I was just wondering if anyone here could get me up to speed on the STD heads specificly for the XL engines, I can't seem to find much info/details on them on the net compared to the stock Thunderstorm heads. I was planning to order a set of Buell 1.9 valve heads this year but I would like to get more info on the STD's, like valve sizes, diffrence between stage 2/3 and if the raised ports will give me header problems in the X1 frame or any other issues (like intake?, covers?) with fit in a X1. I now have also seen that the XB heads are better? than my Thunderstorm heads?, is it not worth using these heads anymore?. What about xb VS std heads?

Here is a link to info about the STD heads at NRHS. Don't think it talks about header issues but I'm sure Aaron or Dan will post an answer to that question.

http://www.nrhsperformance.com/partsstdheads.shtml

Thanks, also now I am assuming that all STD heads would need to be cut to use on the 00/01 X1 engines for the pistons?

Kazoom, I'm glad that you posted this; I've been wondering how a set of ported STD heads compare to the Stage 2 or 3 XB heads myself.
As far as you Thunderstorms go, they are no good send them to me.;)
There is a large post on heads here hopefully someone will link to it, but I don't believe that it mentioned the STD heads much, but I need to re-read it . I believe that your Thunderstorms are still good heads, but I believe that it was said that the XB's have more consistent casting.

I will be purchasing a set of heads from NHRS soon for my S1 and have been wondering about the STD heads as well. Hopefully NRHS will comment on this one.

LB is right, the Thunderstorm castings are bad and getting worse. They're all over the map now. The earlier the set of Thunderstorms you get, the better they tend to be. By comparison, the XB heads tend to be pretty consistent from one head to the next. Although I have to admit, we had one come through the shop recently that had a ton of core shift evident in it's exhaust port. But that was the first one I'd ever seen like that.

Basically what we saw was very poor centering of the exhaust seat to the port. The exhaust seat has a smaller id than the port diameter, for anti-reversion, and this one was WAY off center.

At stock level, the Thunderstorms give up a fair bit to XB heads, as much as 5-6hp, and the Thunderstorm hardware also can't handle as much lift as the stock XB 7mm stuff (Thunderstorm springs/guides/retainers etc are the exact same pieces that all 86-03 XL's and BT's came with, don't let anyone tell you otherwise). As the prep level goes up, though, the difference narrows. I'd still rather work with an XB head particularly because the chamber gives more material to work with, but power wise, a well prepared Thunderstorm head works good.

STD's are a different animal. Their standard configuration is a round raised intake port, with the breather holes raised to match so that the carb support still fits, and with extra material on the intake port surfaces so that the stock intake manifold fits. On the X1 application, it probably won't work with the stock airbox. But we've done it on at least one X1 that used a Forcewinder instead and there were no issues. You can get those tank accents from ASB to cover the gap left when you take off the stock airbox (and the stock air scoop on the left side).

Standard configuration on the exhaust is stock port height, so exhaust systems aren't an issue.

In the standard configuration with their porting job, they come with 1.940" intakes and 1.650" exhausts. With a factory head it's almost impossible to go that big because there's not enough room. With the STD head, they put an additional .060" onto the deck, making the head 3.750" tall instead of 3.690" tall, and this allows them to move the valves a little farther apart for more valve to valve clearance while still having enough eyebrow room. The problem it causes is that the chamber is typically on the order of 78cc as delivered with a bathtub chamber, where most XL pistons are made for a 67 or 62cc chamber. So CR is real low if you want to run something resembling a stock piston. If you deck the bejeezus out of the head to make it work, the eyebrow clearance goes away.

We have a piston with a dome that goes into this chamber and we deck the head down a little to get it around 76cc to get 10.5:1. Or, we can do angle domes.

What I'm getting at is this head is not really a bolt-on.

What we really like about STD heads, and where we move the most of them (and we do sell quite a few), is that they allow us to custom order everything about the head. We can configure it with valve angles that support the exact valve sizes and bore sizes we want, oval ports if we want, raised or not raised on either side, etc.

What we don't like about them is that they're time consuming to prepare, We're not set up to CNC the ports since every head seems to be ordered in a little different and there's not enough volume of any one configuration to justify the expense and trouble of digitizing. So they're all done by hand. And the material is rock hard, much harder than the factory aluminum, it's almost like grinding cast iron.

On the flip side, a well done set of custom configured STD's on a race bike can make some serious power. And the heads are really durable, great for boosted or nitrous applications.

