SMTCapeCod

Hi,

I have a cooler thermostat in my '83 Euro, its 73C vs 85C, I think, approximately 165F vs 185F (or so). I installed it do to my paranoia about overheating an aluminum engine, and some preliminary indications that the temp was climbing in traffic....

The temp gauge hangs right around the first tick mark...I'm thinking that has to be well above the temperature where the Warm Up Regulator functions in warm-up mode, manipulating fuel pressure. Anyone think otherwise? I thought I read a rant years ago warning against running the cooler thermostat in CIS cars.
I have a stock heat-range tstat on the way.

ErnestSw

Where in Nova Scotia?

Doug Hillary

Hi,
SMTCapeCod - I agree with you and the Porsche design Engineers did too no doubt!!

Some contributors on here will not however!

The core temperature (IR measured) is usually around 91-97C in an engine in reasonable condition

Hi Ernest - your contribuition here will be of great value!

Regards

jpitman2

SMT, I ran my CIS 83 on a 75C thermo for a couple of years, based on the same paranoia - living in highs of 120F at the time. Never noticed a problem with fuel mix that could be related to the thermo. Since returning to more moderate climes, I have recently returned to a stock thermo, and it is running more at centre scale to near second mark. I think the down side of running at lower temps is more to do with moving part running at optimal temps and clearances than anything much on the fuel side.
I may be wrong of course, I sometimes am.
jp 83 Euro S AT 49k

Garth S

Most Bluenosers* and Newfies** use 85 C thermostats year 'round .... and wear Stanfields longjohns in winter ...

glossary of local terms:
* bluenoser = inhabitants of NS, derived from the famous racing schooners name
** idem reference to Newfoundlanders, even if currently residing in Tx.

SMTCapeCod

Guess I'm being a bit of a poser...I actually have a camp south of Forties, about ten miles through the woods. Forties is near New Ross. Miss it up there, want to move.

John thanks for your sound advice. Voice of experience is always much-appreciated. I know there is a percieved tension between reduced clearances at lower temps vs the advantages. I seem to notice a little difference Iimprovement) when my car does get near the middle of the (indicated) temp range...but I can convince myself of just about anything now. Something weird is going on though, periodically it will be idling warm smoothly/happily and then give a brief hiccup and totally 'reset' to a differnt idle baseline..still smoothly/happily just a couple hundred rpm up or down. Wonder if its that A/C related thing on the strut bar...

Dennis Wilson

If the WUR heater is functioning properly, the lower temp thermostat will not affect its operation. If you do a lot of stop and go driving, the lower temp thermostat AND a matching lower temp radiator fan switch would be better option.

Dennis

SMTCapeCod

I did install lower thermostat and fan switch, but thank you.

Turns out the vendor sent a lower temp t-stat with the recent order...now theres a conundrum. I guess I can install it anyway (since I've got it) and go back to thinking about whether the WUR is working properly.

jpitman2

Do you have any symptoms that point at WUR problems? To my mind, if it starts well cold, and has good power hot, and acceptable economy, WUR should be ok?
jp 83 Euro S AT 49k

SMTCapeCod

It was starting pretty well cold, but the running state has been getting richer...and this is a good thing as it was real lean to start with. So as I've leaned it out to keep the idle good, the start has become a little harder. Or actually, I'll have to see tomorrow for the next cold start after my last adjustment, maybe it was loading up/rich.

I've been thinking it doesn't have good power hot..but maybe its me. When I get it into the good power band slowly and then nail it, or if I back off a bit and floor it with the rpms spinning, it delivers an OK push. Down low its softer than I remember. BUt perhaps my VR4 has been spoiling me for too long.

jpitman2

CIS mixture adjustment is very sensitive, I would be careful about adjusting this without co2 measuring gear. As stated many times, best real test is to get pressure gauge on WUR line and check cold and hot pressures. My cold (<=15C ambient) is around 20psi, rising to ~50 fully warmed. The tendency is for the inlet port in WUR to slowly clog with fine debris, and pressure to rise, leaning out hot mix and making starting harder.
jp 83 Euro S AT 49k, getting a new tank...

SMTCapeCod

Mine is getting richer though, so i think it is purging some buildup. And I do have an 02 guage (albeit a narrowband).

SMTCapeCod

Tested pressures, the cold was a little high so maybe the WUR isn't great, but it started. The ambient air temp was pretty warm so I'm reserving judgement. System pressure was right at the high end.

Got the waterneck powdercoated, standard temp thermostat and fan switch in hand. However, I'm not smart enough to leave entirely well-enough alone. With stock temps Tstat 83, Fswitch 92; and the coller options being Tstat 75 Fswitch 73 (I think) I wasn't following the logic. I though I had a line on an 88' fan switch, but couldn't find anyone this side of the atlantic with inventory. So I've got 85' coming. I think that should allow the thermostat to open fully but still kick on the aux fan early on and keep the operating temp within a slightly tighter range.

Now on to the next project- lower ball joints and MSD ignition.