Ted,

Good point. On a 6 cyl engine, could you definately tell if there was a problem monitoring with one EGT sensor on each 'side'?

Jamie: only to the point of knowing what side the problem was on. Narrows it down to three cyl.
Actually an all cyl engine monitor/scanner is pretty expensive, and it's full value can probably only be realized by a race team. The driver could radio his pit that"#4cyl has a plugged injector" When he pulls in, the pit crew has the part in hand and knows exactly what to do. No lost time trouble-shooting. I would be suprised if no racing teams are not presently using this technology.
Ted

My question is, on a two sensor set-up, would there be a big enough temp delta for you to see a problem if 1/3rd of the cyls monitored on a bank is out of spec?

Another Option.....
 

Check out the this baby:

http://forums.pelicanparts.com/uploa...1112392475.jpg

4 x EGT or CHT for $147


http://www.sportflyingshop.com/Instr/Stratomaster/SmartSingles/smartsingles.html

That's a really good point. Having two sensors isn't really any better than having one. To be really useful, you would need to monitor every cylinder, so maybe I will stick to one gauge.

I always get useful info on PParts!

Eric,

Cool (or hot) Too bad it can only be configured for 4 cyl.

if anyone believes that having 6 cyls producing equal power is worthwhile then 6 EGT probes is a great tuning device.. especially when using carbs.

Jamie:
Yes.
Ted

Am I to understand the 400 degrees is OK?

Well, its the max limit of OK, like driving 120 MPH through death valley.

BTW - I have the VDO CHT gauge with sender, new and still in the box, if anyone wants to buy it off of me for $100.

I bought it a while ago but will no longer need it since I am now taking the computer instrumentation route.

pm on CHT
 

A pm for you 350HP on the gauge.

Yes. An old time trick is to run an airplane engine and stick something against the exhaust header to see if it melts. No melt, no fire, no fire no spark or fuel. Also can feel the cylinder to see if its warm. Usually easy to find the one that is not firing. The big trick is staying away from the propeller!

An EGT is a lot better tool for this, especially if you have a sensor in every cylinder. More money but then more information!

Jacko,

400 degrees is usually regarded as a max constant temp limit. You could go a bit higher for a few seconds. Do a search on the internet (or look at the links I posted on the first page) and you will see that most of the aircraft engine makers feel that 400 is their limit.

What is Porsche's limit on a 911 engine? Who knows. Would be nice to find out but for safety would prefer cannot see it taking more than and airplane engine until we find data from the factory, or someone like Bob Anderson or Andial.

JoeA

I have talked to several respected Porsche race prep shops, and the concensus I got was at race speed normal temps are 300-350 degrees.

Most races don't occur in 100+ degree temps though. ;)

I ordered a combo gauge from Westach (aircraft gauge manufacturer)-- dual CHT, EGT and Volts. It is a serious piece of equipment and looks like it. For EGT there's a probe put into the exhaust, and for the CHT there are connectors through which the sparkplugs fit (you remove the sparkplug washer).

When you order the gauge, you can specify the range(s) which you want the gauges to read.

Between these gauges and an LM-1, you've got the info you need to tune.

Highly recommended.

JP

O.S.: Aircraft spark plugs are 18mm dia, did you specify 14mm for automotive plugs? (for the CHT thermocouples)
Ted

Ted - Yes I did. The guys at Westach were very helpful and anticipated a lot of what I'd need once I told them what I was going to use the gauge for. The car should be with me sometime near the middle of the week; when it gets here, I'll take a pic of the gauge and post it.

JP

The last two Formula One races had temps over 100 for practice and qualifing...


JP, when you go to install the EGT probes in the pipes, pls pay attention to the size hole they specify. If its not right on it can damage the probes. BTDT! :)

JoeA

350HP, you should try racing at Sebring in August!

Joe -
Thanks, man. Fortunately, the Westach instructions were very complete, so that's one ... and I mean one ... mistake I haven't made. :D

I really can't say enough good things about the Westach stuff. And you don't need to get a 4-way combo; they sell dual gauges and singles as well.

One thing relative to 350HP's point -- these gauges are set to measure relative temperature, and you specify to Westach what you want the "base" temperature to be. So if your gauges are set at 70 F base temperature and it's 90 F out, you've got to adjust the gauge reading by 20 F. Not a big deal, really.

JP