The HTCC heads have a huge 2" intake valve. Although HD claims this helps with low lift air flow, it also reduces the velocity of the intake charge. The velocity of the intake charge helps with cylinder fill and will improve the Volumetric Efficiency of the engine. IMO, a 2" intake valve is best used in larger engines and with high top end HP and is not as effective in the Low RPM range. I am not familiar with the porting that was done to the heads but IMO, the HTCC heads are typically improved at the top end of the scale with porting. When we port the HTCC heads we concentrate on low lift flow and not top end flow.

More to consider. Did you CC the combustion chambers? Often times the combustion chambers are larger than the spec. Stock heads are a prime example. Stock heads are suppose to be 85cc but fall anywhere from 84-91cc and average in the 86-87 range. The SE heads are no different and vary considerably. This can dramatically effect your compression ratio. In turn the compression ratio effects the cam choice or vice versa. Through into the mix the deck height and you may find your compression ratio is no where near where you thought it was.

Next, the HTCC heads have a large quench and when coupled with HTCC piston, the quench is often larger than is should be. Sometimes falling in the .060-.075" range. A better quench would be in the .035-.040" range. To accomplish this, the deck height and/or the head can be adjusted (milled). The choice of head gasket will also effect this. In the HTCC builds, adjusting the quench also effects the compression ratio so it is a fine balance between head gasket thickness, deck height and combustion chamber volume to determine compression ratio and setting the quench. If I'm not mistaken, the SE 16101-01 head gaskets are .060" and this compounds the above mentioned issue. I have not measured a SE head gasket as we don't use them but for some reason I have the .060" thickness stuck in my head (I could be wrong).

Valve springs. I am a little confused as it states you used 18273-00 valve spring kit. These are the springs that come on the HTCC heads when you buy them, if I'm not mistaken. Not sure why they were changed out but that isn't affecting your specific question. What did catch my eye is they are designed for up to .575" lift and the SE-251 is a .579" lift cam. It seems 18223-98 with slightly less spring pressure and higher lift (up to .620") might fit your application better if you are looking for more low end torque and don't plan to ride in the 5500+ RPM range as much, of course this depends on the aggressiveness of the cam as well. Higher spring pressures require torque/hp to compress. Choosing the right spring for the cam is free HP.

According to your parts list, 22440-00a is a +.005" Piston. Curious as to why you started with a oversized piston. In pointing out the obvious I have to ask if the cylinders are +.005" as well. Did you start with your stock cylinders or purchase SE 95" cylinders. I can see boring the SE 95" cylinders to get a better fit piston but if starting with stock this could be achieved going to 95" STD bore.

Also I didn't see mention of the exhaust gaskets used. If stock exhaust gaskets are used and the exhaust not perfectly fit and then over tightened, it will crush the gasket into the exhaust port blocking your port. SE exhaust gaskets help prevent this.

Whats the Cranking Compression? I would not be concerned about the stock throttle body, it should get you well into the 100's before it is holding you back.

Now, please don't take this post wrong. I am not picking on your build but merely pointing out the things that jumped out at me. With stock engines and 2 identical bikes, same years etc. You can have a good one or a bad one. If you get the one that has 84cc combustion chambers, a -.007" deck height and nicely fit exhaust AND your buddy gets the one that has 91cc chambers, -.015 deck

 

Springer makes some great points, if you are running .060 or greater quench distance, you give up the benefits of a turbulent chamber. It makes them fussy on fuel as well as the resultant low compression and lack of some mid range

In addition, if you have stacked tolerances when it comes to deck clearance, chamber size,piston crwon design, you could be well UNDER the compression you think you are at, add the big ports and big cam and you end up losing power

Springer---question for you, how does the head change quench distance on a Harley? I can see the issue of using a thick gasket, or having excessive deck clearance, but generally a cylinder head's quench pad the same as the head gasket surface. Basically they rely on the quench area of the piston and the deck clearance, milling and/or changing heads in other engines wouldnt affect quench.

That is of course assuming the quench area is on the same plane as the head gasket surface and not a hemi style head or something like that

Finally, how do the HD guys degree their cams? Intake centerline can make a huge difference on where cyl pressure peaks and also cylinder fill / power

Learning the HD stuff particulars now, thanks

 

The HTCC piston/head combination uses an angled squish area (quench), therefor milling the heads also reduces the quench. With a stock head/piston combination this doesn't apply.

 

Springer,

Great points. I sure appreciate your thoughts. I want to try and call you at the shop to make sure that I understand some of the points that you observed. I am trying to prepare for a "what went wrong" discussion with the service manager and head wrench at Mancuso. So, I want to make sure that I have my points straight in my head.

How's the best way for me to contact you during the day? When I call, who do I ask for, Springer?

BTW, I have a buddy up in Carribou who farms potatoes. I have driven through Maine. A great State for sure.

 

Can you post up the dyno charts? Like to see what your torque curve looks like. That may tell a lot.

 

Good info Springer

Myself I am not fond of an angled quench pad, I like to see the whole pad flat into the chamber with the whole thing being .035 or so (no more than .045) with a matching quench pad on the piston, and if compression is too high, you use a reverse dome that matches the chamber shape to make some room, but leave the tight quench area.

A setup like I described is very detonation resistant and generally keeps the flame pattern moving fast toward the chamber

Lots of guys trying new things though, some guys are even grooving the quench pad with an agled groove that allows a burn path toward the center of the chamber for any trapped air/fuel during quench. Been pretty promising

Cool stuff, cant wait to play with my 07, but I think I'll let it break in first LOL right now <300 miles on it

 

Dont know as much as some of the guys here on line when it comes to engine builds only my experience but I think youre tq # seems low also I also have a 06' intake (46mm I think ) and I am making 94 tq on a motor runing 9.5:1 with se203 cams seems your set up should do what you were looking for I did not want more than 10:1 but one dealer wanted to do basicaly youre build and guaranteed 100+ tq with the se251and around 95hp. But I know dyno's very quite a bit the one @ my dealer that I use for tuning reads lower than some of the independant shops in my area with the same bike? diffrent dyno? diffrent tuner? dont know but when it comes to dyno's I realy only look @ my lines and air:fuel ratio's because peak #'s seme to vary a lot.

 

Guys,

Here is the Dyno Chart. I hope!

 

Everyone that I know locally who used Mancuso came up short on the numbers with their build. Each time a different excuse was used. This is not rocket science, people get 100/100 all day long with a mild build, unless they went to Mancuso. Ever since they lost a tuner named George their tuning leaves much to be desired. I would not let them grease a jiffy stand. My oldest friend let them do his 95" build and the end result was worse than your. He sold the heads, bought some new stock ones, and sent them off to another porter. When he bolted it back together with the new heads it made 17 more hp and there was an even bigger increase in the torque. Good luck getting it worked out.