Which XS/XJ is the fastest?

[FSCGunslinger]

So, from reading some of the comments on people's various bikes, it seems like the older 1100's are faster than their newer kin. Is this correct? Is, for instance, a '78 XS11 faster than an '81 XS11 or '82 XJ11? Is there a definite "you want a [year] XS/XJ if you want speed" bike?

Not that I'm looking for another bike already (to customize similar to Da-Bubble's bad-a$$ street demon)... I swear...

You guys believe me, don't you?

[DiverRay]

The '78 was the fastest in the 1/4 mile. I believe they produced the most HP, with the '80 on up losing out to the "smog" rules. The difference is SMALL, as all of the XS1100s ARE fast.
I have a '78 that I will make into my "hot rod", but I did put some of the '78 parts onto the '79 to make it a little faster. The biggest/only mechanical change between the two years was the mechanical advance unit. The '78 has 5 degrees more advance than the rest of the XS11s.

[HobbyMan]

is this 5deg ignition timing? If thats the case, couldn't we just advance the timing on the 79 by 5 deg if that would make a diff? Might be something to play with.

[DiverRay]

It's 5 degree MORE movement. I know when I put the pickup coils and advance from the '78 into my '79, there is just a little more "seat of the pants" at 6K RPM and above. I don't run up there all the time, but it DOES make it nice when I do.

[FSCGunslinger]

Thanks DiverRay! Looks like for my street cruiser mod project I'm gonna need to find me a '78. Well... that is... if I was looking for one... which I'm not...

[FSCGunslinger]

'78 Standard or Special (was there even a Special model this year)?

[DiverRay]

'78 was a Standard only. XS1100E, '79 came in both flavors, XS1100F, XS1100SF. One real trick is the '78 cams on an 82 head. There is a thread on this type of "hop up".

[FSCGunslinger]

Originally posted by DiverRay
'78 was a Standard only. XS1100E, '79 came in both flavors, XS1100F, XS1100SF. One real trick is the '78 cams on an 82 head. There is a thread on this type of "hop up".

Whereabouts might I find this thread? I checked the Modifications section and didn't see anything. Is that sort of a reverse of what the final-drive mod does? How does the power enhancement from the mod compare to the '78? (I'm sure all these questions are probably answered in that thread, though)

[red bandit]

Is the 82 head better than the 80-81 head?

[TomB]

What about 78 cams in an XJ engine?

You've started something now Ray



When building old unit engined Triumph 500 specials I used to swap about the centrifugal advance units, and even filed more metal off the units to get them to advance more, I'm sure this would work on the XS units.

[TomB]

I just noticed Trbig's signature

'82 XJ with '78 cams. "Mad Maxim"

Guess he's the bloke to ask

[DiverRay]

The '82, or MAXIM, as it's known here, has 1mm larger valves, but a larger combustion chamber as well. a strait swap will give the slightly better breathing, but at a lower compression ratio. In my case, my plan is to "boost" the bike with a turbocharger, so the lower compression is a good thing. I know one of the other members, and I can't remember who, was talking about ordering custom pistons from Weisco. That way, he can have a "big bore, and keep the higher compression.
Todd just swapped the early cams, and still has the higher compression because of the stock '82 pistons higher dome.

[TomB]

I have an 82 XJ, bought cheap as an accident wreck, its only done 19K miles.

My old XS has done 80K miles so I'll eventually swap the engine, carbs and ignition from the XJ into my XS.

I just wondering if I could up the power a little with an easy mod.

I have a few XS engines that could donate parts.

[madmax-im]

Originally posted by DiverRay
The '82, or MAXIM, as it's known here, has 1mm larger valves, but a larger combustion chamber as well. a strait swap will give the slightly better breathing, but at a lower compression ratio. In my case, my plan is to "boost" the bike with a turbocharger, so the lower compression is a good thing. I know one of the other members, and I can't remember who, was talking about ordering custom pistons from Weisco. That way, he can have a "big bore, and keep the higher compression.
Todd just swapped the early cams, and still has the higher compression because of the stock '82 pistons higher dome.

That was me.In order for Wiseco to do this custom cut profile for the late model heads...they would need to have a set of heads and pistons.Only with this custom cut profile would one be able to achieve the 10:1 compression ratio that the earlier heads already achieved without the need for a special order profile....for a big bore kit..1196cc/76mm...

[FSCGunslinger]

Originally posted by DiverRay
The '82, or MAXIM, as it's known here, has 1mm larger valves, but a larger combustion chamber as well. a strait swap will give the slightly better breathing, but at a lower compression ratio. In my case, my plan is to "boost" the bike with a turbocharger, so the lower compression is a good thing. I know one of the other members, and I can't remember who, was talking about ordering custom pistons from Weisco. That way, he can have a "big bore, and keep the higher compression.
Todd just swapped the early cams, and still has the higher compression because of the stock '82 pistons higher dome.

I gotta get me a book on mechanical vehicular jargon or somethin', because I honestly don't understand what most of this means. What part of the above directly relates to power/speed (are they the same thing)?