Bonneville America Forums Forums Technical Forums Performance Mods Propper engine temperature

After a year and about 5000 miles on my bike I removed the AI and balanced the carbs to get rid of the yellowing on my headers.I am still getting the yellowing( I have long TOR's) and I know now I'm running to lean.Besides the yellowing(which I can't stand) I am also worried about my bike running to hot.So my questions are
1.what temperature should my engine be running at ?
2.can I use my lazer thermometer and were on the engine ?
3.and if to high how much damage has been done ?
Right now I am waiting on my UNI filter,main jets,and shims to come in from Brent.Any input from any one would be welcomed so feel free to dip your ore in!

Oil temp is the most important reading. Oil does upwards of 50% (or greater) of the overall cooling of an engine.

Since you aren't "blueing" your pipes, I'd think you are in pretty good shape.

What you can use your laser temp thermometer for is reading the individual ex. pipes for temerature difference, especially at idle. That'll give you and idea of whether or not you have decent carb fuel mixture balance.

Been considering a dual cylinder head temp gage to keep an eye on just this. There are times in stop-and-go that the top end just feels like it getting hot enough to do damage.

This operating temp thing is just the reason I don't care for wrapped ex. pipes. Peak temp in a combustion chamber (on gasoline) can be as high as 1400º F, when a lean mixture is run. A lower temp of about 1250º is much better, though and signals that your fuel mixture is about right.

While making heat makes power, there certainly are limits. One thing I played with on my old front engined dragster (Small Block Chevy) was coated piston tops, combustion chambers, and intake and exhaust ports. It was easy to do with a can of VHT white header paint. (I "baked" the heads in the wife's oven before installing them.) Yup, the engine ran rather cool.

My idea was to keep as much heat in the chamber as possible, to maximize the expansion/push on the piston top. Learned this trick from a Formula 40 racer (old stock 40 hp VW powered open wheeled race car) in the mid '60's.

The first thing I bought from Brent was the fill plug temp guage. Don't know how accurate or how it relates to head temp, etc., but it is great for judging overheating. In stop 'n go traffic, if the thing climbs over 200 F., I'll turn right and go the long way. Normally it sits at about 175 to 190 depending on ambient temp and hard riding. Also, don't need tool to remove.

I've just ordered one of Brent's gages. I've noticed a lack of information concerning oil temperature and what's too high. I'll try to start a thread to get some information.

I get the same results as lonzo. There was a decent thread awhile back about them with a lot of temp input from various guys. It seems 200ºF is normal, higher in the hot areas and in traffic. 250ºF is starting to get hot, p[ull over and rest or go faster.

mine has come close to 200 but not broken past that yet. now the weather is getting warmr we'll see if it changes

Frank

Mine was right at 200 all day today. Actually a little lower than normal... I'm usually around 210. Temp around 75...

Mine hit 275 last year and I had no problems.

all day today it stayed just under 200, that was mixed back roads and 80mph highway

Frank

I too am using one of Brent's oil temp guages...mine is in degress C. I find the bike generally runs below 100 C (212 F), so yeah, around roughly 200 F would seem normal. On cool days, it's well below that. On a couple of hot days, riding in the city it hit 110-120 C (230-248 F), so I expect that wold be considered hot...dangerously hot? I don't know for sure, but I don't think so. I think if it got over that, I'd be lookng to hit the highway and get some airflow, or just park for awhile and have a beer.

I'm with you on the beer. As far as temp goes, I also have Brents oil temp guage. On the trip back from Georgia, Sat. temps were hanging around the 90 deg. mark, I went from Georgia to N. Carolina and never went over 210.

Mine got as high as about 210 yesterday running all day in fairly warm weather, and some slow traffic.

Mine averages about 170-180 unless ambient temperature of 80+ F, then I go as high as 210.

I shot mine after a run once a while back and if I remember it was around 160-170 degrees in the front of the cylinders and slightly warmer in the rear. It was not a hard run. Just bopping around town on a 70 degree day.

Mine hovers around 200 in 103 degrees weather, 75 mph.

I know this is an old post/topic but i actually did a "search forum" before creating a new post!

I was just wondering about engine temperatures...sitting in 2 1/2 hour interstate delay in Tennessee yesterday my Brent Oil guage registered 250F+.

The first time I looked down and noticed it I actually heard a POP under my seat (ok...not from me but the bike) and I started searching for oil or something!! Everything was fine but suppose the air box had an issue or something??

Anyway, my beloved TBA made it another 5 hours so no issues.

I'm so proud!! A sucessful searcher

I've hit 250 a couple times too. I hear that's about as hi as you wanna go... I usually either pull over into the shade for a while, or try to get moving!

As for the pop, could have just been a random backfire?

