SE 203 cams versus Dan Mackie 510

[ken6217]

What is the performance difference in terms of low end torque and smoothness between SE 203 versus Dan Mackie 510 cams. 95" Motor.

[838]

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[838]

What is the performance difference in terms of low end torque and smoothness between SE 203 versus Dan Mackie 510 cams. 95" Motor.

You can call Gene Thomason, he tunes most of Mackies local builds (but doesn't have a pony in the race). You can find his number online, or PM me and I'll shoot it to you. Hard to get him on the phone though... he's always working.

He tests rides every bike he tunes, so he can comment on both smoothness and torque.

[calgary56]

Doubt you would see much of a difference. I have run both the 203 and 204 cams, I loved the sound of the 203 at idle, both pulled amazing at low.mid rpm, both would cruise all day at 70 -80 mph, but for the top end, I'd have to give the nod to the 204. As you can see by the attached, the 510 cam is damned close to either,

[ken6217]

I decided to go with the 203's if I can find them. Is it still currently sold?

I'm actually more interested in low end torque, and that's why the 203's. I had also wondered about the Andrews 21 bolt in.

Bike is an 95" '04 Road King, S&S Power Tune Duals (2-1-2), Supertrapp Fatshots with closed end cap. stock heads, 9.4 compression, TTS Mastertune.

[wolf_59]

for low end power consider the S&S 509 or Andrews 21 cams

[smoserx1]

I'm actually more interested in low end torque, and that's why the 203's. I had also wondered about the Andrews 21 bolt in.

I have used both of them and could not tell any difference in low/mid range acceleration.  Both were significantly better than the stock cams.  I have a carbureted bike and from day 1 had issues with cold weather "carb farts" (snorting and bucking at low speeds) with both the stock and 203 cams.  The 21s do considerably  better in this respect.  I had to use an N65C/48 needle/slow jet combo with the 203s to get decent low speed driveability below about 50°F.  With the 21s I now run a NOKK/45 combo and that saves a little bit of gas.  Plus I am using a conversion edition of the 21s with the 07 cam plate and hydraulic tensioners which gives me better peace of mind.

[rigidthumper]

95"/TW21 is an excellent touring combo, makes heavy bikes feel light.
The conversion edition (TW21N) with the late model plate, pump, chains and tensioners, along with new lifters and inner cam bearings, are the best way to address the cam cavity durability concerns in one shot.

[harpwrench]

How are you tuning this, with the headpipe and muffler changes you've made it's already probably way off? Has it been converted to having O2 sensors? What I'm driving at is when you bought it you liked how it ran so nicely. The other thing is that the disc count on the trapps can have a dramatic impact on low end tq

[ken6217]

95"/TW21 is an excellent touring combo, makes heavy bikes feel light.
The conversion edition (TW21N) with the late model plate, pump, chains and tensioners, along with new lifters and inner cam bearings, are the best way to address the cam cavity durability concerns in one shot.

I already did the cam tensioner conversion using the Screaming Eagle kit. Also added Johnson lifters.

[ken6217]

How are you tuning this, with the headpipe and muffler changes you've made it's already probably way off? Has it been converted to having O2 sensors? What I'm driving at is when you bought it you liked how it ran so nicely. The other thing is that the disc count on the trapps can have a dramatic impact on low end tq

I'm aware of the amount of discs and its impact on power, torque, and sound.

The bike is tuned with the combo currently on the bike now, of course. The slip ons that were on the bike were Crusher Mellows, which were too loud for me. I am going to play with the discs to get the right seat of the pants torque (and sound) for me, and then it will go on the dyno. The O2 sensors are used for the tune, and each cylinder will be tuned and make certain that both are the same.

I'm not looking to get the last drop out out of the slip ons with the discs, and play endlessly with the discs. I will just go by feel with it still not being too loud for me. I started with 12 each side and closed end cap. I'm going to take a stab at 8 each side today and compare, and then I'll go from there.

[harpwrench]