304 camshaft

Hello all,
This has probably been asked before (perhaps many times), but I was unable to get a good hit with a search. I am looking to purchase a new cam for my '80 304, but I don't know what type of cam will do what I want. I'm not overly invested in power, but I would really like to have a nice lope at idle, just to bring back my racing days. I used to know which specs to look for, but 30 years is a long time
Any ideas?

 

The nice lope comes with no low end power and really crappy fuel mileage. It's caused by cam timing that kills the cylinder pressure, and efficiency, at low rpm in exchange for a better top end.

You might try Comp Cams or Crane. They both claim to have cams that give you that choppy idle with good power.

 

The RV grind is popular for jeep owners......

 

Many 360 Wagoneer owners have used the Summit 8600 cam. It's very inexpensive, though maybe too wild for a 304 - depends on your wants and needs. If you go to http://www.summitracing.com/ and search for "AMC V8 camshaft" you will find lots of choices. The Summit cams don't come with much description, but you can look at the description for cams with similar lift and duration on the other cam makers sites (Comp, Crane, etc.) and then infer what the 8600 is like.

Another possibility is a "RV" cam from an over-the-counter replacement parts company like Melling. You local parts store will be able to get these for you.

 

RV cams don't give that nice rolling lope at idle like the old high performance cams had. They're very smooth by design.

 

Comp Cams Extreme Energy XE262H, PN 10-215-5. It's a relatively small cam, but for a 304 it's huge. With a 110-degree LSA it'll give you a decent lope and it'll really wake up your 304. Change out the springs to Comp's PN 926-16 to better deal with that cam's increased ramp rates. The lobe isn't as fast as some of the other XE profiles, but it does come off the seat rather quickly and can throw the old school stock springs into chaos. The springs will be needed anyway to deal with the cam's .493/.500 lift.

The XE has really nice lobe profiles. Waaay better than the 30 year old junk that the Summit, Edelbrock, and other cams are designed off of.

 

:iagree:

 

I agree the comp XE cams are good torque grinds. I have used them on chevys with good luck. They also have XE 4x4 grinds as well but I am not sure on the AMC grinds. That said, I helped put a couple of 304s together for some friend years ago and both engines ran really strong with the cams I helped select. One was running a Comp 260H with a two barrel carb and Fenderwell headers. The other we put together with an edelbrock performer cam, really old school edelbrock sp2p intake and edelbrock performer 600 carb with fenderwell headers. This was a really strong combo and ran great. That Jeep later got swapped to a 401 and in comparison the old 304 was still a great performer. I would still recommend a performer package of cam, intake, carb along with some headers. I would stay away of anything with a serious lope as it will kill bottom end. These cams mentioned here are as big as I would ever entertain on a 304 in a Jeep. You will still get a solid 5500 RPM out of all three of these grinds. Good for keeping the tires clean in a mud hole. As a rule of thumb you should almost always go one cam smaller in the catalog of what you are dreaming of if torque is a concern.
Greg

 

Man! Thank you all for the great advice. I was looking at the summit cams, since they are fairly inexpensive. Outside of the lope (vanity, I know), I'm just not that interested in mega power or anything. I plan to go with fenderwells, 4bbl, and a holley. I'm sure at that point, it will have more power than I will ever need. Heck, I've had it almost a year now, and have yet to go off the pavement. (wimp). I just like it too much as a DD.

 

Interesting. I looked for a summit cam for my '80 and the years only go up to '79. I didn't think there was any difference in ANY of the 304s. Anyone have info on this?

 

Punch in FSJ in the search engine and it should come up with a camshaft for that year. Semantics. Don't worry about it.

Yeah, I get it - $100 for the Summit cam & Lifters kit is easier to swallow than $288 for the Comp cam and lifter kit, but to me it's worth the extra $180 since a cam swap is a major upgrade that you'll probably only do once.

