Author Topic: Time to freshen up the F Model bracket bike (Read 120317 times)

dragracer · « **Reply #575 on:** October 04, 2016, 08:45:48 PM »

60' ranged from mid 1.40's to 1.50's this time out. Couldn't get in a rhythm of consistency for some reason. We ran 1/8th mile at this event. ET bounced from 6.50's to 6.60's. Was having serious rider error. I'll get my MSD rpm window switch on the bike to activate my launch light by the Cup race. It'll help with the consistency on the launch rpm. You can't win a bracket race without repeatability.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #576 on:** October 04, 2016, 08:48:10 PM »

I like .000 better than just saying triple zero

Helluva job. Looking forward to seeing one next month.

dragracer · « **Reply #577 on:** October 04, 2016, 09:54:46 PM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on October 04, 2016, 08:48:10 PM

I like .000 better than just saying triple zero Helluva job. Looking forward to seeing one next month.

Lol Jerry. It was just a hair from a red light. I think that's the reason my reaction time the next round was way to conservative. Scared to push hard again for fear of a foul start. Instead it left me at a deficit right off the line that resulted in a loss before I even crossed the finish line.

I've got to get myself another pocket practice tree soon. My lights need work to get more consistent.

See you in November bro.

dragracer · « **Reply #578 on:** October 04, 2016, 10:06:06 PM »

Sunday eliminations.

Bill/BentON Racing · « **Reply #579 on:** October 05, 2016, 09:31:02 AM »

You cleaned it! Looks great! You don't need to get any better! Lol, Bill

Medyo Bastos · « **Reply #580 on:** October 05, 2016, 03:30:43 PM »

red, gives you an extra 10HP, everyone knows that

dragracer · « **Reply #581 on:** October 06, 2016, 08:45:38 PM »

Quote from: Medyo Bastos on October 05, 2016, 03:30:43 PM

red, gives you an extra 10HP, everyone knows that

Well, that explains it all!! Might be time to freshen up the paint then. It could net me another 3
tenths off my ET.

scottly · « **Reply #582 on:** October 06, 2016, 10:04:05 PM »

A 6.55 1/8th is about 10.28 in the quarter; knock 3/10ths off that and you'll be in the 9s. Not too shabby for a worn out motor. I think it's just getting broken in.

Seriously, did you ever run a leak-down test? Are you running aluminum rods, which have a tendency to fail catastrophically from fatigue?

dragracer · « **Reply #583 on:** October 06, 2016, 10:53:58 PM »

Quote from: scottly on October 06, 2016, 10:04:05 PM

A 6.55 1/8th is about 10.28 in the quarter; knock 3/10ths off that and you'll be in the 9s. Not too shabby for a worn out motor. I think it's just getting broken in.
Seriously, did you ever run a leak-down test? Are you running aluminum rods, which have a tendency to fail catastrophically from fatigue?

Scottly, the old motor only has HD steel rods. Never did a leak down but really need to soon. I've been trying to concentrate on only racing the bike at Cup events this season for the most part. Trying to preserve it as much as possible to get to the end of the season. I won't feel comfortable doing another race season with out tearing it down. I'm truly more concerned about the crankshaft than anything else as it's shown signs of wear for a while. I just keep installing fresh bearings to keep the clearances from getting out of hand. I'll be installing another crank in the off season and will reevaluate the worn bores to see what my options are for salvaging this particular 72mm bore cylinder. I've been holding onto a set of new Arias 73mm pistons just for that reason. Hopefully the mtc pistons aren't so beat up. I'd like to put them in another block and keep running them in a back up engine.

Will post the results of the leak down test.

Bill/BentON Racing · « **Reply #584 on:** October 07, 2016, 10:26:01 AM »

Valdosta should be fun...Frank's 60ft times, ........we'll I'll keep trying, but did run 6.69 @ 106.xx in the 1/8, with .2 slower 60fts! I'm getting closer, lol, Bill 10.54 my best so far, Frank 10.345 I think!

dragracer · « **Reply #585 on:** October 07, 2016, 04:26:23 PM »

Bill, you're more likely to hit that 9 second on raw horsepower long before I do. It's just not a practical goal for me.

