F24 stroker kit for race use
06-15-2015, 03:46 PM
#1
F24 stroker kit for race use
Greetings- I have bought an s2000 roller that was previously in HC1 NASA. So this is a race car without a motor. I am thinking of putting the f24 stroker motor into it from inline pro. I would of course run an oil cooler but don't know what I could expect for motor longevity/issues. I have read the posts I could find by searching, but mostly these were street cars or dual duty at best. Anybody with experience or good understanding of what to expect from such a motor in a pure race use? I would be looking for roughly 270-280 whp and would like to run sprints and enduros.
06-15-2015, 08:36 PM
#3
Strokers work but don't the HC1 rules require stock components? A strokers allowed? It is possible to build a 2.4 stroker with a TSX crank and Prelude rods and pistons, most of the parts requiring machining, but I don't think that would be a reliable high rev solution. It is probably more of a street solution.
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
06-16-2015, 02:52 AM
#4
Strokers work but don't the HC1 rules require stock components? A strokers allowed? It is possible to build a 2.4 stroker with a TSX crank and Prelude rods and pistons, most of the parts requiring machining, but I don't think that would be a reliable high rev solution. It is probably more of a street solution.
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
06-16-2015, 07:20 AM
#5
2.4 here that tracks only. As long as its tuned right and built right, why would it not last???
Rev limit on mine is set at 7800. Im using Wadziis kit (CNC Speed Shop) and he has been very helpful! Check out his group buy for the kit, Its what I use with stock pistons.
Motors dont last if they are not built right and/or tuned right...or reved to high hell lol
Rev limit on mine is set at 7800. Im using Wadziis kit (CNC Speed Shop) and he has been very helpful! Check out his group buy for the kit, Its what I use with stock pistons.
Motors dont last if they are not built right and/or tuned right...or reved to high hell lol
06-16-2015, 07:25 AM
#6
Originally Posted by DavidNJ' timestamp='1434429397' post='23649618
Strokers work but don't the HC1 rules require stock components? A strokers allowed? It is possible to build a 2.4 stroker with a TSX crank and Prelude rods and pistons, most of the parts requiring machining, but I don't think that would be a reliable high rev solution. It is probably more of a street solution.
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
The rules don't seem to spec reciprocating weight so I imagine keeping everything light, cleanup, x-ray'd for crack detection, cryo'd, and then revved high would probably be the better solution. After all of this, is an S2000 competitive in HC1? Is there a viable HC1 class were you race?
The solution is better quality parts. Cranks made out of 300M or 4340 billets (Inline Pro has a billet crank for $1900, I don't know the metallurgy, Crower will build whatever you want). Ditto for rods. One advantage: the shorter rods and less compression height pistons weigh less. All high stress situations also let you spend a fortune on rod bolts. If you look at a catalog for high end rods you will often see options for different ARP bolts.
Toda has a 2.4 kit (expensive) which I'm pretty sure is used in racing. I'm not sure what rev limit they apply but I'm pretty sure it is at least stock and maybe quite a bit higher (e.g. 11k rpm). In the picture you can see the prepared crank with minimal journal overlap and the low compression height on the pistons.
But it comes down to what is you maintenance schedule. When you get into serious race engines you get cam profiles that are hard on valve springs and valves. When an engine spends it life spinning from 7000-11,000rpm with WOT loads it will have more wear than one cruising the highway at 4000rpm and part throttle making maybe 80hp. There are on engine valve spring testers and valve spring changing tools, in some classes a weekly exercise. Race engines often have regular, the most I've ever done is annual, rebuilds that include new valves and often new pistons and pins. Camshafts also wear but many new ones are made from harder billets and have a surface hardness treatment. If the engine is stressed enough cranks and rods also could be maintenance items. Drag racers use aluminum rods and in some classes swap them between each run. But then, I don't think you are planning on 5000hp.
Which gets back to how much do you want to spend? How much maintenance do you plan to do? How competitive is the class you are racing in? The top two S2000s in STU at SCCA's runoffs had $15k Quaife sequential transmissions.
