Summit cam for a 318 LA

[AJ/FormS]

That 466/455hp Magnum5.9, is a great engine. I have a very similar engine, except in an LA, and with one size smaller fast-rate cam.I shift mine at 7000.

With peak power at 6000, and an automatic,for low-ET, it will want to be shifted at over 7000 on the 1-2, and maybe 6700 on the 2-3.
On the track, this has the potential to go 112ish, in the low 12s perhaps at as low as 11.8x, in a 4000pounder.
In a streeter, you will want/need a modest TC, and 3.73s will get you 60mph@6600 with 88s(28" tires), at the top of first gear.And, of course you will never get past first gear/WOT,cuz that would be speeding,lol. Since it has so much power, you will need some very specialized suspension to take advantage of it; or 275s, (which are about the biggest you can fit in the stock tubs),will spin forever.....even at part throttle. The 134VP is right in line with a hi-C teener.But of course that won't matter much,cuz you'll probably run a TC over 3000

Of course, since maybe 85% or more of the time, she will be idling around in second gear at 2200Rpm, it will use gas at an alarming rate with that 291/311/107 cam. And the 2900(zero-slip) at 65 will also use up a lot of fuel. Hopefully you don't care about those things. You think your pinching pennies now,lol, just wait..........

But boy-O-boy that cam will sound fantastic idling in your driveway.

As a side note, you can spin 275s to 60mph with a heck of a lot less cam, and a lot less gear,and get mileage in the low/mid 20s, and heck;even a smaller than 5.9 engine ........jus saying.

 

[nm9stheham]

That kinda apples and oranges there. Clevelands have awesome heads, 318s have awful heads. Cleveland heads will provide a lot of air even if the valves aren't open long. Plus the Cleveland 1.7 rocker ratio makes big lift with short duration easier.

You DO know a few things LOL! Yeah, I know.... I was just trying to show the OP that long duration numbers aren't everything, and that good breathing parts like what he has added aren't compromised by a shorter duration cam in regular street operation. The whole point is to help him not get into the big cam/low compression non-performance corner and be unhappy... which I think is everyone's goal.

And I have done that myself...300 duration cam with 7.6 SCR. A DCR in the low 5's put me way deep in that non-performance corner.... with the result being an engine that worked from 3800 to 7700 RPM. I was racing so I kinda got a way with it but it would have been better with 1-2 steps down in cam. Certainly not a street performer LOL!

 

[nm9stheham]

For the OP, FWIW.... The Summit slow ramps cams (supposedly made by Crane) and the Crane cam listed do have a good feature for you, and which RRR alludes to. Those slower ramps put less acceleration on the valvetrain parts, and so put less force on everything, will break in with less chance for problems, don't float the valves quite as readily, and can work better with stock valve springs. In that regard, they are easily to put in and run for first timer.... which I think is part of what RRR has been driving at.

And if you aren't into changing out the valve springs right now, then a lower range RPM cam is also better. The valve spring stiffness is what is mainly used to fight valve float at high RPM's.

 

[TrailerParkGinger]

That 466/455hp Magnum5.9, is a great engine. I have a very similar engine, except in an LA, and with one size smaller fast-rate cam.I shift mine at 7000.

With peak power at 6000, and an automatic,for low-ET, it will want to be shifted at over 7000 on the 1-2, and maybe 6700 on the 2-3.
On the track, this has the potential to go 112ish, in the low 12s perhaps at as low as 11.8x, in a 4000pounder.
In a streeter, you will want/need a modest TC, and 3.73s will get you 60mph@6600 with 88s(28" tires), at the top of first gear.And, of course you will never get past first gear/WOT,cuz that would be speeding,lol. Since it has so much power, you will need some very specialized suspension to take advantage of it; or 275s, (which are about the biggest you can fit in the stock tubs),will spin forever.....even at part throttle. The 134VP is right in line with a hi-C teener.But of course that won't matter much,cuz you'll probably run a TC over 3000

Of course, since maybe 85% or more of the time, she will be idling around in second gear at 2200Rpm, it will use gas at an alarming rate with that 291/311/107 cam. And the 2900(zero-slip) at 65 will also use up a lot of fuel. Hopefully you don't care about those things. You think your pinching pennies now,lol, just wait..........

But boy-O-boy that cam will sound fantastic idling in your driveway.

As a side note, you can spin 275s to 60mph with a heck of a lot less cam, and a lot less gear,and get mileage in the low/mid 20s, and heck;even a smaller than 5.9 engine ........jus saying.

I'm not worried about gas haha. The 19 gallon tank lasts a little while. Its just the current purchases of a Hellwig sway bar, ESPO springs and new shocks kibda ate my budget. So I'll just have to wait a little to make bigger purchases. Its a fun weekend car, or thats the goal. I'm slowly making it what I want, or so think.I got the 360 magnum from a 1993 Van and it had 120,000 miles, its dirty, but it as perfect cross hatching in the bores still, I've yet to look into the bottom end, but hopefully it all checks out.

 

[TrailerParkGinger]

Should I just forgoe the 318, keep her all nice and standard and just do a overview of the 360 magnum and do a budget build up? Eventually I'd have to put the forged pistons in if I'm going to build that 466/455hp mopar muscle engine. My 318 has a special place in my heart, the only reason I got the 360 was so I'd have something to thrash on and not destroy my numbers matching heart to the Coronet. Its like my baby lol

 

[nm9stheham]

IMHO, that approach has a lot of merit to it, and makes a lot of sense. Seems like that has been mentioned a few times and the Magnum block is a bit lower (higher inherent CR) and Magnum's have 1.6 rocker ratios and so breath better with the same duration cam (as mentioned). Not big changes, but ones that move it the right direction for better street performance (wider torque band).

FWIW, and if you don't mind, I'll relate one story of upgrading..... it is from the prior owner of my son's '65 Cuda. He had a '68 273 in it and it was a great, fun family car, for cruising, drive-ins, going for ice cream with the wife and 2 sons, etc. He built a big stoker and put that in.... and then pulled and sold the stroker, and the Cuda. His comment to us was that the stoker ruined the car for what he and his family valued it for; a family fun cruiser. When I read your comment on the 466/455HP enigne, it kinda brings that to mind. Just food for thought with that nice car.... a big engine is gonna change its 'personality'.

BTW, you can reliably do 455 HP from 466 ci with either forged or hypereutectic pistons. I've had 1.75 HP/ci on a turbo'd rally engine and both lasted fine in that use. Forged are better for surviving detonation if you ever get to that bad situation, but I have detonated holes into even forged ones .... YMMV! Forged ones run looser clearances so may or may not last as long and may or may not rattle a tad when cold, before they get up to temp.

 

[318willrun]

Should I just forgoe the 318, keep her all nice and standard and just do a overview of the 360 magnum and do a budget build up? Eventually I'd have to put the forged pistons in if I'm going to build that 466/455hp mopar muscle engine. My 318 has a special place in my heart, the only reason I got the 360 was so I'd have something to thrash on and not destroy my numbers matching heart to the Coronet. Its like my baby lol

'sorry, I havent' been keep'n up with this thread. If I remember right, your goal was to just "add a little performance and burn some rubber", correct? Just so you know, those valves/seats play out in a hurry on the older heads like yours. Make sure your valves are sealing "Top Notch". you should have no problem laying a patch of rubber now. IF you can't, you have an issue. My '65 belvedere would lay rubber to no end. I could even go 5 mph and mash it and it would burn rubber.

 

[toolmanmike]

Should I just forgoe the 318, keep her all nice and standard and just do a overview of the 360 magnum and do a budget build up? Eventually I'd have to put the forged pistons in if I'm going to build that 466/455hp mopar muscle engine. My 318 has a special place in my heart, the only reason I got the 360 was so I'd have something to thrash on and not destroy my numbers matching heart to the Coronet. Its like my baby lol

You could keep what you have engine wise and switch out the rear end to where you want to be in the end. You would be surprised how much fun a 3:55 Sure Grip will wake up your Teen 2 barrel.

 

[TrailerParkGinger]

Well I rejetted her today and she cruises great! I guess I'll just save up and put money into the 360 and just enjoy the 318 for what it is, a reliable cruiser. My plans for the 360 include FITech fuel injection and a less aggressive cam than the mopar muscle 455hp magnum. I like my Coronet, but I would like more power. My 50 Chevy 3100 is my cruiser. Inline 6 chugs along great, everywhere.

 

[TrailerParkGinger]

I thought about a 408 stroker, but the bores in the magnum are way too nice to just have overbored.

 

[nm9stheham]

I almost bought one exactly like that 2 years back..... but the '62 Dart is what will stay here for now.

Hone and put in new rings at a minimum. Make sure you check your piston to bore clearances and pull the pistons and check the ring to groove side clearances. If the grooves are worn, new rings and a hone won't last long.

 

[TrailerParkGinger]

I really appreciate all the tips and recommendations you guys game me. I'm gonna start down a different thought process in the build up. Gear, TC and then motor. Rings, bearings and a hone are pretty cheap, then it'll just be IMM EQ heads

 

[nm9stheham]

That'll be pretty good. The same thinking process on the cam selection vs compression goes as here.

Some random thoughts: I personally would be thinking ahead at the gear and TC for the 360 installation.

Examine your 360 block cam bearings to make sure they are OK.A good, and new, timing chain of course. And a new oil pump! Cheap insurance. See what valve springs the heads come with and get them with spring rates no higher than necessary.

 

[Dartfreak75]

I give up.

I've tried preachin it before, but no one listens. Slow lazy ramps are good for an everyday driver. Who wants to beat their valve train to death? Ok. I told myself I wouldn't comment anymore. I am out.

I know this is old but I'm just reading it those two comments made my decision alot easier so dont give up and comment away please you are almost always right and a huge help to everyone!

 

[Wyrmrider]

RRR get's it right
Summit Cams are/were Crane in name only- Crane Marketing bulk Detroit cams
slow lazy ramps on a mopar size tappet grind are much better than almost race ramps designed for a chevy- like the summit cams
mopar grind cams are easier on your valvetrain given the same lift and duration

 

[ir3333]

Looks like you've made your decision but for the benefit of others contemplating this...a couple of thoughts.
every cam suggested but one is bigger than a stock 340 cam.The Summit K6900 gets my vote.
Maybe better if it's just driven on the street would be the cam installed by a friend in a very similar build.I believe it was the stock 360 2 barrel cam,about .410 around 256 duration.Lots of lo end..and his 318 in a B body pulls very hard to well past highway speeds with excellent mileage!

 

[Dartfreak75]

Looks like you've made your decision but for the benefit of others contemplating this...a couple of thoughts.
every cam suggested but one is bigger than a stock 340 cam.The Summit K6900 gets my vote.
Maybe better if it's just driven on the street would be the cam installed by a friend in a very similar build.I believe it was the stock 360 2 barrel cam,about .410 around 256 duration.Lots of lo end..and his 318 in a B body pulls very hard to well past highway speeds with excellent mileage!

That is the cam I have havent installed it yet we will see how it runs. Btw this thread is a year old I just read it last night for the first time and had to comment on it. Lol