Dyno runs with Nate

Well guys, Nate and I have been figuring out a time for the past couple months to bring the Coronet over to Capitol City performance for a few runs and to dyno tune my Coronet. Now my reason for choosing Nate are my own and this isn't meant to create a huge dynodick meauring contest, so lets leave that stuff aside. What I'm planning on doing is presenting the data, hoping for people to analysis it and give me some pointers on the build recommendations

First off here is the mill

440 bored .40 over total cubic inches are 448
set of stock aluminum 440 source heads
1.5 stock rockers
comp xtreme cam XE268H 480 lift .050 224degree/230 degree
Holley Street Dominator intake
headman shorty headers 1 3/4" at 2/5 inch collectors
800 cfm Thunderseries edlebrock carburator Jetted up 2 sizes

First off, I have to thank Nate for his efforts. The Coronet often has hiccups and slight maladies whenever things are altered automotively. It is always been this way, its kind of like playing with voodoo. This night was especially no exception. When initially doing our first run on the car, it just ran flat at 3500 rpms and would not go more. Well we quickly diagnosed that the car was slightly on the lean side. This resulted in Nate getting a crash course in jetting an eddy carb. Now I've done them before, but not 8 feet up in the air off the ground with poor lighting. I had visions of dropping butterfly clips down the carb or all over his floor, not a fun idea that late at night. Well Nate and I tackled it together. Eddy carbs are simple, but....interesting. Nate discovered and I quickly (re)discovered Edlebrocks fucked up numbering system when dealing with jets! The jet numbers were off and it was hard to read what size was what. Eventually we shrugged and threw the biggest jets we had in it and figured good enough!.

Well the car was much stronger, air fuel was better and it got rid of that pesky 3500 rpm hiccup. The car pulled all of the way through, and sounded good! Here is the results from the last pull.



hp 304 and torgue at 416.

A couple of nice things about the graph. I have a very nice broad power band it arches well between 4600 and 5400 rpms. As is a rule my 440 is a torque monster. It seems to make my Converter flash about 3300. The torque band is pretty impressive and remained high through the whole run. Now we are going to continue to work on this a bit. Nate's father is a carter expert and he is going to look at it as well as take some time to adjust timing with it and we will do it again. For the most part, I was hoping for more, but am satisfied for what the engine is, which is a mildly built big block car.

Mike

Nice...Like the torque numbers its holding in so long.

Very cool mikey!

Might be a dumb question.......But, Do the mopars not like alot of lift? .480 seems real small for a big block?

I took some random pics and videos when we went to get Logans downpipe. I wasn't there when he did any full pulls, just some warm up runs...also, cell phone pics :/

Great pictures Peter

Now to answer the quetion about the build, 480 lift is not real high, but keep in mind this is a street car that needs to be handled by my wife, who on occasions likes to drive it. My initial plan was to go much wilder with lift in the area of .557 or so, but with power brakes and all it became more of a hassle.

Mike

FWIW mike lift is not what makes a cam "big" is does not change power brakes and has very little effect on the drivabilty..... duration and LSA make a much bigger difference. we can talk about this sometime if you like.... didn't know that the mopar had 1.5 rockers BBC uses 1.7's so that same cam in a big block chevy has .544 lift......

Steve

Sure we can talk some time. I do understand the basics of cam design, but I'm always up for learning. I just threw out the .557 lift as an example of another commonly used mopar big blocks cam, to just show that higher lift sizes are available and are common, it was more to answer Andy who thought .480 might be standard in mopar.

My engine was built to be a mildly built 440, and its components are such as well as the cam design which is mild.

Now to answer your questions all mopars big blocks (excluding the hemi) run stock 1.5's. Its an strong rocker and I know plenty of mopar big blocks that run well with them. Now a lot of the hotter 440's will be found running around 1.6. Yet, thats it!

Mike

feel any stronger on the street after adjusting the carb?

Seems like a pretty cool setup over there.

Overboosting wrote:

feel any stronger on the street after adjusting the carb?

yup, much snappier and better overall feel, it feels as if it picked up in the mid range, top end I'm not sure. I don't see north of 5000 rpms often with it in third gear especially with 3:23 gears!