Engine temp vs boost

[mhagie]

Took the truck out today for the first time since last November.
since I bought the vw the truck just sits.
Any way I noticed on the way home the water temp would go up and down in relation to boost& egt.
65mph on cruise level ground egt 500 boost 2 psi water temp 192*
start up a hill and boost rises to 3 psi, egt to between 600 and 700*, water temp to 200* all this with a empty truck.
I am afraid to guess what would happen if I had a trailer in tow, where would the water temp peak?
The temp is taken by a mechanical gauge with sensor located in the t/stat housing with a tee into the heater hose outlet so I am sensing temp as it leaves engine for radiator.
Why is water temp so darn sensitive especially with a empty truck.
When it was a gasser temps didn't fluctuate squat uphill or down.
Any ideas?
Merle

[john8662]

I've never measured temperature with a gauge in the location you've got your probe installed. Do you have a sender located in the stock location that is right below the A/C compressor on the Drivers side head near the front of the engine? If so, what type of a temperature range do you see on it while measuring at the crossover?

I'd also like to find out what thermostat you're running, the standard style stats seem to vary tremendously. Also, what radiator are you running, the stock 6.2 radiator, or something custom to fit your unique truck?

[jcomp]

What is the condition of your fan clutch?

[mhagie]

The radiator is a new modine replacement for a 1980 4 row 454 it has only 3 rows but they claim that it is more efficient than the factory 4 row.
I put 6.2 tanks on it so the cooler lines matched up.
T/stat is a single r/shaw 195 using stock 1984 housing.
It also has the 90 gpm pennisular water pump.
I have read somewhere that the high flow water pump can cause issues if not used with a 97 up dual t/stat setup, but lack the knowledge to say for sure.
The factory sender in left head moves basicly the same as mechanical but not as responsive.
am considering going to a remote oil cooler but unsure if it will make much diference.
Fan is a 7 blade from the old 350, fan clutch is a a new unit from Hayden.
Merle

[ 08-26-2005, 06:31 PM: Message edited by: mhagie ]

[john8662]

I think the thermostat is doing it's job, it's just a 195, so thats why you see the range from 192 - 200*F. Thats why I run the 370 series 180* stat.

Which R/S stat do you have? The one that looks like this:

http://www.cooperstandard.com/us/en/images/Fluid/Aftermarket/thermostat2.gif


(taken from the Cooper Standard website, who bought out RS)

Thats the only one to use in one of these engines IMHO.

so, is 200 the hottest that it's gotten coming out of the crossover?

[mhagie]

John, My stat is the same 370-195 I have a 180 on the shelf but haven't used it cause most postings I've read sugested the 195.
Personaly I never ran a 195 in any of my old gassers I was always inclined to go with the 180
so it would make more power,but by postings on the DP I believed that 195 was right for a diesel.
Truck has never been above 200 as yet, but its running empty.
What bothers me the most is the oil presure, at temp running down the road @65 mph 1950 rpm I only carry 28-32 Lbs oil presure, 12-14 @ idle.
That just bugs the crap out of me as I am used to 40+ with my old 383 stroker.
Engine is a Diesel Depot Reman which should have the oiler pump which is high volume but obviously not pressure.
Thinking about putting some washers behind the oil pump spring and boost that sucker up about 10 Lbs, might not do a thing for the engine but it will do wonders for me.
Merle

[doncannon]

hi mhagie,
did you try another gauge? i know sometimes the gauge will go bad or even a sender for the gauge. hope this helps,
don

[Peter J. Bierman]

Hot oilpressure is withing factory spec's 10psi hot @ idle.

Peter

[84 C2B2]

I seem to recall an old tale that it was decent to run 10 psi for every 1000 rpm's. Try a remote gage that is calibrated. Sure beats pulling a pan for a washer insert. If you do go the route of "boost the pump", try a different spring (different color spring for different oil pressure) instead. I've known folks that used washers to only find out the relief valve was restricted and shortened the life of the pump and oil.

Jerry

[mhagie]

I think I will go the spring route with one from Summit.
I know the what I have is acceptabe, only not to me, I have a brand new auto meter gauge which is the 100# gauge and it just bugs the crap out of me to see such low pressure.
I haven't seen such pressures since I had the old 216 I6 w/babbit bearings, Of course that was when I wore a younger mans clothes.
Already have the oiler pump just need to give it a little boost.
Merle

[john8662]

Never messed with changing out the springs or adding washers. But, I have a friend that had a 305 gasser that installed a high pressure oil pump. Before installing the oil pump he read the instructions included with the pump describing the various included different colored springs. He decided to install the higher presure spring included with the pump, and wound up with some REALLY high oil pressure readings. The thing would run 60psi on a mechanical gauge at hot idle and go up to 80psi. The unfortunate side of the story is that this thing used 1qt of oil after doing this every 100 miles :eek:

First off, you'll want to try another mechanical gauge, I've heard some bad things about the autometer gauges. I'm purchasing a digital gauge and sender for my testing now, because I think these are a little more calibrated and more accurate.

Dakota Digital www.dakotadigital.com (http://www.dakotadigital.com) has some nice gauges and senders, but be sitting down when looking at the prices.

Another thing, you might not have the HV oil pump installed in your engine, if you do, that pump is more than sufficient to provide ample enough volume to generate good pressure in the engine.

Also, where are you connected for your gauge on the block?

[doncannon]

Hello All,
mhagie: I have heard the same as 84 C2B2. 10lbs/1000rpm and if you do run more volume or pressure it does take horsepower to run these. I read a gasser article by David Vizard that he just uses a stock pump that has been internally cleaned. After all the way to have more hp is to not give any up?
Don