TomSS Posted January 19, 2009 Share Posted January 19, 2009 I'm a newbie (sort of), but would someone tell me the difference between an oilhead and a hexhead? I'm and RT driver and I know it's oil cooled. But I think there is another subtle distinction. Thanks TomSS Link to comment
T__ Posted January 19, 2009 Share Posted January 19, 2009 Tom, we just addressed that question a short while ago.. There are many small differences & a few more major differences.. It will probably take a full multi person thread here to come up with ALL the differences.. To start the thing rolling here I will state both the hex head & oil head are the same design engine,, that is a boxer engine design,, opposed twin,, internal combustion engine.. The oil head basically got it's name from the oil cooling of the cylinder heads & valve area.. The hex head is still basically an oil cooled design but the cyl heads & valve covers now have a hexagonal shape (that is why they are called a hex head).. Probably the biggest mechanical difference between the hex head & the older oil head is that the hex head has a single balance shaft added where the oil head didn't.. The hex head has slightly longer stroke as the displacement is now 1200cc (actually 1170cc).. The older oil head came in many versions from 850cc to 1150cc & even came in a 1200 version on the 1200C.. The 1200 (hex head) has a better electronic fuel control system,, higher compression,, knock sensors,, automatic cold fuel enrichment,, idle control stepper motors,, balance shaft,, 2 spark plugs per cylinder (but so did the late oil heads),, twin 02 sensors,, more.. I will let someone else list the models that fall under oil head vs hex head & add more engine differences between the hex head & oil head.. If everybody adds a little more you will soon have a good idea of the differences between the hex & oil head.. Link to comment
Rich06FJR1300 Posted January 19, 2009 Share Posted January 19, 2009 actually, aren't they pretty similar? I know one is 50 cc's bigger LOL. Biggest difference i can think of is that the throttle bodies are computer controlled (on the oilheads you have to synch them more often as they are mechanically adjusted). I'm sure there are other differences like the oil cooling is enhanced on the hexheads, there is a bigger alternator or it puts out higher wattage than the oilhead alternator. Similarities are that they both have 4 valve heads, both have dual sparkplugs in the heads. On the hexheads you have a detonation sensor that retards the timing of the engine. The oilheads don't have one. Last but not least, horsepower...the hexheads have about 10-15% more HP than the oilheads Link to comment
TomSS Posted January 19, 2009 Author Share Posted January 19, 2009 Thank you, Twisty1 I called it an oilhead the other day, but something was nagging me, that wasn't right. I followed your thread. I notice your part of the tech mod squad. Engine or touring gear? TomSS Link to comment
hopz Posted January 19, 2009 Share Posted January 19, 2009 Before Oil Heads was Air Heads... air cooled. After Oil Heads is Hex Heads... still oil cooled but with updated stuff. Link to comment
tallman Posted January 19, 2009 Share Posted January 19, 2009 Before Oil Heads was Air Heads... air cooled. After Oil Heads is Hex Heads... still oil cooled but with updated stuff. And to further obfuscate, some Air Heads were oil cooled (as in had an oil cooler, of course the obvious oil in engine). My 1980 R100 RT had an oil cooler 13 years before the Oil Heads were introduced. There are difs betweeon OIl/Hex heads vis a vis the paralever design, use of LED's, cruise control (although the R1200CL Oilhhead had cruise), CANBUS, type of ABS systems, design of wheels (some early oilheads had issues), final drive drain plugs Oil , early Hex recent Hex , tag I'm out, who's next... Link to comment
Boone60 Posted January 19, 2009 Share Posted January 19, 2009 1100s had a five speed transmission, and the hexs are running with a six speed. The wieght of the hex is less than the oilhead. Link to comment
smiller Posted January 19, 2009 Share Posted January 19, 2009 1100s had a five speed transmission, and the hexs are running with a six speed. That's not really a 'hexhead' difference as the 1150's also had a six-speed. Link to comment
