Racing exhaust for laker 49 OMC

[Mark75H]

the stock exhaust is a through back from cross flow days, it's for trolling, cuzz weekend fishermen buy new motors. best melted into some thing else unless trollin is what your lookin to do.

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[formeone]

CANT WE ALL GET ALOOONG,,,HEHEHE,,,,,, well let me tell ya straight up,,, after retireing and now getting back into the sport and testing everything i can think of from a poor mans perspectuve,,,, only cause you guys mentioned my name,,, ugg ,,hehe,,, i have bin testing every thing i can thionk off.... different versions of my exhaust bigger dia pipe out let smaller and different box area on the motor,,,,, i have 3 motors allll different in porting also,,, the v-rude like a bit of back pressure,,,, and i dont care what exhaust ya run,,, ya need to cut it .. to tune it to your porting,,,,.. ie pulse tuning,,,, and if ya run it out the bottom,, it doesnt pulse tune,,, cause of the fireing order,, proven to me by a x-merc engineer race engine builder,,,, as far as ignition,,, i run v-rude,, no limit power pack,,,, have bin blowing them every 3 races ,, have head engineer on it for me at rapair.... other wise bullet proof,,, and i turn mine over 8k even with the 11 lbs stock flywheel.... i tried similiarities of tims front case that i built,, ie snowmobile/seadoo,,, intake,, was good but lacked torque,,, so shelved,,,, came up with my own version of reeds useing socke cages,,,, way better down low power and mid and the usuall top end,, since reed usually always open for most part at top end... i use small rods,,ie early motors,, wiseco or v-rude pistons.... since me small budget... i dont bother balanceing them,,,, i do hone rods,,,, as far as porting them have worked over the intake and exhaust,,, moveing the center intake a little better,,, on top end that it,,, the key is in the exhaust port,,, wont tell ya what ,,,but for the 75$ that john meyers charges me.... he my man,,,,,,, as for the intake i have tested big 75hp carbs and the normal 65-75 hp carbs ,,, not mutch differance ,, bigger 75 hp carb suck more fuel that it ii actualy set record with the early 55 or may be 60 hp 3 cyl carb,,,,, smaller venturi,,, as for milling the head,,, dont do much there,,, i have heads stock heads milled up to .250,,, to test,,, got to watch your timeing on the motor,,,, i have tried other peoples heads that advertise v-rude parts on here,,,, they waste of money... slower...,,, you need torque in this class,,,,, also some of the props well known prop builders pedling,, no where neer what ya need.... i run 8"-9" dia,,,,3 blades....,,, as far as boost porting/finger ports like the mod 50.... you guys suk,,,, unless ya want to run small d-mod wheels,,,, the extra ports take the torque out of the motor,,,, ni have worked stock intake over a few different ways to no avail as of real kik in the but power or speed,,, i just match to block,,,,, and i miss match them all the time,,,, this is from cheyney,,, straight up[ ,,, i ran 84mph at lawrance in the turns and 93 on straights,,,, my faster set up was 88mph in turn and 95mph straight,,, but wanted to blow over,,, that 1mile course with new certifed speedo,, old school,,,,,,,, i only wrote this cause i think lots of people think it expensive to race class,,, it not,,, i would spend twice that on a merc.... and have,,,, most people dont realise you need a different boat,, to accomadate the v-rude... like yamato was 30 years ago,,,,what REALLY REALLY gets my goat is people charging alot of money for v-rude parts that arent tested,,, and are NOT that mutch of a improvement..... over what they can do with a grinder themselves,,, seems to me..... if ya cant put a 90 mph ride together in v-rude from what ive coughed up here... e- mail me and will answer your questions,,,,, it not hard,,, iii want the class to grow and push the speeds... my next and in works project 2 piper c-mod/102... also working on v-rude runabout, overdrive,,,mmmm,,,cheyney

[Tim Kurcz]

Cheney is right, The OMC loop triple runs very well as designed with a decent exhaust system. Here's the factory "sandwich plate" system. Wall thickness is 3/32". There's little you can do with it except go fishing. Grind much anywhere and you break into water.

One of my best engines (the Pooch) was exhaust ported with no finger ports, stout compression, Boyesen reeds, and my fabricated steel top outlet exhaust. 95.5 GPS every day down the straights. My Kestrel "special" delivers the century mark, but takes alot more work and $$$.

Traveling again through the weekend, so the "laker" exhaust (improved Nydahl copy) is delayed until the week of Feb 25th. More then.

Tim

[OUTBOARDER]

Well a lot of pontificating been going on but reality will knock sometimes.
inboard APBA mod kilo record was set using NLA Inland Jet pipe on Kawasaki Triple.
Not as much power as three pipes but enough to do the job. The Engine Guy that developed the pipe for inland jet is dead now but I did talk twice about the exhaust system.

PS: I never have given away parts to be tested, I know what they will do beforehand, Just do not need a endorsement based on opinion of someone that is getting free stuff. If you want to know to whom this is adrerssed email me I aint scared.

In closing if you aint got patents you aint a designer.

[sabine river killer]

why was this last picture on ebay

[OUTBOARDER]

why was this last picture on ebay

measured the system and can make them for outboards .
Won't use silicon couplings, v-bands hold up .

[formeone]

just some pics of my 3 motors soon to add another copy of the one that did104mph,,,,bounce pipe motor slowly tuneing on,,, seems to have some good potential 88mph so far...

[Tim Kurcz]

Hi all,

Have been building three NBRA legal powerheads to send down south and stir up some controversy, diverting energy from the exhaust program.

But, just compared the OMC Mod-50 exhaust which sticks out 2.660" from the engine block to the modified Nydahl which is another .090" so it will fit under the factory cowlings.

Many thanks Cheney, for posting images of your work. Looks like alot of work & testing.... I hope your hunt proves out.

Tim

[ultrafast30]

Any updates on your exhaust ?

[Tim Kurcz]

The Kurcz-Nydahl exhaust system is on hold for one more week while four powerheads are assembled. The pattern has yet to be sectioned, welded, and massaged for casting. First castings should be available mid-late April.

Tim