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Saetun

Saetun

Sinister Swinger
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Finally ready to get back to work on the Dart for this season. This year's budget is meager so I'm just going to focus on getting more out of the basically stock 318. I came across a set of 302 heads for next to nothing & after some consideration have a prospective build that seems to fit my budget. I'm hoping a few folks could talk the pros & cons with me.

Wont be racing but would like to show off when I want to. I'm not trying to be radical but ideally would like to push over 300hp. Here's the setup in question;

I already have:
Intake: Edelbrock performer
Carb: Holley 600
Exhaust: 2 1/4" duals w/ stock manifolds
& I just picked up the 302 heads from a local wrecking yard.

Next is head work:
mill the heads .050" to help compression & port & blend
2.02/1.60 valves

Narrowed the cam selection down to two prospects:
224/230 at .050 110deg lobe w/ 477/.480 lift

or

218/228 at .050 114deg lobe w/ 441/441 lift

Looks like parts would run just under $500. Haven't quoted head work yet, if someone could ballpark me I'd appreciate it.
 
What is your gear ratio?

The smaller cam will get you 300hp but if you have a 3.23 or higher gear ratio, certainly get the bigger cam.
 
I just built a 318 with the 302 heads. I put the KB167 pistons in it and it brought my compression up to 9.5 with no deck or head milling needed. I know this isn't exactly what you were asking, but I thought you might be interested
 
I wouldnt bother with 2.02s. A 1.88 will get the seats up and out and flow more than the port is capable of. I'd also use the 224/230 cam. Milling might push you too far compression-wise depending on what pistons you've got, as Garth mentioned...
 
rumblefish360 said:
What is your gear ratio?

The smaller cam will get you 300hp but if you have a 3.23 or higher gear ratio, certainly get the bigger cam.
Click to expand...

Still running stock gears 2:96 peg leg. If I do change gears i would only go as short as 3:23 (or 3:21 I believe for the 8 1/4).


moper said:
I wouldnt bother with 2.02s. A 1.88 will get the seats up and out and flow more than the port is capable of. I'd also use the 224/230 cam. Milling might push you too far compression-wise depending on what pistons you've got, as Garth mentioned...
Click to expand...

Moper, I've read a bunch on this debate & both sides of the fence seem pretty convinced. Can you tell me more? I don't plan on touching the bottom end if I can get the power I need out of top end adjustments, so stock pistons will stay unless something unforeseen comes along during the build. Thx much.
 
Get those heads magnafluxed to make sure they are crack free. You might have to make another trip to the yard?
 
I wouldn't run that bigger cam without about a 3000 stall.
 
A 73 318 with stock pistons won't have much more than 8.0:1 as delivered. You're driving a hard bargain IMO to get 300hp from that. Not impossible, but a taller order. I'm not a fan if milling the heads beyond .030 or so. You have to mill the intake side too, and beyond .030 or so you may have to mill the intake's flanges to fit it. Plus it will require checking and getting new pushrods. The extra milling and pushrods mean more cash. If it were up to me I'd say build it with stock pistons, stick that XE268 in it, and don't worry about what the resulting hp will be. My impression is it will end up a little shy of that 300 number, but who cares. It will sound close and you can tell them what ever you want...lol. On the valve sizes. There's really no "sides" as port flow and valve size go hand in hand and ideas of how they work are like assholes. Everyone has one. Mine opinion is go just large enough to be able to put the seats out at the edge of the chamber with enough flow to not be the choke point and you're fine. Personally I'm fairly good at feeling performance and I know I can't drive a street car that's properly tuned and in good order and tell you what's in the heads for intake valves. So in that application really what difference do they make?
 
