ccreddell
I'm Awesome
OK, I screwed up when I rebuilt the top end of my 5.7 a year or so ago-after swapping on the higher compression Vortec heads, I also switched over to Mobil 1 synthetic oil. Ive since been told this is a no no. At least Im doing my part for mosquito abatement..... Anyway, it has caused me to start thinking about what to do with my motor-rebuild it, or replace it. So, I have a 94 LT1 with aluminum heads, that has been sitting at the machine shop for a while waiting for me to give the green light. So after a bunch of research, I came up with an idea. Thought I'd run it by you guys to see if I missed anything.
So, my LT1 will be .040 over, and Im going to run the Lunati LT4 hot cam. Specs are 218/228 at .050 with .503 lift with 1.5 rockers. I'll be running 1.6s for .5635 of lift. I was originally going to run a TPI setup, but it would require running a 411 ECM and I have too much money at the moment in an EBL setup that I have the tuning software for already. I got to looking at the dual plane 4V intake from GM performance, and with a carburetor, it pulls 30 ft.lbs. over a stock LT1 setup. As I am already running a 4V manifold with adapter under my TBI, the thought occurred to me that the LT1 dual plane with a TBI could work out real well. Not only does it have the low end grunt of a TPI, but also breathes well into the 5800 RPM range-unlike the TPI. The cam is also good from 18-5800 RPM so that looked like a good fit too. This manifold will also let me run the stock distributor getting rid of the Opti-crap and send the proper signals to my ECM. The 10.5:1 compression with keep the efficiency up too and I should get just a good or better mileage than I do now.
I put the numbers into my desktop dyno-including complete flow numbers for the LT1 heads and 490 CFM for the TBI. At the rear wheels its showing 416 ft.lbs. at 3000 and 337 hp at 4750. If I replace the TBI with a 454 unit, at the rear wheels, I get 426ft,lbs. at 3000 and 346hp at 4750. Looks like the throttle body will naturally limit over rev.
Any thoughts?
So, my LT1 will be .040 over, and Im going to run the Lunati LT4 hot cam. Specs are 218/228 at .050 with .503 lift with 1.5 rockers. I'll be running 1.6s for .5635 of lift. I was originally going to run a TPI setup, but it would require running a 411 ECM and I have too much money at the moment in an EBL setup that I have the tuning software for already. I got to looking at the dual plane 4V intake from GM performance, and with a carburetor, it pulls 30 ft.lbs. over a stock LT1 setup. As I am already running a 4V manifold with adapter under my TBI, the thought occurred to me that the LT1 dual plane with a TBI could work out real well. Not only does it have the low end grunt of a TPI, but also breathes well into the 5800 RPM range-unlike the TPI. The cam is also good from 18-5800 RPM so that looked like a good fit too. This manifold will also let me run the stock distributor getting rid of the Opti-crap and send the proper signals to my ECM. The 10.5:1 compression with keep the efficiency up too and I should get just a good or better mileage than I do now.
I put the numbers into my desktop dyno-including complete flow numbers for the LT1 heads and 490 CFM for the TBI. At the rear wheels its showing 416 ft.lbs. at 3000 and 337 hp at 4750. If I replace the TBI with a 454 unit, at the rear wheels, I get 426ft,lbs. at 3000 and 346hp at 4750. Looks like the throttle body will naturally limit over rev.
Any thoughts?