318 build opinions please.

-
340 Dart

340 Dart

I don't know ****.
Joined
Feb 5, 2007
Messages
2,358
Reaction score
30
Location
San Antonio
My goal here is to get the wife's 66 into the mid 12's with a 318.
I am going to keep it as simple, and inexpensive as possible using parts I already have.

I have a freshly rebuilt .040 over 318 shortblock.
Stock height pistons with valve reliefs.
cast crank
The cam is a purple shaft lift 508/508 duration I think is 292/292
Stock mopar adjustable rockers
Windage tray
Double roller timing chain
650 Carter
Clutch fan
1 5/8" headers
2 1/2" exhaust with "X" pipe.
FBO ignition

318 smog heads (not 302's)
OR
360 small valve heads (flow 230 at .500)

Eddie performer intake
OR
Stock 360 4bbl

If I break parts I want it to be cheap to put the engine back together. I am thinking about shaving down the 360 heads and intake to make CR 9.5 instead of getting high dollar pistons.

I know the 318 heads will have better port velocity but that is alot of cam and the 360 heads are at least small valve heads.

I don't want to get into the transmission or the rear here, only the engine itself. I will start other threads for them when the time is right.

Anyone know the weight of a smallblock 66 Dart in street trim?

What are your thoughts?
 
Headwise i'd go with the 360's,intake the Edelbrock performer.. thats a lot of cam for a 318,i'd say you'll deffinately need more stall speed.. whats in it for rear gears?? any 318 i've seen in the 12's were either spraying or had a "lot" of money in them,good luck:-D
 
I have about $1200 in fully rebuilding my 318 (machine work to carb), that went 13.6 running 30.5" tall tires (it needs 26") and with a full weight ebody at about 3,550 with me in it. Did have about a 3,500 stall converter with 3.91s however

Wouldn't take much to get it into 12s since it's basically built from cheap/donated parts and only a .480 lift cam. Don't think it'd be a problem in the light '66 dart he's running.
 
I agree with Stroker340. If you're looking at 12's for that 318. More $$ and or sprayed is the only road to 12's with what I've seen. Good luck.
 
The big problem here is the low compresion pistons. There good for ash trays or melted down for fishing weights. Look for a high comprsion piston. I'd recomend the KB model for a zero deck height and mucho squeeezzzeee.


pocket port the 360 head, MP mechanical vam 284/.484, rpm intake, 750 cfm carb, holley, 4.56 gear and 28 inch tires, proper stall verter. tie the frame and look into s/s sprigs and/or cal tracs

sell the other stuff to fund.
 
rumblefish360 said:
The big problem here is the low compresion pistons. There good for ash trays or melted down for fishing weights. Look for a high comprsion piston. I'd recomend the KB model for a zero deck height and mucho squeeezzzeee.


pocket port the 360 head, MP mechanical vam 284/.484, rpm intake, 750 cfm carb, holley, 4.56 gear and 28 inch tires, proper stall verter. tie the frame and look into s/s sprigs and/or cal tracs

sell the other stuff to fund.
Click to expand...
:cheers:
 
Nitrous is not an option.

Does anyone know how much will have to come off the 72cc "J" heads to make a 9.5 to 1 CR or is this not possible with the stock pistons? There is a possibility of supercharging this engine in the future and I want to make my CR with shaving the heads and not buying pistons. IF do supercharge it in the future I will put new and better heads on it to drop the CR.

I wanted to concentrate on the engine in this thread and not get sidetracked but we might as well talk about it now:
The car will have 4.10's, 3,600 stall, a 904 with reverse manual valve body, bolt in sprag and low band apply. SS springs will be used and the tire will either be a 26" or 28". I don't know what will fit yet.

Thanks Goody, your engine in our car would probably hit high 12's as it is.

Rumble: Except for the gearing, that is the build on my 340 in the Duster. I hope to start it next weekend. The 318 will have more cam, more gear, and better heads.
 
Buy the Keith Black 11.1 hyper's run the 360 heads 11/32 stem small valves [yea like a chevy] with the guides profiled skinny & long and bump cut out of roof & might as well leave the pushrod pinch but blend it a lil. then roll the short turn back to where it really starts and blend out that bump thats off of the wall on the short turn straight shot.

