Big Bore Kit

[Shuriken]

So when I do the big bore (winter / never) project, will I need a ring compressor? I can't imagine having enough "fingers" to do hold different sets of rings at different degrees apart from the others on 4 cylinders......

So aside from having the normal tools like compression guage, torque wrench, etc., do you need a valve shim tool, ring compressor, valve lapping tool, etc?

Ben

[xssiveone]

When I put mine back together, I made a couple of ring compressors. Conventional ones are just too big to fit into the space available. I got some plastic pipe, think it was 4 inch, and cut 4 pices about 1 1/2 -2" long. Clamped 2 on each piston over the rings with a worm-gear hose clamp. I also beveled the top edge so it would mate better with the bottom of the cylinders.

Make sure you use lots of oil or engine assembly grease when putting them back together. And you must have 2 sets of compressors, as either 2-3 or 1-4 will be up and entering the cylinder at the same time.

[strom]

A small screwdriver and fingers combined with cursing always did it for me....

LP

[TopCatGr58]

Needed Tools

Well, I guess Strom and I went to the same high school auto shop class?? What I found was that the jugs don't have to come down exactly level, you can tilt them a little, and you rotate the crank so that the inner two pistons come up first, you slide the jugs down to meet them, and then with it slightly tilted and coated both pistons and jug/cylinder walls with lots of oil, the rings/gaps will stay pretty much in place once you get them postioned on the pistons, and then I just used my fingers to squeeze the top most ring, and allow it to slide into the tapered opening of the jugs, then the other piston, rocking the jugs slightly front to back as needed, then a little down pressure till the next ring was close, and repeat until you get the center 2 pistons placed, then turn the crank SLOWLY, until the outer two pistons come up, and repeat process again, once you get the jugs over the rings, then just press down to seat the jugs into the case!!

A low scale torque wrench, not just a standard one will be needed, cause several nuts/bolts only need 7 lbs, and regular wrenches start at 10 and are not accurate enough at that low reading!!!!

The valve lapping tool is a double ended suction cup, one large, one small, for about $5.00, with the compound another buck or two...READ THE DIRECTIONS that come with the compound!

On the old Yahoo XS11 site, there is a picture of the valve spring compression tool I made to work with the 8" C-clamp. I used a metal pipe section, might work with PVC and would be safer for not scratching the inside of the valve lifter cylinder walls when using!!

And, since you'll be taking the cams out, I didn't use a valve shim tool, just did my clearance measurements before removing the cams, then noted the shim sizes, did the lapping, put the cams back in, ONLY 1 AT A TIME if you plan on turning the cams like I did to recheck the clearances, then pulled the cam again, calculated the required shims and replaced them, did the same for the other cam, then put the bike together.....worked fine without having to get that special valve shim tool!!

T.C.

[tony7914]

Re: mototuneusa break-in "secrets"

Originally posted by Mike Hart
Not TOO gentle now...

check this out...
http://www.mototuneusa.com/break_in_secrets.htm


This guy is also a porting fanatic, and mostly says SMALLER is better! It being all about port velocity... interesting stuff.

just curious but has anyone on this forum tried the tips in the artical this link goes to?? what kind of results did you get?? i think i would be more likely to try some of these tips if some of the old timers here have and had good results with them....

[fusionking]

In my auto-engine building business we always broke everything in "HARD" = many years= no regrets! Read the instuctions on sealed power ring sets....same kinda thinking. High velocity is something I have been practicing in my porting for many years now. Looks like the only thing he has relavent to us is Harley stuff on the 2 valve part, tho it still sounds good.

[pgg]

A high velocity airflow into the cylinder head is not a ground breaking big secret as this website claims. Any engine tuner knows the princible. It may work well with a high revving modern 600, but on an xs11 it may have a negative effect on overall performance, but you'll never know until you actually try it for yourself. As I have a spare stock standard xs11 cylinder head, when I have time I'll try the experiment and do the epoxy fix on the inlet ports and see what happens. I'll run it and give my opinion of the result.

