318 combo

[Ausydad]

I have a Duster that was originally running a 225, but now has a '67 318 a block with a SP-2 intake and an Edelbrock 600cfm carb, Hedman headers, Accel coil, 904 trans, and my 8 1/4 rear with 2.45. Recently, a friend gave me another 318 ('73) that has fresh 360 heads and .060 over pistons (not flat tops) with the 318 crank. I'm looking for a really good but inexpensive combo to complete this thing. My extra trans in the closet is a J.W. Performance 727 and I'm on the lookout for a 8 3/4. Any thing would be a great help and appreciated.

[Jims451]

More info would be helpful.
There is many ways you can build an engine, but what you want is to choose parts that compliment each other for the engines intended useage and/or RPM range.

When you design the engine combination, you can take several routes, but you have to first determine the intended useage for the engine/car.
Secondly you may want to determine what parts you will want to use and which ones it would be ok to change/replace. This selection of what will be re-used and/or replaced can have big implications on the vehicle performance and on the cost of the project.

Lets start with the easiest, the engine short block. It appears that you have two 318 LA engines. Assuming that you don't want to spend money rebuilding the short block, you would want to check and see which one is in the best condition. Assuming no major problems, like a spun bearing, probbly the most important factor is going to be which engine has the best ring seal. A leak down test should be helpful here.
The next consideration might be which engine has the highest compression ratio pistons.

Some assumptions are: Bearings should check out OK or they will be replaced, main and rod bolts will be , Engine will be assembled using a quality gasket set, While the oil pan is off, install a Melling High Volume oil pump (only about $35), The cam/lifters will be replaced for performance to match the intended useage (RPM range) and engine compression ratio, the timming chain and sprockets will be replaced (unless they have already been replaced with a good timming set, and the new cam will be correctly installed (degreed-in.)
Also, this is a good time to replace the freeze plugs before they rust through and start leaking.

Moving to the cylinder heads, you have '67 318 heads which are closed chamber which helps compression, but they have the smaller valves. The 360 heads have large open chambers which hurt compression, but they have larger valves.
The problem is we don't know the condition of the cylinder heads? Are the valve guides worn? are the heads cracked? Plus there are other cylinder head choices, like the later swirl head design and you mat find some comerically rebuilt heads to be less expensive than having your heads rebuilt (depends on the condition of your heads?)
If both sets of heads are good and useable, then I woul at least have a 3-angle valve job done on the heads/valves. If the engine is going to be fairly mild (300 HP or less), daily driver with high gearing (Low RPMs), then the 318 heads would work fine and should also give you better gas mialage.
If you need 300+ HP, higher RPMs, and lower port velocity at low RPMs the the 360 heads would be better. On either head you will need new valve stem seals and the valve springs that work with the cam you choose.

The headers are good, and you should have dual exhaust system with 2-1/4" to 2-1/2" tube.
The 600 CFM carb is also correctly sized for most applications. The SP-2P 4-bbl intake is OK if your intended use is low RPM power and gas mialage, but there are much better manifolds avaliable. You din't mention if you have points or electronic ignition, but the electronic ignition is a good upgrade and if your on a really tight budget you can use junk yard parts with a distrubitor recurve.

For any real performance use, you will need to get some lower gears, the 2.45:1 is just too high.
Either transmission will be OK as long as you have the correct stall speed converter for the cam you use. The 727 will use more power to run, but it will last longer between rebuilds. If you go with a mild cam, Manicnni racing has factory hi-stall (up tp about 2,500 RPM) converters on sale for about $130.

Once you know your application, gear ratio (and tire size), and about what your compression ratio is, then you can start selecting cams that will bring the combination together.
Just guessing, but most 318 street performance cams will have duration @ 0.050" ratings between 205 on the small side to about 230 on the big side. Generally cams up to 210 Duration @ 0.050" will work good with lower compression ratios (9.2:1 and below), and mild driveline parts like 3:1 gears and tight torque converters. They should be OK with the SP-2P intake. Cams in the 210-220 range will work better with 9.0 to 9.5+:1 compression, and will require a least a 2,000+ stall converter. Look at intake manifolds like the Edelbrock Performer. Cams in the 220-230 range will want 9.5 to 10.0+:1 compression, and 2,500+ stall converters (probly closer to 3,000 stall with the 230 duration @ 0.050" cam.) Look for a large runner intake like the Performer RPM.
Cams larger than 230+ will require alot more attention to the heads (ported 360 heads?) and compression ratio and the strength of the shortblock (ARP rod bolts at the minimum) and a larger carb and single plane intake (the RPM is still OK unless you go to a really big 240+ cam.)

