Thumper Club Forum
Technical => Project Progress => Topic started by: JOOLZ on December 17, 2011, 03:13:54 PM
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Well im well into the guts of the engine, its fully stripped down now. The crankcases have been cleaned and some new stainless steel studing put in to hold the oil pipes, the alternator cover has been rubbed down and polished as has the clutch cover, they took some serious work, started on the 800 emery to get the pitting out then on to 1000 then 1200 before I could get on to the liquid polish. The next items on the list are a new gearbox output bearing and seal and a new kick start seal, then I shall think about rebuilding the engine.
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Hope you've used plenty of copper-grease on those stainless threads Joolz or they'll likely drag the corresponding threads out of the alloy(?) should you ever need to remove them..................Regards.........Dave.
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Dont worry im an experienced engine builder. Im making quite a few changes to the fasteners along the way so some stainless and titanium and a lot of aluminum nuts and bolts. I am aiming to get the bike weight down to 300 lbs or less, and the hp to over 55, that should make for a very exciting power to weight ratio ideal for the very twisty roads that I ride, im also making quite a few changes to the oiling to solve the cooling problems experienced by the rvfc engines including a large oil cooler and 80 / 20 methanol water injection system for a quick power boost but mainly to help cool it and stop any pinking. picture is my ported and flowed head
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hi joolz good luck with your project i intend to do something similar with a xbr using a dominator motor weight down ..power up.are you planing any running gear mods? tommy
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Sounds a pretty potent brew Joolz.............keep us informed !..........good luck with it !.
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hi joolz good luck with your project i intend to do something similar with a xbr using a dominator motor weight down ..power up.are you planing any running gear mods? tommy
Hi Good luck with your xbr, Im mainly concentrating on the engine as the rest of the bike has already been heavily modified, mainly a frame respray and some cleaning, but I have to make a new battery box and I am having the fork legs shortened by 35 mm before they are rechromed pic of new conrod
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If you are aiming for 55bhp at the rear wheel then thats a big incease over stock (around 32bhp), what tuning parts are you planning on using?
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Hi engine tuning parts include flowed head, 601cc high compression piston, special grind cam (will be sorted out in the new year) modified ignition timing, the 40mm amal carb and the goldstar exhaust that I am already using also there will be some benefit from a tuned intake and exhaust length .. Im not sure of 55hp at the rear wheel I was basing my figures on engine hp, I have already tested my engine on my engine builders dyno software, I have used this before to build several other engines and the accuracy works out to be within 2% of actual dyno readings, the numbers im getting up are 55 hp @ 6900 rpm and 42 ftlbs @ 5700 rpm
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The top end is finished. I stripped down the top end and checked all the rocker sub rocker and valve guides specs, and I was pleased with the lack of wear from this 60,000 + mile engine. there was a heavy build up of carbon on the valves but a quick clean with the wire brush sorted that out, I gave the head a respray black this time.. I recut the valve seats fitted new valve oil seals and springs and reassembled. Im now waiting on a bearing for the mainshaft then I shall re assemble the bottom end
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I have finished the engine cases all new bearings and seals, although I cleaned the cases I wasnt happy about the finish, so I am trying out some chrome paint, if I dont like the overall look I will tone it down a bit with an aluminum look paint. ( Word of caution to other xbr and probably xl xr owners there is no stop for the gearbox output shaft oil seal, dont push it in too deep)
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I used to use Zinc-Ox cold galvenizing paint which is very good but I have also used Simoniz Engine paint too. Both are pretty resliant if prepared properly.
HTH
Ian
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Thanks for the tip
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Im not sure of 55hp at the rear wheel I was basing my figures on engine hp, I have already tested my engine on my engine builders dyno software, I have used this before to build several other engines and the accuracy works out to be within 2% of actual dyno readings, the numbers im getting up are 55 hp @ 6900 rpm and 42 ftlbs @ 5700 rpm
55bhp at the engine is quite feasible. I'll look forward to the results, I haven't seen many dyno runs from other people. How noisy do you like your bike? I found that as soon as you start silencing the bike you start loosing power. Running a Micron pipe I was topping out at 45bhp but compared to 53bhp with the extremely noisy HRC pipe but I gained a huge power boost in the midrange so on the road is was much faster 95% of the time.
I used to run the forks dropped through the yokes about 1", I'd like to hear some details on how you are shortening the forks.
