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that's fast man for stock engine.
Our rules allowed a nosecone, a 1" hole in each side of the exhaust channel on the lower unit, aftermarket reeds, must have reed stops installed to factory spec, Tohatsu's allowed to tack weld crankshaft, all else stock.
D
no port & head work, yammie is bit sluggish
Mark - your new design looks very innovative. i'm glad that the TBDP software has worked so well for you. Your hull is a great looking boat! Good work!Originally Posted by MN1
I note you're using an "s-shaped" aerofoil section. Let me know how it is working out for you....very high lift shape, so very efficient....as you know, this shape also shows a somewhat dramatic shift (foreward) in dynamic CG during deceleration, so can require some nifty "driver input" under conditions.
stay in touch, and send pics!
/Jim
Jim,
Today was the first test of all of the changes I made to my boat. All went better than expected. We have not lost any RPM's but gained 1 to 2 hundred. The boat is now very close to blowing over but not so fast that it's easy to catch and trim under. The cornering has improved but we need more test time to improve the technique. It's seems like the boat wants to be trimed out in the corners. So, more testing of different driving styles in the corners will be tested next time out.
Here are a few photos from today.
Mark
Looks good! is that the tunnel design that we corresponded about recently? The modelling we did showed some good results. Glad that the testing is showing same. Send me some details of your performance observations. Good work, Mark!
Well, the last one we taked about was a SST-60 which is planned for this winter. For an un named driver.
It will be an improvent of the exisiting SST-60 designs out now. I need to send some more drawings for you to looks at. But work is still busy here. I hope to in a couple of weeks.
Mark
Mark,
Will you be bringing your Sport C to Minnesota to race next summer?
Tunnelboat and V-bottom Plans for 15-35 hp, 40-60 hp, 60-80 hp
Dillon-Racing.com also on YouTube, on Facebook, on Twitter
Yeah Mark, will you be bringing the boat? Have Sam bring his 60 boat!
For those of you who are not familiar with Mark's and Sam L's project, the boat was extremely fast during the debut. It looked to be keeping up with 45 boats! But with the weight being added to meet the rules the boat seemed to kill the momentum. I hope in time he'll have it iron'd out and most importantly showing up at every C race in the midwest.
The TCPBA (MN boat club) would really like to see the Nelson boat, Kratochwill, and Carl Barrett sport c boats racing again. Those are three very strong teams that all have good equipment.
Regards,
Brian
OMC 45 twin on a tunnel
If it is a stock 40 hp I would suggest 6 part swaps to make it a 50hp.
and 2 more after that to make it equivalent to 45ss = 62 hp.
1. 50/60 hp carbs (1.5" dia throats)
2. 50/60 hp reed cages(stop height was different in some models 50 vs 40).
3. 50/60 hp cyl head smaller dia chamber with less cc's.
3a. mill 50 head for .515 chaber depth = 45ss spec.
note: milling 40hp head IS NOT the same.
4. set timing to 21degs(you can run more but 21 is a good place to start)
5. make a cowbell tuner
6. make sure power pack does not have rev limiter.
1-5 = about 62 hp @ about 6,200 rpms on pump gas
1987 is a good block and hp won't fall off significantly until 7,200 rpms that will put you in
low 50's with stock OMC original 21 p (made for 50twin has extra cup from factory to run engine a litte higher on the transom)
after that see Ron for a prop and he will get you dialed in
ANTHONY McCULLOCH
modifiedoutboard@hotmail.com
Some things never change!
They Want it cheap..............
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