Heads Porting & 1250 conversion

[Dr.]

Originally Posted by ptotoole

I converted my 1997 883 sportster to 1250 a couple of years ago. I put on Buell thunderstorm heads(without extra porting), harley screaming eagle bolt in cams, SE air filter assembly and (at first) SE mufflers on the original exhaust system. That assembly had great torque and acceleration up to about 75mph, when everything went flat for a while then began a slow acceleration.

I tried different things, then replaced the original exhaust with baffled straight pipes. That got rid of the flat spot, but top end is ????. HOWEVER, I get pinging whenever I crank too much on the throttle in higher gears.

Presently, the bike has great torque, is not great at top end, and (with a recently installed mikuni carb??) gets close to 50 miles per gallon. But still pings when twisting too hard on that throttle in high gear.

So, that's my experience so far with a 1250 conversion. But, at my age, 66, the end of my thirty some years of biking is closing in.

Pat

Thanks Pat for that it is actually very helpful. What size cams did you put in?

Dr.

[jollyroger83]

I JUST installed the 1250 kit on my '06 883C. The bike came with SE2 slip-ons and I put on an AN Big Sucker. While I've never rode anything more powerful than what I have now, just putting the jugs and pistons on seemed to give it a real kick in the nuts.

Granted I'm not done with the break-in yet (which is killing me), so I can't speak on how the topend is, but the lowend is awesome.

[steelworker]

Originally Posted by Dr.

Thanks Pat for that it is actually very helpful. What size cams did you put in?

Dr.

He said he used SE bolt-in cams. They're .497" lift - identical to Andrews N4's.

[Bob F]

Hi Dr. I see it's your first post. Hello from Pittsburgh and welcome to the XLForum.

[Dr.]

Originally Posted by steelworker

He said he used SE bolt-in cams. They're .497" lift - identical to Andrews N4's.

Okay... right missed that as well... thanks Jolly, Bob and all, nice to have those who have been down this road take the time to get me going in the process.

So, far what I am hearing is the best fit for .497 cams is porting and clean up 883 heads up to stage 1 and the XL1200R maybe up to stage 1 but too much head will possibly cause some engine issues or mismatch troubles.

With stock cams D grind what is the best improvement match and how much head work can I have without causing major issues ... I really think this answer would benefit a lot of beginners wanting a 1250 HIGH!

Thanks Dr.

[jessearias]

I would just go with stock 1200R heads like the ones NRHS sells. Perfect match for the SE 497/N4 cams. No additional porting needed. If, you were going to run a hotter cam like a 536, THEN it would be advantagious to port as you would get more power.

So, save your money and spend it wisely. I would not waste any money on 883 heads. Better spent on the 1200R heads from NRHS. Think about this; The Buell Thunderbolts came with 497 cams AND thunderstorm heads. I do not need to tell you how well those ran.

Like Mr T said, he , Terp1984alum, myself and others have gotten 90+ HP using stock Thunderstorm and/or 1200R heads using SE 536 cams. So, if we can do that, you can make great power and torque as well with your combination using the stock 1200R heads and 497 cams.

[Dr.]

Originally Posted by jessearias

I would just go with stock 1200R heads like the ones NRHS sells. Perfect match for the SE 497/N4 cams. No additional porting needed. If, you were going to run a hotter cam like a 536, THEN it would be advantagious to port as you would get more power.

So, save your money and spend it wisely. I would not waste any money on 883 heads. Better spent on the 1200R heads from NRHS. Think about this; The Buell Thunderbolts came with 497 cams AND thunderstorm heads. I do not need to tell you how well those ran.

Like Mr T said, he , Terp1984alum, myself and others have gotten 90+ HP using stock Thunderstorm and/or 1200R heads using SE 536 cams. So, if we can do that, you can make great power and torque as well with your combination using the stock 1200R heads and 497 cams.

Cool! I think that is what I am going to do then.. can't wait! There is the matter of sealing the deal with the one installing it... he said huge discount when summer ends... probably can't wait... Dr.