Is bottom end work necessary?
Current: 2007 96 Ultra, 67K miles, SE 255 cam upgrade - running well
Considering: SE 103 kit, larger valves mildly ported to current heads, new guides, MCR's, new dyno. Expect a gain over current of 10-15 TQ and 8-10 hp. Cost $2100
Concerns: Dealer/tech tell me that given the mileage and added TQ, I should have the crank welded/plugged. If I do that, I will probably change to a larger cam. Cost $3700
I'd like your thoughts on the need to do the bottom end work. I would like to ride another 100K on the bike without major work. Am I just putting off the bottom end and will need to do it eventually? Should I just have the 103 upgrade now and worry about the bottom end if and when it poops out?
Considering: SE 103 kit, larger valves mildly ported to current heads, new guides, MCR's, new dyno. Expect a gain over current of 10-15 TQ and 8-10 hp. Cost $2100
Concerns: Dealer/tech tell me that given the mileage and added TQ, I should have the crank welded/plugged. If I do that, I will probably change to a larger cam. Cost $3700
I'd like your thoughts on the need to do the bottom end work. I would like to ride another 100K on the bike without major work. Am I just putting off the bottom end and will need to do it eventually? Should I just have the 103 upgrade now and worry about the bottom end if and when it poops out?
Called the dealer about checking the runout. Said they have to pull the cams, etc. Not an inexpensive check. So that's out. I will likely wind up just leaving the bike as is and riding it for another 60K before doing anything. Really disappointed.
Others please weigh in with your recommendations. Thanks
Others please weigh in with your recommendations. Thanks
Um, $1600 for the crank? Holy **** man, they are raping you.
Click here for prices from Rev Perf
I would do the bottom end with the miles and while it's down. Spend the money now to spend less later.
Click here for prices from Rev Perf
I would do the bottom end with the miles and while it's down. Spend the money now to spend less later.
The jump from $2100 to $3700 included new TM 555 cams, around $300 + labor to install.
So if I take a chance and go without the welding, should I at least put the SE compensator in? I've heard it is a weak design on the 07-10's and could lead to crankshaft issues.
So if I take a chance and go without the welding, should I at least put the SE compensator in? I've heard it is a weak design on the 07-10's and could lead to crankshaft issues.
I wish I lived as close to WI as the OP, I would go over to Fuel Moto, have a 107 and cams, have them send the crank over to Dark horse, or Rev perf, and come out with a better build for less $$$ IMHO, just a thought.
Patriotmc, my bike is also a 2007 and 2 years ago I decided to put in a S+S 106 kit and a mild 255 cam. I was very, very happy with it's performance, but it had a noticeable "rap" in it. I ran it for about 7,000 miles like that and it slowly got worse. Last winter I tore it down looking for that "rap". Well, I found it! The crank scissored on me! I tore the engine out, had the crank trued and welded, then I added the goodies listed in my sig. Now I am one happy camper!
If you really plan on doing any major upgrades, especially with that kind of mileage, I would strongly consider doing the bottom end for peace of mind. Just my 2 cents.
If you really plan on doing any major upgrades, especially with that kind of mileage, I would strongly consider doing the bottom end for peace of mind. Just my 2 cents.
Trending Topics
Checking the runout before you make any decision is the right answer. If you can't do it yourself and don't want to spend the money to have it done, that is understandable.
If it were me, I would go ahead and do the top end work you were planning on doing and not sweat the lower end. A 103 with 255 cams and mild head work will not be pushing the limits of the lower end.
If burnout, wheelies, hard down shifts, and drag race style launches are part of your riding style then all bets off. A stock motor will twist a crank if ridden like that.
I'm running a Headquarters 103" making 114/120 on a stock lower end and it is still at .0045 TIR, which is where it was when I did the engine almost 20k miles ago.
Zach
If it were me, I would go ahead and do the top end work you were planning on doing and not sweat the lower end. A 103 with 255 cams and mild head work will not be pushing the limits of the lower end.
If burnout, wheelies, hard down shifts, and drag race style launches are part of your riding style then all bets off. A stock motor will twist a crank if ridden like that.
I'm running a Headquarters 103" making 114/120 on a stock lower end and it is still at .0045 TIR, which is where it was when I did the engine almost 20k miles ago.
Zach
Thanks for all your input. So I asked the dealer why he hadn't said anything about bottom end work until today. He said it was because the tech was now talking about oversized valves instead of the stock ones. That would result in a little more perf and he is concerned about how the bottom end will hold. I don't want to get just the stock 103 - the gain isn't worth the money to put it in, but how exposed am I with 67K miles already on the bike?
My concern is that if I do decide to get the bottom end welded, what is next: new compensator, oil pump, other - when does it end. If I go with the bottom end and don't do the other, is that also a time bomb?
I don't hot rod but have inadvertantly downshifted a few times - bad on the crank. I've been trying to run 2500-3500 so trying not to lug. What to do - what to do?
My concern is that if I do decide to get the bottom end welded, what is next: new compensator, oil pump, other - when does it end. If I go with the bottom end and don't do the other, is that also a time bomb?
I don't hot rod but have inadvertantly downshifted a few times - bad on the crank. I've been trying to run 2500-3500 so trying not to lug. What to do - what to do?








