That sums up my second attempt at a race weekend! The good; I got the thing down the track three times! The bad; I failed to check the main fuel filter(hey, it's huge, never been a big deal-wrong!) The filter was plugged with white crap from alky being left in the system. I got away with murder for twenty (yes 20!) Years, but the buzzards came home to roost and it cost me a half day at the track chasing down the gremlins. So Friday I finally get two passes in. I had some new Hoosier 10.5 x 33 slicks mounted on 14 inch rims. I tried nine pounds pressure on the first pass, tires warmed up. Car felt mushy on the run and moved around the whole pass.. Poor 60 foot of 1.349 and the new MSDdigital 7 never fired the airshifter. Hit the rev limiter in low, manually shifted and went 9.06 at 149.5. I really put heat to the new tires in the burn out box, may have been too much, plus new tires. I called MSD and was told I had the rpm switch set too tight at 7200 on and 7300 off. Raised the off to 7600 and on the second pass it shifted, but looked like it went past 7600 on both shifts! I suspect the rpm switch was activating higher than the on setting by as much as 400 rpm? I tried to download the run off the RPM data logger and the laptop couldn't open the serial port! Fun stuff! Grrrrrrr! Ok, refuel, raise the wheelie bars and try another pass. I set the tires at 9 psi could figuring they will gain at least a pound in the burn out. ft 1.319 60 ft 8.970 at 150.5 with a 7 mph tail wind and decent air. Now I feel better. Car felt stable at 10 + psi in the slicks. I ran out of energy about this time so I put the car in the box for the night. Saturday the wind switched to a cross wind of about 7 to 10 mph. I was looking everything over so intensely to not miss any prep that I forgot to drop the rpm switch rpm! Old age? I'm 69. The car left better, 1.287 60 ft. More there for sure. It seemed like the rpm went through the roof going past 7600 on each shift. Ran 8.949 at 149.31 mph bucking that cross wind. We only get one time trial on Saturday so I refueled, put 8.94 on the window and went to staging. As I got motioned toward the burn out box the oil pressure started to drop as rpm rose. Must have a stuck bypass in the oil pump. I pulled the filter and have very fine metal in the oil. Gee, what fun! Probably took out the bearings if oil pressure was low on previous pass. So the whole motor needs to come apart. So that's it for this year! I sure hope I can get a handle on these issues. I suspect a rocker arm bearing failed again but won't know for sure until the autopsy is complete.

Damn!
Maybe you used up all your bad luck?
Keep us posted.

Let's hope!😒 I am pushing this motor fairly hard with an .870 lift cam, and previous cams were ground with pretty harsh lobes. So I figure there will be issues from time to time!

Greg, I saw your car in the staging lanes, but sorry I never tracked you down to say hi. Good luck with the fixing!

Greg....... your car has reached a point where it’s “way too much fun”.

I think I’d be willing to give up a couple tenths to have a little less “fun”.

Hopefully the issues inside the motor are minor.

Dwayne, there is no such thing as too much fun. Haha, slowing down a little, unheard of. We never do what we “ should” do, makes too much sense. At least that’s how I think. Jim.

I agree! My problem is I am like the monkey with his hand on the grape in the bottle. He got his hand in there to get the grape, (fast car)but can't get free unless he lets go of the grape! And he stays caught by being stubborn. So,,,,I take the beatings for the et I chase! There is a combo of parts that should support the power level I am getting out of these heads with less failures. I don't expect it to repeat like a crate motor , but would like to get more than two passes between issues!
Trust me, I have given thought to what you say Dwayne. It is not rocket science to go from 8.80s back to 10.00s to make life a ton simpler! At being 70 next year with less energy has its' appeal for sure. But being a bit stubborn I have decided to try and put the motor back in good shape as is. At the least I expect to need rings, bearings, gaskets, Polish the crank, and have the heads checked.
It will be a while before I get to it, but will post autopsy results😒

Good for you Greg! However, I'm sorry to hear of these troubles. Keep moving, you got this.

