'hot' cyls

[Lance]

Does anyone have any idea which two of our cylinders run the hottest?

[MrwassmanNA2T]

you could try a Raytek temp guage to the exhaust ports... I am actually gonna try this today probably.

[Lance]

cool, let me know how that turns out

[MrwassmanNA2T]

apparently I got the job i wanted... So i couldn't do it.

The freakin battery is also dead

[OR-Zman]

Re: 'hot' cyls

Lance wrote: Does anyone have any idea which two of our cylinders run the hottest?

Just curious......why are you asking this?

If I was to venture a guess I would say 6 and 5. They have the farthest route from the radiator and they receive less air flow cooling due to their location. However... I cant imagine they would run more than a couple degrees hotter than the 1 and 2 cylinders.

Perhaps I am being simplistic here but I just don't see the point. :shock:

[Dan-TSS]

I think I understand the intention behind the question.
*You need to remember that there are a couple of things that will play a role in this though. Are we speaking in terms of a completely stock VG30?
Things like a gutted plenum, porting, and the like will effect which cylinders typically run the leanest, not to mention the variables like an injector that isn't upto par or the such.

I would want to re-word the question for better results....
"Which two cylinders on a stock VG30 tend to run the leanest"?(this answer should be based on airflow, but isn't always the case)

*In my limited experience, I have found that cylinder #1 and #5 on two different occasions, on a mostly stock high mileage engine, showed less compression. This doesn't mean that they were the leanest, but the plug coloration tends to make me believe that was the case. Others posting thier findings will only help confuse or clarify things.
~Remember, there's a few variables involved that can cause this, but I assume that you are looking the simplistic answer that I have yet to find out. The supra inline guys tend to have issues with the last two cylinders closest to the firewall(which happen to be the furthest from the radiator)

[Lance]

my friend whom does a lot of engine building says if I really wanted to be anal, I should put the slightly more flowing injectors on the hotter cylinders =) but it's not that super important.

[Butter]

http://cgi.ebay.com/ebaymotors/Aircraft ... otohosting

[OR-Zman]

^ Go figure...

[FreeLanceBum]

That thing is cool as hell.

[SATAN]

Lance wrote: my friend whom does a lot of engine building says if I really wanted to be anal, I should put the slightly more flowing injectors on the hotter cylinders =) but it's not that super important.

If your friend was truely anal then he would cure the inconsistancies in the engine instead of running larger injectors for his lack of mechanical skill! :twisted:

Just kidding, trying to get each cylinder to run equal would mean having different comp ratios in each cylinder different lobes for each one also. lots of different things to taylor. This is what they do in nascar since they have to run carborators they cant taylor fuel to indiviual cylinders SO What do they do then???? They make every single cylinder have the exact same Volumetric efficiency.

On an engine like what you or I would run, you generally tune for the two leanest cylinders. This causes the rest of them to run rich. Unless you can do the 6 probe egt(and hell since you are made of money 6 egt gauges too!) and run say an Electromotive TEC 3 with individual injector and ingnition cylinder trimming. uuuuhhhhhhh droooooool.

[Dan-TSS]

Not that it even applies to your scenario because of all the possible variables involved...(original poster)...but here is some more findings with a current car I am working:

Cylinders #2 & #6 are the hottest.

I managed to melt off the spark plug electrodes(stock turbo heat range) to these cylinders and create a head gasket leak near cylinder #2.

*I am now replacing headgaskets and switching up to the one step colder plugs for the application, along with upgrading to a stage 3 turbine wheel.

Cars modifications:
~Full port&polish of exhaust manifolds/intake&exhaust runners to heads, combustion chambers and piston tops/ intake manifold topped with a TSS Gutted Plenum.
~270-62H cams retarded 3 degrees.
~500cc injectors.
~Nistune.
~3" SS mandrel exhaust w/o cat. and a flowmaster 40series muffler.
~Treadstone I/c with 2.25" mandrel piping.
~TSS E-fan.
~Z32 Fuel pump, Fuel Filter, AFM
~was using a Nissan T3/T4ob V-trim turbo(upgrading hot side to a stage 3)....18psi.
*and a few ther little goodies....

Dan

[Jason84NA2T]

While that device is cool, I can do the same thing with a K thermocouple connected to a good DMM. I did it for the plenum temperature testing that showed the intake spacer dropped temps over 80 degrees F.

The down side would be having to do 6 pulls to collect the data instead of one, and that small variances will pop up between pulls that similtanious logging would be nice to have, but I'm not sure it's 100% necessary.

Dan-TSS wrote: Not that it even applies to your scenario because of all the possible variables involved...(original poster)...but here is some more findings with a current car I am working:

Cylinders #2 & #6 are the hottest.

I managed to melt off the spark plug electrodes(stock turbo heat range) to these cylinders and create a head gasket leak near cylinder #2.

*I am now replacing headgaskets and switching up to the one step colder plugs for the application, along with upgrading to a stage 3 turbine wheel.

If you are melting plugs, peoiple should not expect going to a colder heat range to save them. You may want to adjust your fueling a little more into the black smoke direction :-P

Are you stepping up the turbine wheel to gain power, or because you believe it resulted in the higher charge temperatures from increased exhaust gas reversion?

[Butter]

[quote]SATAN wrote: [quote=" Unless you can do the 6 probe egt(and hell since you are made of money 6 egt gauges too!) and run say an Electromotive TEC 3 with individual injector and ingnition cylinder trimming. uuuuhhhhhhh droooooool.[/quote]
Get started.
http://cgi.ebay.com/ebaymotors/Aircraft ... 0054436156

[SATAN]

Yeah I wish I was made of money, I would end up getting the TEC3 before that though.