Comparing a set of off-the-shelf ported STD's to prepared XB's or T-storms, I'd say the standard STD flows about like a Stage 2 XB or T-storm, peaking around 150cfm on our flow bench.

Don't ever go comparing flow numbers from one shop to another, though. There's a lot of variation in benches and setups. A flow bench's numbers should really only be compared with numbers from the same bench, same operator, same setup.

Thanks again for the info, I think then the STD heads might not be the way to go for me because I allready have a 88" cly kit. I was reading on your site about the stage 3 xb heads look good and see a custom mount avalible, what about my rocker covers, do I have to change them too?. Whats the diffrence from the too?

Nope, rocker covers interchange all years. All you have to watch for on that is the breather setup on 4-speeds. Don't want to put a 4-speed middle box on a 5-speed, it won't breathe.

STD's are actually best on big bores, because they move the valves apart to take advantage of the bigger bore. And of course that allows for bigger valves. I can only remember doing one set for small bore, a 1250 kitted bike, in all the years we've done them. And that was a race bike that was displacement limited to 76ci and he wanted everything out of it that we could get him (got him 129hp btw).

Wow...okay I will take a set of the std heads with huge valves and raised ports. When can I have them....is tommorow possible? :wonderlan

From what I'm reading, the Thunderstorm heads on my 98S1W should be decent heads as that was the first year they came out, correct?? The casting molds should have been brand new when my heads were cast.

If I were to consider a 88" kit for my Buell, I should consider the STD heads and then the Thunderstorm heads could be used for the conversion of my 06 883 to a 1250 with the proper pistons.

The STD heads can be ordered with the proper exhaust ports to keep any exhaust pipe problems out of the mix on my S1W. I plan on running a Forcewinder intake on the Buell so I wouldn't have any trouble on the intake side, correct??

Have any of you guys had any experience with the S&S heads ?? Are they worth considering also??

CJ,
Yes to all your questions.

As for the S&S heads. The STD heads are a whole lot better. S&S are about the same as XB heads.

That's all correct. Also, STD will do intake ports at stock height on request. We have to do that for Dan Norlin's race bike for example because AHDRA doesn't allow raised ports in his class.

Yes, we've messed with a lot of S&S heads. It's not my favorite casting, but with enough work we can make a good head out of it. I'd sure rather work with STD's. STD will custom configure the head for us, in terms of valve angles, port shapes and locations, chamber configuration, etc. That's the main advantage. Plus the material is a lot harder and stronger.

Once again thanks for all the info. I've got 2 grand saved and my S1W should be here next weekend :clap :clap :clap

Ok, one more question, if I were to get my original 00and01 X1 heads moded for 1.9/stage 3 VS buying stage 3 XB heads, what kind of power diffrence could I expect???, I want the 10.5 compression for sure. Maybe the STD heads would be over kill for what I am doing.

The parts I have so far for this engine is, SE 536 lift cam (KIT), Chrome Moly Adjustable Pushrods, zippers Collapsible Pushrod Covers/bases, s&s 1.725 Roller rocker arms, 88" big bore/Thunderstorm 10.5 forged piston (KIT), bike will have a baker chain drive and turning a 200mm tire.

I want to stay with using my buell race ecm, k&n filter and exhaust. I was panning on redoing my heads but now got confused with the other choices, I am also not sure now about other topend stuff like if I should be installing a Big Bore Throttle Body Kit and what I should do for my ignition Coil?, msd?, wires?... not up to speed on this stuff, any thoughts?

So you've got an 88 incher with stock Thunderstorm heads and stock throttle body, using 536's with high ratio rockers, right?

The stage 3 t-storms and stage 3 xb heads are pretty close in terms of flow. We can make a little nicer chamber out of the XB head but depending on what you've got for a dome configuration, it may or may not matter. So at Stage 3, it's almost a toss up between those two heads.

Once you do that, your throttle body will likely become the constraint.

Also, on those rockers, make sure you take a close look at the geometry. You may have to raise the rocker box with a spacer or extra gaskets to actually get more lift from those. High ratio rockers aren't really a bolt-in, geometry corrections are almost always necessary. I've literally slapped'em into a motor and with a dial indicator on the retainer, measured less lift, because they jacked up the geometry so bad.

Thanks for the tips. On the rockers the idea I had planned to try was to use s&s 1.625 on the intake and the 1.725 on exhaust, I know in the auto world this can help with a bit more power. I am happy now, I will stick with my old plan but now I will get my heads redone instead of just buying new sets. I was kind of hoping for about 120hp at the end of all this.