.-
#23.1canook2u commentedThanks for the reply. . .
I like to build motors as well & look forward to building a 3.4 or 3.5 for my '89 NA.
(going from auto to manual as well).
I know nothing about conversions for these cars, never driven it, given to me by a family member when it broke.
But looking forward to the project & insight like yours is priceless. . . .
You talk about assurance & convenience, I get the assurance, but the convenience:
" There are several differences in engine brackets, accessories (AC and alternator), intake castings, and various ancillary devices (vacuum solenoid valves and such)"
Are you saying the JDM 3.3 blocks are a better fit for our cars than domestic 3.3s?
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I'm gonna do this but boosted on my pathfinder. But scat rods cp pistions (EP Racing does a collab with cp. All you do is call or email they guy say you want pistions for VG30E and the bore you want and bingo bango forged pistions at your doorstep) VG30E crank (modifed and treated buy the same guy) and ported auto/turbo oil pump. Hoping for 600 crank. -
This truck is running great, and it's for sale on San Luis Obispo CA Craigslist. Time for another project
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This was very well done but I think a lot of power was left on the table with stock tuning.545 RWHP & 540 RWTQOriginally posted by Andrew84zx
tell her your car is so fast it will make her panties fly off
Comment
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I think you're right, Andrew. Had I teamed up with somebody like you, I'm convinced this thing could've achieved what I hoped for i.e., to meet or exceed power and torque output specs of the supercharged truck, without the supercharger. I suspect the factory computer is retarding the timing, due to change in sound/frequencies created by higher compression and the steel-on-steel of the piston pins against the small-end rod bores. Anyway, it feels waaaaaay better despite the less-than-optimized implementation. Maybe the guy that's buys the truck will "tune" it
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Everything you need to build another one. PM me if you're interested. It will not go cheap, but it will go for a more-than-fair price.
Includes the following:
Known good block with stock bore (factory-delivered block, from the truck in this thread)
- Required clearance grinding (to clear longer piston skirts) already done
- Your machinist will bore as per your desires
New 94mm hypereutectic pistons with coated skirts
New Mahle ductile iron, plasma-moly rings (you must fit)
Torque plate 94mm max bore (with OEM head bolts
Crankshaft (in spec./no grinding needed, just polish and install)
Crank nose bolt and washer
Rods (have your machinist remove bushings and size to piston pins)
Both heads (mild port/polish work, just like what's shown in this thread)
Original springs, retainers, keepers
New head bolts
New Sealed Power rod and main bearings
New Sealed Power CS843 CS844 camshafts
Original rear cam bolts and fat washers
New Gates water pump and gaskets
New Nissan oil pump and gaskets
New Brass freeze plugs
New Continental Timing belt kit
New FelPro head gaskets (26219PT)
New FelPro valve stem seals
New FelPro rear main seal set
New Beck Arnley metal exhaust gaskets
New Victor Reinz intake gaskets
New Beck Arnley cam seals
Rear main housing
Crank toothed timing pulley and slinger
Cam pulleys bolts and washers
Original lifters (disassembled, cleaned and prepared with emery cloth)
Lifter retainers, rocker shafts, rockers (all accompanying fasteners)
Intake and exhaust valves (spotless and all within spec/no grinding needed)
Kit for double checking timing/PTV clearance
Intake fasteners
Engine bracket fasteners
Denso Iridium plugs (good used, but a little dirty, too good to throw away)
Timing covers
Original main bolts
Intake manifold
Long bolts/guide pins for installing manual transmission and pilot tool (makes it much easier)
Correct length bolts for mounting on engine stand
Bag of miscellaneous fasteners used mostly for ancillary parts on the motor once you're near fully installed
On a 40" x 40" 330 lb. pallet and ready to take to the truck shipper's dock of your choice, in San Luis Obispo CA
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