964 hot rod running hot

[RL technical]

Hi there have just installed a 964 engine in my 77, it has high comp je 11.5.1, 993 cup cams, flowed heads lwf. Anyhow the motronic has a s.wong chip in it from back when the motor was relatively stock sports exhaust, I've ordered a new chip from Steve for all the new mods, however I drove the car today in very cool temps 10celcius, and only around the streets, it didn't take long at all for the oil stat to open and I noticed that to be unusual compared to previous where it would take ages to even open the thermostat. The car has dual carrera coolers in the wheel arches oil coming back from coolers is Luke warm so they are working. I'm thinking that the car must be running very lean, I know it's a tight motor as well. As you can see it is concerning me, I've also noticed that previously when cold it used to be very rich now it's not, so does anybody out there think it's a problem totally related to fuelling ? I can't see what else it could be I understand the hotter the motor the more heat, but in cold conditions like this I did not expect this?

[RSTarga]

so what is the temp reading?

[RL technical]

Measured the oil tank oil and got 105 Celsius after ten minute drive in cold conditions around the st. I'm cretain it's a lean issue.

[Tony911]

After installing a similar engine in my 78 a couple of years ago I found I had to add a significant amount of cooling capacity. The car originally had a single 930 fender cooler, this was ok for a quick drive around the block, anything more and too much heat. Next step was adding a cooling fan, still no where near enough, next came a second fender mount cooler in the other side (satrab with a manually controlled fan) This was ok for general driving and a bit of hill work, but didn't cut it on the track. Now has a centre mount in series with the fender mounts, that did the trick, only have to use the fans when engine is hot and car stationary. I probably could loose one of the fender coolers but like having that extra cooling capacity. Engine is developing around 350 fwhp.
For road use dual fenders may be only be just enough capacity, there is not great air flow in the front of the fenders, for me a centre mount was a must.

[RL technical]

Ok, the return oil temp is quite cold so the coolers appear to be rejecting the heat, as the cores are very cool, I'm more going down the track at this stage of running lean due to not enough fuel, on cold start she hasn't got that rich smell any more that I used to get. I think I'm going to have to wait for steves chip and then re visit the problem, but it its a concern as its all setup for track use, rebel/elephant suspension the works you know the slippery slope......
How quick did it take to get the thermostat open when running dual carrera coolers on your car?

[Joe Bob]

More than a few threads on this. A search will help.

The short version, I run two coolers nose and fender. I speak Fahrenheit. The external T-Stat opens at 180. Coolers help maintain the op temps and shed heat until the capacity is exceeded.

If you are running over 210F and just driving and have two coolers, something is wrong. Now we assume correct tune, stock FI, ambient temp under 120F.

I also have a hand held pyrometer and have been doing big motor conversions for 30 years. My advice is free. Feel free to PM or email me.

[RL technical]

Well that's what I'm getting at I'm awaiting a Wong chip for the mods, will a chip not providing enough fuel cause hot running from being lean.