I'm planning to build an extension this year, hopefully when thats finished I'll be able to get started on rebuilding my XBR, meanwhile I'll look to your build for inspiration :)
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My xbr has no silencer, I run an original goldstar exhaust which is basically a reverse cone mega, very free flowing, you can hear me for miles, however I have an extra baffle that I put up the tailpipe when I am going to be riding around town that gets it to an acceptable level. Shortening the forks is relatively easy, just lop off what you dont need from the tops and recut the internal threads, then shorten the tubes that fit on top of the fork springs to the corresponding length, or cut them longer for a harder suspension. Good luck with your extension its nice to have room to work. Im lucky Suzanne has allowed me to rebuild the xbr in the dining room ( plastic sheet down and some old carpet on top of that) as my shed has to be taken down to allow for the workmen to put a new sewage system in for a hew house thats being built at the bottom of our garden
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I polished the clutch and alternator covers this week, they were in a right state, pitting and corrosion from the salt on the roads last winter, and some really deep (0.5 mm in some cases) scratches that were there there from when I bought the bike. I started off with some 180 grit paper and rubbed the cases down all over to remove the deep scratches and pitting, then went on to the 500 grit and got rid of the scratches caused by the 180 paper, then on to the 1000, then the 1200 then finally I could get it on the polisher, I can now see reflections again, I have a little more polishing to do to get it to a full mirror finish but I have broken the back of that particular project thank goodness. I now have very sore fingers and aching arms.
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hi joolz i tryed those chrome paints and they dont really work ,my mate sprayed my xbr crankcases ,head and barrel in 2 pac about 3 years ago and its still on them the other covers are polished i will do the same on my new xbr project . make sure any surface to be painted is spotless but 2 pac works well and you can get a good range of colours
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I have assembled the crankcases now, I had to wait a long time to get my crankshaft from Eastwood racing not their fault, they stripped my crank 3 weeks ago and when reassembling the new conrod discovered there was a roller missing from the kit, so I had to contact the company I got the rod from to send a replacement, the first one they sent was the wrong size but they got it right in the end. The only major problem I had during reassembly was as I torqued the cases down the shaft got tight, It took some head scratching, and I thought the only variable was the new bearings, but I looked, and they looked fine. Suzanne disagreed and said there was a very slight gap (I installed the bearings by putting the crank in the freezer for 6 hours and heating the bearings to 125'c they slide straight on) not quite far enough as it turned out. The remedy was simple. I cut some pipe that fit the inner race of the bearing to 60mm length, cut a square plate to fit over the top of the pipe with a hole drilled in the center and used the flywheel bolt to gently pull the crank into the bearing, it only moved a fraction but it did the trick. Crank now spins freely and all the gears are selectable, thats as much of the engine as im going to do for now as the rest will be built up when the bottom end is back in the newly rebuilt frame
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Bottom end finished, ): Next stage strip the frame and sort that out.
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The final piece in the mechanical jigsaw, my special grind cam
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What timing and lift does that give you?
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Hi the timing is left inlet 26 54 with the right hand inlet advanced by another 6' and exhaust 53 23 and the lift is 8.6mm on intake and exhaust. The engine has been tuned for max torque and a wide spread of power rather than all out peak power
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Hi the timing is left inlet 26 54 with the right hand inlet advanced by another 6' and exhaust 53 23 and the lift is 8.6mm on intake and exhaust. The engine has been tuned for max torque and a wide spread of power rather than all out peak power
You do need a good spread of power with the stock gearbox.
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Hi the timing is left inlet 26 54 with the right hand inlet advanced by another 6' and exhaust 53 23 and the lift is 8.6mm on intake and exhaust. The engine has been tuned for max torque and a wide spread of power rather than all out peak power
Hi.
Just belatedly been reading through your rebuild with interest.
I wondered why the "staggered" timings for the inlet valves? Also, is the difference 6 mins or 6 degs?
Cheers.
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The staggered inlet cam timings are a result of some ideas that Phil Joy and myself were researching individually.
When I went to get the cam reground we were chatting about various things and "split phased" cam timing was mentioned as a way to get a very high swirl into the mixture and keep a high velocity in the inlet tract despite a more aggressive cam timing.
6 degrees by the way.
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The staggered inlet cam timings are a result of some ideas that Phil Joy and myself were researching individually.
When I went to get the cam reground we were chatting about various things and "split phased" cam timing was mentioned as a way to get a very high swirl into the mixture and keep a high velocity in the inlet tract despite a more aggressive cam timing.
6 degrees by the way.
Thanks for reply. Fascinating stuff. Your forecasted power/torque figures suggest you've not had to go chasing rpm rpm to achieve a decent power figure. No point in trying to cram more of the stuff in there if it won't all burn, I suppose! Did it yield the results your expected?
Any videos (+audio :))
Cheers
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Ps: I assume the 6 degrees is crankshaft "phasing"?
Also, I may have missed this, in reading through your posts, but did you have the forecasted hp figure confirmed in practice? If so, how close were you? I find it incredible that such a thing could be calculated with the accuracy you mention. Presumably all this data, for the computer to crunch, is all gathered empirically? Or mostly?
Again, fascinating stuff.
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Those timing figures are the same as the Megacycle X34 cam.
