I was just wondering how strong is the bottom-end of LT1s. After my heads and cam i'm probly going to spray it after i break it in good(i'm doing a total rebuild). I was wondering how much it can handle. Thanks

 

I have seen numerous people spray a 150 shot for a long time. You have to have it set up right as in a/f and what not, a quality set up window switch and msd dig 6 to retard timing is the norm.

 

If your going to spray it, as long as its tunned well and has a good fuel system the stock bottom end will last a while.

 

I'm putting forged piston in and rasing the compression to around 11:1-3:1. And i'm planning on spraying a 200 shot. Well the stock bottom-end hold that easy?

 

As long as you keep it out of detonation it will be fine, I know guys spraying that on heads/cam untouched bottoms even then the only real risk is detonation hammering a bearing, same thing you have to watch for.

 

can u adjust the timing on the LT1 with a digital 6 ignition??? i thought you had to get your computer reflashed??? how about just a mds timing adjuster that plugs into the msd ignition because i have one of those sitting in my back garage.

 

The powdered metal rods in the LT1 engines are rated up to 450 hp.

 

Another good box to look into is the Mallory p/n 685. It has a built in single stage retard, where the MSD doesn't. That's only if you're going to run a 200 shot in one shot. If you make it a 2 stage, you'll need to look into better boxes.

 

ummmmm not trying to bust the bubble but the MSD digital 6 has 2 stages of retard. FYI
2 stages will run fine with that box.

 

Yes you can adjust timing with the Digital 6

 

That is what GMPP sells them as good too. In reality they are good well beyond that.

 

Exactly

 

after reading many of the stories on the Impalassforum I and many others would not recommend the 685 box. It's not that the box is bad, it's just they break a lot and it's hard to get a good unit. My friend had his returned twice to have it fixed and after the third time it broke he sent it in, had it fixed w/ new software and a bigger heatsink, and then he sold it.

Matt

 

so is the Digital 6 is the only MSD ignition that can retard timing??? as i stated, i planned on getting a 6a ignition and i have a ignition controller that i took off my mustang sitting in my back garage. if i can use that i will. can i use it???

 

Guys thanks for all the info it helps alot. If i spray it i'll be doing 2 stages. If i get a tune with i still need to a Digital 6. how much can the crank handle just being a 2-bolt main?

 

I would get the MSD 6A igniton, but stay away from mallory they can't take any abuse at all

 

Problem with using stock rods in a high HP aplication is that its trully hit or miss, my buddy Tim ran stock rods in his 383, 300 shot, he used good bolts and never spun the motor up to high. Another friend throw one through the block in a heads/cam car na. Its worth the upgrade.

 

As long as you don't see any detonation.

All in all the bottom end is fairly stout, just have to be VERY careful with tuning especially with N2O or FI....detonation will kill the hypers.

 

fireblade, check your PMs