+5 Crank on a 727??

[socalrappy700]

Troy,
What was your build before you put the +5 mill in?

[preddy08]

Yeah what he said

LOLOLOLOL

[Troy]

stock bore and stroke.  I still don't see where big bore alone is much faster than stock bore.  The guys that I know around here that have went big bore don't seem to be alot faster.  It seems like the stroker guys are fast as hell.  He already has the big bore right?  It only makes sense to get the crank and he'll like the gains for sure.  I know we've had plenty of discussions on what makes more power stroke or bore, the 5mm hotrod will give a stock bore 727 just like the 105 bore will.  If I had to choose how to get 727cc's, I would get the crank hands down.  I have both though so I'm happy with my little 770, I can probably be able to follow Raptor Randy on his little 780 and actually be there beside him by the time he stops and takes his helmet off, LOL

[socalrappy700]

Both krandall and I have 105 bore 727 and some of the people that have added the +5 crank to that have only seen the gain on the bottom end and not as much on the top end.  That would be my biggest hang up.  I want the gain on the top end.

[Troy]

I know my bike has good top end, I can reel in guys and blow by them now that I couldn't catch in a race before if they got the holeshot on me.  Maybe I got lucky.  Keep in mind my bike is pretty slow, maybe the faster guys aren't seeing the gains I did.

[socalrappy700]

but you were a stock bore/stroke before.  I saw those same gains when I went to my 105 bore 727.

[Troy]

I'm probably wrong then.

[Colorado700R]

so since HP is a function of RPM, would a shorter stroke (IE shave the jug) with a Big bore produce more total HP and less torque?

Aaron

[Troy]

If strokers didn't work the big boys wouldn't be running them IMHO.

[socalrappy700]

I'm probably wrong then.

Maybe not, its hard to see where the gain came from on your build since you added the 105 bore and the +5 crank.  I think it still might be a good combo and I bet you saw gains from both of those mods.  What did you get on the dyno?

I'm just trying to see if adding a +5 to my 727 would be worth it or if I should think about something bigger if I really want to go with more power. 

[socalrappy700]

If strokers didn't work the big boys wouldn't be running them IMHO.

Totally agree, my only concern with this one is that its a shorter crank so it can be used with a stock piston.  I'm not sure I'll see the power gains where i want them if I add it to my 727 105 bore.

[Krandall]

so a bored 727 w/ a +5 crank turns into a 770?

that's awesome. :grin_nod:

[Troy]

I would go bigger if I was planning a stroker motor for sure.  The 5mm Hotrod is a great crank for what it was built for.  It is a cheap alternative and better built crank then a stock replacement crank and it won't lose power for sure.  I'm going to be tuning in some new parts in the next week or so, I'll report dyno numbers then.  My bike probably won't even get the rollers turning now.

[Troy]

If strokers didn't work the big boys wouldn't be running them IMHO.

Totally agree, my only concern with this one is that its a shorter crank so it can be used with a stock piston.  I'm not sure I'll see the power gains where i want them if I add it to my 727 105 bore.

I would go bigger and be done with it.  The offset of the crank on any crank determines if you can use a normal piston or not.  If it's a 12mm crank offset 6mm, you can still use a stock piston.  The long rod is where it will change things i think.

[RaptorRandy]

I think your being too modest Troy....I'll bet that thing hauls the friggen mail and there's not but 1mm of difference between your +5mm stroke 105mm bore  and my +6mm 105mm bore. I'm sure you would give me all I can handle in a race