I thought it'd go faster....

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MB43

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So, I finally got out to the track last weekend.

Last season I was running 12.30s - 12.40s (depending on the weather). I swapped out the Crane 454/480 lift cam for a Lunati 513/533 lift cam and got rid of the small stock radiator and put in a big aluminum jammie. I was hoping to pick up at least a tenth.

The first run was a 12.48, but afterwards I found that the throttle wasn't opening all the way. So I fixed that, but didn't get a second time run so I had to guess on the dial for 1st round. I wound up racing against the other Mike Beck and dialed a 12.40. I was ahead of him at the line so I got off the gas and broke out with a 12.38. If I had stayed in it it would've been a low 12.30-something.

On the first time run the plugin for my shift light fell out so I had to keep an eye on the tach to shift. 1-2 I shifted at 6000, 2-3 I shifted at 6200, but it nosed over right before I shifted so I guess I was shifting too high. In the 1st round I shifted at 6000 (with the shift light working) but at the top of 1st gear it kind of sputtered, then at the top of 2nd gear the tach freaked out and it sputtered again. I'm not sure what was going on there... I didn't get a chance to check the plugs, so I don't know if it was fuel related, or spark related, or what.

I was really hoping for a low 12, even thought about a high 11.

:-(
 
Sounds like you had your hands full and did a good gob of it. :headbang:
It is still early in the season so hang in there
and you may find a high 11's pass.
At least you did not get rained out. sounds like a good day to me. :salute:
 
Thats not bad for a new combo that doesnt have any tuning on it yet. Im sure between tweeking the carb and timing you'll beat your old best. Then find were it likes to be launched and shifted at you you should hit you 12.00-11.90s

If all else fails I can guarantee you that high 11s time slip for $150
 
If the tach is going nuts at the same time you lose torque, I would say yo have something causing noise in your ignition system. The air inside the cap may also be ionizing, causing spark scatter at high RPM. Make sure all of the ignition wires to and from your spark box are well shielded and securely connected. You may also want to try a ventilated distributor cap.
 
I was there on Sunday (the 27th).
 
Thats a very good cam...whats the rest of your combo??engine,converter,gears...
 
Don't get discouraged man.

So, your tach is acting up and your not sure where yet this cam likes to be shifted, it was hot and really humid, and you lifted and still ran a 12.3. I would not be dissapointed at all untill I had 2 or 3 more trips at the track to tune and troubleshoot.

Check your record and see what the temp was like the last time you ran 12.3's.
Is your 60" any different?
 
More cam could mean extra strain on already marginal valve springs. This could explain some of your problems but you should eliminate electrical and fuel possibilities first before jumping to mechanical solutions.
 
The rest of the combo:

'73 Duster, 3120 pounds with my fat *** in it.
360+030, around 9.5:1, shaved and ported X heads, Edelbrock Performer RPM, Holley 750HP, 727, PTC 9.5" converter, 8-1/4 with 3.91 gears.

Previously the best 60' was a 1.69, on my 2nd run on this day the 60' was a 1.67 (I think, I don't have the slip in front of me).
 
mikelbeck said:
I wound up racing against the other Mike Beck (
Click to expand...

??????????WHAT!!!!!!! Another MB!!!!!!! Whats with that????????
He he he. I also ran into a guy with the same name as myself.
 
rumblefish360 said:
??????????WHAT!!!!!!! Another MB!!!!!!! Whats with that????????
He he he. I also ran into a guy with the same name as myself.
Click to expand...
Ya, I thought that was kinda funny. A couple of years ago I looked at the points and saw that "Mike Beck" was in 3rd place. I knew that I wasn't, so I called to ask. I told the lady on the phone that "Mike Beck" wasn't in 3rd, he was more towards the bottom. She said "No, he's in 3rd, I should know... he's my husband!". Then I found him one day in the staging lanes, said "Hey, you're Mike Beck? Me too!".

:lol:
 
I had a look at the plugs and wires, they're in pretty sad shape...

What plugs would be best for this motor?
 
Mikel, Do a search for Spark plugs under my user name. There were a bunch of recommendation. I think Autolite 64s are what I usually use. I also like the MSD 8.5mm wires.
 
Guitar Jones said:
More cam could mean extra strain on already marginal valve springs. This could explain some of your problems but you should eliminate electrical and fuel possibilities first before jumping to mechanical solutions.
Click to expand...

I agree with this diagn.

If the thing was nosing over at the top end, thats a classic case of valve float...............you never mentioned spring pressure or how old they are/were.

I also agree that it may be a tuning issue but I don't feel that changing the cam all of a sudden makes the plugs any better or worse than they were before..............

Is this a vacumm secondary or mechanical? You may have a slight vacumm loss (based on overlap) and thus not bringing in your power valve or secondaries early enough............
 
MomsR/T said:
I agree with this diagn.

If the thing was nosing over at the top end, thats a classic case of valve float...............you never mentioned spring pressure or how old they are/were.
Click to expand...

The springs were new when I put these heads on 3 years ago and I've only put 20 or so runs on it since then.

I also agree that it may be a tuning issue but I don't feel that changing the cam all of a sudden makes the plugs any better or worse than they were before..............

Is this a vacumm secondary or mechanical? You may have a slight vacumm loss (based on overlap) and thus not bringing in your power valve or secondaries early enough............
Click to expand...

It's a 750HP, mechanical secondary carb. The jetting is square (73 all around) and a 6.5 PV.

The problem with the plugs is that they're old... I didn't change them this season (oops) and when I was checking out the wires this afternoon I found one that's cracked. I've got a new set of wires and will pick up some plugs for it this week... I've also got an MSD distributor that's been sitting on the shelf for a while, maybe now's a good time to put it in.
 
I've had good results from the autolite iridium in my 318 4 bbl.Car idles better,emmisions are better,mileage improved,bottom end power improved.

Nothing short of a miracle.

They replaced the splitfires.
 
I'd replace the plugs and wires first and run it. See if it helps, then play with the distributor. I would avoid making too many changes all at once if you are trying to diagnose a problem.
 
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