| Author | Message | ||
     Battyone |
Just brought this up to date. http://www.badweatherbikers.com/buell/messages/290 431/578293.html?1278812190 | ||
| Fast1075 |
Degreeing the cams to suit will not be a problem with slotted cam gears. I know for a fact, as I have seen them in person that at least ONE 1190RS engine has slotted cam gears. A mill and indexing table should handily slot the stock gears. We used to do that very trick on our race motors before the aftermarket began producing packaged slotted gears. | ||
| Battyone |
The chain wheels are slotted as standard. But you can't change the relationship between the inlet and outlet cams without redrilling the dowel that locates the gear on the exhaust cam. I'd rather find out why they are different. | ||
| S21125r |
Reading through your reply on the other thread... Are you saying the lobe separation angles are different by 4 degrees between the front and rear cylinder? Thinking out loud here...wondering if that maybe due to emission/heat management differences between front and rear cylinder? Wonder if the index location is different on the gear or the cam? Good observation though! | ||
| Zac4mac |
Did Twin remove the article where they degreed the 1125? I can't find it. If I can ever catch up on heads to port, I will get Loretta on a lift. I plan on looking at the heads to see if I can get some gains, not expecting much there tho. If I can rig the fixture, I might mill a few thou off the head and raise my compression. I believe I remember EBR having a spec... Right now I have 6 sets of heads waiting... probably work some tomorrow while the wife cooks the turkey. Y'all enjoy the football games for me. Zack | ||
| Noobuel |
Looks like they moved a few things around, this may be the one linked from the other thread: http://www.twinmotorcycles.nl/artikelen.asp?cid=6& aid=62 | ||
| Battyone |
"Reading through your reply on the other thread... Are you saying the lobe separation angles are different by 4 degrees between the front and rear cylinder?" That's what I'm getting,rear exhaust opens 4degrees earlier than front. "Thinking out loud here...wondering if that maybe due to emission/heat management differences between front and rear cylinder?" It's the one of the possible reasons,other being header route/length? "Wonder if the index location is different on the gear or the cam? " That's something I've still got to check,problem is that front to rear are mirror images not the same cams,but it's a possibility. Otherwise to match them it's a pita. move the gear one tooth back = 16degrees retard - the original 4degree advance,gives 12 degree of retard,so advance pin location 12 deg to get to 0. Then remember not to use the original timing mark! | ||
| Battyone |
Zack! If you're a "Head guy" you NEED to look at the 1125 heads. Not sure you'll be able to get any more out of them,but there are some issues that need looking at. Cast iron valve guides? shims that will fall out if over revved -very easy when dragging and a few comments have been made about valve durability. And the inlet port is too big for road use.probably the main reason for the poor low speed running. I was amazed to discover I get better launches at half throttle than I do at wot. | ||
| Zac4mac |
Interesting Nigel. Yeah I hand port/polish Sportster/Buell/H-D Big Twin heads. That's all I have tools for. I never put iron guides back in... bronze only. I haven't heard any issues with the shims, how big is that problem? Inlets too big? PITA but possible to re-seat and cut for smaller valves. If anyone makes compatible valves and seats... You've done a bit of logging, does it still look fat when up near redline? I've seen quite a few 1125 heads on eBay. Might pick up one or two to play with. The shop I'm at goes to Bonneville every year, I want to trick out Loretta a bit and try her on the salt. This year we ran a naked Sporty that hit 160mph.  Zack | ||
| Battyone |
It's very easy to massively over rev when accelerating flat out in 1st and the revlimiter can't stop it. Li'l Joe hit 13,400 when he forgot to "arm" his shifter and I hit 12,500 when it lit the tyre up at the top of first gear. Joe got away with it,I didn't. Shims pop out then the rocker works on the retainer until the keepers lift out,you can picture the rest!!! I dropped both inlets on the front cylinder,head would have been fine if it hadn't snapped the end of the valve guide off with then chewed squish areas to pieces. So I'll be buying a set of those heads off fleabay.Then looking at running a shim under bucket set up with better valves,guides and retainer/keeper combo. It's not the inlet valves that are too big but the port itself. | ||
| Smoke |
zac. sounds like you are working with Dan now. if so, say hi to him and Lil for me and have a great rest of the year! looing forward to hearing about your trip to the salt on the 1125. tim | ||
| Zac4mac |
Tim - Yup, and it was Cil on the PINK Sporty that did 160. She's little-bitty and fast. I stayed home and worked while they had fun. not next year... Z | ||
| Fast1075 |
I see no place to put buckets without an awful lot of custom work. Perhaps some detail work on the valve train. Better springs and lighter valves. SOMEONE is making valves for EBR...my guess would be Ferrea or Kibblewhite, or possibly even APE. It it hard to beat the Ferrea in Ti. I would also run the valve clearances a bit tighter than stock for a drag only application. Your motor broke because valve motion went out of control or "floated". Plenty of room for a shim to jump out. A few races back Danny Eslick revved his motor to the moon when he blew a shift. Rumors put it in excess of 14K. The retainers killed the valve guide seals, resulting in a black flag due to engine smoke. The motor ran fine. At least you don't run nitrous. If you spun like that with nitrous, you would have picked your motor up in a bucket. There is no rev control on earth fast enough to reign in an unloaded nitrous motor. Been there, have the pieces. | ||
| Zac4mac |
Nigel I just realized what you meant by " the intake PORT is too big." I suppose I could have my welder add material to the port and then shape it. That would definitely require a set of eBay heads. I love food for thought. Z | ||
| Battyone |
Fast,I'm already going through the Kibblewhite catalog. At first I thought that buckets would be a no no,but then realised that as I was looking for new -better/lighter- valves anyway lowering everything to make room for a bucket wouldn't be too hard,there's room to machine the spring seat a few mm. Planning to try all power adders next season to see what gives best results vs reliability. so nitrous,turbo and a centrifugal blower. Already run valve clearances at minimum, 0.006" for inlet and 0.010" exhaust. The shim jumping out doesn't do the damage it's after it's gone that you're in trouble!!! And we all know what a PITA it is to check the valves if you do over rev. I'm also worried about rate of engine acceleration with power adders. Springs are in the 1" diameter region so plenty of nice parts available. | ||
| Fast1075 |
Sounds like you have a good understanding of the situation. Best of luck with the mods. For the power adder (especially if you are running ET), I would strongly recommend the nitrous. It will make the bike more consistent. A progressive system will help with launches and still give you power on the top. I used to buy mine in 125 pound cylinders. I used a scale, bucket, ice and a transfer hose to fill my 3 pound bottles. MUCH less expensive than having them filled at the track. | ||
| Battyone |
I've got a Hays hand slider to get me off the line !!! Will be using fixed hit to start with,dry setup so much easier to configure if it's not progressive. Going to be a huge amount to learn about the 1125motor.That's why it's important to fix any known issues now. So mechanical cam chain tensioners and find a way to keep shims in are top of the list. | ||
| Battyone |
Hey Zack... now I've got a head completely stripped I think that any improvements will require adding material. Some interesting shapes inside! I'm going to need a couple of new heads,now I've broken one. |