Boone60 Posted January 19, 2009 Share Posted January 19, 2009 1100s had a five speed transmission, and the hexs are running with a six speed. That's not really a 'hexhead' difference as the 1150's also had a six-speed. True, and why I wrote 1100 instead of oilhead. Link to comment
T__ Posted January 19, 2009 Share Posted January 19, 2009 1100s had a five speed transmission, and the hexs are running with a six speed. That's not really a 'hexhead' difference as the 1150's also had a six-speed. True, and why I wrote 1100 instead of oilhead. That isn’t totally correct either as the 1100S did have a 6 speed trans? Twisty Link to comment
smiller Posted January 19, 2009 Share Posted January 19, 2009 Well maybe he meant that the hexhead had the first usable six-speed, in which case he'd be correct... Link to comment
ERdok Posted January 19, 2009 Share Posted January 19, 2009 Before Oil Heads was Air Heads... air cooled. After Oil Heads is Hex Heads... still oil cooled but with updated stuff. Wow. Finally an explanation even I can understand. Link to comment
Penforhire Posted January 19, 2009 Share Posted January 19, 2009 Rich, you're neglecting vibration. The newer hexes also have noticeably less objectionable vibration (counter-balancer IIRC). Link to comment
Boone60 Posted January 19, 2009 Share Posted January 19, 2009 Well maybe he meant that the hexhead had the first usable six-speed, in which case he'd be correct... I got tripped up with the op's RT jockey statement. That R1100S is a great looking bike. Check the video on the bottom of the link, it's just what this snowbound rider needed this morning Link to comment
tallman Posted January 19, 2009 Share Posted January 19, 2009 Before Oil Heads was Air Heads... air cooled. After Oil Heads is Hex Heads... still oil cooled but with updated stuff. Wow. Finally an explanation even I can understand. Yes, but, as I said, not all Air heads were bereft of oil coolers. Now some Airheads ride oil heads and hexheads, but that's a different story. Link to comment
russell_bynum Posted January 19, 2009 Share Posted January 19, 2009 Well maybe he meant that the hexhead had the first usable six-speed, in which case he'd be correct... LOL! Link to comment
cali_beemer Posted January 19, 2009 Share Posted January 19, 2009 I am suprised no one has mentoned the biggest difference and that is the hex head is counterbalanced. The throttle bodies are now computer controlled so you dont need to contantly synch them. The idle is now computer controlled as well so you dont need to use the fast idle feature at start up. Link to comment
T__ Posted January 19, 2009 Share Posted January 19, 2009 I’m surprised you didn’t read the first answer in this thread.. “Probably the biggest mechanical difference between the hex head & the older oil head is that the hex head has a single balance shaft added where the oil head didn't..” “The 1200 (hex head) has a better electronic fuel control system,, higher compression,, knock sensors,, automatic cold fuel enrichment,, idle control stepper motors,, balance shaft,, 2 spark plugs per cylinder (but so did the late oil heads),, twin 02 sensors,, more..” Twisty Link to comment
tallman Posted January 19, 2009 Share Posted January 19, 2009 Actually, the biggest difference, is the price. Link to comment
cali_beemer Posted January 19, 2009 Share Posted January 19, 2009 I’m surprised you didn’t read the first answer in this thread.. “Probably the biggest mechanical difference between the hex head & the older oil head is that the hex head has a single balance shaft added where the oil head didn't..” “The 1200 (hex head) has a better electronic fuel control system,, higher compression,, knock sensors,, automatic cold fuel enrichment,, idle control stepper motors,, balance shaft,, 2 spark plugs per cylinder (but so did the late oil heads),, twin 02 sensors,, more..” Twisty You caught me. Now where the heck are my reading glasses. I think I need a thicker prescription. Link to comment
smiller Posted January 19, 2009 Share Posted January 19, 2009 Actually, the biggest difference, is the price. Yep, in terms of a larger view that's probably the best answer... Link to comment
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