The .508/old.509 are light switch cams but with some unmentionables could work I guess though the .528 or .557 solid would be better MP choices IMO.

RPM intake, your carb sounds good if the port volume/flow is there if not then a lil bigger would help like rumble mentioned.
1 5/8 headers & 2 1/2 exhaust sounds good.
I would get a set of full roller rockers [ohio crank=$139] and don't forget the Harland S adjusters and rckr spclties shafts and 1.6 would get that valve moving a lil faster and a lil further.
Block off the heat cross over, install valley baffles and windage tray.
Get a deep sump pan and pick up [STOCK OIL PUMP]
Stock prep'd FULL FLOATING rods w/ARP bolts

And when you bore and hone USE A TORQUE PLATE.

A set of total seal rings or at least some hastings single moly rings.

And don't forget a good [like JP performance or rollmaster/mancini billet timing chain.
 
I have used the 509 cam a number of times when I was younger and as predicted it produced the lumpy idle us kids were looking for but the term "Lightswitch cam" is the perfect description of the power band. If you haven't purchased it, don't. If you have purchased it, I'm sure you'll find someone less educated to buy it. The 484 is milder but has a better power band, but I would go with a solid and if you're loking to take advantage of the stock rocker gear only, I would look at a .510" lift max.
My 2 cents .

Dan
 
I found out the Dart weighs around 2900. Lets say 3,000 just in case.

To get this to:
12.9, I need 275RWHP +20%= 330 at the flywheel
12.5, I need 300RWHP +20%= 360 at the flywheel
12.2, I need 320RWHP +20%= 384 at the flywheel

This is a light car and I will make it 60' decently. Of course this is approximate but I really don't think cheap 12's is asking that much. I don't think cheap low 12's is asking that much either.

Can I mill the 360 heads enough to get the CR down to 10.1?
Stock 4bbdl intake or eddie performer?
360 heads or pocket port the 318's?

Remember I am not picking parts for the ultimate 318 build. I am picking from the parts I currently have to make the best engine I can.
 
I talked to a local shop about an hour ago Rumble and you were right, just getting the new pistons to raise the CR will probably be the simplest way to go. I didn't think about how much it would change the geometry of the valvetrain trying to shave so much off the heads.

The cam should be in the 2,800-6,200 rpm range. Do you think there is a problem with turning the stock internals to 6,000?
I plan to run an 8 1/4 with 4.10's for now and step up to a 4.56 when the new rear is finished. I also plan to call John at CRT for his input on a converter for this when the final combination is decided upon.

Does that performer have 360 or 318 ports?

I don't have a Desktop dyno to crunch numbers with, but the Comp cams site is predictin 396HP at 6300 with the 360 heads and the performer intake. Even if its 50HP off I think it will still touch 12's.
 
340 Dart said:
I talked to a local shop about an hour ago Rumble and you were right, just getting the new pistons to raise the CR will probably be the simplest way to go. I didn't think about how much it would change the geometry of the valvetrain trying to shave so much off the heads.

The cam should be in the 2,800-6,200 rpm range. Do you think there is a problem with turning the stock internals to 6,000?
I plan to run an 8 1/4 with 4.10's for now and step up to a 4.56 when the new rear is finished. I also plan to call John at CRT for his input on a converter for this when the final combination is decided upon.

Does that performer have 360 or 318 ports?

I don't have a Desktop dyno to crunch numbers with, but the Comp cams site is predictin 396HP at 6300 with the 360 heads and the performer intake. Even if its 50HP off I think it will still touch 12's.
Click to expand...

In a 'perfect world'.

Stock steel crank & 340-360 rods can be turned up to 9000rpm,
trust me I know.
Cast crank and same rods 7000rpm TOPS. and even there **** can happen.

The performer has 360 ports that taper down to 318 size but can be port matched, BUT don't use this manifold it's all over at 5500-5800 and going away at 6000.

The rpm eddy,LD340,stealth, are way better pieces for dual planes.

2800-6200? sounds like .528 solid pwr bnd=2800-6900 rpm and idles good too.hee hee.
 
