budget minded 300/325hp heads for a 318,..delivered to ya door less than 500 bucks a set... rockauto's 302's hard to beat! More Information for FAMOUS BRAND 2D31
I agree with the stall and gear recommend, to me that's the main problem with smaller displacement you need deeper gears in a world where most want to run 3.55 at most, that's why my signature says "If your willing to gear it build it if not build a larger displacement, Or take solace in your compromises." I don't know about "325hp out of a 318 ain't no small thing" guess depends what you mean, it's just cam 4bbl headers and a bump in cr away to me that's basic hot rodding build but yes stock 318 heads make you run a little larger cam than you'd need with even 1.88 360 heads, but it don't need big heads it's just dollar wise for most it's don't make sense to put money into stock heads of any kind why people are saying cheap aluminum heads not cause he needs them but there price so it's hard not to. And yes the OP should at least bump cr up to 9:1.
"325hp out of a 318 ain't no small thing", means; principally, that it costs money. and with bolt-ons, as you know, the fun-factor is delayed..... unless you spend even more money now on the chassis.
325 hp 318 stock heads = 9:1 xe268h 4bbl headers 325 hp 360 stock heads = 9:1 xe256h 4bbl headers Where the extra expense ?? beside 360 would have slightly cheaper pistons Give them both the same heads and 318 would need less cam probably the same cam as the 360. The OP still hasn't shown any desire to build a 360 why push it ?? would a 360 make slightly more power in a streetable powerband like idle-5200 rpm = yes if built to make the same power would the 360 be slightly more streetable since = yes will the 360 need less stall and gear = yes at 325 hp does it matter all that much = no if the OP is ok with this why can't you be ???
Just pretend I'm drinking a beer and rambling off my thoughts on it...cause I am. I see your point. LS have a better port, its tall n skinny and velocity is abundant flowing 300's cfm vs sheistmaster. I threw bait out there for the age old debate if when everyone used to say NOT to use 360 heads. "Kills the bottom end" "kills the cyl pressure" And so on...@160cc...175@.300 Why am I picking .300 lift? Because it's a real good indicator of how well the head will do on average and the valve spends a good amount of time there x2 compared to peak. Ok... So...Now its let's put some sheistmaster 170's something cc ports on that do 175cfm@.300 as well... see? Now I went with 175 on the j head.1.88 though I've seen a few more on 2.02 version. You get a 65cc chamber, or 68cc after minor seat blending and a new valve job.. that's stock 675 318@68cc ..but back to the comparison..The sheistmasters need a valve job to flow any better till .475- .500 lift. Yes they do 240's ootb..but lag below that and run with a regular iron head that is less port/more velocity. Yes you can use'em, have the valve job fixed. Would it show a difference in the low end and over all snap of the throttle and any rpm..I believe it would. Its basic. 2 ports... One 15cc bigger than the factory designed port. If both flow near the same, which makes more power? Which would put you back in your seat more? It's not always the cheaper route and not always the way to go.. But imo it's the truth. 160cc is already a jump from 125cc and I have ported a lot of 318 heads to 360 flow numbers and ridden in the cars that have'em. They amazingly pull hard @132-134cc port 175cfm@.300 199cfm@.400 204-210cfm@.500. There is a close relation to rpm/cid with port volume when it comes to efficiency and torque.
He doesn't need 4.10 gears. 3.73 Regular old 2400 stall 'cut' convertor you can get anywhere for 200 bucks. good vj 360 heads with .025 milled off to make them 67cc would work great. Might not be the cheap route or best future potential, but it's the right size shoe for the foot. Build it for what it's for... not for what it "might be"
I agree ... for a 318 use the old 302 castings 1.88 valves or so and some good pocket porting/bowl blending pretty hard to beat. Now when the magnum heads came out they are a out of the box performance head for a 318 and probably the best out of the box 318 head. And without a doubt the best performing factory 318's the factory ever put out. I'm not so sure that the 360 magnum is the best performing factory 360. But that's a different topic Almost all small block mopar parts available are centered around a 340/360
Problem with 302 heads not many are into porting so the 302 offers very little in performance gain over stock for most. Plus 273/318 heads was designed for 273 in mind and not as a performance head. 273 head volume and cfm is in similar ratio with 273 displacement as a X is with a 340, a 318 is 47 cid bigger than a 273 and 22 cid smaller than a 340 less so after an overbore. A 1.88 360 heads would be closer to right if you kept volume and cfm ratio for the 318 the same as 273 and 340. With and overbore a 318 is 12-17 cid less than a 340 and 0.060”-0.030” smaller than the so called magic 4” bore can see these aftermarket heads being that far off. Not needed for 300-325 hp but for the money can’t see a reason not to. But yes a 1.88 360 or a ported 1.88 302 or magnum heads would right inline with 300-350 hp 318.
I agree, so can the head that come with the 318 he buys, unless he wants to build quench for a 300-325 hp motor there’s little point in them. A 1.88 360 will make 300-325 hp with a lot less cam than the stock 318 or 302 heads making for a more mild and streetable combo. Plus if you buy the right piston you still can build quench if one chooses with the 360 heads.
Indy does bowl work for $150 a head add $150 a head into a good 3 angle valve job from them. Or just get magnum heads and a good valve job. IMHO those are the best options for a 318. For a budget head. You would have to go with a step top piston with 360 heads. And that's fine other than adding rotating mass. Or get the edelbrock magnum heads. But with 2.02 valves in less than a 4" bore valve shrouding becomes a issue and it gets to a point of diminishing returns. I think we should start a group build gather up donations and heads and send to holdner to do the dyno with same engine and cam just different heads.
The 318 hater speaks again! It’s the same cost to build minus pistons if so the route goes. It doesn’t take as much cam as others have listed and think it does.
They upgraded the server and something got corrupt somehow and they had to use a backup all the way back to the 27th. So everything after that is gone. Don't know if they can retrieve it or not.
