Question for Scotty/Midas - Head Temps?

I didnt see any significant temp drop when i removed the cat, just a small amount but there was a marked difference when i fitted the XIED's.
You must remember for an accurate reading of any of this, it would have to be done with the same air temp on the same day and having covered the same distance from cold to be completely accurate. And that is virtually impossible to do over here, our air temps fluctuate that much from day to day.
But in answer to your question, yes the XIED's made a difference to head temps as far as my testing went and the bike runs noticeably better with them fitted.

Funny really i just read a post by Whittlewhatsit on the other forum and he aint even got his own bike running smoothly after all the ins and outs on the XIED thread. Here is a link, scroll down..

http://xlforum.net/vbportal/forums/showthread.php?p=1702870#post1702870

Quote
"Now I am going to start playing with the AFR mostly to get rid of the engine hunting at any time the motor is in the 2500-3500 RPM range. ."End Quote

This EFI stuff is way beyond all the time and efort i have seen some folks go to to try and get it right.
All i want for now is to richen the mixture up a bit on the XR until i can decide which way to go with a tuning unit.
There is a guy who shall remain nameless until he has given me the info i am waiting for, and the permission to say who he is, who has a buddy who is extremely clued up with this stuff, and is in the process of sorting this XR EFI stuff out, it is not something i am very settled with as yet, as this is the first EFI HD i've owned.
I have done a lot of reading on different forums on the EFI on HD's and no one seems to agree with anyone else, so until its all sorted out I'm pleading the fifth as you say.
There is even a possibility that at sometime in the future i might just stick a carb on the XR if i can find a set of performance heads that will give me what i want, and in doing so i will be getting rid of the oil cooler.

Dallara, i forgot to mention this.
The other point to what you have asked is this, whilst taking the cat out of the equation might cool the motor down a bit it can also cause the bike to run slightly differently so the only thing at that time i was interested in was that it didnt run any hotter than it did with the cat.
When i fitted the XIED's i was looking for a temp drop and i got one of around 50 degrees.

maybe not Windows Vista

I'm kinda in the boat with Scotty on this. This subject, as we saw on XLForum, can become black magic.

Bill Gates became the richest man in the world with the "good enough" philosophy regarding his product. My EFI seems to work "good enough", just like Windows. I'm doing xied's next week (floridacars did his yesterday) and we'll see how that goes.

In the meantime if one of the mad scientists like Dallara or LoftyBob come up with a high performance solution then I'll be all over it!

First impression

Installed XIEDs yesterday, but haven't ridden but 50 miles today. Seems to run better, less stumble at low end, less lean surge, Air temp is about 15 degrees less than Friday, and it is quite humid today about 95 to 98 percent. I do believe there is a difference. Will try to run the same route I ran Friday and check mileage.

I don't know if the XIED's improve power at all but I have noticed that the stumble off idle when the throttle is cracked open is gone and, maybe my imagination, but the engine seems to run more smoothly and rev more quickly.

I didn't really ride it along time with just the XIED's as my Remus exhaust was becoming quite insistent that it be installed.

Has anybody shot the heads with an IR temp gun to see what readings they get?

cbass said:

Has anybody shot the heads with an IR temp gun to see what readings they get?

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I'll try to get a thermal image posted up by the end of the week.

But, what we measure won't necessarily be the same as what the ECM sees, since the temp sensor is in the top of the rear head (unlike the TC that measures in the side of the back of the front head).

Right, I am not concerned what the sensor measures. I am more concerned what an IR temp gun measures around the spark plug. What an IR gun measures will differ from what the sensor records. I have a carbed 1200 sportster and I was curious on how the head temps compare on the XR1200. Since it's carbed it doesn't have a sensor like the EFI models so I can't do a direct comparison that way. If anybody is in the chicagoland area they are free to use my IR temp gun for measurements (if anybody is even willing to do it) or go on a ride and use it to gather head temps.