3404spdvaliant said:
In a 'perfect world'.

Stock steel crank & 340-360 rods can be turned up to 9000rpm,
trust me I know.
Cast crank and same rods 7000rpm TOPS. and even there **** can happen.

The performer has 360 ports that taper down to 318 size but can be port matched, BUT don't use this manifold it's all over at 5500-5800 and going away at 6000.

The rpm eddy,LD340,stealth, are way better pieces for dual planes.

2800-6200? sounds like .528 solid pwr bnd=2800-6900 rpm and idles good too.hee hee.
Click to expand...

Stock steel rods and crank when preped go that high. For the cost of preping the rods, sell'em and purchase aftermarket rods.

OH wait, building this with what you have on hand. So much for reading the post huh? LOL

Use the Iron intake and the 360 heads for now. Space the carb up to gain plenum.
The stock internals are fine at 6000. I'd limit it to 6500 for longevity purposes. You really don't want to go there at all, but a breif finish line run that high is OK.
 
I will throw in my opinion lol,I would port the 318 heads and shave them,the vleocity will make the engine zing and keep much needed torque,and run the airgap.I recently built a 360 with 8.5 compression,ported 318 heads (stock valve sizes),xe274,port matched performer and a 600 holley with 1 5/8 headers and it was impressive,it acted alot like a well built 383.I had it in a 70 dart with 3.23s,904 with a mild stall so it had more in it,I didnt get timeslips before it sold but I can say it was defintely in mid to low 13s with street trim and radials.Also fwiw I have a buddy that built a 318 in the 80s,it had the 292,m1 intake,ported 318 heads,headers and 3.91s in a dart and it ran 12s.
 
Check the archives on the 400 HP 318 builds. There are several versions. Magnum heads is the deal on one.
 
Here's my take, you need to think about the amount of horsepower required, and not the displacement when considering parts. You CAN make 400 HP with a 318, but it will not have much low RPM torque (you aren't driving this on the street right?) so don't give up HP trying to bring back low end. When selecting heads, intake, carb and exhaust, focus on parts that will support 400 HP with minimal fuss. For the bottom end, focus on parts that will be reliable at 6500 RPM, as you will need to spin this engine pretty fast. The cam, converter and gears will have to be appropriate for this goal as well.

From the bottom up:

Stock 318 crank and rods (avoid the early rods) will work fine with careful prep and quality fasteners.

Don't even think about the stock 318 cast pistons. They will make compression difficult, they're heavy and they will not hold up well at those RPMs. If you never plan to use nitrous, a high quality cast piston like the KB hypereutectics will be fine. If you can swing it, a set of lightweight forged pistons/pins would be a wise investment. The stock crank and rods get exponentially stronger with a reduction in piston mass.

The 292 .509 MP cam is a tried and true choice. If you already own one, it will get you there. If not, there are more modern alternatives. Call Hughes, Comp, Crane and the other usual suspects and see what they recommend.

Run the 360 heads. You need high RPM flow over low RPM throttle response (you aren't driving this on the street right?). The 1.88 intake valve is adequate, and a good valve job with basic port cleanup should support 400 HP fairly easily. Avoid heavy cutting to raise compression. It gets expensive, you'll need custom pushrods, and head gasket sealing can suffer.

Run the 360 iron intake and eBay the Performer, its a better intake. Better still would be a Performer RPM or LD340. A Victor junior would be reasonable too if you score one cheap (you aren't driving this on the street right?) People will tell you that you need "velocity" with a 318, and this is true to a point. Remember that the smaller ports and runners create their velocity through restriction. This may be nice on the street at 2000 RPM, but will kill you on the track above 4000. You want this thing to BREATHE.

Rethink the carb. You could possibly make 400HP with a 650 (625?) but you can easily make 400HP with a 750 (you aren't driving this on the street are you?) A Holley 750 vacuum secondary would be my first pick, with the 750 Thunder AVS a close second.

Your exhaust will be OK, but 1 3/4" primaries won't slow you down either, especially with the symmetrical pattern cam. Consider weld-in cutouts if you aren't dropping the exhaust at the track. You will be running fenderwell headers on the 66 if performance is your goal.

