ADVICE NEEDED: compression on a 95"
 

I read the following link
http://www.nightrider.com/biketech/h...ompression.htm

So are these conclusions correct?

1) my 2005 FLTRI with 95" inch TW26a cams and stock heads most likely has 9:1 compression ratio.
2) Increasing my compression ever so slightly will increase low end torque and overall HP.
3) If I DON'T do any mill work and use a .030 gasket, I should have a 9.5:1 ratio (still pretty much stock; and NOT high compression)
4) If I Port and Polish the Heads AND the throttle body; this won't increase my compression ratio

am I wrong on any points?

RE: ADVICE NEEDED: compression on a 95"
 

Not getting too much...but is this right???

Camshaft, Rod Length, Boost and Altitude Correction to Compression

Your engine summary is as follows: Bore 3.875 inches, stroke 4 inches, rod c-c length 7.440 inches, with a static compression ratio of 9.5 :1. Your camshaft specifications call for an inlet valve closing of 37 degrees ABDC (after bottom dead center). (TW26 Cams)

Your chamber volume is 90.94 cc's. With this camshaft your dynamic, or effective stroke is 3.70 inches. Your dynamic compression ratio is 8.84 :1 corrected for cam timing, altitude, and rod length. Your dynamic cranking pressure, corrected for cam timing, rod length and altitude is 180.84 PSI. Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and 0 PSI is 8.84 :1.

Knowledge is power.

RE: ADVICE NEEDED: compression on a 95"
 

As for the 1st post...

1) agree
2) agree ~ in most cases
3) DISagree ~ I don't think you get but about .2 ~ .25 increase with the .030 gaskets over stock AND 9.5:1 is NOT pretty much stock. More than likely, it will be beyond the "sweet-spot" for the TW26A's ~ espically w/TX heat. I would check with Andrews before increasing CR to 9.5:1 with those cams. 9.2:1 "may" be OK.
4) agree
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Regarding the 2nd post...

Uhhhhh.....

WTF?

Dunno where all that came from but, unless someone has cc'd "your" combustion chambers, the manufacturing varainces and tooling tolerances will make it near impossible for anyone to say definitively what the size is. Therefore the rest of the values from their equasion become suspect, at least to me...

:)

RE: ADVICE NEEDED: compression on a 95"
 

Yes..Andrews agreed that 9.25 is the limit for tw26a. (But they didn't say if that was a dynamic or static limit) I guess I should stay with a stock gasket and no millwork to maintain a compression ratio that is good for my cams.