Honda Prelude Forum banner

BB4 NA drag build (in for the long haul)

20K views 87 replies 12 participants last post by  H22A LUDE BB1 
#1 · (Edited)
Some background: Been slowly chipping away at modding my auto 4th gen since 2004. Got an invite to drag racing and everything progressively spiraled out of control from there. Got the auto 4th gen from running ~16.3 to 15.3 but this was not good enough... The need for speed had me looking for a Crx del sol chassy (non transtop manual) for an H22A transplant but after no luck, a 4th gen manual Prelude caught my eye... A phone call + one plain ticket + a heap of cash later I found myself the owner of manual 4th gen.
Having lead a humble life in stock trim for 250k kms, the time has come for a transformation... In the short term, I am aiming for 13 second passes down the ¼ mile and somewhat more long term I aim to get 200wkw NA out of the H (eventually, after much $$$ and hard hours...lol.).

Current mods (Jan 2013 - April 2021):

Engine accessories:

Custom CAI (2.75" staggered to 4") with 4" Blox velocity stack filter
"Mildly ported" stock intake manifold- 70mm inlet tapering to ~66mm.
70mm Skunk2 Alpha throttle body
Three butterfly plates, one operational, one without valves and one gutted.
Vision ignition leads
Iridium plugs
Blox phenolic intake gasket
D1 Spec FPR
Skunk2 Pro cam gears (6 bolt type)
Jun Stage III cams
Ferrea S10070 Valve Springs (80LBS @ 33; 190LBS @ 23)
Ferrea E11000 Titanium retainers (7degree)
Ferrea K10034 Keepers (7 degree)
Ferrea SL1003 Seat locators
Supertech and Ferrea Valve Stem seals (long story lol).
New Crank Pulley (non-OEM but with harmonic balancer)
Kaizenspeed manual tensioner
Hytech replica header (with a 2.5' collector mod)- 3' outlet
3' header back "custom fabricated" exhaust (no cat, small flexi, two resonators, mandrel bends welded together)
3' inlet mufflers
AEM UEGO wideband
SAFCII
P72 (OBDI) with Neptune basemap road and dyno tuned
ACT clutch with stock flywheel
T2W4 Box
Innovative 75A engine mounts

Body work:
Milano Red paint job (for now)
Lip kit (Value Sport type1 front lip, Mugen Sides, Hiro rears)
Custom Mugen Rear spoiler - Drag spec
Some light to moderate weight reduction
Retro fitted S2000 Seats
TunerView App with tablet display
Carbon fibre bonnet
Honda Access shocks and springs (from the 5th gen- modded to fit) and Mugen shocks and springs
16 x 7 BBS RG rims (& other similar looking rims; with Vitour Tempesta Enzo Drifting Tyres).

Future plans- mainly engine work (2021-20xx):

Parts acquired:

Supertech valve guides
P13 closed deck with balance shaft delete and P5M pistons.
Spare T2W4 tranny in unknown condition...
Synchrotech T2W4 rebuild kit (Carbon)
Cometic head gasket
ARP main and head studs
Gates RPM Racing Timing belt


Parts still required:
Ferrea 6000 series valves
Dry sleeves + 12 to 12.5:1 comp. pistons
ACL (Rod + Mains + Thrust) bearings
Competition Clutch Stage III 2600
Fidanza flywheel

Some pic-highlights below (will be updated over time) and the rest of the thread is as per normal.










 
See less See more
9
#87 ·
Finally understand the Covid toilet paper craze, great for cleaning up oil when rebuilding the engine during a lockdown… lol





After endless struggles with the valve spring compressor tool and the rope either not protecting the valve or the rope getting stuck behind the valve, or the rope literally tying a knot inside my cylinder (heart attack), I tested a heap of other ropes to find one winner. The winning rope was: Zenith Sash Cord No 6 (Polypropylene, solid braid)





Mistakes were made… Colour coding sometimes isn’t enough lol



Spot my error lol



Done bar a few, needed new valve stem seals…



New seals obtained. Also switched to a different valve tool. Hammer action worked much better than the spring compressor. Likely just because the rope is too soft to absorb the valve tension with the spring compressor.



Validating the rope, this one coiled up well in a bottle and had a good rigidity while also being soft.



Organised chaos





Done done





Stem death



360k kms and now retired

 
#88 ·
Euro R vs Jun Stg III



Slight ware on the Euro’s but to be fair they were worn when I got them about 50k kms ago.









Torque wrench won that round.







Never felt worthy of a red cover but now I’ll make the exception. Not entirely black top any more lol.






Exhaust port cleanup. Burning oil means…







Had more soot on the ports with leaking stems, about twice as much soot!





New unit:





Ran the engine in and started up fine but then on first run after reaching operating temp it started with a loud internal metal on metal slapping sound… Feared the worst… Valve lash was set to Jun specs and checked like 8 times, including a 0.01mm larger feeler gauge to confirm the lash.

Cover off, all looked ok, keepers were still there…



Block teardown maybe…



Decided to work backwards. Stethoscope indicated the noise was coming from the head junction, so likely valves slapping. Could be work guides on the previously leaking stem valves. Removed all auxiliary units and just left the timing belt and balancer belt. Started her up and the noise was gone!!!

Refitted one by one and the noise has not come back. I presume that means there was maybe some rope or something that messed with valve seat. Or who knows… Run in complete. ~500kms. Saw Vtec a few times. Tune is ok, bumped fuel pressure and removed adjustments on Safc II. Retune soon, but also keen for some intake manifold porting before that.

Jun first impression. Beefy primary/secondary. Noticeable increase over Euro Rs. Vtec not that impressive so far but its running super rich and I haven’t gone over 5600rpm.

I guess the Jun Lemon Prelude would be the best point of comparison. The Lemon Prelude had 12.3:1 compression (I am still on 10.6:1), a big tube header (45mm primary, 50.8mm secondary, 60.5mm outlet), Euro R intake manifold, likely 2.5 inch exhaust, stock valves and uprated Jun head gear. If they had 269ps / 7650rpm and 27kgm / 5500rpm, I would hope to get to 249ps and 25kgm on the current setup. Likely only revving to 8k max given the well-aged bottom end.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top