Which is better choice for performance? 2.4 or 2.6?

[Johnboy72]

Ok, so talking to this guy that races a Mighty Max on an asphalt oval, I'm still stumped on which direction to go. First, here is what Ray had to say.

"You are assuming right. it is a 2.4 EFI. It seems to run well with the trucks. Here's the low down. when I first got it , the truck had just over 146,000 miles on it. I pulled the head , checked the main and rod bearings. Had the head plained .010 because it had a bad head gasket, Changed the gaskets, added a balance shaft elimination kit, and went racing. I did not bore the engine nor change any bearings. It has been stock minus those changes sense day one. It seems to run ok where I start and I have passed a few trucks in the 5 years that the little guy has been running. With the normal tune ups and oil changes, which now by the way I add a quart about every week to keep it going.I am thinking it burns it but the plug's don't seem to tell that tail. Otherwise it runs pretty strong every week. We did do a compression test a few weeks ago on one cylinder and came up with 149 lbs. The engine is definatly still strong."

Ok, so this tells me that I can run with the other trucks but looking on the site, his truck isn't as competitive as I'd like to see a MM/Ram50. I hope to run towards the front if possible. I don't want to be an "also ran"...so do I rebuild my Starion block (stout bottom end), run a really good carb and pacesetter header? Or should I just go the 2.4 route? I don't know what to expect hp numbers from the Starion block. Can you slightly tweak a 2.4 to get some better numbers? I posted up the track rules on my "newbie" post.

[Rahtid]

what are you allowed to do to the engie

[Johnboy72]

4 CYLINDER LIGHT TRUCK (MEN&WOMEN)

O.E.M = ORIGINAL EQUIPMENT MANUFACTURER
ELIGIBLE TRUCKS
ONLY 1998 OR OLDER , MAXIMUM EIGHT VALVE , FOUR CYLINDER PICK-UP TRUCKS ARE ALLOWED. TRUCKS MUST BE NON-TURBO , OPEN BED , REAR-WHEEL DRIVE ONLY
NO FOUR WHEEL DRIVE CONVERSIONS
LOCATION- ALL TRUCKS MUST MAINTAIN ENGINE LOCATION AS MANUFACTURED NO MOVING MOUNTS OR LOWERING OR MOVING BACK OF ENGINE
ENGINES- ENGINE MUST BE IDENTICAL TO THE MAKE OF THE TRUCK. ALL ENGINE PARTS MUST BE UNMODIFIED AND IDENTICAL TO STANDARD PARTS FOR THE MAKE OF SAID TRUCK .
ENGINE COMPONENTS-
A.- PISTONS MUST BE OF OEM STOCK HEIGHT , OEM STOCK MATERIAL , WITH AN IDENTICAL OEM STOCK COMBUSTION SURFACE , BUT MAY OVERBORE UP TO .060” IN DIAMETER ONLY. ANY REPLACEMENT PISTON MUST BE EQUAL OR GREATER IN WEIGHT THAN THE OEM STOCK PISTON NO EXCEPTIONS. MUST BE STOCK , OEM ENGINE COMPRESSION FOR YEAR AND MODEL OF TRUCK .
B.- ENGINE DECK HEIGHT MUST REMAIN OEM STOCK
C.- CYLINDER HEAD MUST REMAIN STOCK THAT MEANS NO LARGER VALVES , OR PORTING. THE CYLINDER HEAD MAY BE RESURFACED. THE USE OF AN OLDER MODEL CYLINDER HEAD FROM SAME CUBIC INCH ENGINE MAY BE USE TO CONVERT TO CARBURATION.
D.- FUEL/AIR- MAY RUN A CARBURETOR NO LARGER THATN A HOLLEY 350 CFM . MAY USE A SPACER FOR CARB. NO THICKER THAN 1”. MAY USE ADAPTER TO MOUNT CARB OR MILD MODIFICATION TO CARB MOUNTING POSITON ONLY NO PORTING INTAKE MANIFOLD. FORD RANGERS MUST USE ONLY THE GREY OEM COLOR INJECTOR WITH A 14Lb/Hr RATING NO EXCEPTIONS , ON FUEL INJECTED MODELS.
E.- FUEL INJECTED MODELS - OEM FUEL INJECTION MUST BE USED , OEM SIZE INJECTORS , OEM SIZE THROTTLE BODIES MUST BE USED. ECU MUST BE STOCK STYLE, BUT COMPUTER CHIP IS ALLOWED. MAY USE ADJUSTABLE FUEL PRESSURE REGULATER AND MAY ALTER SENSOR READINGS BY WAY OF RESISTORS. MASS AIR FLOW SENSORS IF EQUIPED MUST REMAN OEM SIZE.
F.- MUST USE STOCK IGNITON FOR MODEL OF TRUCK MAY USE AFTERMARKET PLUGS AND WIRES. AFTERMARKET IGNITION COILS ARE ALLOWED ON CARBERATED MODELS.
FUEL TANK- MUST RUN AN APPROVED FUEL CELL ENCASED IN A 20 GUAGE STEEL BOX.
8 GALLON MAXIMUM FUEL CELL IS MANDATORY NO EXCEPTIONS. MUST BE LOCATED IN CENTER OF CHASSIS LOCATED BEHIND REAR END AND A MINIMUM OF 8” GROUND CLEARENCE.
EXHAUST- AFTERMARKET TUBULAR HEADERS ARE PERMITTED. TRUCK MAY HAVE ANY STYLE EXHAUST BUT MUST EXIT BEHIND THE DRIVERAND HAVE SOME TYPE OF MUFFLER .
COOLING SYSTEM- ELECTRIC FANS MAY BE USED. MUST ANY TYPE RADIATOR MOUNTED IN STOCK LOCATION. MUST HAVE A MINIMUM 1 QUART OVERFLOW TANK SECURLY FASTENED UNDERHOOD. OVERFLOW MUST BLOW-OFF ON THE PASSENGER FRONT LOWER QUARTER OF WINDSHEILD. ABSOLUTELY NO ANTI-FREEZE IS PERMITTED. ATER ONLEY MAY USE “WATER WETTER’ ADDITIVE OR EQUIVALENT.
RUNNING GEAR- MUST USE OEM TRANSMISSION NO MODIFICATIONS.
REAR ENDS- MUST USE STOCK REAR END FOR TRUCK GEAR CHANGES ARE ALLOWED