If you just want to have fun...pick a class that lets you do the least modifications but remain competitive. SCCA E/Production? You won't have many race long fender-to-fender battles, but you will have a few cars in your class (many who look like they belong in vintage racing) and be trailering a real race car while the rules will keep costs in check.
06-16-2015, 07:52 AM
#7
Thanks for the info davidNJ. I guess my answers will seem vague but, I am currently racing a k20 in sprints. Motor has been fantastic with only a cracked RBC after maybe 25 races. The s2000 project would be to run in 3-4 enduros that are 3-4 hours long. I think a stockish F22C. would struggle against a perelli WC Miata, TC Kline built z4 and a few k24 crx/civics. My experience with these enduros is they run a lot on the Rolex config at homestead. The FWD set ups rarely last the race without Axle issues. They seem to hate the banking. Not to mention that as much as I like racing, driving my civic with no power steering and no muffler on race rubber for a couple hours is a total nightmare. I would want a motor that could give me a 10:1 power to weight ratio and could potentially run a full season. Maybe it's not possible but I am trying to figure out what to do with this car.
Regarding those tip of the spear s2000 with 15k tranny, that not me lol. I would love a better power to weight s2000. I ran one at lapping days for a few years with test pipe, exhaust, track tires and aggressive alignment and my civic is probably 2 seconds a lap faster with me behind the wheel.
Regarding those tip of the spear s2000 with 15k tranny, that not me lol. I would love a better power to weight s2000. I ran one at lapping days for a few years with test pipe, exhaust, track tires and aggressive alignment and my civic is probably 2 seconds a lap faster with me behind the wheel.
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06-16-2015, 09:26 AM
#9
That kit is using a TSX K24 crank with what looks like minimal machining to make it fit an S2000. You ran it with an 8500 limit.
If it lasts that's great. If I was spending the money for the complete teardown/rebuild I'd probably have sprung the extra $1000 or so for a billet crank. How many hours of track time did it have per season?
It looks like you kept the VTEC. Was this a race/street application? If not, why not replace the rockers to lose the VTEC? It dramatically reduces valvetrain weight.
It says in the thread that it is 13:1 compression ratio. Are you able to do that on pump gas or does it require race gas? If pump gas, how far back did you need to dial ignition advance?
Wadzii recommended either custom pistons (
) or a thicker head gasket to bring down compression. I'd be mixed on the thicker head gasket for an endurance application. In a race only application where race gas is allowed, go for it! I've generally raced in classes with a compression ratio rule and frequent enough teardowns that I carried spare gaskets (never needed it though).
BTW, do you plan any coatings. Minimally, isn't your header coated? That was mandatory IMHO with small block Chevys to reach the plugs without burning your hands. Read the plugs was necessary to check the carburetor jetting. While that isn't an S2000 problem it still keeps heat out of the engine compartment. If allowed, there are coatings to improve oil return to the pan, insulate exhaust ports (to retain heat in the exhaust), insulate intake ports (to keep heat of the mixture), piston crowns, piston skirts, etc.
An important thing to consider is reciprocating weight. In racing, we see acceleration that can exceed 1000rpm/sec. Those numbers are rarely seen on a dyno. Some dyno test at 600rpm/sec acceleration. When accelerating reciprocating and rotating weight counts. That leads to lightweight pistons, lightweight rods, lightweight clutch. Lightweight comes at the cost of strength so it is constant tradeoff of strength, weight, and money.
Isn't speed measured in cubic dollars?
For example, small block Chevy cranks are made with early 2.3" main bearings and Honda 1.88" rod bearings. The smaller rod bearings allow for a smaller big end on the rods and therefore less weight. Highend metallurgy (4340) allows strength to be maintained.
You didn't mention bore. Any increase will have some improvement in unshrouding the valves.
The other area weight can be saved is the clutch and flywheel, if the rules allow. Some classes require stock components or stock weight components. Others allow 4.5" multi-plate carbon clutches. There are also lightweight driveshafts. All of this adds force accelerating the car without increasing hp on the dyno.
If it lasts that's great. If I was spending the money for the complete teardown/rebuild I'd probably have sprung the extra $1000 or so for a billet crank. How many hours of track time did it have per season?
