481ex dyno sheets

[MR FDO]

Here are some dyno sheets for you die hard 400ex lovers to look at. I've also got a 518ex (92mm x 78mm ) with a 14.7mm long rod that makes these numbers on gas and will rev to 11000 rpm. Who said that strokers cant rev! Oh yeah , 2 years and the same cases.

[MR FDO]

This goes with h.p. graph

[bwamos]

That thing is a monster. I love it. :)

[Chino886]

yes, tell me what all is done to it.....forget 416.....LOL! :devil:

[MR FDO]

This was ,origanally, a Trinity 460ex . The customer said that it made between 42 - 44 h.p. with 89mm bore x 74mm stroke. I installed a 91mm JE 12.5:1 piston , re-ported the head , installed 34.5mm stainless intake valves , a set of my heavy duty head studs , balanced the crank , made a custom air inlet to replace the stock air box and inlet , MSD ignition with a 6 degree advance key , installed a G T Thunder exhaust for the dyno ( Laz's pipe makes the same peak h.p. as the Sparks x-6 big core stainless shorty , but , Curtis's pipe gives a broader t.q. + h.p. curve by about 300-500 rpm's ) , I used one of my cam's ( approx. 260 degrees at .050 and .420+ lift , Kibblewhite spring kit and bronze guides , 41mm fcr with a 260 main ( that was the biggest jet that we had and it picked up ,allmost , 1.5 h.p. over a 250 main . That's about the whole 9 yards . He did install a fuel injection system on it , later on , and he said it picked up a serious amount torque + mid range without changing the top end.

[Chino886]

Originally posted by MR FDO
This was ,origanally, a Trinity 460ex . The customer said that it made between 42 - 44 h.p. with 89mm bore x 74mm stroke. I installed a 91mm JE 12.5:1 piston , re-ported the head , installed 34.5mm stainless intake valves , a set of my heavy duty head studs , balanced the crank , made a custom air inlet to replace the stock air box and inlet , MSD ignition with a 6 degree advance key , installed a G T Thunder exhaust for the dyno ( Laz's pipe makes the same peak h.p. as the Sparks x-6 big core stainless shorty , but , Curtis's pipe gives a broader t.q. + h.p. curve by about 300-500 rpm's ) , I used one of my cam's ( approx. 260 degrees at .050 and .420+ lift , Kibblewhite spring kit and bronze guides , 41mm fcr with a 260 main ( that was the biggest jet that we had and it picked up ,allmost , 1.5 h.p. over a 250 main . That's about the whole 9 yards . He did install a fuel injection system on it , later on , and he said it picked up a serious amount torque + mid range without changing the top end.

That's it.....:devil:

[chad502ex]

6 degree ignition advance key with all that tq????

being that engine has tuns of crankshaft leverage and bottom end, I would think the "power" balance would be to remove 6 degree advanced timing in the upper rpms to crank up the hp numbers even further. ;)

I mean ,..... great numbers.

[tar]

!:eek2: !

[MR FDO]

Your theory on less advance = more peak h.p. is true , but , different engine combinations have different requirements . In this application , I feel that the shorter rod ratio ( rod length [122.7MM] divided by stroke [74mm] = 1.66:1 ) which is caused by adding stroke and not lengthening the rod , and the use of methanol were the main influences for the advanced timing . I classify rod ratio's as follows ; 1.50:1 - 1.70:1 low/mid , 1.70 -1.85 low/top , 1.85 + mid/top . What happens with short rod is , the piston enters and leaves t.d.c. at a faster rate then the others do , causes it to try to outrun the flame front when the piston is leaving t.d.c.. The trick is to try and start the flame earlier without getting in to a detination situation . As for the methanol , it usually requires more timing because it's burn rate is much slower than gas . Everytime we advanced the timing it allowed us to raise the main jet . Anytime you can burn more fuel you'll make more power .

[armoks]

got damn that's some awesome power!!!!!!!!

[kory]

thats sick give me some ideas to do to my quad beside touching the motor i have a hmf slip-on skid plates k&n airfilter white bro rev box bars different clutch

[slipp]

can you build me one similar to this?

[ride_red666]

u got pics of that quad?

[MR FDO]

This was a one time deal . I took his existing combination and made it a little better. I don't use 4mm strokers , by choice. I normally 6mm or bigger. I am currently working with another shop on a kit that will have a 78mm stroke , 9mm longer Carillo rod with a 12.7 mm spacer plate . This kit will allow the use of any off the shelve piston with a stock wrist pin location . Displacement would be anywhere from 442cc's ( 85mm bore ) to 518cc's ( 92mm bore ) . Any bore from 89mm and smaller will not require any case mods . If you have anymore questions , you can email me at FDORACING @ ADELPHIA .NET .


MR. FDO
MIKE

PS; I have a project going on right now that will take the 400ex to 552cc's ( min. ) or 600cc's ( max. ) .:macho

[hondaexryda]

FDO, how much do you charge for porting, and valve size reccomendation (440) ?