[Ausydad]

O.k., the dist. is a Ma Mopar electronic from 1973 and was converted last week. Curve is stock. The hopeful horse comes in right at 300 and I was thinking about the 484 purple cam with a 2500 stall, torker II and a 750cfm, as well as changing to TTI headers for clearance. The rear I'm looking for would be a 8 3/4 with 3:56 and my tires in the rear now are 295/50/15 and 175/70/14 in the front. It will be a daily driver and would run on pump gas, so compression should stay 9-9.5. The 318 ('67) that's in the car now has about 200k without a rebuild and the '73 LA was redone about 2 years ago. They are different blocks. The '67 is a A block with a cast iron water pump and different timing cover. I also have the March billet pulley system that will be used although I have to use a GM Saginaw p.s. pump for that. What about cam valley baffle to keep hot oil off the bottom of the intake? Also, what about windage trays? Should I keep the 318 crank or mill for a 360 crank for stroke?

[Jims451]

I'm supprised you haven't got more replies to your post?
Your Cam, Carb, Intake are pretty big for a street car with a 318, and you should have more gear, stall and compression to use them. They will make power above 3,000+ RPM, but they are the worst setup for torque below 3,000 RPM.

I thought you mentioned an inexpensive combination, but you quoted some pricy parts like TTI headers, March pulleys, and possably stroking the 318. I don't know how stroking a 318 would even be considered "inexpensive" because it is less expensive to just get a 360! not to mention there are more off-the-shelf parts like pistons, etc to fit the 360 engine.

Anyhow, 300 HP is pretty easy using mild parts that will give a broader, more useable torque curve.
First, you only need to spin the 318 to about 5,500 RPM to make 300+ HP.
Second, 600 CFM carb is plenty in size.
Third, An Edelbrock Performer intake is all that is needed.
Fourth, a cam in the 260 to 270 duration range will work, figure about 216 to 220 duration @ 0.050".
A stock 1.88"/1.60" valve cylinder head will flow fine to make the power. Additional flow / porting that dosen't hurt velocity will just add to the overall power output.
AeroHead has complete 318 heads with the 1.88"/1.60" heads for $399 if you need heads.
You may want to use the Mopar P4452761 cam with 268/272 duration, 0.450"/0.455" lift. This cam will work with the valve springs that come on the AeroHead heads and the Mopar cam/lifter packages are fairly inexpensive.
Hughes Engines sells some nice cams, but they are more expensive, and will require buying their valve springs and retainers.

[Ausydad]

I mentioned the .060 over pistons and the 360 heads as that's what my other 318 has already, with a 318 crank. My math tells me thats a 328. If I went to a 360 crank, it would be 354. I don't really care about the extra cubes. The bottom end seems prettty clean still as it has a bare minimum of carbon buildup on the pistons and I can still see the honing marks as well as the 360 heads I pulled are still clean enough for eating. The dist., intake, and carb are missing though. I mentioned also TTI headers as ground clearance sucks and I thought shortie headers were designed for a different R.P.M. range. My Hedmans are consistintly smacking the ground. Do you rec the Ed. Performer RPM or standard. Should I recurve the Ma Mopar el. dist. I have in the 318 I'm still running. What about the Miloden hi-vol oil pump someone else mentioned. I would like the 1970 340 double roller chain. And I have no clue as to what size the cam in the '73 318 is. The extra 318 was given to me by a friend that wants help installing a 542 in his '73 Space-Duster. My ultimate goal was to have a slightly lowered front with stock height rear (springs narrowed, kit already given as gift) and a 300 h.p. or more 318 (using existing block). March pulleys also already given as gift.

[Jims451]

Don't mis-understand my, I like the TTI headers and they should help the ground clearance problem. Before you buy the Headers, There was someone on here that is a TTI dealer and can get them at a discount price. I'll see if I still have his name at home. Also, I'd like to run a few Desktop Dyno simulations just to see what it says.

I have ran a 318 with the 284/0.484" cam and a Holley Strip Dominator intake (4.10 gears) and it was OK for the strip, but sucked on the street.
The setup has a rough idle, low vacuum, and not much low end torque.
I have also built a 318 more like I just described above, but using older technology parts (built in 1985.) The engine is a great street engine and with 3.55:1 gears and a 2,500 stall converter it is pretty quick too

There is no real problem with stroking a 318 with a 360 crank, it's just that there are not alot of pistons avaliable for doing this (the piston pin height has to be changed because of the different stroke length) and they are not cheap, plus you have to spend extra to re-ballance the engine assembly.

Since the 360 heads are in good condition, use them, just double check the compression ratio when using them. You may have to shave them to increase compression ratio. I would shoot for 9.5:1 compression ratio using the thin steel shim head gasket (0.019"), then if the compression is too high for your fuel octane (I doubt it will be) you can alaways install the thicker 0.040+" thick head gaskets.