Warm up, approx 1-2 minute F=135, R=132

After idling for 10 minutes F=205, R=202

20 minute easy ride F=258, R=250

This was noted for a different reason, checking the head temp sensor, so i didn't do tons of testing or after a hard ride. Shot the IR at the head right next to the spark plug. This is with a Top Fueler installed

I think those temps are interseting but I feel the oil temp is more improtant. Using the oil temp in the oil tank on by bike at 98 degrees in traffic mine never goes over 210-215 degrees in traffic. The cylinder heads and cylinders get hotter but it is their job to move the heat away through inside of the engine via radiation. The hot oil from the cylinder heads dump into the oil tank first. The oil tank is the first place to dump heat and the oil cooler second after 190 degrees open the thermostat. Regular oil looses its ability to be stable over 250 degrees. Synthetic is good to 350-400 degrees. All this indicates is that if you are going to cook french fries synthetic is recommended. LOL Later,

Fat Billy said:

I think those temps are interseting but I feel the oil temp is more improtant. Using the oil temp in the oil tank on by bike at 98 degrees in traffic mine never goes over 210-215 degrees in traffic. The cylinder heads and cylinders get hotter but it is their job to move the heat away through inside of the engine via radiation. The hot oil from the cylinder heads dump into the oil tank first. The oil tank is the first place to dump heat and the oil cooler second after 190 degrees open the thermostat. Regular oil looses its ability to be stable over 250 degrees. Synthetic is good to 350-400 degrees. All this indicates is that if you are going to cook french fries synthetic is recommended. LOL Later,

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To me both temps are important. The oil temp to see what is going on with respect to heat and danger of breakdown, but the head temp to watch the danger of head warpage and gasket failure (CVO 110'ish). My oil for instance runs in the 210 to 220 range, or what I would consider to be normal. Having the front head temp run 30 deg hotter than the rear, and hit 320 on a relatively mild day gives me something to watch for diagnostics.

After 1 min (warmup) - Front, 137 deg F / Rear 120 deg F
After 5 min (slow warmup ride) - 258 / 224
After 15 min (70 mph hwy) - 310 / 283
After 25 min (70 mph hwy) - 320 / 300, and
After 30 min (stop and go) - 320 / 295

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Thanks for the data. It may bore others, but feel free to post more if you like. 1 hour ride in city traffic, etc. That's in line with what a stage 1 XL1200 runs.

It makes me wonder though, since I never expected the rear cyl to be running cooler than the front...

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I have had an engine builder tell me that it's a misconception that the rear cylinder runs hotter. He claimed that the rear cylinder can run cooler than the front and I have seen the same thing.

I think those temps are interseting but I feel the oil temp is more improtant. Using the oil temp in the oil tank on by bike at 98 degrees in traffic mine never goes over 210-215 degrees in traffic. The cylinder heads and cylinders get hotter but it is their job to move the heat away through inside of the engine via radiation.

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Both are actually important. I have grabbed some temp readings from big twins I have ridden with and what I have noticed is on the big twins the oil temps run hotter than on my bike, but their head temps run cooler.

Phaedrus, Richen the mixture to the front cylinder to cool it a bit. Head temps on the XR may not be as critical due to the oil cooling on the exaust side. Yes, no, maybe? Later,

I have had an engine builder tell me that it's a misconception that the rear cylinder runs hotter. He claimed that the rear cylinder can run cooler than the front and I have seen the same thing.

You know that is really interesting, the data says that is the case but everything I have read and the simple thought of it would make you think otherwise. Ok all smart uns school this jar head as to why it is so.

Fat Billy said:

Phaedrus, Richen the mixture to the front cylinder to cool it a bit. Head temps on the XR may not be as critical due to the oil cooling on the exaust side. Yes, no, maybe? Later,

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I'm going to play more with AFR but for now it's balanced at about 13.4 at idle, 13.8 - 14.1 at cruise, and 12.8 under heavy throttle. The plugs are showing a perfect burn.

Going plus or minus 10 degrees timing didn't do anything significant to heat

I'm going to see how much fuel I need to add to cool the front down a bit, but it runs well, isn't really excessively hot, and I'd hate to just dump in fuel at the expense of the tune.

Maybe I'll stack a second oil cooler....

It is interesting that the front cyl on this bike runs hotter when you consider that on the new FLH's, Harley has a mode that will shut down, are you ready for it, the REAR cylinder when the bike gets too hot idling. Also known as the Parade Mode.