moper said:
A 73 318 with stock pistons won't have much more than 8.0:1 as delivered. You're driving a hard bargain IMO to get 300hp from that. Not impossible, but a taller order. I'm not a fan if milling the heads beyond .030 or so. You have to mill the intake side too, and beyond .030 or so you may have to mill the intake's flanges to fit it. Plus it will require checking and getting new pushrods. The extra milling and pushrods mean more cash. If it were up to me I'd say build it with stock pistons, stick that XE268 in it, and don't worry about what the resulting hp will be. My impression is it will end up a little shy of that 300 number, but who cares. It will sound close and you can tell them what ever you want...lol. On the valve sizes. There's really no "sides" as port flow and valve size go hand in hand and ideas of how they work are like assholes. Everyone has one. Mine opinion is go just large enough to be able to put the seats out at the edge of the chamber with enough flow to not be the choke point and you're fine. Personally I'm fairly good at feeling performance and I know I can't drive a street car that's properly tuned and in good order and tell you what's in the heads for intake valves. So in that application really what difference do they make?
Click to expand...

So 1.88/1.60 with the 302 heads & bigger cam, screw the mill work & roll? How close to 300 do you believe I can get with just that change & after that would it worth my while to pursue some 340 hi-po manifolds or TTI's after that?
 
On the heads check out 1wild&crazyguys sticky on porting 318 heads with the factory port size & valve size and stock valve job they flowed 175 cfm which is good for 350HP ootb and after porting he got 210 cfm with stock valves and valve job which is good for 420HP since your only look for 300Hp I wouldn't worry about the heads other than 3 angle valve job and a very minor clean up of the ports but if must go bigger valves go 1.88-1.60. Plus there's an Engine Masters article comp cam XE262H with 4 barrel and headers on a stock long block made 282@5000 rpm probably would of made 300hp with higher compression.
 
to add to that, I am also running the 1.88/1.60 combo valves in my 302s. The heads were mildly ported and gasket matched. I don't have any flow numbers, but most of the research I did pointed toward the 1.88 valves
 
I dont think you'll see 300 HP without headers with all those parts....just MHO.
 
interesting reading http://www.hotrod.com/howto/113_0304_318_small_block_build/ Don't expect quite the same results as the magazine guys as they have several advantages most of us don't. Like a dyno, mucho experience tuning on a dyno and "corrected" numbers. Even so , it could give you an idea of the expected Hp and torque curves of a similar engine. Just expect the numbers to be lower.
 
theothergarth said:
to add to that, I am also running the 1.88/1.60 combo valves in my 302s. The heads were mildly ported and gasket matched. I don't have any flow numbers, but most of the research I did pointed toward the 1.88 valves
Click to expand...

Garth, it seems like we're on similar paths any idea on gains you've experienced? Would you be able to give me a rough figure on what the head work to that extent might run?

Also, would 360 heads be a better choice due to the fact the valve sizes are already 1.88/1.60?
 
Main problem with 318 is cam & compression 340/360 heads just make compression worse, a closed chamber magnum type heads like EQ's would be a better over LA 340/360 open chamber. 273/318 come in closed and open chamber heads but even open chambers are smaller then 340/360. You have 302 heads port them put in 1.88-1.60 with performance valve job and some milling to raise compression it's all the heads you'll need.
 
Here's the basics of what I did with mine...
block bored .04 over
Keith Black "167 - 040" pistons
302 heads with 1.88 Int/1.6 exh stock 1.5 rockers
Comp Cam XE275HL
Edelbrock 7576 Performer RPM Air Gap Intake
Edelbrock 1406 600 cfm carb
TTI step headers
Electronic ignition w/ orange box

I don't recall how much was put in the head money wise. The 1.88/1.6 were already in it when I got it and I port matched them myself. I think the thing that made the biggest difference that I did was the kb pistons. I don't know what my hp numbers are, but I would say conservatively 300, hopefully 400, but realistically, somewhere in the middle.
 
I say don't get the big valves. First of all, you would have to notch the cylinders to prevent valve shrouding. Second of all, you wont need that breathing capability with this budget build.

Porting will be helpful if you don't go overboard.

Stock 318 manifolds just plain SUCK. Get rid of them, they will hold you back. There are a few options for headers to choose from. they will really help the teen over stock manifolds.
 
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