Look at the specs:

Summit 8600 - Adv Duration: 272/282, Duration @ .050: 214/224, Lift: .472/.496, LSA: 112
Comp XE262 - Adv Duration: 262/270, Duration @ .050: 218/224, Lift: .493/.500, LSA: 110

There's 58-degrees difference between the adv duration and duration @ .050 on the Summit cam, while only 44 on the Comp. That valve is staying closed longer and coming off the seat way faster meaning more area under the curve. More torque, better operating characteristics, snappier throttle, less loss of cylinder pressure, etc. There's also more lift. Plus, the 110 LSA of the Comp is going to give you a rowdier idle than the 112 LSA f the Summit cam. With less overlap, the Summit cam will actually idle fairly smoothly compared with the Comp. Low end torque will also be down thanks to the limited overlap.

In the end I'm sure you're gonna do the Summit cam since the $180 difference will buy you a nice aluminum Edelbrock Perfromer RPM. I don't blame you. I went with a Summit cam in my '85 Ramcharger's 318 for the same reasons. It's a decent cam. Just wanted to point out that the Comp one will give you a nastier idle while providing a more driveable engine with better throttle response and more overall hp and torque.

Good luck with it.

 

From my admittedly limited experience, the Summit cam is going to be made from cheap Chinese steel. The Comp Cams one will typically be carved from a better quality chunk of billet. That’s part of the cost savings, its in the material.
If broken in properly there shouldn’t be much difference but the Summit Cam will be more likely to flatten a cam lobe during break in shooting any cost savings to hell.

 

Only the rollers are billet and even then they've got some lower priced rollers that are cast now.

The flat tappets are, however a higher quality than the Summit/Melling/etc brands. They're all cast, but then Comp welds material to the lobes before grinding the profile. The welding hardens the lobes.

Either way, you've gotta run the company's zinc-rich oil additive in the crank case for the cam's break-in. Not doing that will ruin a flat tappet in the first 500 miles. Then switch to 15W-40 diesel oil (any type but the CJ-4 for newer emissions diesels). Shell Rotella is okay, but I'd still run the additive for the first 3 or 4 cam swaps. That's what I did with the new GMPP 350 I put in the M-715 and it's been good so far.

 

All pretty good info posted here. This is the combo I would recommend. Use the edelbrock 2132 cam and lifter set. It is only $55 more at $154.95. Add their timing chain set. Standard performer intake 2131 along with their 600 cfm performer carb, or if you want to spend a little more money a Holley truck avenger carb. Along with some fenderwell headers, you will have a good performing package. The edelbrock cam has a little less lift than the summit cam as well as a 110 deg lobe separation angle. I know this cam and a similar combo from experience.
#2132

ENGINE: AMC 290-401 V8
RPM RANGE: 1500-5500

CAUTION: Use only Sure Seat Valve Springs, #5832 or 5932 Use stock ratio rocker arms only

Duration at 0.006" Lift: Intake: 278° Exhaust: 288°
Duration at 0.050" Lift: Intake: 204° Exhaust: 214°
Lift at Cam: Intake: 0.280" Exhaust: 0.295"
Lift at Valve: Intake: 0.448" Exhaust: 0.472"
Timing at 0.050" lift: Open Close
Intake: 3° ATDC 27° ABDC
Exhaust: 42° BBDC 8° BTDC
Centerlines: Lobe Separation - 110° Intake Centerline - 105°

CAUTION: Use Performer-Link Timing Set, #7818. Do not use late model timing sets. They are machined in a retarded position and are not recommended for this camshaft installation. Edelbrock Performer-Link True Rolling Timing Sets feature three keyways for specific timing selection. Always use the “0” or straight-up timing mark when installing Performer-Plus camshafts with Performer-Link Timing Sets.

Use only Sure Seat Valve Springs, #5832 or 5932 Use stock ratio rocker arms only

I think this is a good price compromise compared to the comp cam. If you wanted to go one step further you could do a little head clean up with 3 angle valve job new spring like edelbrock recomends and maybe even a port match and bowl blending. The bowl blending and port match/gasket match can be done yourself with a die grinder. Then take them to a shop to do the valves, springs, and such. The AMC dogleg style exhaust port heads are quite good flowing and underrated by many that don't know much about AMC engines. A (little) 304 can perform fairly impressively and 360/401s can be a force to contend with. It's too bad that the parts cost more than some other engines. Anyway I hope that helps you out with some info of a good combo for a Jeep.
Greg