Which Camshaft For This Brute?

[haywire 440]

Details: Vehicle 1965 Chrysler 300L
Engine: Original 413, .030 over bore
and hoping for 10-1 compression but it probably will be lower.
Heads: Closed chamber 516s with the small 1.60 exhaust valve.
Intake & carb: Stock 4-barrel
Transmission: 4-Speed manual
Rear Differential ratio: 3:23 Sure Grip
Weight: 4200lbs

Currently the short block is together.

The original cam had these numbers and is not being used.

Next up is the cam from Melling and is now in the short block

I wonder how the above cam will act in this heavy car. It will not be a high rpm use engine and looking for a lower Torque & Hp range.

Now two more camshafts are listed below. The first one is the recommended replacement cam from the Chrysler 300 International Club and is made by CamCrafters. The second is a Comp Cams RV cam that is new but 30 years, or more, old.

COMP CAM specs are shown below in 2 pictures, the cam box and the card inside with the cam.

Which is your pick for this application?

Haywire is not sure.

 

[RoasterStrudel]

My pick? The Comp, but that's personal opinion. What's your max desired operating RPM?

You'll need to pick your preference based on your driving style/use. If you want to squeeze the loud pedal once in awhile, the Comp would be more fun. Lots of stop and go traffic, carload of passengers, and parking lots? The current cam would suffice.

If I'm reading this right, the second and third cam are very mild at .050" and would be near identical in performance. It's definitely the equivalent you'd put in a truck, RV, or heavy towing application. Idle will be smooth, and it won't have any problem with vacuum for power brakes.

The Comp would be a mild performance-oriented cam.

206°/209° .434"/.431" for the Melling
210°/210° .429"/.429" for the Camcraft
224°/224° .470"/.470" for the Comp

The Comp would net a little more mid-range power, but shouldn't make it into a high-rev engine. This at the expense of a slightly rougher idle, needing a little more idle speed, and provide a little less vacuum for repeated stops. The Comp may need heavier valve springs at .470" lift, but I don't know your cylinder head situation.

I don't know if any of that helps. But just some thoughts!

 

[PurpleBeeper]

I'm surprised you haven't seen 50 different opinions by now! I suggest a cam similar to the comp cams you have listed, with similar lift/duration, but a little bit longer duration on the exhaust side (split profile) because you have the smaller exhaust valves

 

[WileERobby]

What cam I'd recommend is meaningless. I'd recommend contacting Hughes for a good cam for your application.

 

[haywire 440]

My pick? The Comp, but that's personal opinion. What's your max desired operating RPM?

You'll need to pick your preference based on your driving style/use. If you want to squeeze the loud pedal once in awhile, the Comp would be more fun. Lots of stop and go traffic, carload of passengers, and parking lots? The current cam would suffice.

If I'm reading this right, the second and third cam are very mild at .050" and would be near identical in performance. It's definitely the equivalent you'd put in a truck, RV, or heavy towing application. Idle will be smooth, and it won't have any problem with vacuum for power brakes.

The Comp would be a mild performance-oriented cam.

206°/209° .434"/.431" for the Melling
210°/210° .429"/.429" for the Camcraft
224°/224° .470"/.470" for the Comp

The Comp would net a little more mid-range power, but shouldn't make it into a high-rev engine. This at the expense of a slightly rougher idle, needing a little more idle speed, and provide a little less vacuum for repeated stops. The Comp may need heavier valve springs at .470" lift, but I don't know your cylinder head situation.

I don't know if any of that helps. But just some thoughts!

The heads are redone already with the stock springs installed, a valve job done and hardened seats installed for the 1.60 valves.
This build was based on keeping it as close to stock as possible. I was concerned about the Melling cam because of the advertised duration of 284 and 293 at .006. I was thinking that would create a rough idle.

It will probably be driven like an old man wearing a hat but maybe a good song might stimulate my right foot and right hand to row the boat a little faster. But I regress, rpm power range would stay below maybe 4k to 4.5k range. Also this is an air conditioned car so it needs to handle that stress at low rpm’s. That’s why I’m thinking it needs a low rpm torque range.

I’m also planning a full dual exhaust that’s is stock quiet.

Good to hear your feedback!

 

[haywire 440]

I'm surprised you haven't seen 50 different opinions by now! I suggest a cam similar to the comp cams you have listed, with similar lift/duration, but a little bit longer duration on the exhaust side (split profile) because you have the smaller exhaust valves

I have heard that a longer exhaust duration would be a benefit for the 1.60 valves.

Vacuum for the power assisted brakes is a concern too because I’m staying with the drums all around. I am upgrading to the dual master cylinder though.

I appreciate your comments and I know there may be a boat load of good options that may crop up.

 

[haywire 440]

What cam I'd recommend is meaningless. I'd recommend contacting Hughes for a good cam for your application.

That makes perfect sense and I will.

 

[Geoff 2]

It is a very heavy car with a 3.23 axle. It is a 413, not a 440. 4500 rpm max.

All this means: choose the cam wisely because an unwise choice could turn it into a dog. Which would rule out the Comp 270 cam which is listed as 2000-5500 rpm.

The Camcraft listed would be my pick. The tight 110 LSA will pick up the midrange, right where you will feel it. You do NOT need extra exh duration because the engine is not going to higher rpms where that would be a benefit.

