| Author | Message | ||
     Mr_wizard |
does anybody have thunderstorm heads on there M2 and if so how do you like and what cams did you go with. I was thinking thunderstorm heads with xb rocker box covers and andrews n6 cams with the hi4 single fire ignition system? Looking for some input, thanks. | ||
| Buellistic |
Your M2 already has THUNDERSTORM Heads ... XB rockers arm covers(complete) is a better head breather system over the EVO SPORTSTER Head breather system ... The N6 cams are a better cam the the N4's that are OEM in the X and S3 models ... The single fire ignition is better than the dual fire system ... | ||
| Phelan |
I would be careful which cams you use with stock pistons, because too high lift in the cams will cause the valves to smack the piston. Forged pistons, like the Hurricane pistons made for NRHS by CP, have deeper valve pockets on the top to keep this from happening. If it were my build one of the first things I would do is put a Mikuni 42 on there and call it good until I could save enough to do a 1212 or 1250 and cams. 1212 any CR from NRHS is $400 IIRC, and the 1250 kits start @ $700. 1212 bores your stock cylinders, 1250 includes new cyls, and 1250 is also the biggest you can go on the stock bore cases. If you have the dough I would include stage 1 port & polish on the heads, which is $550. | ||
| Eboos |
Are you keeping it street or going to race it? If you are racing, don't change the displacement. The sky is the limit for Thunderbike, but if you want to do any of the lightweight classes, they have a displacement limit of 1210cc for air cooled twins in CCS. Over 1210cc, and you will be slugging it out with the middleweight guys 40 deep in the grid. Not much fun. By the way, my engine is stock and I am running a Mikuni HSR42 carb. I was thinking about dropping in N6 cams this winter. (Message edited by eboos on November 28, 2008) | ||
| Buellistic |
Phelan is right about checking valve clearance on high lift cams ... A 44 or 45 MM Carburetor is a better Carburetor up-grade ... If you have the money the biggest CUBIC INCH Engine build is the way to go ... | ||
| Eboos |
Phelan, I was licking my lips as I was reading your post.  | ||
| Phelan |
 . To be honest, that should read "if it were my build and I was planning on keeping a carburator." my next build will be next year (hopefully EARLY), and it will be from the cases up with Delphi EFI. It will go in an S2T. | ||
| Phelan |
As for the carb, Buellistic and I hopefully can agree to disagree on it. I personally prefer the HSR42, but the others mentioned have strong points as well. | ||
| Buellistic |
Phelan, "i" also prefer the 42 MM Carb. as it works better in the RPM range that "i" ride ... What is th MM on the Throttle Body on the Delphi FFI ??? | ||
| Phelan |
40mm I think? Not sure, but the cost is small to have Dan bore it out to whatever size will best suit my build. Maybe I'll go even more oddball and bore it 43mm. | ||
| Mr_wizard |
Mikuni has a 48mm carb for buildt motors that I was looking at. I've done the typical to my bike so far, air cleaner and exhaust and I had my cabr rejetted and drilled and dyno tuned but I still hate it. It doesn't run consistently and I still get hiccups. I've never been sold on the cv carb though. I was thinking about the 99 cubic inch motor from zippers. My girlfriend is fine with everything until she saw the page marked in the drag book that had the NOS kits! She said thats going to far and my couch isn't that comfy. LOL. I'm only going to be street racing it, not on the track. My bike is tore apart in a million pieces right now and it is sad but it is going to be so worth it!!!! I really appreciate all the help, this is my first (defenently not my last buell) and I like going somewhere were people don't ttalk to me like I'm an idiot. I know harley's but not the sportster. Thanks, I will post pics of the progress and the custom paint job when I get it back. Hope everybody is having a great holiday | ||
| Phelan |
Tge 99" Zippers kit will not fit in the tube frames without significant modifications. The motor with that installed is too tall. Your best bet is an "88 kit from NRHS. It is stock stroke and will give you more than enough oomph. The "90 kits require cast iron cylinders and can adversely affect cooling and center of gravity. With the 88" and some stage II headwork, you can order any CR and squish you want, and drop in some .536 cams and A Twin Tec and you're in business. Make sure to slightly clearance the rockerboxes if you don't convert to the XB tops though, because .536-up cams can make the rockerarms and springs tap the stock covers and cause you a whole bunch of problems. | ||
| Mr_wizard |
I'm defenently going with the xb rocker boxes. There is a guy on here that has a set and is going to e-mail me a pic when he gets home on sun. If they are reasonable I am gana get them. Thanks for the motor info. I will talk to zippers, they are the ones that are gana do my heads for me and pic there brain a bit to see what they sugest. I might be able to just change out the pistons for now. |
