The oil temp, oil viscosity, max rpm thread...

[Cobra4B]

Ok... wanting to see what everyone is seeing/running.

314 rwhp carb'd 302 with 6500 rpm limiter

Castrol 20w50 organic

271 max oil temp w/ ambient air temp in the upper 80s.

Thoughts on this oil temp? It's nothing for a LSX motor. Anyone running lighter oil? For reference we were seeing 210s (cold months) 230s (hot months) with the car bone stock w/ the stock 5.0 turning 5000 - 5500 rpms.

[panozracing]

351W Dart block stroked to 427 and drysumped (4gal drysump tank and stock GTS oil cooler). We run 500 FWHP/450 RWHP up to about 6500 RPM using 15w50 Mobil 1 syn (the red label on the bottle). We run 250-265 deg. in 80-90 ait temps. We change all the oil every other weekend.

[Cobra4B]

You mean 15w50? Mobil makes a 0w40 and then 15w50 I believe.

[panozracing]

Originally Posted by Cobra4B

You mean 15w50? Mobil makes a 0w40 and then 15w50 I believe.

Ooops...edited and corrected.

[Gatorac]

Originally Posted by Cobra4B

Ok... wanting to see what everyone is seeing/running.

314 rwhp carb'd 302 with 6500 rpm limiter

Castrol 20w50 organic

271 max oil temp w/ ambient air temp in the upper 80s.

Thoughts on this oil temp? It's nothing for a LSX motor. Anyone running lighter oil? For reference we were seeing 210s (cold months) 230s (hot months) with the car bone stock w/ the stock 5.0 turning 5000 - 5500 rpms.

You are pushing your luck with that stock bottom end. The 5.0 power drops off around 5500 rpms (stock induction). Pushing the revs consitantly over 6k is asking for trouble. Especially with the oil temps that high. Look at your dyno chart. You may find you are gaining nothing running the rev's that high rather than shifting.

I shift at 5200. I want to replace the engine on my schedule. Not because of catostrophic failure.

[Cobra4B]

Not with our build.... car makes power all the way to 6500 and then some; doesn't fall off at all. Around VIR shifting at 5200 would make for some mighty slow laps.

I shift at 6000 rpms when I can, but certain parts of the track necessitate winding out the gear. Namely coming throuh nascar bend (turn 3) and coming into the uphill esses. You could shift to 5th going into the esses, but then you'd have to downshift into 4th to come through the top fast.

[NZGTRA17]

Whether sprint racing or endurance, my 302 (340rwhp/335rwtq run to 5800rpm) is running
194 F water temp and 210 F oil temp. This is with OAT of between 60 - 80 degs F so consistent with what you are seeing with your colder temp running.

I am running 15/50 Elf SM Competition Semi Syn. We actually tested a couple of oils on the dyno last time on. There was a measurable power difference between oils but the 15/50 only dropped power by around 3hp and torque by 2ftlbs.

Kel.

[Cobra4B]

Interesting... I haven't run this new setup in the colder weather yet... only super hot weather.

Last time out w/ NASA in 95+ weather I was seeing 250-255 (3.50 gears), but this past weekend i was in the 260s w/ a 271 max w/ the 3.89 gears. I'm sure if I kept it under 6k rpms it'd be cooler, but that's a no-go w/ the new gears in the car.

I'm putting 10w40 amsoil in it next and will just have to do a cooldown lap when I hit over 265.

Hopefully I don't aerate the block

On another note... I really like the PFC 97s now... They only were hard before becuase I wan't getting the car fast enough to get any temp in them. Now that the car is fast I'm getting them up to temp and they're really performing. Pedal effort is lower, bite is better, and they last forever.

[boothkc]

Seems a little toasty to me. My 450hp (flywheel) never gets above 240 oil and usually <200 water with air temps in the high 90's low 100's. We run 20-50 Redline.

So IMHO that is tooo hot for 314hp. Back the timing off, put in a racing thermostat (flow restrictor only), and re-burp the engine. Not uncommon to get a vapor pocket in the intake manifold that causes flow changes. We burp it via the watertemp sender.

Kevin

[Cobra4B]

Just to clarify the car makes 314 rwhp... so about 360 crank. The coolant stays right at 200. What rpm do you turn your motor to? If I kep the RPMs down and short shifted the car stayed around 250 oil temp. It only ran up when I was running as hard as I could. W/ the 3.89 gears there are a few sections at VIR where I'm over 6000 rpms for awhile. Nascar, coming into the esses, bottom of roller coaster, and coming out of hogs pen... all places where the motor is up high and there's no point in upshifting.

Any link to a racing t-stat? How do you burp it via the water temp sending unit? Do you pull the sensor out and run the car?

I don't think it's tuning... I think it's the dino oil and high rpms. We'll see when I run it w/ new synthetic 10w40 next event.

[boothkc]

Brian,
the GTS is rev limited to 6400 and I hit that several times inluding most of the last part of the straight at our local track.

To burp it run it warm (not too hot) and loosen the sender with a wrench util the bubbles stop and some water comes out. Some cars have a bleader valve to do as well...same procedure. Do this with the radiator cap on.

You can get a flow restrictor from Panoz or Summit etc....looks like a thermostat but doesnt close off. Cars need some flow restriction to slow the water flow in the radiator to allow proper heat exchange.

I think the timing may be too advanced for hot days as well...play with this.

Kevin

[NZGTRA17]

Originally Posted by Cobra4B

I don't think it's tuning... I think it's the dino oil and high rpms. We'll see when I run it w/ new synthetic 10w40 next event.

Brian, have you run the car with synthetic? How did it compare temp wise.

I have stripped my 6 hour engine in the process of fitting the 347 shortblock. Found that the valve guides were severely worn (i.e. - drop the valves 1" off the seat and had .060"+ movement).

We have found 3 potential contributing causes so far;

1 - All 8 exhaust valves were bent from over revs and contact with pistons. This is a result of missing 5th and getting 3rd and running engine up to approx 7800rpm. 125lb hydraulic roller cam valve springs are to light to stop exhaust valves floating and contacting pistons at this engine speed!! The bent valves then accelerate the wear in the guide.
2 - Running exhaust guide seals. We are running 98 octane (no sure what the Stateside equivalent octane would be) unleaded fuel which does not have lead etc to aid guide lubricity. Running the exhaust guide seals aggravates this as less oil gets into the guide area. Engine will be assembled this time round without exhaust guide seals.
3 - Low ZDDP (zinc/phosphorous) levels in the oil. The 15/50 oil that we were running had a low ZDDP level. We are swapping to an Elf Speedway 25/50 that has 50% more ZDDP in it.

Its no drama to replace the guides/exhaust valves this time around as I have the engine stripped down anyway. But for those of you running "modern" oils with aluminium headed engines (which are likely to have bronze alloy guides fitted) the ZDDP levels in the oil are something to consider.

Kel.

[Cobra4B]

I don't remember... it was so long ago. Might have the car out at the end of the month, but my father keeps it at his place in North Carolina now, about 4 hours from me.

[feqrags]

Running this weekend at motor sport ranch-cresson tx. water @ 190- oil @ 195 at end of session. Weather temps-73 --stock 5.0 gtra. rev-limiter set at 5800 rpm. still a beginer but having tons of fun... Bill

[Panoz26]

Brian: for what it's worth. In the LS before she popped. I was running @ 200 oil temp and never above 215 water temp with redline set at 6200RPM with Mobil 1 15W50. Outside weather temp was @ 65+.