The benifit of the HV oil pump is that it will maintain good oil pressure when the engine gets older and the bearing clearances get larger. The extra oil that the engine dosen't use is just bypassed back into the oil pan. The only drawback is the pump takes a few more HP to run compared to a stock pump.

The stock Electronic distrubitor may need to be re-curved, but it will depend on the engine setup and how the distrubitor curve is now. I wouldn't worry about it untill after the engine is assembled and running, it's just a tuning thing, like changing jets in the carb.

You can get the double roller timming chain from several manufacturers. Summit even sells their own brand (I think it may be a re-packaged Edelbrock?), but I like the Cloyes brand for a few bucks more as they seem to fit tighter. Some shops sell the RollMaster (I think that is the name) and it is supposed to be really good with many adjustable keyways, but it is also $100.

You never said what the intended useage of the car is? Is this a race car, or a daily driver, or a sreet/strip car? This would really help.

The Parts you mentioned, the torqer intake, 750 cfm carb, and 284/0.484 cam can be made to work. The problem is the setup is not very streetable because it makes all it's power in the upper RPM range, and low end torque really suffers.
On a street driven car you usually are driving ar RPM that would be below the engines power band, so you really are giving up power where you use it the most when driving on the street.

For a street and street/strip car you need to ballance the power curve to provide good torque for sterrt driving. It is possable (and common) to have a engine with a high "peak" HP that is slower than the same engine built to have a "wider" power band (More torque, but less "peak" HP.)
Torque is what actually accelerates the car. If your power/torque curve is at High RPMs (more peak HP), it takes the car longer to accelerate the car up to the RPMs of the power band, unless you use steep gears and high stall torque converters.

[Ausydad]

I understand your comments about powerband and agree that it is torque that brings your front wheels off the ground and gets you going. Horse is a by product of torque. I want the car with a balanced setup that would be a zipperheadstomping, yuppyeating daily driver. Tired of those boys with Daddy's money walkin' from mine and pointin, lol, calling mine "Al Bundy Special". Getting time to change those rear gears so I can use what I got and come back a bit. 2.45 ain't good off the line. Anyway, yes, a more subtle combo would work out well and since most of that is missing, just about any setup is a possibly. I work about 110-120 hrs. pr. wk and have a budget about 50-100 pr. mo. I like swap meets. I seem to be getting off track. Talk again soon

[Ausydad]

I haven't heard anything new from you guys. I've been directed towards maybe a .442 cam and going ahead and using those 360 heads. In my parts closet I have a stock cast iron 360-4 intake which I doubt I would use ( I kinda like the RPM Performer) and I have a 4779 Holley carb (750) as well as the 1400 Edelbrock 600cfm I'm currently running. You guys mentioned Spitfire shortie headers for around $120 compared to TTI's. How would they work on a daily? And how can I figure out if my other 318 already has the cam I'm looking for? I doubt someone would go to .060 slugs and 360 heads without doing something with the cam. I like the expense ratio of the Spitfires and they should both have the clearance I want.

[451Mopar]

I ran dyno 2000 on this combination:
318 cid, 9.2:1 compression,unported heads with 1.88"/1.60" valves, 600 cfm on a dual plane intake, small tube headers with mufflers, and the Mopar 268/272 duration, 0.450"/0.455", 110 LSA cam.
The Results: 310 HP @ 5,000 RPM, 347 ft/lbs torque @ 4,000 RPM.
I also ran the simulation at 8.8:1 compression and power was only down 7 hp and 6 ft/lbs, so you should be OK with compression in this range of 8.8:1 to 9.2:1.

Here is more detail on the 9.2:1 run.
RPM HP TQ VE BMEP
2,000 122 320 73.4% 153.7
2,500 156 327 75.7 157.2
3,000 191 335 77.9 160.8
3,500 230 345 81.7 165.6
4,000 265 347 84.7 166.9
4,500 294 343 86.4 165.1
5,000 310 326 86.1 156.5
5,500 308 294 83.4 141.1
6,000 288 252 78.4 121.1
6,500 264 213 73.8 102.4
7,000 229 172 68.8 82.5

[Ausydad]

Thank you guys for jumping in and helping to dissolve some rumors and disollutions I may have had with my other motor. Sounds like a combo that should work well with a low stall converter and mild rear gears. Now all I have to do is come up with a few more pieces. Maybe after I move. Anyway, Thank you.

[mr_340]

I'd follow 451Mopar's advice. Definitely lose the SP2P intake, the ports are really tiny. Almost any dual plane intake will be a good choice, Performer is probably the best. I'd use the 73 318 with 360 heads, a 340 type cam (270°/.450" lift). The gears need to go. 3.55s would be a good choice. You can have the 360 heads milled down around .030" to get some more compression. Make sure they mill the intake surface on the heads accordingly so your intake will fit