Well, I wasn’t thinking about 10.0’s........ but it seems like when you got that last .3-.4 the reliability issues really started showing up.

I wouldn’t have expected a combo like that to have so many top end gremlins.

I know you weren't thinking of slowing it that much Dwayne. I just remember1997 when I first raced with this new chassis. I had an offset ground 440 crank, a hydraulic cam that had sbc lobes, a 750 alky carb, and given a little more chassis education for me would have repeated 10.10s like a Xerox machine! STRESS LEVEL----LOW!

[quote=gregsdart]That sums up my second attempt at a race weekend! The good; I got the thing down the track three times! The bad; I failed to check the main fuel filter(hey, it's huge, never been a big deal-wrong!) The filter was plugged with white crap from alky being left in the system. I got away with murder for twenty (yes 20!) Years, but the buzzards came home to roost and it cost me a half day at the track chasing down the gremlins. So Friday I finally get two passes in. I had some new Hoosier 10.5 x 33 slicks mounted on 14 inch rims. I tried nine pounds pressure on the first pass, tires warmed up. Car felt mushy on the run and moved around the whole pass.. Poor 60 foot of 1.349 and the new MSDdigital 7 never fired the airshifter. Hit the rev limiter in low, manually shifted and went 9.06 at 149.5. I really put heat to the new tires in the burn out box, may have been too much, plus new tires. I called MSD and was told I had the rpm switch set too tight at 7200 on and 7300 off. Raised the off to 7600 and on the second pass it shifted, but looked like it went past 7600 on both shifts! I suspect the rpm switch was activating higher than the on setting by as much as 400 rpm? I tried to download the run off the RPM data logger and the laptop couldn't open the serial port! Fun stuff! Grrrrrrr! Ok, refuel, raise the wheelie bars and try another pass. I set the tires at 9 psi could figuring they will gain at least a pound in the burn out. ft 1.319 60 ft 8.970 at 150.5 with a 7 mph tail wind and decent air. Now I feel better. Car felt stable at 10 + psi in the slicks. I ran out of energy about this time so I put the car in the box for the night. Saturday the wind switched to a cross wind of about 7 to 10 mph. I was looking everything over so intensely to not miss any prep that I forgot to drop the rpm switch rpm! Old age? I'm 69. The car left better, 1.287 60 ft. More there for sure. It seemed like the rpm went through the roof going past 7600 on each shift. Ran 8.949 at 149.31 mph bucking that cross wind. We only get one time trial on Saturday so I refueled, put 8.94 on the window and went to staging. As I got motioned toward the burn out box the oil pressure started to drop as rpm rose. Must have a stuck bypass in the oil pump. I pulled the filter and have very fine metal in the oil. Gee, what fun! Probably took out the bearings if oil pressure was low on previous pass. So the whole motor needs to come apart. So that's it for this year! I sure hope I can get a handle on these issues. I suspect a rocker arm bearing failed again but won't won't know for sure until the autopsy is complete.




Correct me if I am wrong but I seem to remember that the MSD activating switch [ OFF ] was a lower RPM than shift point not higher. Could that be why It shifted at 7600?

Rpm switch comes on with the lower rpm setting and off with a higher setting. Turns out the switch was set to "on" at 7200 and actual shift rpm was 7450 on the data logger. So my concerns about too much rpm were not as bad as it appeared by watching the tech. Once I widened the rpm window to 400 rpm the system worked fine. When the shift occurs the rpm drops below the 7200/7600 rpm window the switch turns off again. With the switch activated, it provides a ground for the airshift solinoid, shifting the trans.

Greg....... I know you’ve posted it before.......but.......

What’s the current cam/spring/spring load/rocker ratio situation?

Mike Jones cam, lobes85510 intake and 89480 exhaust. 114 co in at 110. Lift is 1.7 rockers .870 gross intake. Exhaust is .840 gross lift both sides run at .021 lash hot. Springs are Pac 1228 intake and comp 947 exhaust. Set at as close to .070 from coil bind as I could get.