Well, got the gauges installed today. Oil Pressure, Boost/Vacuum, and EGT

The boost/vacuum went inline with the heater assist line (the vacuum helps move the vents when you change from defrost to legs only, etc.) I used 1/4* nylon tubing from Home Depot (tough stuff, rated to 150 psi and 90 degrees celcius). It works well for vacuum and should work well for boost.

EGT was an easy install, although the sender took a bit of time to drill the hole. I put it on the #3 cylinder, about 1.5* from the head. I also drilled a hole in the HOT plate so the sender could portrude (and so I could keep the heat shield). The fitting self-tapped, so that was a savings. 1/2* taps are expensive $25+

Oil pressure was a *****. Well, the gauge was okay, but the hex plug on the end of the head took forever. I progressively drilled it, and the 5/16* bit finally got it out. This next part is VERY important: I then stuck in a magnetized screwdriver several times to get the metal shavings out. And there were plenty in there. After about four trips in with no shavings, I was fairly confident that I had them out. However, I also cranked the engine twice with the plug open and caught the oil *spit out*. There were no shavings in there, so I installed the sender. 1/8*-28 (1/8 BSP) was the thread tap. I used thread sealer/locker (rated for 350 degrees).

To run the wires, I removed the driver's side quarter panel and went through the main grommet. The inside looks like crap, but I plan on redoing the A-pillar gauges sometime next month. I'll have pics Monday for Random to put on the server.

Results:

Oil pressure starts at 80 psi and then goes down to around 40 psi once warmed up at cruise. Under heavy throttle it peaks back up to 80, and after a long time running, it can drop to 15 or 20 psi at idle.

EGT seems to settle in at 950 degrees at idle, before loading. Then at cruise, it stays at either 1150 or 1250, depending on loading. A testement that our cars run rich at WOT, I got the gasses really hot and then floored it (basically went from 80% throttle, to 100% throttle) and the temps actually went down! Too much fuel there is cooling the burn.

Vacuum is really cool to watch. -18 mmHg at idle, stays around -10 mmHg at cruise, goes to 0 at WOT, and at closed throttle (coast or downshift to slow down), it can get to -25 mmHg. I can't wait to see it registering boost. smile.gif

well, that's it. I was just wondering if these results were normal. As mentioned earlier, I will have pics on monday.

later,
ac

 

Sounds dead-on with what you should be seeing. The only thing that didn't look 100% is your oil pressure across the board (from my memory anyway) seems just a tad low... I remember hearing reports of 90-100psi at high RPM's and idle pressures around 25-30. What weight oil do you use in this puppy?

Otherwise, it's all good And I see you installed the EGT the correct way; good man

 

Red, you're right his oil pressure looks a bit low at cruise rpm's ,my little 1.5 usually push around 55 psi on the highway with a hot engine and 10w30 oil (but my engine might be revving a bit higher)
hot idle oil pressure in my car is around 15 psi
his cold presssure is similar to mine to

Denis

 

I'm using 10W-30 synthetic blend. I'll check for low oil level, but those results were consistent yesterday. 80 at startup, 40 at cruise, and 10 to 20 at hot idle.

I may also need to *spec* the sending unit. I will need to buy a mechanical pressure gauge to set my fuel pressures under boost, so I'll put that on the oil tap and see if the meter is calibrated.

thanks for the input guys,
ac

 

If you're using 10w30 synthetic, it's probably just fine. The synthetic stuff (especially 30 weight) reads a bit lower than the standard dino-oil while still providing the same protection.

Your numbers aren't THAT far off, which is why I asked what weight. Usually numbers that are just shy or just a tad too high are weight-related.

No worries smile.gif