cam question
- Thread starter commando
- Start date
- Joined
- Mar 16, 2005
- Location
- Archer Lodge
It's not quite that simple.
What intake? what carb? Exhaust ? Rocker arm ratio? installed valve spring height ? stock valve springs ?
The application the engine will be used for ?
A thumpin cammed up engine will not do much of anything on the trail, as there will be no real useable power made until much higher in the rpm band ESPECIALLY with a compression ratio that low. Unless you happen to turbo charge or supercharger, but then that adds a whole list of other issues.
slapping in a lumpy cam isn't a cure all power fix, there are other considerations to be made.
What intake? what carb? Exhaust ? Rocker arm ratio? installed valve spring height ? stock valve springs ?
The application the engine will be used for ?
A thumpin cammed up engine will not do much of anything on the trail, as there will be no real useable power made until much higher in the rpm band ESPECIALLY with a compression ratio that low. Unless you happen to turbo charge or supercharger, but then that adds a whole list of other issues.
slapping in a lumpy cam isn't a cure all power fix, there are other considerations to be made.
The house brand Summit 8600 is a good cam for offroading and safe on the stock valve springs. Its got gobs of torque, it just falls flat on its face over 4600 rpm. If you need more from it, swap in a set of 1.7 rockers and a set of matched lift height valve springs and itll be a screamer. Then if you do that, your going to have to drill out the mains for better oiling. AMCs are a real PITA, but once built right - itll tear ass.
Do yourself a favor early on, get the heads ported. The volumetric efficiency % of that engine stock is horrible.
Do yourself a favor early on, get the heads ported. The volumetric efficiency % of that engine stock is horrible.
- Joined
- Mar 18, 2005
- Location
- Reidsville, North Carolina
Simply not true, compared to other production heads of the same era AMC heads out flow them all. Flow bench numbers are posted on www.bulltear.com or www.amcforums.net. Most people have many misconceptions about AMC motors and this is just one of them. Unless you are all out racing about the most that needs to be done is some minor bowl blending and gasket matching the heads and intake according to those who regularly build AMC engines. The summit 8600 cam is a good chice for mostly stock engines and works well in 360's, I have used several in motors that I have done.StudNuts said:
As blackvoodoo said though what you are planning to use it for means more than anything in picking a cam. You can put a 320 duration .625 lift cam in a stock 360 but it will be a real dog.
OK now I'm really confused. John you have seen my commando @ willow springs. It has a fresh built 360 in it with maybe 15 hours run time on it. Paul fowler helped me build the jeep, it has a 10 bolt front, 14 rear, 410 gears,and a 4 speed granny. I am running a set of 39.5 boggers on it. Although the engine is fresh, it's still bone stock, but I put a cast intake (4 barrel) and a 600 cfm holley and amc in frame headers on it.
What I am looking for is more power, so I can run this thing in the renegade class mud boggs only! No trail riding. I built another jeep identicle to this one but kept the stock axles and used 35 boggers, and changed the gear ratio.
I would like to get max power without spending a ton of money. My buddy is going to help me install a cam and lifters, but he says the compression ratio is 8.25 and that I would have to stay under 280 duration and 480 lift, otherwise it would reak havoc on my new engine. So that's the facts ,what do I do? Ihave about 800 to 1000.00 to spend but don't want to spend that much if I don't have to. I did buy a new aluminum intake so I could get rid of the cast one. (one step at a time if you know what i mean.) Theres an Isky cam kit on ebay with 280 duration 490 lift, is that good enough? I'm open to all option and thanks for the help.
What I am looking for is more power, so I can run this thing in the renegade class mud boggs only! No trail riding. I built another jeep identicle to this one but kept the stock axles and used 35 boggers, and changed the gear ratio.
I would like to get max power without spending a ton of money. My buddy is going to help me install a cam and lifters, but he says the compression ratio is 8.25 and that I would have to stay under 280 duration and 480 lift, otherwise it would reak havoc on my new engine. So that's the facts ,what do I do? Ihave about 800 to 1000.00 to spend but don't want to spend that much if I don't have to. I did buy a new aluminum intake so I could get rid of the cast one. (one step at a time if you know what i mean.) Theres an Isky cam kit on ebay with 280 duration 490 lift, is that good enough? I'm open to all option and thanks for the help.
Hey bud, didnt realize that was you. I think the Isken cam may be too high in the RPM band for your engine - without you doing any oiling mods I wouldnt rev that thing over 5500 rpm, and with your low compression its not going to benefit you much overreving it. IMO, i would run something like edelbrock edl-2132 cam or with your granny first gear find a cam that picks up a little higher in the rpm like the comp 270H. Definitely ditch the cast intake and find put your aluminum intake on. Take the heads to a machine shop and have them shaved down to get your compression up a hair and do some head work. Toss on some roller rockers and fling some mud. 
commando said: