318 Cam Suggestions

496 polara said:

3-8-Teen Dream

Something like the Comp XE256 (or similar specs/brand unimportant) with NEW VALVE SPRINGS will make a nice responsive package. Sure you can go one step bigger with the cam and find yourself wanting a better torque converter,then head work,etc,etc.

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That or the Summit K6900
Advertised Duration 278/288, Lift .421/.444

The Comp 256 only gives up 10 HP to the next size up 262, but the 256 has a MUCH broader and flatter torque curve.

Those two would be my top picks.

Airwolf222b said:

Thanks for all the great suggestions. To answer a couple questions I guess I would like to see if I can get another 30HP or so out of it without any major work. I also know I've got a lower compression engine due to it being a 1973 so I'm just hnt sure what my best options would be. So I'm not looking for a drag strip car, but a little more fun to drive would be great. Right now it's a wonderful daily driver. But its "get up and go" wouldn't be much better than driving a honda or toyota. It's got plenty of power to get moving but nothing too fun if that makes sense. Budget would be somewhere between $1000-$1500.

I guess I'm asking, if you inherited this car today and wanted an increase in power and torque, what would you do?

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Not sure about your list. Which ones are necessary and which items are wish items?

It looks like you have already changed the wheels and they look like a nice upgrade from what you posted in any earlier thread.
Old:


The car sat for awhile? I would flush the cooling system and take the radiator to a shop for cleaning and pressure test. Maybe you already have? Flush out the brake system too.



Below is what I did to my '71 Satellite (318-2V) a long time (50 years ago); and I'll note I was on a tight budget:
1) Cast iron 340 intake (spread bore)
2) Holley carb (600 cfm?)
3) 340 purple shaft (I don't recall the specs)
4) Direct Connection double roller timing chain & gears.
5) Local shop "refurbished" the heads (e.g., replace bad valves, valve guides, and replaced valve guide seals). They might have taken off 0.010" from the cylinder side. I did not go with a 3 angle valve job.
6) Thin steel head gasket from Direct Connection. No longer available.
7) Added dual exhaust. I did not use aftermarket headers. Used 2-1/4" exhaust pipes and tail pipes.
8) Transmission shop rebuilt the "904". I drove it for a few months and then I installed a B&M Trick Shift kit. I don't recall which level I used. Drained the torque converter too since it had a drain plug. Used B&M trick shift trans fluid.
9) Light centrifugal spring/weight in the stock distributor.

I cannot suggest a cam for you because I don't know...there are so many options available today. Also, there are more options now for heads than when I was working on my 318; and 340 cylinder heads were not in my budget back in the day.

I would do the following to your car before going with different cylinder heads:
1) add/upgrade front and rear anti-roll bars.
2) use a sure grip unit in the differential.
3) maybe you should consider a higher stall torque converter.
4) how are your shock absorbers? I use Bilsteins on my newer cars. My older cars don't need shock replacements yet.

Maintenance items...
1) front wheel bearing seals when you grease the bearings.
2) brake piston caliper seals
3) rear brake wheel cylinder seals
4) various stuff with an old car (e.g., U-joints)

Have fun!!!

DeltaV said:

Not sure about your list. Which ones are necessary and which items are wish items?

It looks like you have already changed the wheels and they look like a nice upgrade from what you posted in any earlier thread.
Old:
View attachment 1886521

The car sat for awhile? I would flush the cooling system and take the radiator to a shop for cleaning and pressure test. Maybe you already have? Flush out the brake system too.

View attachment 1886522

Below is what I did to my '71 Satellite (318-2V) a long time (50 years ago); and I'll note I was on a tight budget:
1) Cast iron 340 intake (spread bore)
2) Holley carb (600 cfm?)
3) 340 purple shaft (I don't recall the specs)
4) Direct Connection double roller timing chain & gears.
5) Local shop "refurbished" the heads (e.g., replace bad valves, valve guides, and replaced valve guide seals). They might have taken off 0.010" from the cylinder side. I did not go with a 3 angle valve job.
6) Thin steel head gasket from Direct Connection. No longer available.
7) Added dual exhaust. I did not use aftermarket headers. Used 2-1/4" exhaust pipes and tail pipes.
8) Transmission shop rebuilt the "904". I drove it for a few months and then I installed a B&M Trick Shift kit. I don't recall which level I used. Drained the torque converter too since it had a drain plug. Used B&M trick shift trans fluid.
9) Light centrifugal spring/weight in the stock distributor.

I cannot suggest a cam for you because I don't know...there are so many options available today. Also, there are more options now for heads than when I was working on my 318; and 340 cylinder heads were not in my budget back in the day.

I would do the following to your car before going with different cylinder heads:
1) add/upgrade front and rear anti-roll bars.
2) use a sure grip unit in the differential.
3) maybe you should consider a higher stall torque converter.
4) how are your shock absorbers? I use Bilsteins on my newer cars. My older cars don't need shock replacements yet.

Maintenance items...
1) front wheel bearing seals when you grease the bearings.
2) brake piston caliper seals
3) rear brake wheel cylinder seals
4) various stuff with an old car (e.g., U-joints)

Have fun!!!

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You could do way worse than that 340 replacement cam.

If you can do the work yourself you are well ahead. Even if you are paying someone a cam and lifter swap with new timing chain and valve springs should be within your budget. Having the distributor recurved is a must in my book.

Or you could look around for a good running 360 that would be a candidate for a cam swap. Whatever you do be sure to drive it and enjoy it instead of letting it becomes the never ending project. Ask me how I know.

Find the '128 rule' on the web. And use that to calculate the reqd LSA for your cam.

The dual exhaust, 4-bbl carb and intake should get you about 30 HP with the stock cam. Tuning will be important. Look at the FBO re-curve kit: FBO Ignition - Home of the HRR688
First, the headers are pricy for headers that wrap under the drivers side tierod. The tubes get damaged easely on speed bumps. Stiffer Torsen Bars will help node dive and handling.
Second, Good choice on intake and carb. The throttle and trans kick down linkage usually are an issue when swaping the intake and carb. You will want the chrysler throttle lever adaptor for the carb. On your model, I'm not sure how long the throttle cable is? Many times the new intake moves the carb a bit forward and the throttle cable is too short although it can usually be made to work. Same with the Kick-down rod usually needs to be extended. Usually the stock throttle cable is in bad shape if its original, so I replace it. The Lokar kit with throttle cable and cable kickdown is decent and makes the swap easier, but the kit needs better instructions for the install.
Third, has the engine been rebuilt? what condition are the heads and timing chain in? Asking to figure out if the heads need valve seat or guide work. At the minimum, I would replace the valve springs and the valve stem seals at the same time.
Forth, the cam. With the stock torque converter, you should stay on the smaller duration side like around 260 advertised, 210 @ 0.050".
If you get up around 220 @ 0.050" duration your at the point where at least a factory Hi-stall converter should be used. Beyond that an aftermarket hi-stall converter should be used.
I like the Hughes Engines Mopar cams. More lift and area under the lift curve, so usually get as much or more power than the competition next size larger cam, but with better low rpm torque. The SEH0610AL-13 would be great for something that gets driven on the street alot.
If you get their lifters, springs and break-in oil they have a "no flat tappet guarantee". No, I don't get anything for recommending them.
Wrap this up with the timing chain set. I usually use at least a 3-Way adjustable keyway timing set to help when degreeing the cam. Mopar used to sell off-set cam keys for degreeing the cam, but I'm not sure if they still sell them? Summit says not avaliable: Mopar Performance P5249600 Mopar Performance Cam Keys | Summit Racing

I spoke with summit yesterday. Based on my current setup they recommended this Cam. Have any of you ever tried this one? He said I wouldnt have to do anything to the car other than install the cam, that my particular engine, compression and current parts would all work together great.

Airwolf222b said:

I spoke with summit yesterday. Based on my current setup they recommended this Cam. Have any of you ever tried this one? He said I wouldnt have to do anything to the car other than install the cam, that my particular engine, compression and current parts would all work together great.

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Not a bad cam. The 110° lobe separation will give it some chop at idle but it won't produce a lot of vacuum. 114° would be better if you have power brakes.

If it's a real RR, it's already got dual exhaust.

I'd do the Summit cam I posted (6900) before the one just above.
It's a more modern profile and better for factory exhaust manifolds.

Wait, I see you have headers.

If you do get that cam from Summit you should confirm that the 318 has at least a 9:1 compression.

Airwolf222b said:

I spoke with summit yesterday. Based on my current setup they recommended this Cam. Have any of you ever tried this one? He said I wouldnt have to do anything to the car other than install the cam, that my particular engine, compression and current parts would all work together great.

Click to expand...

As mentioned above the Summit Cam with 216 @ 0.050" duration would work best with around 9.5:1 compression. The cam will work with the lower compression, but it hurts low end torque. I was suggesting a pretty mild cam thinking you want to use the stock torque converter. A high stall converter is a great addition when going with a larger cam in a low compression engine.
I think some people believe that cams magically make power. Burning fuel makes power, and you need oxygen to do that and we use the approximate 20% oxygen in air to do this. The inert gasses in the air actually help control the burn speed and temperature, but getting off topic. Anyhow, what you want is maximum cylinder filling by mass (volume is a bit mis-leading as it don't account for density) for the RPM range the engine is intended to operate.
The cam is tuning the way the engine makes power. Larger lift allows the heads to flow more air, the usual cam specs listed are just a rough guide as to the RPM power range.
A smaller duration cam normally closes the intake valve sooner After Bottom Dead Center (ABDC) which increases the dynamic cylinder pressure helping low end torque, and usually has less overlap so smother idle, and more vacuum. The down side is that the small cam prevents gaining airflow at higher rpm. Because of air mass and the flow velocity through the cylinder head, the air/fuel gains inertia with RPM so as RPM increases the intake valve can be closed later ABDC capturing more mixture. Larger cams normally have more overlap also where the exiting exhaust gasses can help pull the air/fuel into the chamber while the piston is dwelling around TDC. The better tuned and less restrictive the exhaust the better this works, but again low RPM operation can result in reversion where exhaust gasses try entering the intake.
In general, the bigger the cam, the higher the RPM power band, and the higher the compression ratio should be.
Somehow, I'm trying to get to the point that the cam can only tune for your application using the parts you have, and that the cylinder head size and flow really are where the power is built. Just a multi-angle valve job and minor bowl work make a large difference.

I just found these YouTube videos from "Bain Racing". They are really good and go over what I was trying to say. Highly recommended.
He covers in a few videos what took me over 20 years to learn.

I hate to be that guy, but I am that guy.
People come to me after they do it wrong.
You have no compression. Summit?
Don't go to a counter person for performance advice.
From their info...screenshot
They say it works best with 9.0 compression and higher. You got 8.2 on a good day.
340 and 360 heads are great. They will also lower your compression by .5 -.8 of a point. Going the wrong way.
Post #2 by me said a 252° cam. Better to have good torque, its better than no power.
Yes, too much cam with no compression will be slower than a stock 318.

Rule of thumb. Find the camshaft you really like then go 1 size smaller. You won’t be disappointed.

DeltaV said:

Not sure about your list. Which ones are necessary and which items are wish items?

It looks like you have already changed the wheels and they look like a nice upgrade from what you posted in any earlier thread.
Old:
View attachment 1886521

The car sat for awhile? I would flush the cooling system and take the radiator to a shop for cleaning and pressure test. Maybe you already have? Flush out the brake system too.

View attachment 1886522

Below is what I did to my '71 Satellite (318-2V) a long time (50 years ago); and I'll note I was on a tight budget:
1) Cast iron 340 intake (spread bore)
2) Holley carb (600 cfm?)
3) 340 purple shaft (I don't recall the specs)
4) Direct Connection double roller timing chain & gears.
5) Local shop "refurbished" the heads (e.g., replace bad valves, valve guides, and replaced valve guide seals). They might have taken off 0.010" from the cylinder side. I did not go with a 3 angle valve job.
6) Thin steel head gasket from Direct Connection. No longer available.
7) Added dual exhaust. I did not use aftermarket headers. Used 2-1/4" exhaust pipes and tail pipes.
8) Transmission shop rebuilt the "904". I drove it for a few months and then I installed a B&M Trick Shift kit. I don't recall which level I used. Drained the torque converter too since it had a drain plug. Used B&M trick shift trans fluid.
9) Light centrifugal spring/weight in the stock distributor.

I cannot suggest a cam for you because I don't know...there are so many options available today. Also, there are more options now for heads than when I was working on my 318; and 340 cylinder heads were not in my budget back in the day.

I would do the following to your car before going with different cylinder heads:
1) add/upgrade front and rear anti-roll bars.
2) use a sure grip unit in the differential.
3) maybe you should consider a higher stall torque converter.
4) how are your shock absorbers? I use Bilsteins on my newer cars. My older cars don't need shock replacements yet.

Maintenance items...
1) front wheel bearing seals when you grease the bearings.
2) brake piston caliper seals
3) rear brake wheel cylinder seals
4) various stuff with an old car (e.g., U-joints)

Have fun!!!

Click to expand...

Back in the 1980's, I took a stock 318 two barrel out of a wrecked '72 Satellite Sebring Plus and rebuilt it with a kit from Performance Auto Wholesalers. The kit included 0.030 over stock replacement pistons, stock rods, stock crank, and a stock 340 cam. The rotating assembly was also balanced. The heads were rebuilt to stock specs. I added a cast iron 340 four-barrel intake, and a 600 cfm Holley vacuum secondary carb. I put this engine in a '66 Satellite with the factory dual exhaust and 3.23 gears with a 904 trans. This setup worked great. I don't know how many times people asked me what I was running for a cam because of the idle. They usually didn't believe me when I said it was a stock cam until I added it was a stock 340 cam. I'm sure there are modern cams that would be better but based on my experience, upgrading to a stock 340 cam with your current setup would be a good budget project.

Only two production LA 318 engines had anywhere near 9.5:1 compression.
The 67-69 was advertised as 9.2:1.
I have not seen one blueprinted stock as such.
Not saying it won't.
...and the 84-ish-91 LA roller, also advertised as 9.2:1.
I have seen at least one of those (on FABO) blueprinted stock as IIRC 9.18:1.
Those are also advertised at 150 HP with "302" swirl/quench heads, electronic carb, and single, air injected exhaust.

I was thinking about this as:
Do you want the cam that works with your current combination, or
the cam that works with your future combination.