[DroppedMitsu]

If its pretty much all stock motors the 2.4 is definitely better, although I would think it would be better regardless of being able to mod it or not

[turbomax]

Ok, so talking to this guy that races a Mighty Max on an asphalt oval, I'm still stumped on which direction to go. First, here is what Ray had to say.

"You are assuming right. it is a 2.4 EFI. It seems to run well with the trucks. Here's the low down. when I first got it , the truck had just over 146,000 miles on it. I pulled the head , checked the main and rod bearings. Had the head plained .010 because it had a bad head gasket, Changed the gaskets, added a balance shaft elimination kit, and went racing. I did not bore the engine nor change any bearings. It has been stock minus those changes sense day one. It seems to run ok where I start and I have passed a few trucks in the 5 years that the little guy has been running. With the normal tune ups and oil changes, which now by the way I add a quart about every week to keep it going.I am thinking it burns it but the plug's don't seem to tell that tail. Otherwise it runs pretty strong every week. We did do a compression test a few weeks ago on one cylinder and came up with 149 lbs. The engine is definatly still strong."

Ok, so this tells me that I can run with the other trucks but looking on the site, his truck isn't as competitive as I'd like to see a MM/Ram50. I hope to run towards the front if possible. I don't want to be an "also ran"...so do I rebuild my Starion block (stout bottom end), run a really good carb and pacesetter header? Or should I just go the 2.4 route? I don't know what to expect hp numbers from the Starion block. Can you slightly tweak a 2.4 to get some better numbers? I posted up the track rules on my "newbie" post.

If you use the stock starion pistons they are low compression pistons. If your running NA you will need to swap it out for truck pistons or you'll be down in hp.

I'd run the 2.4 since it should have a higher rpm capability over the 2.6. The 2.6 will have more low end torque great for drag racing, but the 2.4 should be better for constant higher rpm for oval racing. When I autocrossed my starquest I always felt it needed more rpm. I just could't stay on it long enough.

[LSR Mike]

stick to the 2.4, chip it for a higher RPM limit, and go for Really Strong valve springs to up the RPM (no valve float), hack the MAF see

http://www.vfaq.com/index-main.html

Do the balance shaft elimination, and anything else you can do within the rules.

[Johnboy72]

I just looked up 2012 rules...well the classes that are updated. But a new rule is sport compact class will include trucks and the engines can be modified but must be correct block. I'll try to post rules tomorrow for that class.

[Rahtid]

you can use 99-05 kia optima 2.4 pistons for higher compression pistons around 10.5- 11.5 compression or 99-05 4g64
galant eclipse pistons for 10.1-10.5 compression pistons,that way you can say its a factory replacement,

http://img846.imageshack.us/img846/4899/g4jspiston1.jpg (http://imageshack.us/photo/my-images/846/g4jspiston1.jpg/)

[Finnie3d]

stick to the 2.4, chip it for a higher RPM limit, and go for Really Strong valve springs to up the RPM (no valve float), hack the MAF see

http://www.vfaq.com/index-main.html

Do the balance shaft elimination, and anything else you can do within the rules.

Who has upgraded valve springs for our motor? I've got a '94 MM 2.4 EFI...

[LSR Mike]

If you're looking for a Kit I don;t think you will find it. Mine were done by the guy who ported my head and they were sourced from a spring catalog , intended for another type of engine but happened to be the same size.