Preparing For Honda K24a3/AST5 6spd Conversion

lookforjoe

True Classic
EDIT (Aug 2019): K24 Install Thread Here

Going to use this to keep (myself organized) track of the parts and process for this build. I will edit the list as I proceed. Plan is to do this next spring.

So far, I have on order:

1) '05 Acura TSX JDM K24A3 (190bhp) / AST5 6spd (no LSD) with harness, ECU# 37820-RBB-E05. Claimed 65K miles.
Engine Code 6RBB-QA000 592 / K24A3-401753(x possible missing digit)

Engine Spec:

Trans Spec:


Or maybe this? (first entry)
Screen Shot 2020-04-01 at 8.52.56 PM.png


NOTE: Use of the later transmission requires replacing the right inner axle, shifter gate and shift cable bracket with the earlier (RSX) style, if you are using the MWB axles and shift kit. Also, the MWB transmission mount brackets don't work as the mount points don't exist. Additional brackets/attachments have to be fabricated in order to attach them.

Rear adaptor bracket




2) RSX Type S K20A2 oil pump with baffle, oil pan & hardware (recommended to clear MWB kit & gain ground clearance, and oil pump design has higher volume/less parasitic drag)

Other stuff needed:

ECU will get a modified K-Tuner User Board installed (Xenocron.com, authorized dealer) ✓

Accord ECU (drive by cable) 37820-RAD-A04 Replaced with 37820-PND-A63 (03/2020)

02/20/20 EDIT: Accord ECU has no MIL cluster feed (E31), will be looking at using '05 RSX ECU 03782-PND-063

K20 Swap Kit from MWB ✓
Rear adaptor bracket for AST5 transmission
Forward adaptor for AST5

Engine:
'07 TSX higher lift (.9mm) Intake Cam (used) ✓
Modified VTEC Gear (30º vs. 25º advance) EDIT: Installed RSX 50º gear, limited to 40º
Oil pressure sender adaptor
Red powder coated valve cover
Oil Filter 15400-PLM-A01 ✓
Spark Plug set - NGK 6994
Used RSX Oil Pump, Baffle, hardware & Oil Pan ✓
Oil pump chain 13441-PCX-004
guide 13460-PNC-004
Front crank seal, cover oring
Rear crank seal BECK/ARNLEY 0523424 ✓
Serp. Idler Pulley/Bearing 31180-PNA-003
Blox oil baffle kit
Crank pulley tool
Breather housing oring 19322-PCX-003
Oil Cooler base oring 91316-PE7-730

Nippon Racing RL5 (11.13:1) 87.5 pistons
Rebore & hone bores to 87.5 ✓
King Std. Rod Bearings
DNJ K24A head gasket set
K24a Timing chain kit
VDO 100psi Oil Pressure Sender, 1/8npt
90005-PNA-003 head bolts x10 ✓
12251-RBB-004 OEM head gasket ✓


Intake/EMS:
Throttle Cable - Venhill
Throttle body extension housing x (Modified intake plenum instead) ✓
Modified RBB Intake/Plenum
Throttle body (to replace drive-by-wire setup?)
K-Tuned 80mm (KTD-TB8-RBC) 09/18 ✓
IACV - 16022-PRB-A01, pigtail
IACV - 16022-PRB-A02 OEM ✓
TPS - RAA-A02 pigtail
Dorman 977-022 TPS
'05 Accord ECU 37820-RAD-A04 ✓
Bosch O2 sensor 15482
Billet fuel rail (black) x Use stock rail (for AC Comp clearance)
Fuel Pressure Gauge Adaptor
410cc Denso Injectors
Reference list of applicable engine sensors

Cooling:
19410-RBC-000 (BA 131-2373) Water Pump (fits K24A3)
GMB K20A3 Water Pump (w/oil cooler) (returned) x
Water Passage Outlet gasket 18714-RAA-A01
Oil Cooler hoses: 19422-PRB-A00 19423-PRB-A00
Oil cooler hose fitting o rings (2) 91311-PRB-A00
Coolant expansion tank Dorman 603-027
T/stat Volvo C30/RNC 31319606
Volvo 84ºC T/stat ✓
Note: 1 3/8" Fiat tubes
1 3/8" Hose Couplers (maybe)
1 1/4" 45º silicone elbow hose, 4" legs ✓
1 3/8" - 1" silicone reducer elbow hose (instead of above) ?
1 3/8" - 1 1/4" 45º silicone reducer elbow hose, 4" legs ✓
Intake manifold adaptor housing (modified) KTD-K24-IMA ✓
T/stat Extension Housing (custom) + gasket ✓
Modified Rad & heater feed housing

3/8" NPT aluminum bungs
Recirc hose Gates 19498

Gaskets:
Exhaust Manifold Gasket 18115-PNA-004 ✓
PRB/K20 Intake Manifold Gasket 17055-PNA-004 ✓
RBB Intake breather system gasket
17146-RAA-A01
RBB Intake Runner Gasket Mahle MS19475 ✓

Valve cover gasket kit 12341RTA000
HondaBond Hi-Temp Silicone
Permatex Ultra-Grey
LukOil Assembly Lube
Honda Ultra Flange Sealant 08718-0009

Exhaust:
Shorty Header x
Custom Header - 2" SS tube, 2" SS 90º Mandrel bends ✓
Cone Engineering Collector/merge collector
SS Muffler 2.5" I/O (Magnaflow 11236) ✓
SS Cat 2.5" I/O
2.5" SS mandrel bend U- Y pipes ✓
2.5" SS rigid liner flex liner ✓
3" - 2.5" SS reducer ✓
Saddle O2 Bung (x2) ✓

AC Mods:
Compressor mount
Accumulator
Alternate AC setup
Compressor Hoses, #6, #8, #10
Orifice Tube/expansion valve bypass (bore out expansion valve)
Daytona Serpentine 6PK1650
Additional Idler 31180-PNA-003
Cone seat 31185-PNA-003
many #8, #10, #12 hose beadlock fittings
AC Heater Box

Driveline:
Stiffer (progressive rate) rear springs for my coilovers: QA1 12HT175/350
Honda CV's 44310-Ta0-A60 & 44310-Sda-A60
Right inner axle assy. 44500-SCV-A00 (different length than K24 application)✓
New boot kits & outer CV's
Clutch & Flywheel Kit ✓
Right Axle Seal 91206-PHR-003 ✓
Honda Urea grease (08798-9002) ✓

Clutch Slave LUK LSC452
Left axle seal (SKF 15888) ✓
RSX Shifter assy (2002-2004 Acura RSX) ✓
Drilling& Tapping for RSX shift module
RSX shifter cable bracket (24601-PNS-000) ✓
New Mount for RSX shifter Bracket
Honda MT Oil # 087989031 2qts.✓
MFactory LSDInstall
Torco A200022CE -MTF 2qts ✓

Heat sheath for shifter cables (1" ID?) ✓

Modified clutch pedal pivot (Rodgers) (remove from parts car)
(Rodgers)
Modified throttle pedal pivot (Rodgers)
Modified return spring setup
Hydraulic slave cylinder hose adaptors
Brake pedal box mods for Dual Master

Engine offset/positioning
Engine Install

Body:
Sheet metal supplies for frame/firewall alterations
(18ga.) 0.048" T-304-2B Annealed Stainless Sheet 12" x36" x3 (for starters) ✓
.030" SS sheet 12x36" x3 ✓
.048" 13x22" for access cover ✓
.048" 13x31.25 for trunk floor ✓
Spot Weld Cutter tool
Cleco 1/8" fasteners
12' x2", 3'x 1.5" Angle Iron(to make Sheet Metal Brake, in order to make box sections) ✓
6' x1.25" Square Tube (for cross brace above rear crossmember) ✓
6' x2" "C" channel (for rear crossmember bracing) ✓
Firewall Insulation (Dynamat 11905 34"x54", .75") ✓
1/4" closed cell shielded insulation 1x1.4m ✓
Much primer & Sunrise Red spray cans
3M Rocker Schutz 08874
3M Undercoat 08864
2" closed cell foam tape to seal apertures ✓
2x Dynatron seam sealer/caulk
edge guard for SS panels

Electrical:

10' 4ga battery cable
15' 0ga battery cable (taken from Volvo V70)
Buss bar
Drivetrain ground strap
Relay/fusebox
Fuseblock
Ground buss
Alex Tech sheathing, 25' pkg of 1/8", 1/4", 1/2" ✓
ODBII port
Marshall Tach & Speedo install

In place:

Coilovers (change rear springs - done, OCT '18)
Front swaybar (Volvo 760)
Larger brakes (Vick Auto) EDIT: CEIKA brakes
Modified fuel delivery (Bosch M4.4 FPR with return built in)
Electronic speedo (need to adjust signal conversion through Speed Healer?)
Larger all aluminum radiator (custom, HoweRacing)

(Current) Reference threads:

Rodger1 (ECU wiring)
Rodger (Exhaust)
Darwoodious
Fiatmonkey #2
FiatMonkey
Sub-zeroil
AC Retrofit post #15
Compressor mounting and HERE
LarryC's AC Heater Box

K20 Swap Australia
K20a.org
DennisH

"B" series swap - AutoX1/9

Clarks' Dash Thread (not K20-related, but need to keep track of it :)

Resource Forum: K20a.org
 
Last edited:

JimD

Waiting for Godot...
Moderator
First reply!!! No one can take that away from me!

I would say "Good luck Hussein!", but in your case, luck has nothing to do with it. Hard work and perseverance. That's the ticket. :)
 

AKimball92

True Classic
An actual BOM is nice to see. I haven't done much research into the K20 swap as its out of my space, budget, and skills at the moment but haven't seen mention elsewhere of a list of items needed to start. Looking forward to following.
 

kmead

Old enough to know better
First reply!!! No one can take that away from me!

I would say "Good luck Hussein!", but in your case, luck has nothing to do with it. Hard work and perseverance. That's the ticket. :)
I resisted the temptation to be first and clutter up the thread, but there you go Jim, making a mess of things and opening the door to all the rest of us riff raff...
 

dcioccarelli

Dominic Cioccarelli
Going to use this to keep (myself organized) track of the parts and process for this build. I will edit the list as I proceed. Plan is to do this next spring.

So far, I have on order:

....
Hey Hussein,

I'm intrigued as to why you went for the Honda option. In this thread, you seemed to be leaning towards a Fiat DOHC which I'm sure you would have done well with ;).

I'm assuming that the deciding factor was parts availability in North America. I'd note that the Fiat DOHC was able to achieve 210 BHP in the HF integrale Evo2 variant which won, albeit in a highly modified form, the WRC constructors championships in 1987, 1988, 1989, 1990, 1991 and 1992. I've never seen a Honda do that! Johannes Graversen's X1/9 is probably the ultimate evolution of the SOHC motor as well. That said, I'd admit that a Honda swap would probably be a safer bet in the US.

Anyway, good luck with it! Looking forward to seeing the progress.

Cheers,
Dom.
 

lookforjoe

True Classic
Hey Hussein,

I'm intrigued as to why you went for the Honda option. In this thread, you seemed to be leaning towards a Fiat DOHC which I'm sure you would have done well with ;).

I'm assuming that the deciding factor was parts availability in North America. I'd note that the Fiat DOHC was able to achieve 210 BHP in the HF integrale Evo2 variant which won, albeit in a highly modified form, the WRC constructors championships in 1987, 1988, 1989, 1990, 1991 and 1992. I've never seen a Honda do that! Johannes Graversen's X1/9 is probably the ultimate evolution of the SOHC motor as well. That said, I'd admit that a Honda swap would probably be a safer bet in the US.

Anyway, good luck with it! Looking forward to seeing the progress.

Cheers,
Dom.
Hello Dom. Yes, I would have liked to have kept the powertrain Fiat/Lancia. Based on the discussion & info provided, I couldn’t see any practical way to locate parts from overseas without massive potential for error. When it became apparent that Fiat 16V was problematic I lost interest. DOHC 8 valve holds zero interest for me - that seemed to be the easier solution, following Steve’s posts.

The Honda powertrain is much newer technology, and support for swap related parts is easy to find.
 

Hasbro

True Classic
Insert popcorn eating smilies here. Would have been nice to have another 2.0 tc build along with mine but I'm thrilled you're doing a K24 build!
 

Dr.Jeff

True Classic
I'm sure you considered a complete Volvo swap of some sort? Especially with your knowledge of the brand. I don't know what could be used from Volvo, but that would have been really interesting. Curious what you might have done in that direction? And why you didn't?
 

kmead

Old enough to know better
Because the only US transverse engine of note was the T5 which is likely a bit wide for an X.

In Europe I believe they had a 4 cylinder but none here. There always also the preponderance of oh so tragic transmissions ie automatics primarily aside from the early V40/50 and a peppering of C30 manuals.
 

lookforjoe

True Classic
I'm sure you considered a complete Volvo swap of some sort? Especially with your knowledge of the brand. I don't know what could be used from Volvo, but that would have been really interesting. Curious what you might have done in that direction? And why you didn't?
Because the only US transverse engine of note was the T5 which is likely a bit wide for an X.
In Europe I believe they had a 4 cylinder but none here. There always also the preponderance of oh so tragic transmissions ie automatics primarily aside from the early V40/50 and a peppering of C30 manuals.
I would have liked to use a Volvo drivetrain. Karl mentioned the T5, which is actually a modular design (like many companies) that was sold in 4, 5 & 6 cyl NA and Turbo configurations here and around the world. The problem in the US is that the 4cyl was only ever mated with an automatic transaxle, and those were only used 2000-mid 2004. I could use the same manual 6 spd transaxle that is in my C30 with one of those 4 cyl, but then the existing 4 cyl EMS won't operate. Since I would have been looking at a complete 4 cyl engine/trans/EMS to drop in (No support for aftermarket tuning with that) there was no way practical to do it. The drivetrain is also heavy & bulky compared to the Honda unit, and of course I'd have to locate a source for hybrid axles, come up with my own subframe design, etc... Beyond all that, I also want to do this in as an expedient a fashion as is possible when the time comes, which the Honda swap with all the support it has provides.
 

lookforjoe

True Classic
What I've been thinking about today (Karl also mentioned this), is either modifying the stock Honda intake manifold or making my own, to reduce the firewall intrusion & funky TB extension housing business. Found this old K20a thread in my search for data on changing runner design / length on these motors. At a glance (looking at Rodger's intake/plenum), it (the K24a3) has much longer runners, which makes sense since it is a (slightly) lower revving motor with more low-mid range torque. I may use a pre-'99 Volvo V70 TB similar to that which I added to the X1/9, as those are throttle cable operated, cheap, and compact in design, and 2.75" ID.

K24A3 RBB


K20 (Rodger's) PRB



Tim's K20 (?):



The last intake I built was for my old Volvo. That was Turbo-charged. I make the plenum diffuser-style. The shorter ( than stock, 6") runners had zero negative impact on low-mid range torque, on that setup anyway.





 
Last edited:

kmead

Old enough to know better
Nice work.

In perusing the images of intakes on the web, there are a number of companies I found pretty interesting in terms of their approach. Skunk Racing uses a removable plenum box half which allows one to add air horns into the intake runners. Toyota also took this approach with the Matrix/Corolla intake manifold for the 2ZZ engine, a bit different but similar.

Skunk manifold, center feed. It looks like the plenum could be flipped top to bottom given that the gasket is symmetrical.
0E68B415-A58F-41C1-8055-4E4316D930B7.jpeg 7025ECE1-13DF-4757-982E-C434F1F0E5A3.jpeg A2E0FE69-E532-491B-9BB9-FB72ED3A0EC7.jpeg 0528E2B1-F58A-45E2-9D26-FB85E2575B1C.png 135093E2-6332-40C3-A699-FC5CA8198C2C.jpeg

The Toyota 2ZZ manifold installed in the Pontiac Matrix and Toyota Corolla
A2F81360-24ED-4BA2-B4DB-AB0B404EA29C.jpeg 7482A882-987D-41D6-A8AC-08FC15722909.jpeg 30659750-33C0-4CD5-AA44-7BADCC2EE7E3.jpeg
 

kmead

Old enough to know better
A possible approach to the manifold with an upward cant versus downward. The radius into the head is effectively immaterial as the lead in to the valves in basically level with the downward slope to the valves starting beyond where the manifold ends.

26562FF5-47BE-478A-A5CC-E7B1D10ECF52.jpeg BCA92CE3-666D-4D51-B624-54A6EDE2B671.jpeg 250EBFF8-A0E1-4BA7-B244-5F9AA4C84565.jpeg

31926DD9-64DB-4143-AE71-D668AEE75F4A.jpeg
 

stingray250

True Classic
From this...


s-l1600.jpg


To this...

fff.jpg

The Saab turbo manifold is half the size of the stock GM composite... All for 34.95 on eBay... Bolts right up to the GM 2.2/2.4.
I sure love my Ecotec! So many parts that are swappable...
 

fiatmonkey

Tim Hoover
A possible approach to the manifold with an upward cant versus downward. The radius into the head is effectively immaterial as the lead in to the valves in basically level with the downward slope to the valves starting beyond where the manifold ends.

View attachment 15070 View attachment 15071 View attachment 15069

View attachment 15072
Love the idea but clearance maybe? However thinking about it, likely wouldn’t be any higher than the AC compressor or the rotrex supercharger. I was using a 75 engine lid with the red k20+rotrex and I had to raise the hinge side and just used the upper studs (in the lower holes of the hinges). Worked and looked great.
 

kmead

Old enough to know better
Love the idea but clearance maybe? However thinking about it, likely wouldn’t be any higher than the AC compressor or the rotrex supercharger. I was using a 75 engine lid with the red k20+rotrex and I had to raise the hinge side and just used the upper studs (in the lower holes of the hinges). Worked and looked great.
Thanks. I was thinking more of it being a tight winder over the head like the X and its log but you get the idea in any case.
 
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