Lorenfb

"My pinging are most noticable during uphills, low RPM, and open throttle."

Pinging is a function of engine load which is what you've accurately described
in your statement. Check out this web site (www.systemsc.com) on the Graphs
page for some additional info about pinging.

Rocket Rob

Doug,

About 8 years ago, my car began to ping really bad. It began suddenly. I was at an auto-cross and borrowed some 100 octane gas. It didn't help. We then did some quick troubleshooting and discovered that my distributor's belt had broken. Before spending a lot of $$$ on high-octane gas, I suggest checking that both distributor heads are spinning.

scotsman60

OK,

I mixed 5 gallons of 100 octane ($4.50/gallon) with 13 gallons of 91 when I filled up last night.

The pinging is almost completely gone and the motor appears to run cooler!!!

I'm feeling better, but not completely satisfied for two reasons:-

1) I got stuck in stop and go traffic going through Laguna Beach and the motor temp went up. The needle went to just above horizontal - about two thirds of the way between the first and second tick. At this temp the engine pinged under acceleration from low revs. I can live with this fairly easily because it's easy to avoid - keep my foot off the gas (OK - not so easy....)

2) 100 octane gas is not that easy to find and it's expensive.

I'm going to research octane boosters - this may be more economical and easier to live with than trying to find 100 octane all the time.

Does anyoine have suggestions for keeping the temps down in stop and go traffic? I have the under-tray removed already. Can I use a different thermostat (or adjust the existing one) so that the oil cooler kicks in earlier? Will this have a significant effect on the cylinder head temps?





Doug

Randall G.

Hey Doug,

Where did you wind up getting the 100 octane? It would be nice to know if there's 100 available closer than Newport Beach.

With respect to your oil cooling....did your temperature get to just above horizontal, then come down. Then go back up again, go back down, etc.? If so, that indicates normal and proper cycling of your oil cooler fan.

If the temperature reached or exceeded the first tic mark above horizontal (~248F), that's too high.



Easiest way to cause your oil to run cooler is to disconnect the temperature sensor on the oil cooler. Assuming the relay & CCU are working properly, this causes the oil cooler fan to run in fast-speed whenever the ignition is turned on. Once the thermostat opens (about 194F), you get maximum (and very effective!) cooling. You can also install a switch on the affected line = G-12.

Much of this information can be found here:

http://members.rennlist.com/rgranaas...0Rev_0_Web.htm

scotsman60

Randall,


I got the 100 octane at the 76 you identified - on San Miguel. I haven't looked at the one on La Paz because the 76 web site says it doesn't do race fuel. I plan on calling 76 and asking where the closest 100 octane source is - you can't search for it on their web site.

I just finished reading the articles on your web site about oil cooling - in fact i did this just before your last post!!!. A few months ago I checked the operation of my oil cooling fan and it appeared to be working correctly in both low and high speed modes however I didn't measure the temps or really monitor the guages that closely - the slow speed came on first and then the high speed came on later.

The behavior I get in traffic is that the temps go up to close to the 248 mark but they don't come down while I'm in traffic. If I get back onto the open road then the temps come back down. According to the reports on your site the fan should bring the temps back down, even when I'm stuck in traffic right so I seem to have a problem here. Perhaps the cooler is dirty or partially blocked? Perhaps the fan isn't blowing as much air as it should?

Whatever other issues I have, the cooler and fans should be able to maintain 212 temperature in stop and go traffic right?

I'm interested in finding a way of stopping the temp get much above 210 or so because this is when I get pinging.

I think I'll inspect the cooler and fan this weekend - maybe even remove and clean them (inside and out). I'll probably check the thermosender temp/resistance as well - can I just measure the resisitance across the (removed) thermosender terminals with the probe dipped in hot liquid?

If I wanted the fan to kick in at a lower temp I'm thinking that I could put a resistor in parallel with the thermosender.