I also hit almost 250 once when I first got the bike. Before I did the Freak and was still running TORs I regularly ran between 200 and 210 a little higher in traffic.(using Brents gauge) Now with the Freak and gutted stock pipes I run around 180 to 200. I was suprised at the temp too when I first got the bike. My old chopper ran 180 at it's hottest.

so...whats more important to know...oil temp or oil pressure?
I figure if I check my oil level before I ride I shoud be concerned with temp.
If the pressure is low it means Im either losing oil or there is an internal problem pumping oil in which case the motor is probably done anyway.
Please correct me if I am wrong.

Sounds like you're trying to determine which gage to buy...

IMO, both factors are equally important. If you lose the pressure, you'll certainly overheat - Big time. If you over heat to a dangerous level, you won't need to know your pressure. If my guess on the reason for your query is correct - go temp. You already have a perfectly functional idiot light for pressure, so you're sort of covered on that end. Although I'm sure there are at least 50 more opinions for this question with only two possible answers. Oh, I use no gages. Good luck in your quest...

i hit 250 in traffic, i pull over and let it cool, while moveing i never get over 200

Frank

Down here in South Florida, I regularly hit 225 and approach 240 sometimes. I also have the pressure gauge and never see a lack of pressure or power at those indicated temps. Although oil does splash onto the sensor in the middle of the temp gauge, I am starting to believe I am seeing more of a case temp than an oil temp.

In NYC, I hit 225 every day...the only thing I notice is shifting up or down between 1st & 2nd gets clunkier the hotter the bike gets...don't know if it's a coincidence or if it has anything to do with the oil getting thinner at those temps. Think I'm gonna switch to a higher viscosity on the thruxton seeing as it's my primary city bike.

Quote:

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Although oil does splash onto the sensor in the middle of the temp gauge, I am starting to believe I am seeing more of a case temp than an oil temp.

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I think I would disagree with that point Phil. Since the actual temp gauge (probe) is a thermometer positioned in the center of the gauge, in the center of a large rubber seal, it is not in contact with any metal, hence I believe the temp gauge (that Brent sells - the good one ) is showing the actual oil temp since only splashing oil is ever touching the probe itself.
Make sense?

complete sense but I also wonder how much oil is actually slinging onto the sensor. The gear we see is to the right of center.... I guess the only way to really tell is run it with nothing in the hole! Another question is, how much isolation is there from the O-ring? I know that grabbing the gauge when the engine is hot will certainly provoke some choice words!

Anyhoo, I do watch them both and I have pulled over and shut her down when temps approach 250

Phil, what did you do about your oil loss problem?

Bringing it back next week. Riding it in the meantime!

If you pull the gauge off, there is a gear right there pretty much dead center in that hole. I bet it gets a pretty good bath.

I've had the Brent gage for only a few hundred miles. Top temp was 210 to 220 at 90 ambient riding around GA on Rotella synth. We didn't hit any traffic jams though. Minimum temp on long cool morning downhills was around 180 I believe.

Not to completely start an oil thread here, but would a higher viscosity oil drop temps you think? Like Mark, mine clunks a little more when it gets hotter...

I don't know about temps vs. viscosity at operating speeds, but I might run the Mobil / Triumph oil or similar in hot climates, if only to get the 50w piece. I'm currently running the Rotella synth at 40W, and so far, the operating temps seem reasonable with the Spring weather.

I had some real concerns with owning an air cooled British bike used in Queensland Australia. The climate is heaps different (chillsville vs sweatsville).
All the dealers believe running the "good oil" is enough (fully synthetic) so I use the best I can find!
This is the first bike I've owned that has such far forward controls / footpegs, and i worry about how much heat comes off these motors. The heat felt on my legs in summer is really very noticeable and disconcerning! Ambient summer days here range between 36 to 40'C (97 to 104'F).
I've toyed with a small air dam or scoop on the lower fittings on the oil cooler / radiator to grab more air when in motion.... but in heavy traffic...?

However, I have two mates, one with a TBA the other a TSM, and both are absolute RAT bikes. That is, they have never been washed since new, covered in scratches and dents, mods made with little care or attention etc. and basically get ABUSED day in day out. These bikes get FLOGGED all year round, and still perform like champions. Never a hick-up.
It is a true testament to Triumph that these new breed machines are built tough.
Perhaps I don't need to worry about the heat?

Michael888 out west in Arizona,USA it gets Frekkin@#$%^ hot!I wondered if it was hotter down under? I've seen 126F a few years back.I've been in over 120F with the my 05 Speedmaster.I use sinthitic oil and yes the heat is scary hot.Thought of getting a gauge and may one day ,but with the gauge I'll probalby worry about it being to hot.For now I try not to set idle in one spot to long.Really haven't had any problems from it heating up.Now for me you got to watch yourself and drink plenty of water on long trips in the summer around here.I pack a camelpack on long trips.Run a hose up to the front of the bike from the back seat where I strap it on and I can easily get a drink without stopping.And yes I do wear a full face helmet.With the face sheild open and no windshield it feels like you have your face in a blast furnace in the summer around here.So I don't see how these people go with no helmet in this area.