It looks like you kept the VTEC. Was this a race/street application? If not, why not replace the rockers to lose the VTEC? It dramatically reduces valvetrain weight.
It says in the thread that it is 13:1 compression ratio. Are you able to do that on pump gas or does it require race gas? If pump gas, how far back did you need to dial ignition advance?
Wadzii recommended either custom pistons (
) or a thicker head gasket to bring down compression. I'd be mixed on the thicker head gasket for an endurance application. In a race only application where race gas is allowed, go for it! I've generally raced in classes with a compression ratio rule and frequent enough teardowns that I carried spare gaskets (never needed it though).BTW, do you plan any coatings. Minimally, isn't your header coated? That was mandatory IMHO with small block Chevys to reach the plugs without burning your hands. Read the plugs was necessary to check the carburetor jetting. While that isn't an S2000 problem it still keeps heat out of the engine compartment. If allowed, there are coatings to improve oil return to the pan, insulate exhaust ports (to retain heat in the exhaust), insulate intake ports (to keep heat of the mixture), piston crowns, piston skirts, etc.
An important thing to consider is reciprocating weight. In racing, we see acceleration that can exceed 1000rpm/sec. Those numbers are rarely seen on a dyno. Some dyno test at 600rpm/sec acceleration. When accelerating reciprocating and rotating weight counts. That leads to lightweight pistons, lightweight rods, lightweight clutch. Lightweight comes at the cost of strength so it is constant tradeoff of strength, weight, and money.
Isn't speed measured in cubic dollars?
For example, small block Chevy cranks are made with early 2.3" main bearings and Honda 1.88" rod bearings. The smaller rod bearings allow for a smaller big end on the rods and therefore less weight. Highend metallurgy (4340) allows strength to be maintained.
You didn't mention bore. Any increase will have some improvement in unshrouding the valves.
The other area weight can be saved is the clutch and flywheel, if the rules allow. Some classes require stock components or stock weight components. Others allow 4.5" multi-plate carbon clutches. There are also lightweight driveshafts. All of this adds force accelerating the car without increasing hp on the dyno.
06-16-2015, 09:59 AM
#10
That was not my car but the same setup and similar HP that I am currently running. For track rev limit is 7800..even with the best rod bolts on this kit ($200+ a set) I dont need the added wear for a few more MPH. My gearing with AP1 tranny is similar to AP2 2.2 motor and tranny. I max out ~104 in 4th (AP2 is ~101) for example with a 7800 rev limit.
My car is road course only but I do drive it on the road streets every now and then. No need to complicate things considering this kit makes good power and if I can keep it as close to stock without having to replace parts (like losing VTEC), thats how id like to keep. My stock 2.2 has been bullet proof for the last 5 years in my car.
I do about 8 event a year 80 min (hour an 20 min or more each event). I just loved how well my stock 2.2 has held up, along with other buds whos motors held up the same. A lot of people do oil analysis and the tests come back good. No abnormal wear. Keep it simple and things tend to not fall apart lol
I use race gas. 100 octane but the link I posted he runs 93. Car was not timing limited.
I use stock header, stock intake, stock TB, stock intake manifold. Header has factory heat shield so need to coat. My head is pretty much a stock AP2 (stock retainers/springs/cams) with small port work and bronze valve guides.
My car is road course only but I do drive it on the road streets every now and then. No need to complicate things considering this kit makes good power and if I can keep it as close to stock without having to replace parts (like losing VTEC), thats how id like to keep. My stock 2.2 has been bullet proof for the last 5 years in my car.
I do about 8 event a year 80 min (hour an 20 min or more each event). I just loved how well my stock 2.2 has held up, along with other buds whos motors held up the same. A lot of people do oil analysis and the tests come back good. No abnormal wear. Keep it simple and things tend to not fall apart lol
I use race gas. 100 octane but the link I posted he runs 93. Car was not timing limited.
I use stock header, stock intake, stock TB, stock intake manifold. Header has factory heat shield so need to coat. My head is pretty much a stock AP2 (stock retainers/springs/cams) with small port work and bronze valve guides.