 

[BeepBeepRR]

Torque cam.

Summit Racing SUM-K6401 Summit Racing™ Classic Cam and Lifter Kits | Summit Racing

Free Shipping - Summit Racing™ Classic Cam and Lifter Kits with qualifying orders of $109. Shop Camshaft Kits at Summit Racing.

www.summitracing.com

Summit Racing Part Number:
SUM-K6401
UPC:
190861126657
Cam Style:
Hydraulic flat tappet
Basic Operating RPM Range:
2,000-5,500
Camshaft Use:
Street/Strip
Camshaft Manufacturers Description:
Fair idle, good midrange power camshaft. Requires 9.5:1 and higher compression, 2,000+ stall, and gearing. Good mild bracket racing cam.
Intake Duration at 050 inch Lift:
224
Exhaust Duration at 050 inch Lift:
234
Duration at 050 inch Lift:
224 int./234 exh.
Advertised Intake Duration:
298
Advertised Exhaust Duration:
303
Advertised Duration:
298 int./303 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.466 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.488 in.
Valve Lift with Factory Rocker Arm Ratio:
0.466 int./0.488 exh.
Lobe Separation (degrees):
114
Camshaft Gear Attachment:
1-bolt

 

[70bigblockdodge]

The first cam is lazy. Duration at .050 divided by advertised is around 70-72 %, which is a slow ramp or someone is making advertised duration look really big (kind of the problem using advertised duration, no standard on where you measure).
The second cam is a honest number cam around 80%, so better, about the same at numbers of a HP cam in 440, heavier C body cars with automatics.
The comp and Summit cam are similar. I have a cam in my charger in this area. 440/4 spd, no power brakes and headers. I would pick one of those 2 cams since you have a 4 spd. If you have concerns about power brakes I would just go with cam crafters or cheaper yet the one you already have.

 

[PurpleBeeper]

I changed my mind.... it seems like you want to leave the stock valve springs on the stock heads....go with a stock style camshaft, lazy or not

 

[lewtot184]

the melling cam includes all off the ramp timing in the advertised specs. if you're going to run pump gas with 10:1 compression i'd use a cam with a wider lobe seperation that closes the intake valve a little latter. the .430 lift cam is the old factory 4bbl cam. i think with the small heads, intake, and carb i'd look at a stock magnum cam. original valve springs won't take much lift before coil bind. tread very carefully there.

 

[qkcuda]

This is the one I chose for an upgrade from my 361 two barrel cam. It is a Wolverine Blue Racer cam, but Melling sells the same one, and Edelbrock used to sell it as their Performer cam. It is close to the stock 325 HP 383 cam from 66 and very close to what you have in there now. Mine is also a 4200 pound car with factory A/C and it idles at 16 inches of vacuum and pulls strong from idle to 4500 RPM.

 

[PRHeads]

I’d just use the Melling cam, which is a repro of the stock 365hp/426, 330hp/383 cam.

 

[Don Frelier]

If it does come in at 10:1 with iron heads and a smallish/low overlap cam you're going to need some high octane fuel.

 

[haywire 440]

If it does come in at 10:1 with iron heads and a smallish/low overlap cam you're going to need some high octane fuel.

The stock compression is 10 to 1. Here are some specs on the pistons. The original compression height of the factory piston is 2.085. The compression height of the replacement pistons are advertised as 2.015 but I didn’t measure that before the 413 was put together.

I did measure 2 of the removed Chrysler and they both measured 2.022. So I believe they were lower in the cylinder to begin with.

The engine and heads were just decked enough to straighten and clean.
Here’s a link to the FCBO thread on the 300L, it’s 8 pages and the engine discussion is the last few pages.

Cat’s Out Of The Bag, ‘65 300L Manual Trans, A/C and More

 

[haywire 440]

Wow I am getting a lesson on camshafts and what the numbers mean. That’s all good because I like to understand this science.

With the advertised duration being 284 & 293 I was concerned that was too aggressive. The more accurate measurement is from 0.50 so those are 206 & 209. So this Melling camshaft is staying put.

Thanks for your comments.

 

[Geoff 2]

You [ & some others ] are paying too much attention to advertised duration #s. The duration measuring points vary, generally from 0.004" to 0.008". Usually tappet lift, but not always..... The Comp is 270* is measured @ 0.006" of tappet lift. Some cams are measured at valve lift. So if you are comparing cams to say the Comp 270, a cam with 270 @ 0.006" valve lift is going to have less adv duration than the Comp because that equates to 0.004" tappet lift [ 1.5 rockers ].
Some of the cams listed above do not list this important info, so useless trying to compare cams that way.

I suggest you find D. Vizard's 128 rule on the web & calculate the reqd LSA [ It will be considerably tighter than 112....]. While it is for SB Chevs, he has claimed it works well for parallel valve heads....certainly better than GUESSING.

 

[lewtot184]

understanding the lobe's ramps can be tricky. wait until to you start measuring an asymmetrical lobe,...lol. that'll twist your brain! the melling cam is probably a copy of the 256/260 factory cam, or at least very close.

 

[451Mopar]

Run the Milling cam you have. It will work good with 9.5:1 or less compression.
At 10:1 compression, and the 4-speed you could go slightly larger.