engine build up question

[dukeboy_318]

I'm planning on doing a reasonable build up on a 1970 318 out of a challenger.  The engine will be going into a 74 charger backed by 727 or a built 904 and i'd like to build between 350-400 horses but i want it to be streetable.  I'd like to have a good amount of low end torque and horsepower.  I'm thinking about using an Edlebrock performer intake and cam witha 650cfm holley on top.  The bore at this point in time will stay stock due to the engine not needing honed or rebuilt.  I also will be keeping the stock heads but plan on running headers and 2.25 exhuast.  Is this a good combo or am i way off the mark?  Any suggestions will be helpful.

Thanks
Chris

[moparguy01]

Chris,

with what your saying I don't think your going to hit that 350-400 mark. thats alot of power out of a 318. I'm not saying it cant be done, but you probably wont be able to run a lower octane fuel. you'd need to raise your compression up, do some headwork, and put a pretty healthy cam in it to hit that kind of number. the performer intake also won't be that great. the performer RPM is a decent intake i've been told. for streetability you'll want to get a good dual plane intake. but if you want to make more power use a single plane. they both have advantages and disadvantages.

I'm not much of a small block guy, but I try to help if I can. 

[dukeboy_318]

Chris,

with what your saying I don't think your going to hit that 350-400 mark. thats alot of power out of a 318. I'm not saying it cant be done, but you probably wont be able to run a lower octane fuel. you'd need to raise your compression up, do some headwork, and put a pretty healthy cam in it to hit that kind of number. the performer intake also won't be that great. the performer RPM is a decent intake i've been told. for streetability you'll want to get a good dual plane intake. but if you want to make more power use a single plane. they both have advantages and disadvantages.

I'm not much of a small block guy, but I try to help if I can.

What would you reccomend,  i want plenty of power and since I got the 318 for next to nothing and it is a solid motor, I though i'd just use it.  I want it to have a lot of low end to mid range power but must run on 91 octane or less.  I thought about a 400 or 440 if i decide to go all out, which may happen   But for now I plan on running this motor and want it to be respectable in terms of power. 

[moparguy01]

if you want it respectable, your gonna have to open it up. try to get around 9 to 9.5:1 compression, put slightly larger valves into the heads (or find a set of factory J heads) maybe have the ports smoothed off alittle bit. you dont need full out porting and polishing, but just smooth it off a bit. then run a good single plane intake, like i said i really dont know small blocks so i cant recommend a intake. and then I'd check with Engle cams and see what they would recommend for a cam for that setup. we;d also need to know if your using a stock torque converter or a stall converter, and also what rear end gear your planning on running, otherwise you'll put a big lumpy cam in there and it'll fall flat on its face. the 650 carb should be about right though. I've heard of a few people stroking a 318, and that might be a good option for you, granted it wouldn't be the cheapest route.

id probably spend the money trying to build a BB, but i'm biased

[dukeboy_318]

I'll probably go withan aftermarket converter and upgrade the trans with atleast a shift kit.  i think the 8.75 rearend in my charger has 2.73s in it, but i'll check for sure tomorrow.  I might just go ahead and put a bb in it.  Don't know yet.  THanks for the help.

[Bones68charger]

I am building a 318 also. I don't expect 400 horses, but 300-350 is what I am expecting. I just had a set of #302 heads worked on at my machine shop. I put larger valves put it, machined the seats and a little port action. I have a dual plane Mopar intake and a Holley 600 carb. I went with an Engle cam 470 260. I will be running 2.5 exhaust from the Manifolds for right now. I will change the gears to 3.55 and the tranny will be rebuild when the whole engine is being redone. This is an expensive hobby, but a fun one.

Good luck with your 318 if you choose keep it. 

[Chryco Psycho]

you will need better heads to get near the power you want , the 302 or 308 casting will make a lot more power & porting them make s a big difference & there are far better cams then the Eddy , I use a lot of the engle grindswith great results www.Englecams.com , lUnati VooDoo cams are great as well

[Challenger340]

IMHO, Forget the 350-400 mark without much more serious parts proliferation, stroking, Pistons, convertor, gearing, etc., etc.

however, for a budget type thing, rebuild mostly stock

Ditto, the 302 casting heads if poss., stock small intake valve with backcut

If re-using stock '70 Pistons, reverse pin offset before re-assembling, free up friction.

Don't "overcam" the "wee-18", Lunati 60402 for 302 heads, or, Isky 390174 for std "J" style exhaust port heads with headers.

EDDY intake and 650.

Call it good and done, keep saving for the better build later.

just my 2 cents

[dukeboy_318]

IMHO, Forget the 350-400 mark without much more serious parts proliferation, stroking, Pistons, convertor, gearing, etc., etc.

however, for a budget type thing, rebuild mostly stock

Ditto, the 302 casting heads if poss., stock small intake valve with backcut

If re-using stock '70 Pistons, reverse pin offset before re-assembling, free up friction.

Don't "overcam" the "wee-18", Lunati 60402 for 302 heads, or, Isky 390174 for std "J" style exhaust port heads with headers.

EDDY intake and 650.

Call it good and done, keep saving for the better build later.

just my 2 cents

I think I'l take your advice and do that to it.  I got the idea from moparmusclemagizine.com tech area where they claimed to get 400 hp out of a 318, but after reading into it deeper, they went off the wall with it and it would in no way be streetable.

[Plumcrazy]

I am building a 318 also. I don't expect 400 horses, but 300-350 is what I am expecting. I just had a set of #302 heads worked on at my machine shop. I put larger valves put it, machined the seats and a little port action. I have a dual plane Mopar intake and a Holley 600 carb. I went with an Engle cam 470 260. I will be running 2.5 exhaust from the Manifolds for right now. 

Throw in a little distributor work and headers and you have just about the perfect combo for that purpose. 

[Bones68charger]

I am building a 318 also. I don't expect 400 horses, but 300-350 is what I am expecting. I just had a set of #302 heads worked on at my machine shop. I put larger valves put it, machined the seats and a little port action. I have a dual plane Mopar intake and a Holley 600 carb. I went with an Engle cam 470 260. I will be running 2.5 exhaust from the Manifolds for right now. 

Throw in a little distributor work and headers and you have just about the perfect combo for that purpose. 

I hope so, I already have a Mopar electric ignition installed and this year I am putting on my heads and cam. Next year I plan on doing the full rebuild along with the transmission. That is when I will put on my headers. I would love to surprise someone with my 318. I really don't want gobs of hp just enough to have fun with.

[punisher054]

IMHO, Forget the 350-400 mark without much more serious parts proliferation, stroking, Pistons, convertor, gearing, etc., etc.

however, for a budget type thing, rebuild mostly stock

Ditto, the 302 casting heads if poss., stock small intake valve with backcut

If re-using stock '70 Pistons, reverse pin offset before re-assembling, free up friction.

Don't "overcam" the "wee-18", Lunati 60402 for 302 heads, or, Isky 390174 for std "J" style exhaust port heads with headers.

EDDY intake and 650.

Call it good and done, keep saving for the better build later.

just my 2 cents

I wouldn't recommend reversing the pin offset on any cast piston, especially for street use. Not trying to knock Challernger340, this is a great old drag racing trick, because basically at TDC the rod is already kicked over and ready to go down instead of still having to come around on the crank, and will get you a few more rpm's a little quicker, but this will stress out the piston any time you wind it up, and catastrophic damage WILL result. Expecially in a big heavy car like yours.

Hope it helps!