The cylinder head I'm running now has been ported and flowed and it gave a really good power boost.The inlet and exhaust ports weren't enlarged, but were reshaped by grinding out the bulky valve stem protrusions for an unobstructed airflow. A small lip (3 or4mm), where the inside rubber inlet boots don't match exactly with the inlet ports, was also removed. Both my xs11's had the small mismatch - enough to distrupt the flow.

If the epoxy test gives a noticible boost, then doing it to the flowed head would be a logical next step. Only tried and tested results would convince me. We'll see.

[Shuriken]

It sure would be interesting to see more research on the subject. If it were my business, I'd want to have some independent research done so I could have some good hard numbers to rely on.

.....................

On another note, (before we eventually start seeing big bore dyno results) what do you all suppose would be the HP increase provided by the 1178 big bore kit? 1196? By ratio and proportion (hey, just guessing here) I came up with 101.6hp for the 1178 and 103.2 for the 1196 kit. So that's a 6.6hp increase for the 1178 kit and 8.2hp increase for the 1196 kit - assuming nothing else changed from stock configuration. So are we buying 6 - 8hp increase for $1000 dollars?

I wonder if one installed the 1196 kit, rejetted, installed high flow air filter, and installed 4-1 pipe if BHP would reach 110?

Hmmmm........

Ben

[pgg]

Ditto. I want some hard earned proof. I want some proper independant evidence. Two squiggly lines on graph paper, or a photo of one shagged piston and one good piston basically means jack s***. If the outfit is genuine and wants credibility, then they need to show some hard won evidence.

[fusionking]

Go Figure

The big bore kit also has a higher compression ratio.... that alone is worth a good bit of power!

[scalded dog]

I bought my first xs 1100 about two&1/2 years ago, it was such a thrill to ride, I paid $600 for it, when I joined the southern cruisers, one of the guys had an xs 1100 setting outside for about a year he bought a new harley classic in 2001, it was the standard without faring and bags, It had 70,000 miles on it, I paid 400 for it without hearing it run for a parts bike, I started tinkering with it, and cleaned the carbs, alas it run better and faster and used less oil than my first xs 1100, but didn't look as good, so I have been fixing it up too, I bought another xs 1100 off ebay about two months ago, one owner 13,000 miles, hadn't been cranked in four years, stored in a garage, I cleaned the tank$ the carbs, it runs like brand new and is all original. I paid $850 for it, I said all that to ask this, would the big bore kits still be along the same dependability scale. Later 'Dog

[mitch]

Hey Dog

Just curious how did u make out with your carbs ? Did u get the bench synv done ?..........MITCH

[scalded dog]

Hello Mitch, I have done the bench synch, it worked out good, the bike is running great. Thanks again, 'Dog

[pgg]

A deafening silence

Back to this mototuneusa website and their radical performance claims, before experimenting with their 'epoxy port fix' on a spare cylinder head, I sent them this email - twice.

Hi there. Regarding the practice of reducing the inlet port size by around 30%, I have a 78 XS1100 and was thinking of trying the 'epoxy fix' on that. But I'm thinking, well, reducing the port openings on a 4 valve high rev modern 600 may improve performance, but on the torquey 2 valve XS11 motor (lot less efficient breathing) restricting the inlet ports would probably have a negative effect on performance, as the 2 valve head probably needs all the c.f.m it can get! The XS11 redlines at 8500 and has a flat torque curve from 3000 right through. Do you have any suggestions or thoughts on whether the reduced port principle would really apply to this type of motor?

CHEERS.

Well, here we are one month later and - suprise suprise - no reply from them. Not a peep. What does that tell you? Needless to say, my original ' have an open mind' thinking, has turned to straight out skeptisism. As they wont even send a simple response to back up their statements, I've flagged their website as just another scamsite to drum up business for themselves. All I can say is - treat their claims with a lot of caution.

[fusionking]

exactly what is their business? ie....how do they make money and how do their customers make initial contact I wonder?