jaundice

So I am finally rebuilding the track car. I have gone thru both F20 and F22 motors this year. Several different reasons, including a broken con rod on F22 (was spinning it to 9K rpm and supercharged), dropped valve on F20 and spun bearing on F20. These were all supercharged at about 375 hp on a stripped track car on R Comp tires. I am getting faster and faster and fairly certain I am oil starving it. I am planning oil cooler and accusump and new canton pan (if it gets released). I have all the proper cooling mods, including upgraded radiator and SPAL fans and EMS control (KPro). I am planning to rebuild the motor and want opinions from the racers on several things. I am contemplating sleeving and building a F20 or F22. I am also contemplating using the Inline Pro Mahle F24 stroker kit on a very fresh FRM block. Please comment on the following.

Sleeving a block vs. standard FRM block (any difference to a track motor)

F20 vs F22 for longevity. I am using a supercharger, so can make same horsepower on either stroke.

F24 Mahle stroker with K24 crank from Inline pro (FRM block only). This will also be supercharged.

Finally, please do not recommend K24 or LS1 swaps. I have tons of F motor parts and blocks. Not looking to reinvent the S2000.

I appreciate the input.
Brandon

CKit

I would personally stay away from the F24 stroker (higher piston speeds) unless you're going to rev limit pretty low. With a centrifugal supercharger, revs are going to be necessary. I'd stay with a 2.0 or 2.2 using OEM cranks.

My impression is that sleeved block might be easier to re-sleeve later for rebuilds in future.

Upgraded springs and retainers and pull over if any hiccups in power. Consider dropping the pan after a few weekends to see if any shavings coming up.

thepoi

Id suggest dropping some money on a good datalogger. Log oil pressure, oil temp (at multiple locations maybe), EGT in for each cylinder

jaundice

While I appreciate that advice about the datalogger, and I plan to utilize my KPro and other sources for data, I can't go anywhere without a motor. I truly think I only lost one motor to serious oil starvation, the F20, I don't want to repeat that mistake. I am trying to build the best motor for a track only car, and will datalog and provide all of the necessary cooling and oiling mods.
Thanks
Brandon

jaundice

Also, curious if anyone would reuse a crank that had a spun bearing? If machine shop can polish it, would you reuse it?

CKit

You can reuse it, but you have to "nitride" it.

http://en.wikipedia.org/wiki/Titanium_nitride

CKit

(I'm just learning all this myself as I go through similar things)

jaundice

From that Wiki site....

As a constituent in steel making[edit source | editbeta]
Titanium nitride is also produced intentionally within some steels by judicious addition of titanium to the alloy. TiN forms at very high temperatures because of its very low enthalpy of formation, and even nucleates directly from the melt in secondary steelmaking. It forms discrete, micrometre-sized cubic particles at grain boundaries and triple points, and prevents grain growth by Ostwald ripening up to very high homologous temperatures. Titanium nitride has the lowest solubility product of any metal nitride or carbide in austenite, a useful attribute in microalloyed steel formulas.




I am a chemistry major and that is a mouthful...




Thanks CKit, I will start quizzing my engine builder.

Lalasissyboy

There has to be more reliable options out there. I plan on getting an inline pro engine once my motor goes.

CKit

You can have the best built engine out there, but without cooling mods and oil starvation mods it'll blow up just like any other motor.