360 build

[Markzilla88]

I have a 360 engine block that needs to be built to replace the 318 I currently have in my 73 charger. I'm in college so this is a budget build, but I'd still like to get as much as I possibly can out of it. The car has a 904 transmission and an 8 1/4 rear with 2:71 gears. I preferably dont want to change those, with the exception of the gears. I plan on replacing them with 3:55's to pep it up. The car has been primarily used for long hauls (3 hour trips) back and forth from school to home on the weekends and running around on the streets. I really want it to be a respectable car where it can beat mustangs and those kids with their honda civics and such.

So to start I was planning on getting it bored out .030 over. I have a stock oil pan, crankshaft and h beam rods. I plan on getting a set of Keith Black silvolite pistons to get me around 10:1 compression. I have a set of stock 360 iron heads that have no work done to them with stock valves. I believe they were around 77cc average? (Its been a while and I cant exactly remember the cc). They were used in the countys S.W.A.T. mobile. Ill be pushing stock rods and using the rocker gear from the 318. I have a comp cams Xe268H cam with matching lifters and springs. Ill be running headers with 1 5/8" primary and 3" collectors into 2.5" exhaust through flowmaster 40 series. The intake will be an edelbrock performer series and the carb will either be an edelbrock performer 600 cfm or a holley 600 cfm. Ill use the distributor off the 318 and a double roller timing chain. Also, if people think its a good idea, Ill be using an MSD ignition.

If anyone has any programs to estimate horsepower and torque, or personal opinions on what this engine could make, Id greatly appreciate the input.

Thanks

 

[Sublime440]

I think MSD stuff is way overrated and your money could be better spent elsewhere. The Mopar Performance electronic ignition set up is actually a really good ignition system, I have it on all my engines ranging from a stock 318 to a 500+hp 440.

The performer series intake is nothing to brag about, all you'll get there is a weight savings. I would go for the Air Gap if your budget allows.

I would also consider getting different heads. Are the heads you have an open chamber design? If you're going with the KB's (flat tops?) you'll want to make sure the compression height gets the piston up to zero deck (or close) and use a closed chamber style head to get good quench (squish in the combustion chamber). Just from calculating, and guessing a little, I'm not getting the 10:1 compression ratio you mentioned but more like 9.7:1 (assuming zero deck and 4.180"/.039" head gasket). Basically, you will need to measure how down in the bore the pistons really are, then, measure the compression height (center of pin to top of piston) and then choose a piston who's compression height is taller by the amount the piston is down in the cylinder. The only other way is to get as close as you can and have the block cut. That will help you alot with the head design I mentioned earlier.

As far as the closed chamber style head, you may want to pick up a set of magnum heads and the magnum style intake (Air Gap). I think the cam choice is good for streetability. But, the XE series cams are "noisy" which isn't a problem so don't be suprised.

I would think the combo would be good for close to 400hp with the better heads, compression, etc. vs probably more like 300-330hp using what you suggested. Your head and piston choice is the most important thing to get right. You can always swap out a cam, intake etc later on without alot of effort. I would also ditch the idea of the Flowmaster 40's (unless you like the sound) and go with Dynomax Ultra Flo's which outflow Flowmaster and sound better IMO.

Good luck.

 

[charger360]

it all sounds good but the intake is not the best an rpm or an air gap will give you a big! jump in power. the 904 won't live long behind a good 360 in a heavy car like our chargers. i know i have eaten many of them. if you are not to hard on it it will last a bit. that 360 upgrade will really wake your car up. don't bother with msd you don't need it you don't push enough fuel or rpm to need it. save the money and get a good converter it will make a huge difference in the get up an go feel of the car, just don't go to crazy a 2200-2500 rpm stall is plenty for a driver and don't forget you will need to get a set of weights or a flex plate to compensate for the balance of your 360 unless you get it balanced. cheers