Serious Power for a 318 Poly, Tall Task
:iamwithstupid: HP is MPH really, Torque is what moves the car initially, Especially a heavy car... Not very many parts readily available... Anytime you hear or see the word Custom it will cost allot more... A "custom" stroker Crankshaft offset ground maybe, some "custom" size/length connecting rods & "custom" pistons, then probably the most important thing for the engine, would be the cylinder heads flow & valve size, a professional porting job & bowl work, with larger valves they are total crap in original configuration & sizes, even for just a slightly larger 318 @ 0.060" bore will still only be 326ci or so, "custom" ground camshaft, solid lifter or Roller would be best, adjustable higher ratio rockers, better properly sized/length/style push-rods, better valve springs to match what ever camshaft you end up with, lighter & stronger valve spring retainers & locks, much better induction, intake, carburetor, maybe 2x4bbl, maybe FI or maybe even an EFI & seriously updated "custom" fuel system, much better free flowing exhaust & properly sized headers, a K&N X-treem Air filter/cleaner, a much hotter ignition system to help fire all the extra fuel with the new set-up/combo, a better cooling system to handle the added heat of a hi-perf engine, will all help allot but a 318 poly is kind of a boat anchor & very little real performance upgrades are even available, I would highly suggest either, probably you best chances to make 600HP at the crankshaft is, either N20 a Roots or Screw type Blower or Centrifugal Supercharger or Turbo's to boost the power, they would have to be a "custom" application also... that wouldn't be for the novas builder either, but maybe the only way to get enough real HP out of a Poly engine, the Poly engine block may not be the best for boost either, it may not live very long in any 600HP configuration... Hell ! The car/chassis is the easy part... Then the suspension maybe S/S springs would be the least expensive & easiest to improve, quality sub-frame connectors, move the battery to the trunk for weight transfer, a good "quality rebuilt 727 with quality parts & valve-body", a much better & much higher stall speed torque converter, to help the car move initially, rear gears 3.73:1 @ a minimum, to get the heavy car moving early 4.10:1- 4.30:1 would be even better, with a much taller, wider & stickier tire, it will have a much better foot print & will help to get power down to the ground, quality shocks & adjustable preferably, your car/chassis will need to make up for a lack of HP/TQ with the sub-par 318 Poly engine, it all can be done, with the Polysphere engines, but there are far easier & far cheaper alternatives thou, if you dead set on that 318ci Poly, it's going to be a challenge if your not an experienced performance builder... What is your experience ??, is this your 1st venture into making serious power ??, do you have any fab &/or engine tuning skills ??, do you know the basics at least, to be able to know what to purchase ??, if not get a reputable quality machinist, not just some local yokel, unless they are familiar with the Polysphere Mopar engines... That will make the expenses raise considerably also... You may want to find a good knowledgeable automotive machinist, make friends with the guy, you will be spending allot of time & money with HIM/HER & or some S.E.M.A. companies to produce a custom ground stroker crankshaft & custom ground camshaft, to be able to to produce 550-600 crank HP to get an honest 400 RWHP {I'm afraid the block & heads will still be a weak link, may not handle 550-600HP} & getting it all to the ground, that's a very tall task for a 318 poly, even for a seasoned pro, you will loose 15%-25% in parasitic drag/loss thru the drive-train to the ground... Good Luck you will need it... Buy some books 1st, educate yourself 1st & foremost, so you don't waste a **** load of money, because of doing stuff a 2nd time, knowledge is the best thing, do your due diligence & research.... I would also suggest contacting Mancini Racing, talk to some Mopar experts... keep us all posted.. sorry to be a buzz kill, it can be done, with a big enough budget & allot of knowledge plus some serious automotive machine work...
