Calculate engine displacement

[Panhedbob]

If you've ever considered boring out or stroking your pan and wondered how many cubes you'd get I found a neat little site that will compute it for you. If you go to http://www.nightrider.com/biketech/calc" onclick="window.open(this.href);return false; ... cement.htm and punch in any bore and stroke in fractions, decimals or metric it will instantly give you your cubes. So I punch in 4-1/4 bore x 5-1/4 stroke and it says 149 cid. Who the heck's gonna kick this thing?
Seriously, what's the biggest pan you ever heard of? That actually ran? I bet everyone would be interested in the answer to this question.

Personally, I have a hard enough time with 74 cid!

[Ente]

Hi....
You can also use http://www.jalsbo.com/html/ente/z_cubic.html" onclick="window.open(this.href);return false;
with pre-defined sizes and overdimensions.
If you use a standard case and not some S&S or Delkron.... it's hard to use more then 3 5/8 in bore, so you will have to mega-stroke it. I heard one put in 5" flywheels... It make 103 CID.... dont think any 'panlover' will do that to the old lady... All the other big-CID's must be in non-standard cases.... And are actually no panheads...just modified evos with pan-looks.
Just my thoughts...

[dirtydistrict]

Well a friend of mine; real motorfreaker and fine mechanics change for a sidewinder kit, he runs something like 1400 cc on his 52; a real bullet!! In fact after few years with these light weight flywheels and shovel style intake manifold he finally told me that he had lost what makes a Panhead: inertia and torque.
74 is enough for me too, i'm seeking for an everyday scout that can lead me any far i want even if I'm very very interested by how many hp a well prepared pan would give

[Ente]

...and my own lady still have the 3 7/16 bore but the sidewinders 4 1/2 flywheels.. +020 in overdimension, so it's an 'hold your hats' incredibly super-incher with a displacement of 84,5 cid..... *wrooooom*

[Cotten]

Divide your bore by 2 and then multiply it by itself. multiply that by 3.14, then by your stroke, then by 2 .
T'aint rocketscience.

My wife's stock 74" '65 pulls the hack much better than my 4.5" stroked '65 because the S&S wheels are too damned light. If you want real balls get Truitt & Osbourne's nodular iron "Torquemonster" flywheels in whatever stroke you want.

[dereborn]

Now THAT sounds interesting!!! Where can I get more info 'bout dem Torque Monsters??

[Cotten]

I don't know if they have a web presence; They are in Kansas somewhere, but they answered the phone this morning! The TorqueMonsters retail at a very competitive $295 (compared to S&S).
I just assembled and balanced a set (not my first T&O's!) and you cannot get the mainshafts in crooked if you tried. Truing the whole assembly takes a bit more patience, of course, but both sides came in to less than a half-thou out, if you press and pry the wheels instead of resorting to the "lead wrench".
And although I fudged in some evil evo rods (I was surprised how "muddy" they were when I straightened them, even after polishing and shot-peening) the balance was 62% before I started drilling. Not bad at all!

[57stroker]

I've been running the 4 1/2" TorqueMonster set since this spring. I bought them assembeled and balanced with H - beam rods and Jims machining shafts. A LOT snappier than the stock flywheels. The motor won't roll quite as slow in 4th gear, but only about 5 mph difference between the two motors. The only other downside I can think of, is Truitt & Osbourne doesn't include any instructions with the flywheels. Luckily, I had a friend that has stroked a few motors and had a leftover copy of S&S's instructions. As I recall, the cases need to be clearanced slightly and the breather valve needs to be opened up. Cotten probably knows more on this. At any rate, it's not just a drop - in deal. Sure hauls ass though....

[dereborn]

I'm really getting interested in these flywheels! A few more or less stupid questions:
1) What's "nodular" ?
2) Is it simply the weight of these flywheels that increases the torque?
3) Are they available in standard stroke, and if so, can I use my original rods? Any advantages/disadvantages in choosing between original and for example shovel or s&s rods?
4) Suggestions regarding stroke? Stay in standrad or go for a longer stroke? Reliability aspects?
5) Can anyone get me the number/address to the company making or selling these babys?

Thanx a lot!

[Cotten]

Nodular refers to the microcrystalline structure of the cast iron. Polished crossections would show tiny spheres under a microscope. You would have to talk to a metallurgist for specifics.

Flymass (weight of the wheels) is what gives your motor useable power. Horsepower is great for beating the clock, or merging with traffic on the Autobahn, but hauling a healthy ol' lady plus camping gear while pushing a windshield demands torque.
Flymass hinders maximum acceleration. So hotdog raceing parts companies like S&S shaved the weight considerably, so the motor could rev quickly into the powerband. But at the cost of streetability for heavy payloads.

T&O will make you any stroke you want. Just like S&S.
Your stock rods are fine, if properly rebuilt and straightened.
4.5" stroke (giving 84" on a stock bore) is not extreme.

T&O advertises widely, but I didn't bring any address info home to post. Sorry.

[Ente]

...and I guess it's couple of other positive side-effects as well with the increased mass. Smother idle, less jerkiness and wear on the tranny.... Sounds like a must next time the cases are apart. (Right Dereborn ??)

[dereborn]

Yes, this definately sounds like my cup of tea! Only problem seems to be to get hold of these "torquemonsters" here in Sweden... If I go for 4,5" in stroke, how about compression? Should I go up to like 9:1 or stay low? Still high priority for reliability! What pistons (and rods?) do you guys recommend? Should i consider bigger valves? (shovel 1,9"?)
Oh, how lovely that even the upcoming winter seems to be lots of fun!

[dirtydistrict]

Men, i allways been told Swedish were motorfreakers..that's God d....d true !

[Cotten]

Dereborn!
9 to 1 would be much too high here in the States, because our P4gas would pre-detonate. Perhaps your fuel is better?
Even still, the heavier the bike and payload, the lower the compression needs to be for durability.

In practice, your choice of compression really comes down to the availability of pistons. The standard for stroker pistons was set by S&S (TRW), who supply a range of compressions. But common catalog offerings, which are much more economical, normally only offer something in the 8 to 1 range, which is fine. Their source is usually Korea, which is fine as well. (Pistons are rarely the weak link.) Go lower if you intend to pull a sidehack or trailer.
Your stock cam would work well in this range. If you upgrade, stay mild, and avoid 'racing' profiles such as Andrews offers.

As I posted earlier, your stock rods will do perfectly well, if properly refurbished. This includes accurate re-alignment after the races have been re-honed, and the gudgeons re-bushed.
Shovel intake valves in a Panhead are a waste of money and gasoline, as the ports are not efficient enough. If you have your ports "flowed", you may gain a little at RPMs that you would rarely use, and lose the low-end torque that makes a Pan the locomotive that they were intended to be.
Balancing would be your next concern with raw flywheels. It is not hard to do:
http://virtualindian.org/1techflywheel.htm" onclick="window.open(this.href);return false;

(Again my disclaimer: Don't anyone think about sending me motor work! I'm booked up solid for years and years.)

[dereborn]

Cotten - I just don't understand how you can get the time... Thanx a lot for your explicit answers!

I think the gas here is somewhat different, as I hear guys all the time talkin' about ther 10:1 and even 11:1 monsters. I think I'll just stay at 8:1 or maybe 8,5 as my ride is originally an FLH, which (as i learned here on this board!) had just the 8,5:1. Good to hear that I don't have to worry 'bout the valve trick, as it's just the opposite way that I'm heading! I'm looking for "truck passing power" - not top end. I'll stick to the Sifton cruiser cam that I've got.
Again - thanx a lot!

P.S. If you find the time - pls send the address or phone for T&O