I recently put together a RSX for ITE (Improved Touring - Everything) and EP (Solo class, not club) competition in both SCCA club racing and time trials.

I thought that it would be a good idea to put in gauges to watch everything, which has been helpful to an extent, but I don't know what is too hot. Well, actually I can say that my transmission starts having trouble at about 230 deg. F so I guess in a sense I know that is too hot

Last weekend was the first time I had it on the track since I got the car together, and it was a pretty warm day but not very hot < 80 deg. My oil temperatures were getting hot - over 260 deg. F where my temp gauge maxed out, and water temps stay significantly lower 215-230 range (I have a C&R radiator, which seems to be doing well.)

So where should I start getting worried? Are oil temps this high are okay as long as oil pressure is still high? By the way . . . I am using Redline 10w-40 and MTL . . .

 

The first question people are going to ask: Where are your temp probes located? Where are you taking your temp reading from?

 

thats some pretty hot oil you got there

 

The oil temp sender is located on a sandwich adapter on the inlet side of the oil filter and the pressure is on the outlet side of the sandwich adapter. I would have to double check but I think this is before the stock k20a2 oil cooler, which I suspect is not up to track duty

Water temp is on the upper radiator hose. Transmission sender is using a thread adapter where the drain plug was originally.

 

hi.

i run a stock K20A2 in my H1 civic racecar.

i use a fluidyne dual core half length rad in it currently (i will probably soon go to a full length rad). currently just running the oem oil cooler arrangement, but would like to add an aftermarket cooler (probably will integrate it into the full size radiator).

anyway, i have some gauges in the car:

the water temp stays in the "normal" range on the stock gauge; this means somewhere below 230 degrees.

oil temp has maxed out during a hot day at a 30 minute race at an indicated 135 deg C temp (275 F). temp probe is in the bottom of the oil pan. this temp is high, and has me concerned, but i use the mobil 1 oil and the oil doesn't appear "stressed"; i.e. it looks like amber honey after a raceweekend;

i have had other racecars that pegged the gauge over 300+ F and the oil looks black and burned after 1 day (stressed out oil, man!)....

don't know if that helped you, but i hope so....

EDIT: my oil pressure gauge reads 75 psi (max reading on my electric gauge) whenever i am above 3000 rpm hot. it holds this pressure on the track at all times, even at the high indicated oil temps. idle pressure is around 20 psi after a race.

 

Water temp I can't really comment on.. if it ain't boiling, you're in good shape.

Oil temps, I have seen 285 and that is way too hot. 260-265 I'm comfortable with.
(Turbo ITR, C&R Radiator, Greddy oil cooler, Defi gauge measured at sandwich plate).

I'll quote Wai from a non-honda-tech conversation.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wai &raquo;</TD></TR><TR><TD CLASS="quote">I was warned that the oil temp should not exceed 140'C (284'F) or it would blow the head gasket. </TD></TR></TABLE>

Not sure about the head gasket, but it sounds like sturdy advice nonetheless.

Oh, and for the tranny: Cooler is obviously better, but if the lube is roughly like synthetic oil, it should break down at a similar temperature... so 230 might be just fine. I try to ignore my tranny as much as possible.

 

You may want to look into adding an oil cooler if you can see the temp getting any higher.....if you plan on running the car on hotter days or harder.....



260 is towards the top of "comfortable." IMO

270 and I would add a cooler no doubt.

 

The reason I decided to put in a transmission temp gauge is that after I had a quaiffe installed I started having trouble with the 2nd gear syncros about 20 minutes into track sessions. Last year I shredded the 2nd gear syncro completely and had a little mis-shift while arguing with 4th gear which resulted in me finding 2nd instead at about 90mph, scary moment but I got the clutch in before any damage could occur. That's when I stopped using honda's gear oil and switched to redline MTL. It helped a little, but not much.

I notice that the gearbox starts getting notchy at about 230F, above 250F fourth gear gets real hard to mesh and reverse is impossible to engage. I am already looking into the right solution to cool it down, probably just plumb out a pump and put in a cooler though.

 

That is what I figured - so it looks like I need both a gearbox and oil cooler . . . ugh, there goes my tire budget

 

The first thing you should do is add an oil cooler. This is the first thing we do on our cars. It helps us run our engines more then one year.

 

Yeah.... an oil cooler is probably wise. I had the same problem as you with oil up over 270 in about 7 minutes on the track. Cooler in, I ran for about 25 minutes straight and didn't break 220. Its a wise move for sure, and for 300 bucks or whatever I spent to drop it in, its worth saving the engine.

 

How big of an oil cooler are you guys using?

 

Mine's a 24 row - 11x5.75x1.5
http://www.racerpartswholesale.com
Look up Tru-cool oil coolers.

 

Okay, got the oil cooler and associated plumbing ordered. I decided on an Earls from summit. I will revisit the idea of a transmission cooler when I see what effect an overall cooler engine has.

Thanks everyone for your help!