148-x34
.384" 260° 104° Use modified springs, guides and pistons. 26 btc/54 abc .007"
.351" 256° 105° good all-around off-road. 53 bbc/23 atc .009"
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Ps: I assume the 6 degrees is crankshaft "phasing"?
Also, I may have missed this, in reading through your posts, but did you have the forecasted hp figure confirmed in practice? If so, how close were you? I find it incredible that such a thing could be calculated with the accuracy you mention. Presumably all this data, for the computer to crunch, is all gathered empirically? Or mostly?
Again, fascinating stuff.
No camshaft inlet time phasing. I use an engine building computer software, you can build any motor on it virtually, just programme in all the engine specs and it will give you the hp and torque curves, you can then play around with the ignition and cam advance retard, valve shape,etc and move your power curve around and see what it does. The only thing it wont do is calculate 2 inlet valves timed out of phase. They recon to about + or - 5% accuracy I paid enough for it so I would like to get it on a real dyno to confirm all the figures
Real life performance seems to reflect a good improvement in power it will pull at tickover in 3rd and it certainly wheelies almost too easily, I have to be careful when I accelerate away from stopped as it lifts the wheel even from quite low revs.
It is a good fun bike to ride, its super light at 278 lbs so it accelerates like a scolded cat, and its flexible enough to ride about town but its designed for twisty A roads and thats where it comes into its own
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Those timing figures are the same as the Megacycle X34 cam.
148-x34
.384" 260° 104° Use modified springs, guides and pistons. 26 btc/54 abc .007"
.351" 256° 105° good all-around off-road. 53 bbc/23 atc .009"
Thats right, that cam was on my list of cam timing figures when I was talking with Phil Joy and deciding what would be best for the type of use the bike was being built for, we just modified that by putting in the 6' difference between the inlet opening times
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Ps: I assume the 6 degrees is crankshaft "phasing"?
Also, I may have missed this, in reading through your posts, but did you have the forecasted hp figure confirmed in practice? If so, how close were you? I find it incredible that such a thing could be calculated with the accuracy you mention. Presumably all this data, for the computer to crunch, is all gathered empirically? Or mostly?
Again, fascinating stuff.
No camshaft inlet time phasing. I use an engine building computer software, you can build any motor on it virtually, just programme in all the engine specs and it will give you the hp and torque curves, you can then play around with the ignition and cam advance retard, valve shape,etc and move your power curve around and see what it does. The only thing it wont do is calculate 2 inlet valves timed out of phase. They recon to about + or - 5% accuracy I paid enough for it so I would like to get it on a real dyno to confirm all the figures
Real life performance seems to reflect a good improvement in power it will pull at tickover in 3rd and it certainly wheelies almost too easily, I have to be careful when I accelerate away from stopped as it lifts the wheel even from quite low revs.
It is a good fun bike to ride, its super light at 278 lbs so it accelerates like a scolded cat, and its flexible enough to ride about town but its designed for twisty A roads and thats where it comes into its own
So that's 12 degrees of crankshaft rotation, between phasing of inlet cams? Quite a bit.
Re weight. Wow! That is some achievement. That's as light as a 250 RS. Give or take the odd kg. And by default you have raised the combined c of g, I guess. I can see why it might be more eager to wheelie. How do you go on with fork dive?
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Dont know if you have seen these videos already
RnsIw
RnsIw
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Hi joolz, wow yes that is some serious weight saving, can you briefly tell me how you managed to shave so much lard Orf it. Just in the process of stripping my latest project with the main aim weight loss so any help wud be gratefully accepted. Regards moto63
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I junked the electric start system along with the large battery, replaced most of the steel items with aluminum, removed excess lugs from the frame, lightened engine flywheel, replaced all non load bearing bolts and fasteners with aluminum items and all load bearing bolts with titanium items. clipons are an aluminum and titanium unit, I machined up the wheel spacers and oil tank spacers out of aluminum as well and all sorts of other bits and pieces have been shaved or drilled in some way or another. Half an oz here and there starts to add up when its all taken into account and its interesting to note just how much all the nuts and bolts that go into a motorcycle weigh.
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Coolio, I,ve already ditched the leccy start and ring gear etc and replaced the baddery with a lion item. Now where did I put that black n decker. Regards moto63
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There is a also lot of weight to be saved from replacing the stock silencers and double skinned downpipes. I also saved around 2lbs by replacing the steel swinging arm with a JMC alloy arm.
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Mornin all, thanks for the info about the swing arm rhinoman can you tell me where I may be able to purchase one of those jmc arms. Many thanks. Moto63
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I don't know if JMC are still in business. It took me nine months to get my swinging arm and I don't think that was an isolated incident either.
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Yes I,ve been doing some searching today and I think you may be right. The general consensus is that they,re good if you can actually get the guy to deliver the goods. Think I,ll be looking down other avenues, but thanks anyhow. Regards moto63