Doug

scotsman60

Randall,



One other factor that might have a part to play - My car idles lower than it should - around 700rpm. This will affect the amount of air that's getting pumped over the motor at idle - which is where the motor spends most of its time in stop and go traffic.

I can't figure out why it idles low. As far as I know there's no adjustment.




Doug

Randall G.

Hey Doug,

Yup, you used to be able to search on 76's site for stations with race gas. That's how I found the one in Newport Beach. Unfortunately, it looks like 76 has removed the search function on their website.

If you can get the oil cooler fan to run in fast-speed continuously (ignition on), by disconnecting the sender, you should be very happy with the results. This also demonstrates that the fast-speed contact on the relay is good. I would try this first, before doing anything else.

The low idle shouldn't affect oil temperature too much, as you're really relying on the fan to cool the oil passing through the oil cooler. Fan operation/speed, of course, being independent of idle speed.

Aren't you in South Orange County? Aliso Viejo? If so, I wouldn't mind dropping by and checking out your oil cooler & components this weekend. Or, you can bring the car by Dana Point. I can tell you pretty quickly if every thing is in order.

scotsman60

Randall,


I'm in Aliso Viejo - not far from you. I may take you up on the offer to check out my cooling system.....

Well, I went out for lunch and decided to watch carefully how the oil temp behaved. I warmed the motor up - temp stabilized at the 194 tick mark and then parked with the engine idling. Temperature went up, and up - I was outside checking for the cooling fan coming on but it never did!!!! Temperature reached the second tick and still no cooling fan so I quit the test and drove back to work - temperature came down gradually.

I checked the cooling fan out a couple/few months ago and it was working fine. Now there's clearly something wrong so I'll investigate. First off I'll disconnect the sensor and see if I get full speed on the fan or not.....

This will have to wait until tomorrow night 'cause I have traffic school tonight (and next week too) - got a bit exuberant on I5 a few weeks ago.....




Doug

tonytaylor

That's interesting; No matter what I do I never get the oil temp gauge above the "194f", 8 o'clock level. I must have a fault with the temp sensor.

Randall G.

Hmmmm. That, or you never get stuck in traffic. If you're on the freeway, the air flowing across the cooler keeps things nice & cool. Though, I thought you tracked your car....

tonytaylor

Car is used to commute on occasion and is tracked. I will try idiling after a run this w/e.

PC2

Guys,

You may find this web site very helpful in locating racing fuels in southern California. I'm lucky to have one 5 minutes away from my office.

http://www.schube.com/racegas.html

Randall G.

Thanks Pete! I've already bookmarked the page. Besides the Newport Beach station, I see the La Paz station Schubee mentioned earlier. Great, as that's much closer to home.

Oh....Schubee and http://www.schube.com/. Coincidence?

schubee

Randall,

Negative on the site, I'll need to check that one out. Schubee is a nickname I acquired from elementary all the way through college. It's short for my last name, Schubert.

Hey, I'll have to let you guys know when I start my assembly on my engine. It's ready to be put back together besides some powder coating. I'll be assembling the long block in the next few days. I use to live in RSM but just moved to Irvine off of Sand Canyon right off the 405. I wasn't aware of all the 964's here in Orange County. We need to hook up!

One of the delays of assembly is caused by all the recent hype of proper torque methods for rod bolts. I'm debating on using the torque method versus the use of a stretch gauge.

Cya...

Randall G.

>Negative on the site, I'll need to check that one out. Schubee is a nickname I acquired from elementary all the way through college. It's short for my last name, Schubert.

Well dang, I'm extra cornfused. A John Schubert moderates the site's forums:

http://schube.com/openbb/member.php?...=profile&UID=1

If that ain't you, well.....that is quite a coincidence!

Yup, us Orange County 964 owners need to get together. At a minimum, when Arjan (964 owner from the Netherlands) is visiting again in June.

As a UCI alumni, know the Sand Canyon/405 area well.

Please keep us posted on the engine assembly. That outta' be interesting.