| Author | Message | ||
     Ft_bstrd |
Ok, I've been sucked in. I'm planning a complete restoration of the M2. The heart of that is an engine refresh and build. I am comfortable digging into everything on the primary side of the engine, but am not comfortable rebuilding the engine side of it. I'd like to refresh the motor replacing seals, gaskets, bearings, etc. I'd also like to do a performance upgrade, but I'm not interested in doing anything that will hurt durability. I have a manual and am reasonably competent with tools. I just don't like doing something this fraught with potentially expensive mistakes without someone looking over my shoulder. What do you guys suggest? | ||
| Preybird1 |
1250cc big bore kit is just right. I would plan on having it dyno tuned after the build or your just wasting money. | ||
| Ft_bstrd |
Yeah, I was thinking of the 1250cc kit. Since I'm going to be pulling the bike apart doing paint and powdercoating, The engine is going to be out and it's a good time to freshen it up. | ||
| Foximus |
Dont expect power out of a 1250 though.... | ||
| Preybird1 |
If you want power change the cams and have the heads built for better power. I went with stage 2 heads .536 cams and smaller valves. The most i got out of it on the dyno was 117 rwhp. | ||
| Foximus |
you went with smaller valves on a lightning head? | ||
| Ft_bstrd |
The power is fine. A little more than stock would be fine. I'm not looking to build a drag bike or anything to race. My thought is that if I am going to freshen up the motor, might as well add a little umph to it. If I got 100 RWHP, I'd be happy with that. | ||
| Buellistic |
Ft_bstrd: Would tuning ever bit you can get out of your stock engine be satisfactory ??? If so, PM me and "i" will pass what "i" know on to you ... | ||
| Foximus |
Check your compression... find out how much you are making... unless you are low, which I have found is usually not the case.... you wont be gaining anything | ||
| Phelan |
With a 1250 kit, you can expect a 5% increase in power with the right tuning due to the larger displacement, is what I was told by Dan @ NRHS. That's what he's been getting out of similar build comparisons 1200-1250. | ||
| Ratbuell |
Change cams, and see how you like that. Do that BEFORE you yank the motor, that way you know if you like it or not. X1 or S1W cams are a HUGE step from M2 cams. M2 cams are basement-torque cams; I run X1 cams in my S2 with thunderstorm top end and its got good power throughout the powerband, and my S1W is just a freakin' powerhouse anytime it's running. Our M2L is nice and strong down low...but feels like its running out of breath over, say, 3500rpm. And I have yet to get into aftermarket cams...I've been happy enough with these factory grinds  | ||
| Preybird1 |
Foximus I went with smaller diameter valve stems not actually smaller valves. I went down to 7mm stainless. Read my profile for total build. | ||
| 883srfast |
Ratbuell: I have been looking into building my S2 engine this winter. Want to go with Thunderstorm heads and would like to learn the difference between the X1 grind and the S1W grind cams? What has been your experience with the power band and torque with the two? I am going to try to search the KV to see if the specs for the cam timing are in there somewhere. | ||
| Ft_bstrd |
I can get my hands on a set of X1 cams. | ||
| Ratbuell |
I'm not sure if it's the added weight of the S2 over the S1W, or if its the heavy flywheel in the S2...but the S1W seems to be more rev-happy and a little more explosive compared to the S2. Power is smooth from idle to rev limit on both, but the S1W is a little more hooligan, where the S2 is a very competent sport-tourer (I have bags and lowers on it). Going to either of those bikes from my XB or 1125, I don't feel like "c'mon...let's go...where's the power...". They're slower, sure...but not like when I get out of one of my turbo cars and get into the '61 Nash and think "my god I'm gonna get rearended" LOL | ||
| 883srfast |
Thanks Ratbuell, I run bags with narrow lids and lowers on my S2 when I tour and could use more power when I get into higher elevations and the mountains when climbing hills etc. I will look into some of the cam specs more, but I will probably end up going with the Andrews N4's from what I have been reading in the KV. My S2 motor runs smoothly all the way to 6250(rev limit) but lacks any explosive capability with the stock set-up. | ||
| Jsracer |
883srfast: S1W cams and X1 cams are the same thing. They came in all S1's, S1W's, X1's, S3's, S3T's, and international M2's. They are made for HD by Andrews and are literally the same thing as N4's. HD also sells them as the Screamin Eagle bolt-in cams .497 lift. The Andrews versions are marked 1N4, 2N4, 3N4, 4N4. The early HD ones are marked 15-1, 15-2, 15-3, 15-4. The late HD ones are marked 1B, 2B, 3B, 4B. Sometimes people call them "B" cams. The part numbers from HD are 25648-91 for 91-99 models and 25648-01 for 00-up models. The difference is the tooth pitch on the pinion gear. You can put the later cams into your bike but you would have to change the pinion gear to match, best to get the earlier style. Don't believe the story about the stock "D" cams being a torque cam. That's only true if you use the stock muffler because the small overlap of the stock "D" cams keeps the stock muffler from causing a big hole in the powerband. But if you use a good exhaust the S1/X1/S3/N4/SE497 cam will make more torque over the whole rpm range than the stock "D" cams. Also on your heads you would be much better off to get a set of 2004 or newer XL1200 heads which are the same as XB heads except for the cosmetics. They make more power than the Thunderstorms and will work fine with your stock flat top pistons and give about 10:1 compression (Thunderstorms need special domed pistons to get 10:1CR). Also they are available with the highlighted fins to match your stock cylinders which the Thunderstorms are not. The hardware for them is better too and will allow up to .551 lift where the stock hardware in the Thunderstorm will only support about .500 lift. The Thunderstorm is an old head and they are outdated, the new heads are much better in all respects. The only catch is that you need a new front motor mount to use them but they are readily available. | ||
| 883srfast |
Jsracer: thank you for all of the useful information. I am very interested in learning more about the 2004 or newer heads and it sounds like it would be the best way to go now that we are in the 21st century. Do you have any experience with the Screamin Eagle Pro Sportster Performance Cylinder Heads, part no. 16677-05? Remembered seeing them in the parts Catalog and looked them up after you mentioned them here. Thanks again. | ||
| Jsracer |
883srfast: these two links should answer all your questions: http://www.nrhsperformance.com/partsoemheads.shtml http://xlforum.net/vbportal/forums/showthread.php? t=11769 | ||
| 883srfast |
BadWeb is awesome...thanks again. | ||
| Ft_bstrd |
Buellistic, I PM'd you but didn't get a reply. Wanted to make sure you got my message. Thanks. | ||
| Buellistic |
Ft_bstrd: "NO" message received from you yet ??? My e-mail address is Ljenne73c@verizon.net ... |
