Topic: 2024 BMST

[Old Scrambler]

Best run for me was this AM at 133+ sans fairing on 17 x 39 sprockets in 4th gear at 9,200 or so RPM............127.5 jets at 44* advance on VP MR12..........2nd run with 30* advance was slower with less top-end grunt......No time for larger jets and more runs as this was the final day.

Shifting was fixed by returning the left footpeg to original position........that's my somewhat 'bad' leg and ankle. The most disapointing part of this Bonneville trip was the severe 'dimpling' to #4 intake with no evidence of the adjuster coming loose. After hours of filing and emory-paper, a lash cap was snuggly fit while all others popped on as normal...........blue loc-tite was applied to all adjuster theads and no further motor problems were apparent..........I will pull the head in a few days for close inspection.

Sorry guys and gals ........I still have a few things to learn My top speed was roughly equal to my existing gas record but about 8-mph short of the fuel record.

 

[Jerry Rxman Griffin aka MuthaF'er]

Yeah but we had a good time 

We pulled into Co Springs about 7:30pm Tuesday. Good trip home. 700+ miles. 31.1mpg in the Vette mostly at 80+. I-80E, I-15S to US 6 at Spanish Fork then I-70E. Cut through Breckenridge to avoid Denver traffic. Scenic. I got my car detailed yesterday and ready for Bring A Trailer.

Good seeing everyone. Until next year.....

[dragracer]

Dennis. In spite of all the problems and set backs you nrver threw in the towel.  While your efforts did not produce the results you were hoping for on this outing,  it sounds like much progress was still made in gaining knowledge to be applied at the next attempt. I applaud 👏 your determination over the years of running the salt.  If this stuff was easy,  everyone would be doing it. I would have liked nothing better than to have been there for moral support. If its in the cards for you to go again,  i will make a concerted effort to show up myself. I promise to keep my mouth shut and shove my hands in my pockets. My goal would be to listen and learn what it takes to be a record setter like yourself.  We're all proud of what you do!!!

[Old Scrambler]

Jerry...........Glad your home safe..........Thanks again for being a fan and for Kim's great photos

Frank........Thank you for the kind words of encouragement

[scottly]

Dennis, were you running the Ignatech ignition, or the Dyna?

[johno]

ALSO Den,.... a previous trip I remember you had an issue with a loose adjuster and or lash cap etc, just curious was it the same cylinder number 4 or different ?
In my experience if the valve tops dimple out fast with big cams its usually the geometry being pushed too far, it also leads to tappets coming loose etc. If so Not much you can do other than adjust valve lengths or can bearing heights to get the best compromise. Funny I was just reading a thread last week from motoguzzi about 50 mile motors and the joy they bring,

Yeh but its all fun really  🤪
cheers John

[Old Scrambler]

Post-Race motor report:


the plugs were all equal with light-gray to white color............PennGrade #1 oil looks good but I have yet to examine the filter. A minute amount of metal was clinging to the magnetic drain-plug. Exhaust valves have cream color. Intake valves are gray except #1 which is dark-gray. Same for pistons with #1 having clean metal along with dark gray to black blotches. The copper head-gasket looks good with minimal clearances at the valves. Nothing is apparent on the edges of the pistons, but I notice a very small area of interference 'rubbing' on about an inch of each chamber near the spark plugs. In an effort to improve compression I had deleted the .005 copper base-gasket knowing that my valve lift was slightly less with the CX-7 cam.

I will pull the cylinders tomorrow and attempt take pics with my wife's phone for all to examine..........a copy of the dyno chart finally arrive and a copy was sent to Scott........I was using the Dyna ignition.

[scottly]

The peak HP RPM increased from about 9500 to about 10,200; my best guess on this is due to the new cam. The overall power increase was most likely due to the VP fuel, which is supposed to add about 5%. At 9200 RPM the engine would have made about 3 HP less than at peak, so a gearing change would have increased the speed.

[Jerry Rxman Griffin aka MuthaF'er]

The dyno chart looks great. The engine report so far sounds good except for #1 being slightly off. I packed my infrared thermometer with me but unfortunately forgot about it. My intent was to compare cylinder temps 

Dennis, were you able to get it above 8500 rpm with load though?

Scottly, which way are you suggesting the gearing change?

Maybe the carbs could use a good ultrasonic bath? But that wouldn't have anything to do with that damn adjuster.

[scottly]

Since it "hit the wall" at 9200, the gearing was too tall: the rear sprocket needed to be bigger by at least 1, maybe 2 teeth or more.