318 build up

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If you're looking for a streetable cruiser that runs 12s with a 318, look to at least 100hp of squeeze. The deal is, the 318 simply is small. Like the 302 is. But the 302 in a fox body has gearing and an OD trans. So in order to make the power, you'll need to rev it, meaning deep gearing and slippery convertor. Not a good recipie for a street cruiser. You can get a 318 car prety easy into the high 13s with streetable gearing and convertor with a decent performance rebuild. That is what Rumble is talking about. A static compression around 10:1, and the Enging Quest Magnums with the right cam will give you a very nice street package that is strong enough to take a bunch of NOS. I would look to a forged flat top that I'd run .010 above deck. Factory rods w/good bolts, and the stock cast crank will take 200hp easy with the right piston. Hypers are not the right piston for any NOS use, and I would not run a dome. I'd be looking for a cam that is similar to the XE284H, and running a cam like that with those heads means a little work to the heads. But it's the only way to run a decent cam with them. With the right convertor and a gear around 3.55 it should do just fine on pump gas.
 
Moper, the article states the engine combo did worse with the 1.6 rockers, and thats stock on the Magnum heads, which also requires a change of pushrods, intake and you have to make sure you have the proper lifters and do you have valve covers with this? There expensive from MP, the cast black wrinkle one.
Of course, theres stock ugly OE's.
Does come with rockers?
More expense? I'd rather port the 318 head muself. Just my opinion.
 
If I was going converter, lower gears, and big cams, I think I would get rid of the 318 heads completely, and go 308 heads. Just my opinion. It sounds like it will be running over 3K most of the time.
 
TK, cam is only 230 @ .050. Not large by anymeans. Since it's a street car, that is the way I'd go.
The 360 heads would certainly perform better at a higher RPM, but how often are we there at 4,500 plus lookin to go 6500 and possibly plus.

On the cheap, a 360 will do fine. I'll not bash anyone for it.
 
I dont quite understand the obsesion with bore size when it comes to the 318.

The much loved chevy LS1 has only a slightly larger bore size that could easily be matched with a slight overbore.

The 318 falls down on cam,compression, and port size. All easily fixable.

It has a slighly shorter stroke than the 360 so will make it's max h.p higher in the rpm band.
 
rumblefish360 said:
TK, cam is only 230 @ .050. Not large by anymeans. Since it's a street car, that is the way I'd go.
The 360 heads would certainly perform better at a higher RPM, but how often are we there at 4,500 plus lookin to go 6500 and possibly plus.

On the cheap, a 360 will do fine. I'll not bash anyone for it.
Click to expand...

I would go small port too, buut.

I know, and you know I advocate small port heads til the death, LOL, but if he wants to converter it, gear it, and cam it............ (A 230 dur cam, with 360 heads would be good for 6000K, no?)

It was just a suggestion, thats all.

If he wants to use NOS, no reason to go wild with anything. I'm just scared of he stuff..... A burp in the fuel system........ It takes about ten seconds to burn through the top of a TRW forgie with NOS.
 
My reasonig was what each of of could do is moot. I'm not sure what article you're talking about. I didnt read any...lol. Is there a link to it? Also, with NOS, overcamming is what you want to do, and running the smaller port and opening the valve further keeps the velocity up, and lets it be driveable over a wider rpm range. The car will be living between 2200 and 3500 for most of it's life, and with mild gearing it wont be trapping at 6000 rpm.
 
This seems like the right place to ask a question on my own 318 build currently in the planning stages. I have a tired old bone stock 318 in a '68 barracuda. The thing runs beautifully, and the only thing keeping it from being a true daily driver is it's oil consumption; mostly from weeping past every possible gasket I believe.

I'm not after screaming performance; hell I wouldn't even tear into it at this time if it weren't for the oil leakage. But if I need to overhaul it anyway, I figured I might as well wake it up a just a little bit too.

I have the following parts at my disposal: edelbrock performer plus cam, performer intake and 600 cfm 4 bbl carb, mopar electronic ignition kit, and 340 hipo exhaust manifolds which I will run to dual exhaust.

My main question is what to do for heads? Everything I've read seems to suggest that I should stick with the small port original type, so as to not lose low end torque and drivability. This is to be a comfortable, hassle free daily driver that will see no track time. I was thinking about using the 318 heads w/hardened seats from Aerohead Racing - no frills but maybe the right choice? - I couldn't rebuild my originals for less than that. I have a lead on some rebuilt big valve x-heads for a good price, but I think I may be disappointed with them on this 318?

And I guess my second question is on piston selection / compression ratio for the goals I've stated.

Any help would be greatly appreciated! Thanks.
 
Swinger, for a comfortable, hassle free daily driver that will see no track time,....
if your going to rebuild the engine, I'd use stock replacement pistons and a mild cam with the stock heads. OR shoot for a 9.5-1 max ratio. The KB167 pistons and a thick head gasket will do this.

IMO, I would skip the Edebrock cam and use something a little larger. I'd look at a Comp Cams XE256H. It has a little more on the exhaust duration to help it breath.
With what you have, this engine will produce about 270 HP and a great torque curve with plenty from start to finish.

I would not use 340/360 heads.
 
Ditto Rumble, add 260-ish lunati voodoo, or engle. Headers make a real big difference too, one you start getting up there past 250HP or so.
 
Talked to a guy at the track today that had a built 318 in a duster, he was running mid 7's in the 1/8 with it. He said that he had sonic checked the block and bored it all it would take, was running the aeroheads with 1.88 valves ported but with the stock valve springs that came with the heads. Had 5:11 gears and was turning it around 6K in the lights. Was going to upgrade the springs soon but didn't want to turn it too high as he was afraid reliability would suffer. (of course you never know for sure what it was with those drag racers, I've heard that they sometimes lie about their combination's)
 
I guess it depends on how much you want to spend. The 67-69 318s have the lowest piston to deck clearance at least as far as stock pistons go. I'm using them in combination with mildly cleaned up 302 heads. This pairing yields a 9.3:1 compression ratio, which works well with mid-grade gasoline without retarding the timing.

Can't report any performance numbers. The car has a 2.76 7¼ rear that I have to take care of it until I can replace it. A 3.55 8.75 is in the works.

The 302 heads have small intake and exhaust runners. The Eddie Performer matches without modifications. The Performer RPM & Air gap are a better fit for 340/360 heads.
 
swinger said:
I figured as much on the 340/360 heads. So let me hear some opinions on these three options:

1) These AeroHead Racing 318 heads with hard seats:
http://aeroheadracing.com/id6.html

2) These rebuilt and ported heads currently on e-bay:
http://cgi.ebay.com/ebaymotors/273-...c0.m245&_trkparms=72:1205|65:12|39:1|240:1318

3) Or work with the stockers I've already got and a local machine shop.

??
Click to expand...

Not to bust ball or chastise, but your thread hi-jackin.

I like the look idea of the e-bay ported head with OE sized valves myself, but they may even be a bit much for the cam I recomended.

\OE heads well preped, back cut valves with a good valve job, multi angle. Your done IMO.
 
My apologies; didn't mean to take over. Thanks for the input and any further questions I can take elsewhere.
 
ehhh, your question is a good one. Thread worthy by itself no doubt. Ask away...........don't be shy.
 
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