Aside from the pistons the only high dollar thing I would figure in my budget would be a GOOD custom converter. This is money well spent, and you certainly get what you pay for here. Skip the Chinese roller rockers and spend the bucks on SFI approved hardware, a good fuel pump, and the other stuff needed to get the car on the track.

REALITY CHECK: I assume you want to do this with a 318 because you have one on hand. Fair enough, that's reasonable if your budget is tight, but it costs the same to build a 360. At this power level you are getting 50HP for free with the 42 extra cubes. Down the road when (not if) you want to go faster the 360 will be a better choice. For the most part the above suggested parts will work fine if you chose to upgrade to a 360 shortblock down the road. That way you can build the car in stages without replacing everything when you chose to upgrade. In the mean time, you should be able to get into the 12s and have the foundation to set up consistent car will last all season without hurting itself (you aren't driving this on the street are you?)
 
if your not going to run it on the street.you can loose 200to250lbs by getting rid of some weight.....remember every 100lbs= a10th loose 75lbs in glass ....go to plastic,heater box windshild motor and asym..25+lbs...you get the picture....hope this helps kenn
 
Dang Jim this is sounding a lot like what I said on the other board and on the phone a little while ago on the phone! :-D
 
BJS racing said:
Dang Jim this is sounding a lot like what I said on the other board and on the phone a little while ago on the phone! :-D
Click to expand...
Don't it?:-D Thanks Jason.


In the mean time, you should be able to get into the 12s and have the foundation to set up consistent car will last all season without hurting itself
Click to expand...


C130chief it seems you understand and thank you for the breakdown!! Here are your answers:

- It is an 85 .040 fresh short block that I traded for. It has the crank, pistons and cam already in it. I got it, so I'm gonna use it.
- I will never spray and it looks like I will be getting KB's.
- I already own the cam, and adjustable rockers and rods from a 273.
- The "J" heads have a good valve job and mild porting.
- I will keep stock 360 intake. (perfomer for sale:-D)
- Carb is what I have now, it took my 360 dart to 12.9 but can be changed later. I can borrow the 750 off the Duster for testing.
- The exhaust will have dumps on it and I need to learn about and find a set of fenderwell headers.
- Last but not least, I know I will be spending money on a good convertor.

Thanks to all for the replies and talking me through this. This build is only going to cost some of your time, alot of mine, and a set of pistons.
Everything else I will be able to use on future builds.:-D

'll let you know in the spring how far in the 12's it actually went.
 
Jim here is the other info I was telling you I would get for you.

Jim here are some specs for you

318 (5.2)1967-2002 3.91 stroke Main journal 2.50
360 (5.9)1971-2002 3.58 stroke Main journal 2.81

All rod journals were 2.125
 
I would run 360 heads milled with kb399 pistons. I run these heads and a pistons with a 488/510 234/244. Air gap 650 holley dp. I have about $2200 into my engine. Its in a dart it weighs 3400 with me in it. I have 4.10 gears with 3500 stall and run 12.9 at 103. So it doesn't take a lot of cash to make a 318 run.
 
340 Dart said:
To get this to:
12.9, I need 275RWHP +20%= 330 at the flywheel
12.5, I need 300RWHP +20%= 360 at the flywheel
12.2, I need 320RWHP +20%= 384 at the flywheel
Click to expand...

How did you come up with these numbers?
I'm just curious how accurate they are.
 
Welcome to the board uncle Ted.

The numbers were from an ET calculator. Here is a link to alot of them.
http://www.wallaceracing.com/Calculators.htm
They are not perfect of course. and are only as accurate as the information you put into them but they will at least get you close.

They 20% was just estimated drivetrain loss. Could realistically be 16-22%. Just another scientific guess to get me in the ballpark.

When I was racing my Dart the numbers from this calculator were pretty much dead on with my time slip, but again it is only a tool.
 
I am rtrying to sucessfully post a picture from my hard drive to the BB, and haven't had any luck; the picture just doesn't show up. This in just one more attempt. Forgive me for hijacking this thread, just ignore this, please.

Bill

100_3228-2.jpg


100_3230-3.jpg
 
You must log in or register to reply here.
-

Back
Top