[94cobra69ss396]

Originally Posted by BRUTAL64

This current engine is a MULE. I'm testing a few new combos at once. It is an externally balance 400. You gave me something new to think about -I know stand back-when this current engine was balanced it was balance with another flywheel. I but a new Mcloud flywheel in at the last minute that was suppost to be the same balance as factory 400.

Well with the miss fire you said you had after the cruise there's more going on then just the flywheel maybe throwing off the balance. Did you get a chance to look at it yet?

[BRUTAL64]

Originally Posted by 94cobra69ss396

Stick to pump gas. Having to run on race fuel is a pain especially when you only get single digit mpg. I have to run a minimum 100 octane in the Chevelle so long cruises like we did last week are out of the question.

Everything I build is used with pump gas in mind. The current 400 is 11:1 and runs _ well it used too_ great on 91 octane. Damn Chevies.

[Vettezuki]

Originally Posted by BRUTAL64

. . . when this current engine was balanced it was balance with another flywheel. I but a new Mcloud flywheel in at the last minute that was suppost to be the same balance as factory 400.

This wouldn't prevent the engine from revving, especially at such a low cutoff would it? Wouldn't the out of balance engine just vibrate, maybe self destruct in extreme cases, but it'd still rev up through it's range as long as it was breathing and getting fuel right? I could understand some loss of rev potential from balance, but 7,200 down to the 4,000s seems extreme . . . Am I missing something.

[94cobra69ss396]

Originally Posted by BRUTAL64

Everything I build is used with pump gas in mind. The current 400 is 11:1 and runs _ well it used too_ great on 91 octane. Damn Chevies.

My original plan for the current 454 in the Chevelle was going to be 11:1 as well but then I found cracks in the heads (128cc) and bought the Edelbrock Performer RPMs which have a smaller combustion chamber (118cc). The compression is just above 12:1. My next engine build either another 454 or a 496 is going to have 9:1 and a Procharger. That way I can run 91 and a conservitive tune and then when I take it to the track run race gas and more timing. That's the way my Cobra is.

[94cobra69ss396]

Originally Posted by Vettezuki

This wouldn't prevent the engine from revving, especially at such a low cutoff would it? Wouldn't the out of balance engine just vibrate, maybe self destruct in extreme cases, but it'd still rev up through it's range as long as it was breathing and getting fuel right? I could understand some loss of rev potential from balance, but 7,200 down to the 4,000s seems extreme . . . Am I missing something.

You're correct. It just gives it a mean vibration. I had this happen on a 88 Mustang I had. The balancer spun which gave it a horrible vibration but the engine would still rev to 6000.

[BRUTAL64]

Originally Posted by 94cobra69ss396

Well with the miss fire you said you had after the cruise there's more going on then just the flywheel maybe throwing off the balance. Did you get a chance to look at it yet?

The rivbration has been an on going thing. This damn miss -more like misses- showed up about a week before the run. It was just a "little" miss at first. So I threw in a set of plugs the day of the run. It got worst. Then as the temp cooled down outside the "miss" was really bad. Now it's like a hitting a rev limiter.

So, fuel is the first thought, and the electrical is second. Damn Chevies.

I'll look at it on Sat. The 429 runs good. Good Fords.

[Vettezuki]

Originally Posted by BRUTAL64

The rivbration has been an on going thing. This damn miss -more like misses- showed up about a week before the run. It was just a "little" miss at first. So I threw in a set of plugs the day of the run. It got worst. Then as the temp cooled down outside the "miss" was really bad. Now it's like a hitting a rev limiter.

So, fuel is the first thought, and the electrical is second. Damn Chevies.

I'll look at it on Sat. The 429 runs good. Good Fords.

I'm getting out of my comfort zone (easy to do), but is your ignition system points or HEI? I know I couldn't find anywhere to plug a laptop in.

[BRUTAL64]

Originally Posted by Vettezuki

This wouldn't prevent the engine from revving, especially at such a low cutoff would it? Wouldn't the out of balance engine just vibrate, maybe self destruct in extreme cases, but it'd still rev up through it's range as long as it was breathing and getting fuel right? I could understand some loss of rev potential from balance, but 7,200 down to the 4,000s seems extreme . . . Am I missing something.

These are two different problems. The ribration has been an on going thing. Since this is mule motor I haven't sweated it too much.

This damn miss (misses) is new and is a real pain. Hell, right now a Honda Civic could beat me.

Nope you didn't miss a thing. I'm just wining here. Damn Chevies.

[BRUTAL64]

Originally Posted by Vettezuki

I'm getting out of my comfort zone (easy to do), but is your ignition system points or HEI? I know I couldn't find anywhere to plug a laptop in.

It's a stock distributor with electronic conversion. Plug in Lap Top---you funny guy.

[BRUTAL64]

Originally Posted by 94cobra69ss396

My original plan for the current 454 in the Chevelle was going to be 11:1 as well but then I found cracks in the heads (128cc) and bought the Edelbrock Performer RPMs which have a smaller combustion chamber (118cc). The compression is just above 12:1. My next engine build either another 454 or a 496 is going to have 9:1 and a Procharger. That way I can run 91 and a conservitive tune and then when I take it to the track run race gas and more timing. That's the way my Cobra is.

496 is the way to go. That was the spec used in Cam Am racing way back when. That small change in ci REALLY wakes the BB 454 up. I've been working on roller cam specs for a couple of guys. The figures I've been getting are just out standing. Think 600 ftlbs at 2000 rpms.