whats the biggest cam i can run on a stock valvetrain?

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eviper21

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I have stock 973 heads ima put on my 318. Not trying to run 10sec quarter miles just want a cool lope and a little performance.

The motor might get decked a little because the pistons are still 5 feet from the deck at TDC lol
buy other than that stock block stock heads.

Thanks
 
big cam; do you want it streetable? How far down? What is the compression? etc. When I was young, I could buy cams that made the car run like out and out dogshit. Not kidding, I used to have cars that wouldn't idle under 2000 rpm.

Then I learned. CR makes a huge difference, learn carb tuning. Learn clay on the piston. Learn valve spring pressure. Learn duration and lift.

You have a lot of reading ahead of you. Even if you call a cam company, they need cr, convertor stall, and rear gear. And then on to the carb and timing.

We are here to help.
 
yea i know sorry im pretty vague. but like i said its a stock motor 318 that i want a little lope out of. its not gonna be a performance monster. compression might go up to 8.5:1 ?

stock gears in the back. i MIGHT have it decked to zero out the pistons which is why i say 8.5 on the compression. the pistons have valve reliefs in them to, so duration im not to worried about. But im not sure how much lift the stock valve springs can handle. The heads are brand new though. well, reman. brand new ( new valves, springs, seals, retainers etc.) but im pretty sure its OEM replacement stuff.

i guess i should restate my question and say, whats a good upgraded cam to run on a stock 318. "biggest" is a word that comes with too much baggage when it comes to cams lol
 
If your planning on decking the block then you can shoot useing the stock valvetrain idea out the window.
 
If you are rebuilding then this is the right time to match all the components in the engine and drive train to maximize the performance and efficiency of your car to match your goals and budget. Take your time, do your research and plan accordingly.

If your heads and valve springs are stock they will not support much of an increase in lift.
 
eviper21 said:
i guess i should restate my question and say, whats a good upgraded cam to run on a stock 318. "biggest" is a word that comes with too much baggage when it comes to cams lol
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He268h or Xe268h comp cam or something comparable. You will have to change the valve springs to accommodate the added lift.

Comp has kits for this. There are also many other choices in cam manufacturers.

Generally it's not recommended to exceed .500 lift on a 318 with stock heads/pistons.
 
eviper21 said:
yea i know sorry im pretty vague. but like i said its a stock motor 318 that i want a little lope out of. its not gonna be a performance monster. compression might go up to 8.5:1 ?

stock gears in the back. i MIGHT have it decked to zero out the pistons which is why i say 8.5 on the compression. the pistons have valve reliefs in them to, so duration im not to worried about. But im not sure how much lift the stock valve springs can handle. The heads are brand new though. well, reman. brand new ( new valves, springs, seals, retainers etc.) but im pretty sure its OEM replacement stuff.

i guess i should restate my question and say, whats a good upgraded cam to run on a stock 318. "biggest" is a word that comes with too much baggage when it comes to cams lol
Click to expand...

The last thing i would worry about is a "cam" if your planning on running stock gears/stall, you would be better off with a bone stock longblock & bolt-ons, added gears (3.55s) & a small 2800 stall, it'll boogy for a modest 318, then you don't have to deck the block, change springs or valvetrain, I had a 71 factory 318 swinger with 2.76 gears, all stock with dual exhaust & it a tire fryer at 3700 ft. Alt., stock "everything" right down to the 2 barrel, & to boot the engine was a bit tired, it would huff alittle oil, I could only amazin how well it would have run with just these upgrades & being at sea level (running a "stock" cam). I used to wind that sucker to 6000+.

3.23 gears, 2800 stall, 600 eddy carb, Headers, Perf. intake, good ignition.

Sooooo if you want to intall a cam, make sure you have the other goods to maximize the benifits of the cam, otherwise i'll gaurantee you'll be unhappy with the outcome. just my 2 cents.
 
eviper21 said:
I have stock 973 heads ima put on my 318. Not trying to run 10sec quarter miles just want a cool lope and a little performance.

The motor might get decked a little because the pistons are still 5 feet from the deck at TDC lol
buy other than that stock block stock heads.

Thanks
Click to expand...

You should check out Hughes Whiplash Camshaft.....They say it's for low comp engines....Give you that sound you looking for but performance also...You're going to have to change valve springs....
 
eviper21 said:
yea i know sorry im pretty vague. but like i said its a stock motor 318 that i want a little lope out of. its not gonna be a performance monster. compression might go up to 8.5:1 ?

stock gears in the back. i MIGHT have it decked to zero out the pistons which is why i say 8.5 on the compression. the pistons have valve reliefs in them to, so duration im not to worried about. But im not sure how much lift the stock valve springs can handle. The heads are brand new though. well, reman. brand new ( new valves, springs, seals, retainers etc.) but im pretty sure its OEM replacement stuff.

i guess i should restate my question and say, whats a good upgraded cam to run on a stock 318. "biggest" is a word that comes with too much baggage when it comes to cams lol
Click to expand...


i have heard of guys running the summit k6901 cam in 318's with stock springs with no problems. i wouldn't do it myself, unless it was in a old beater or sumthin,. you can get edelbrock performer springs from jegs for $35, and would be great for that mild summit cam. however you decide $35 is cheap insurance if ya ask me. that cam's got a little balls in a 318, it will give a decent lope at idle. if you wanna help c/r. a little, then cut the heads .30 and run thin headgaskets. should be good for about half a point of comp. then you won't have to worry about alignment problems with valvetrain. you said it wasn't gonna be a performance monster, so it should be a respectable runner with a combo simiar to this.
 
the summit 901 is what i was looking at. With the eddy valve springs i think ill be good. i just want something more than stock, that i dont have to change a bunch of components to fit in. How much can i deck before i start running into alignment issues with the intake etc.?

i want to up the compression as much as i can without changing the pistons.
 
and if i do deck, do i have to change pushrods and lifters and stuff? or will the stock ones be fine for that cam?
 
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