Keep working on the launch and you'll surpass my 10.34 ET. You already have me beat on the mph. It's that nice head that Mike work on that's doing the job on your engine. Maybe one day I'll get Mike to hook me up so I can be like you.

Bill/BentON Racing · « **Reply #586 on:** October 08, 2016, 07:36:42 AM »

LMAO, haha, but my bike, you riding.....lol, now that would be a surefire combination! You guys ok? Bill

Jerry Rxman Griffin aka MuthaF'er · « **Reply #587 on:** October 08, 2016, 09:57:52 AM »

Bill, thats a great idea! Throw yer leg over Calendar Girl Frank for one or two passes. Frank's ass dyno

Frank, you staying dry?

dragracer · « **Reply #588 on:** October 08, 2016, 11:29:26 AM »

Lots of high winds and rain earlier. Rain slacked up a bit but the wind is still gusting over 35-40mph. Small limbs downed all over the yard. A few blips on the power but we never lost it for long. Been up since 4am dealing with issues at work. Power outages etc.. Although we're getting plenty of water falling from the sky, we've still got to keep the water flowing underground through the mains. It's going to be a long day.

madmtnmotors · « **Reply #589 on:** October 08, 2016, 12:14:54 PM »

Quote from: dragracer on October 08, 2016, 11:29:26 AM

It's going to be a long day.

I feel your pain! I tossed a note into the wind wishing the recipient "Good Luck", so keep an "eye" out for it!

dragracer · « **Reply #590 on:** October 12, 2016, 06:15:32 AM »

A few pictures of the F model back in the day. Taken during a race at Daytona bike week circa 1999 or so at the makeshift track at Deland airport.

754 · « **Reply #591 on:** October 12, 2016, 08:24:49 AM »

What times was it running then?

dragracer · « **Reply #592 on:** October 12, 2016, 10:06:43 AM »

6.80's/10.80's. Had a 5.5" slick on it then.

Bill/BentON Racing · « **Reply #593 on:** October 12, 2016, 04:00:10 PM »

LMAO, been running 10's at least 18 years or more on a 750!

dragracer · « **Reply #594 on:** October 12, 2016, 04:57:32 PM »

F model head, k model pistons ----- not a Cobra motor. Got good advice from the late, great John Sands on making this combination work.

scottly · « **Reply #595 on:** October 12, 2016, 08:44:38 PM »

Is this the exact same motor after all these years?!

dragracer · « **Reply #596 on:** October 13, 2016, 05:29:08 AM »

Quote from: scottly on October 12, 2016, 08:44:38 PM

Is this the exact same motor after all these years?!

Yes sir- same engine. I've made cam timing and valve clearances changes over the years to compare performance but the basic engine package has not changed internally. Same carbs, exhaust brand and ignition controller including the coils and spark plug wires.

Now do you guys understand why I say its worn out?? I detailed some of the last changes to the bike in this thread. It was mainly to lighten the bike up by installing aftermarket wheels, brakes and replacing the heavier 630 with a 530 chain. My riding style also evolved over the years. Prior to my involvement with this site and then finding numerous parts sources over the internet, I was conservative on how hard I pushed the bike. I had a fear of breaking parts which in my mind would have been hard to find. I then realized that I could theoretically locate and replace broken pieces without a problem.

Medyo Bastos · « **Reply #597 on:** October 13, 2016, 05:42:34 AM »

So basically you have become more aggressive

dragracer · « **Reply #598 on:** October 13, 2016, 06:46:14 AM »

Quote from: Medyo Bastos on October 13, 2016, 05:42:34 AM

So basically you have become more aggressive

Somewhat. Lol. I've never been one to beat my bikes into the ground though.

I still don't push this package to the limit. I'd hate to scatter parts everywhere trying to prove a useless point. The key to longevity of this engine is keeping it as fresh as possible to catch problems before they arise.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #599 on:** October 13, 2016, 09:01:39 AM »

He's just badass

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Author Topic: Time to freshen up the F Model bracket bike (Read 120317 times)