I have a 1976 L48(180 hp). Ive taken off the egr and put on a Edlebrock 600 performer with an adapter to the stock intake, which kinda acts like a spacer. I have the stock exhaust manifolds and pipes with flowmasters. So i dont have much power but what i am wondering is if i hollow out the cat. and put a 350 horse cam from comp cams in it what can i expect to get fro mthis. I realize that this isnt much of a change but ive heard that the camshaft is the best mod you can do. I dont have the cam shaft specs with me but it is a 272 or 270, i payed 25 bucks for it at carlisle w/ about 20 miles on it. So i figured i cant go wrong, i realize that everyone says the biggest i should go is a 268 but for 25 bucks. So id jsut like to know what to expect.

thanks in advance

MAtt

 

You bought a 270 or 272 duration cam...used...with 20 miles on it? thats barely even broken in?. Did you buy the lifters too? I am a bit pessimistic, but why would you believe the seller when he said 30 miles on the cam. Replacing a cam after 20 miles is a poopie pot of work, why did he pull it out?

Flat tappet cams are cheap, throw that one away and call it a $25 lesson..never buy used cams unless you know the seller! That may seem extreme, but you will have a lot less problems if you follow that one rule when shopping swap meets.

All that aside. the L48 in 76 had a horrid iron intake, and poor heads. Adding that much cam to what is otherwise a bone stock motor will not net you much in the way of performance benefits, especially with a single exhaust. Hollowed out cat or not. If your car is an Automatic equipped car, you might also find that your convertor is too tight for that cam.

You are quite correct when you say the cam is the single best mod you can make to an engine, but to get the most out of that you must balance the rest of the engine to it. A hot high duration cam is not going to be as effective in a low compression, single ehaust through an iron intake manifold, through bone stock emissions heads.

You would probably be better served
>add headers - if budget is an issue you can get uncoated ones for about $100 or even less sometimes
>Edlebrock intake, not a huge leap but better than the iron one you have
>the carb you added is fine dont sweat that
>then add the cam
>finally add true duals
If you can afford it, remove the heads and have them at least pocket ported, this will improve the flow on those heads and really wake up your engine to rpm potential.

Give Ganey a shout..he will be able to give you a good idea what that cam will do for you with and without the mods above.


[Modified by fauxrs, 8:12 PM 9/28/2003]


[Modified by fauxrs, 8:13 PM 9/28/2003]

 

:iagree: You also need new springs for that cam, do yourself a favour and chuck it. A friend of mine just did a cam upgrade on a stock L48 and lost a few horsepower. You have to upgrade in stages and in the correct order, everything has to match or you are wasting your time.


[Modified by MotorHead, 10:45 PM 9/28/2003]

 

From my experience with my '76 L-48, the 2 best cheap mods you can do is to go to a true dual exhaust system and to add a decent recurve kit. AFTER doing that I added a CompCam 260H Cam and lifters (so mild the stock springs could be used!) and was there ever a nice improvement compared to Stock! The thing just pulled HARD! Further, anybody who is telling you that the cam they sold you only has 30 miles on it is talkin out the wrong end. Why were they so unhappy to want to change the thing after only 30 miles? 2 cam changes is ALOT of work! Not what you wanted to hear, but its the truth and my $.02 worth :cheers:

 

:iagree:
True duals, recurve and no cat conv. are easy and the best way to start

 

Word to the wise never install a used Cam. "Period" Always install a new cam and lifters as a set. L48 will never make any more power, unless you change pistons, heads, cam, intake, Q-jet best street carb ever made, so keep it.

 

Get a new cam and springs since they are probably tired by now. You can get a set of springs good to about .480 lift that fit in the stock heads. If you do not get to crazy with the cam the stock heads and rams horns will work fine if you switch to a dual set up. I just stuck a Summit cam (214/224 .442/.465) in a 383 with heads that are basically the same as stock L48 heads. Their cam/lifters sets are only $80 and the first one I bought worked fine so I have no doubts this one will too.

 

See my sig for L48 improvement 'pkg'...

 

Heres the story behind the cam.

The guy i bought it from was an engine builder who made a 327 for a guy who had it in a midyear. They guy took it home one weekend after the engine was put in. He left it there for the week then drove it back the next weekend because he wanted a bigger cam since it was a race engine. He removed the cam and lifters, put them back in thier orgional boxes, labeled each lifter to the cyclinder it came from, and put it up for sale at carl;isle for 25 bucks. That seemed like a legitimate reason to me. They look brand new, they are just a bit oily thats all. Im on a really tight buget too. I wouldnt buy a used cam but i didnt see the harm in so little use at such a small price. Intake and recuve i woudl definitly like to do, and i was thinking springs and pushrods at the same time as the cam and lifters. I would like to stay away from swapping my heads or exhaust for money reasons. I just want to wake her up a bit, 180 hp isnt much in a 3560lb car. After that i plan to save up for a few years for a 427 in which case i would do side pipes. Thats why im kinda leaning away from spending too much money. If i do a 427 it will be done to the best it can. Right now im in college and my vette is a state away.

MAtt


[Modified by pillowmeto, 9:47 PM 9/29/2003]

 

You really need to find out exactly which cam it is, if you put in the wrong cam with your low compression engine, you could actually end up hurting the performance of your car. There are so many cars out there with the "wrong cam" that you cound probably fill 1000 wrecking yards. My car originally was a 350/300 HP 69, when a previous owner had it rebuilt they put in a Crane Blueprint Series 350/350 cam. It was basically the 350/350hp cam that Chevy put in the L46, it was a great cam for the 1960's, but it did not fit in an car with a TH400 and a 3.08 rearend. The torque curve was way to high in the RPM range, and the car had nothing in the low end. Now get up to around 4700-5300 and it pulled like a demon, but on the bottom end it wouldn't spin the tires.
Please, do some real research and find out which cam is going to work best with your current setup. Cams and lifter sets are too cheap to try and save a hundred bucks by using a used cam of questionable origin. The real expense of a cam swap isn't the cam and lifters, it is all the time and energy that is wasted doing the job for no real gain.

 

Ill take all the above advice and look into what i ahve, i also can get a good edlebrock manifold locally for about $75 from the local racers. There is a used stuff classified in our area for 75 cents that has alot of car stuff, and alot of that is race parts. Id like to do the heads but just dont have the money, i might just save up for the 427 instead, given that is far in the future.

MAtt

 

OK, let me try this one more time OK? Used cams = :nono: . Any Q's?

 

3,000 mi Compcams HE268 hydraulic cam. New lifters. No problem.

Same lifters, new engine... seems like that could be bad, different engines will try to wear differently I'm sure. I went with new lifters, I figure the lifters are getting the same thing, the cam is just getting a little bit more worn, being broken in twice, but it runs excellent, I guess only the long term will really tell.

-Chris

 

I have some used pistons and some used oil i'll sell you,,, i'll give you a good deal on them both.jk :p:

 

I regularly donate used gas and used air currents to the few who are slower than me :steering: