This all-motor CRX ran with an oem head during the 2009 season and the set-up was super reliable and
lots of fun. For the 2010 season, one engine modification was made and a set of Kelford all-motor
camshafts was installed. The camshafts were supported by a set of SuperTech valves and springs.
These camshafts are an excellent, intermediate choice for many K20/K24 enthusiasts, since they are ideal
for street/track use and they are affordable!
Tuning Specifications:
- low cam angle tuning resulted in 40 degrees up to 4,600 rpm and 30 degrees up to 5,600 rpm
- high cam angle tuning resulted in 40 degrees from 5,600 rpm to 6,800 rpm and 30 degrees until redline
- the ideal iVTEC cross-over for this motor was found to be at 5,600 rpm
- air fuel ratios from 12.7:1 up to 13.5:1 were tested and the ideal level was found to be 13.0 to 13.1:1
- ignition timing advance was found to be ideal around the 30 degrees mark
- all testing was done with 93 octane premium unleaded fuel
- engine temperature was maintained consistent at 178-182 degrees for all WOT pulls
- intake air temperature was maintained consistent at 90-95 degrees for all WOT pulls
Observations:
- the engine is very easy to cold start with these camshafts
- it idles very nicely, like stock
- it drives very smooth, at all partial throttle load points
- the camshafts and SuperTech valves/springs set are quiet and work very well together
- the camshafts are an excellent choice for a dual purpose car that is street driven and track raced
- Kelford provides all specs and has superb customer support
- the camshafts are very affordable at $770 retail
Chassis Dyno Used:
Brand - Dyno Dynamics
Model - 450
Type – magnetic eddy current retarder
Dyno Testing Results:
- 236 whp and 173 tq with Kelford 179-B K20/K24 iVTEC camshafts installed
- 220 whp and 157 tq with OEM K20A2 iVTEC camshafts installed
* both tests conducted at an iVTEC cross-over of 5,600 rpm
* The oem camshafts were tuned at a very low cross-over of 3,750 rpm
* Higher power numbers were found at this lower cross-over (224 whp)
* the Kelford camshafts experience a large a drop in torque at such a low cross-over
* of course, this is by design: larger low cam lobes would support a lower cross-over, but sacrifice a
smooth idle
Dyno Charts:
See below.
1. With OEM camshafts installed.
2. With Kelford camshafts installed.
3. Combination of the two.
Engine Specs:
- K24A2 short block
- ERL sleeved (87mm bore)
- 11.5:1 CP pistons
- Import Builder H-Beam rods
- ACL bearings (STD)
- K20A2 oil pump (& pan)
- K24a2 crankshaft
- K20A2 head (unported)
- Kelford camshafts (stage 2 – all motor)
- OEM K20A2 camshaft gears
- SuperTech flat valves, dual valve springs, retainers, seats, cotters
- new OEM head gasket, valve seals, cam chain, upper cam chain guide
- Floored Fab lower cam chain guide
- Hybrid Racing cam chain tensioner
- ARP head bolts
- Hondata intake manifold heatshield gasket
Bolt-ons:
- CompTech headers (open exhaust)
- IPS intake manifold
- AccuFab 90mm throttle body
- Fuel system (Walbro in-tank pump, RC 750cc injectors, GE fuel rail, AEM fpr)
Vehicle:
1988 Honda CRX Si
weight – 1,867 lbs. (without driver)
not street legal (track use only)
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