hrk

iTrader: (6)

Hi,
I think I cooked my car again at the Road Atlanta race last weekend. Everything was fine and I was pulling from Corvettes when two cars laid lots of oil simultaneously into 10 and 1 corners and the race was redflagged.
While parked temps were around 220-230 F and did not seem to get lower inspite of running the fan. Water was puking out from my small catchcan.
So I shut down the car and after about 10 minutes yellows came back and I tried to start the car. Did not like to start, and I had to let people past. I used uphill on one to bumpstart the car and got it running eventually.

Now I am looking for cooling system which would allow redflag stops from full song in 100+ F heat.

The current plan is to put big and thick radiator into the back of the locost with a fan or two, and use the front nosecone for oilcooler and intercooler.
Also electrical waterpump might be in plans, so I could circulate water without running the engine in these extreme cases.

Any suggestions of sources?

hrk

beerslurpy

CSF makes a big one for cheap. If you need something narrower like a honda radiator, CSF makes those too. I got mine from radiator express.

Also, coolant reroute for a track car. I think jason c recommends an oil cooler as well.

m2cupcar

iTrader: (5)

hrk you need a race car radiator - something that's at least dual pass, crossflow and twin 1" rows. Hopefully you can find something that will fit. I got a circle track stock rad for my Miata from randysracemart.com - specs as above with custom sized inlet/outlets for $220. You can pick up a used spal 16" straight blade 2700cfm on ebay for $70 from one of the guys that sells used nascar parts. That's about half new.

hrk

iTrader: (6)

Yep, this is what is installed at the moment

GRI-2-25135-X
Overall Width (in): 17.000 in.
Overall Height (in): 18.500 in.
Overall Thickness (in): 3.000 in.
Row Quantity: Dual-row

Fan is stock Miata fan.

hrk

m2cupcar

iTrader: (5)

Damn- yeah, I'd agree, you need a good fan. Spal also makes a 3000cfm straight blade. I only recommend the spal because they seem to pull as advertised... important in this case.

cwisenheimer

Also, if you don't have the radiator sealed to the nosecone, that would help. http://www.flyinmiata.com/westfield/racingflip.php?x=33 for an example.

hrk

iTrader: (6)

Yep, got that too. Or AC foam seal jammed between nosecone and radiator.

It does not help when I have IC partially in front of the radiator.

http://russmarshall.com/v/cars/cmc7/...10961.JPG.html

How about that electrical waterpump? Would I need it if I put 30" wide/4" thick/16.75" tall used Nascar radiator on the trunk or does the stock Miata pump provide enogh flow to push water to the other end of the car without problem? The other reason for electrical pump would be having possibility to use the fan(s) and pump to cool system down without running the engine.

hrk

m2cupcar

iTrader: (5)

You're not overheating on the track are you? Just the sitting still - right? Swap the fan first.

hrk

iTrader: (6)

Well, it prevents me stepping on it for full 30 minutes race. In summer I have to short shift earlier and modulate gas more than in winter ambient temps.
But it is ok for 15-20 minutes and with cool down lap it kept the water in until last weekends very high ambient temps, where it puked out half a quart after each session.
I'd think the cooling is marginal at the best and red flag pushed it over the limit.
Fan would help, but the 100+mph wind is more efficient pushing air through the radiator at speed.

Also oil cooler would be helpful, but there is no great place to put it in small nosecone.

hrk

m2cupcar

iTrader: (5)

What are the oil temps? That's one sure way to drive up coolant temps. You don't have to put the cooler in the nose- especially at the speeds you're running. Older 911s just had a hard steel loop in a fender well- and the long lines from the rear. I don't think it would take much of cooler to make a difference either.

hrk

iTrader: (6)

Unfortunately no record of oil temps. I have Bosch sensor there but it is not connected to data aquisition or any gauges at the moment.

The setup is the same as in this dyno thread:
https://www.miataturbo.net/dynos-timesheets-21/no-not-another-dyno-thread-8043/

hrk

beerslurpy

Hey, how do you have your oil cooler hooked up? Do you have one of those sandwich thermostats or do you have a remote mount with one of those mocal thermostats?

beerslurpy

cupcar, what is that black plastic stuff you warm up and bend to make underbody ducting? I would like to get some but I can't find it on BSR. What is it called?

magnamx-5

iTrader: (7)

maybe try some WI on the Rad/IC as well I would be tremendously surprised if the stock WP could psuh water to the back of the car and forward agian. I would love to see an electric WP solution for the miata, though it just makes sense, if you wanna make a bunch of power.

beerslurpy

I dont think it would take that much more work to suck the water horizontally.

And the stock pump doesn't push unless I am mistaken. It is a very loose design that would appear to generate suction at the inlet rather than generating positive pressure at the outlets. As long as there is a continuous column of water between the inlet and the radiator, it should work exactly the same. It shames me to say that I had to take apart the cooling system nearly half a dozen times and discuss online before I properly understood how it worked.

I find it easier to visualize the coolant system by following things from the inlet backwards to the pump outlet. Inlet side restrictions have a much strong effect on where flow goes than outlet side restrictions.

m2cupcar

iTrader: (5)

I think HRK has big oil temps. Figure a Spec Miata running normally aspirated sees 260f during a 20-30 minute sprint race. Where would that put a turbo'd engine making double the power?

Go to bsrproducts.com and type "black plastic" in the search box. The first six products are various forms in which you can purchase it. Heating isn't mandatory- it will bend well with some force.

I'm using a cheap-o hayden sandwich plate with built in tstat. It works, but has 3/8" npt ports - and I believe the mocal has the "real" tstat and 1/2" npt ports (for more dough).

cwisenheimer

You're stuck with a fairly small frontal area to get rid of all the heat generated by your level of power so you've got to get more air volume through the heat exchangers you've got. Once you get a high-flow fan in there, where does the air exit? I can't tell from your pictures if you have a belly pan under your engine or not. Perhaps some hood venting aft of the radiator/fan assembly?

hrk

iTrader: (6)

http://russmarshall.com/v/cars/cmc7/...11083.JPG.html

Hood is vented with louvers and exhaust has pretty big hole also. Side pods have about dozen 2" holes from previous exhaust configurations and suspension arms have big openings behind the radiator. There is some aluminum sheet under the frame, but it has about 2" gap to the oilpan so it should vent out some in addition to gearbox tunnel which is not shileded from below.

I cannot say if these are enough or not but I don't see any bulging of my thin aluminum hood at speeds from pressure.

Oil temps are an issue and I don't have anything else than factory sleeve as cooler. Mobil one seems to take the heat decent.

Thanks for comments, keep them coming.

As an update, it seems that I'll need to change the head, compression 160, 90, 60, 180 and leakdown showed pressure escaping either through valves or directly to adjacent cylinder.

hrk

Racer46

What are you running for coolant? Red Line Water Wetter and distilled water kept the temps in my ITA car under controll, with a stock radiator and fans.

m2cupcar

iTrader: (5)

I say you swap the head, install an oil temp gauge and see what happens.

I don't think it's a question of whether the oil can take the heat or not, but if the oil temps get so high that the cooling system can't manage the engine heat - then oil temp must be addressed.