63mako

But you have to add headers and free flowing exhaust. If you only doing one thing do exhaust.

7t9l82

i agree with a good set of heads being a plus after intake headers tune and Carb set up. if heads are out of the question a three angle valve job and some pocket porting will help more than you think.years ago we swapped in a LT -1 cam in a L-82 and it sucked without a gear. the L-82 was more responsive at lower r.p.m.

scottyp99

A cam swap is an attractive upgrade option, because you can get a new cam and lifters for pretty cheap money. But, doing a cam swap in the car is a pretty big job, plus you have to worry about whether the cam is going to break in properly, and end up with an engine that doesn't really live up to expectations because it is limited by the crappy heads. The L82 cam is already a pretty healthy cam, I think you would be a lot better off if you could come up with a little more scratch and install new heads. The Dart SHP heads are an attractive choice, at about $930.00 for the pair, but they are kinda new, and haven't stood the test of time yet, so they are a teensy bit of a gamble, and the Edelbrock E-street heads are in about the same price range, and are tried and true. The Vortec heads are an attractive option if you want to stay with cast iron heads, but they require new intake manifold, valve covers, and rocker arms, which take a little bit of the shine off of their initial cheap price. If you are planning to upgrade the manifold anyway, they become a much more attractive option.

The stock L82 engine is already overcammed, with it's restrictive heads, exhaust and intake. Upgrade the parts that will let that cam live up to it's potential. You will have to spend more, but you'll be getting a lot more for your money.

The thing a lot of people don't really seem to understand about camshafts, is that the cam itself doesn't so much decide how much power the engine will make, as it decides where that power will be made. It decides the range at which power is made. The intake, heads, and exhaust are what are gonna make the power itself. It really is an oversimplification of how it all works, I'll admit, but it's still a good way of looking at how an engine makes power.


Keep the shiny side up!
Scott

Tim H

I ONE HUNDRED PERCENT guarantee That if you change out the cam for a Comp Cams magnum 470/270 that the car will run better without doing anything else and for the 1/3 of the price and work of a head swap.
If people try to convince you otherwise they are pulling you chain the wrong way.
I gained a 1/2 second in the 1/8 and my car would go 140MPH down the highway, thats all the proof you need.
There is no use changing to expensive heads when the cam will not make them work to their full potential.
It would be like going squirrel hunting with a 12 gauge shotgun and 00 buckshot.

63mako

You replaced an L48 cam. He already has an L82 cam. Look at the csam and head flow specs I posted and compare them to the cam you posted. Your not getting it. Your comparing what your L48 did and trying to apply it to a totally different engine. His engine is overcammed now and the cam is not his restriction. The cam you posted is a single pattern cam. He really needs a split duration but without heads he is wasting his money.
L82 cam 222/222 duration @ .050 450/460 lift
Magnum 270 224/224 duration @ .050 470/ 470 lift
That change is a waste of time and effort with heads that top out at .400 lift. I would guess your difference in power would be Zero.

jim2527

I'll say my words and then keep quiet....each sub-forum has members who's word can be taken without hesitation. C5 tech, C6 Tech, C3 Tech...whatever. Over the years I've learned who knows their stuff, who sort of know's their stuff and who's full of crap.

When I frequented C5 gen/tech it was humorous to watch members tell LG he didn't know what he was talking about.....

Tim H

Oh the L82, yea the big block.
is that the 396?

63mako

Wow.............Really????????? You have no clue what an L82 is????????????

I have a suggestion for Tim H, well, one I can post here.
You have addressed your intake, carb, headers, exhaust and cam on your L48 and slapped in a $54 ebay distributor as it was delivered. You feel it runs strong.
If you put on a set of 195 CC AFR eliminator 64cc heads with a 1094 head gasket and do a performance recurve of the distributor with a carb tune you will likely pick up a full 2 seconds in the quarter and totally transform your car.
You can be set in your ways, inflexible and argue with everyone all the time or read, listen and maybe learn a little.

Solid LT1

I agree that cam is pretty big. I would swap heads for some better heads first. Way more return on your investment.

Tim H

Oh yes silly me, I thought you was talking about a SS 454 truck from the 90s!!!!
You mean a W-30 Pontiac ram air.
I had one of those and sold it.
I had a factory solid lift cam in it.
I get where your going now were on the same page.
Oh yea I got the Bday invite this morning we will be there with mom around 6:00 our time, were driving the Z28 Formula so you can tune the exhaust. thanks again!

Tim H

Seriously men the above statement is very far from the truth.
When I have hot street cars they run mid 7s in the 1/8, what can you teach me??? I build the engine myself.
And my good friend who gives me advice owns a rail that runs 4.48 in the 1/8, what can you teach me there???

63mako

I get your point. No one can teach you anything. I have been doing this for 40 years and learn new things all the time. I aspire one day to even approach the point your at where I already know everything. Your saying your 8.2 to 1 compression vette with factory 882 heads runs mid 7's in the 1/8 mile. That converts to 11's in the quarter and over 400 RWHP. That is over a full second faster than a 1970 426 hemi cuda and faster than any factory production muscle car ever built even a 1967 L88 vette and 66 427 cobra. And you say you built it yourself! Your just too good. I am impressed. I think Carroll Shelby and Zora would be too!.
Scroll down here to compare the cars your faster than. I don't see a factory production car listed old or new that can run with your L48!
http://www.marsh-racing.com/HP-ESTIMATE.htm

Rich's'78

Tim H,
I suggest you dig up a good used factory L-82 engine and dyno it (not too hard). Then build what you think is the best improvement, dyno it and post the results with all the parameters and dyno charts. Then the let the facts speak for themselves......
The rest is bench-racing. And my 2c is that a good 1/8 shows more about traction than power to weight ratio (1/4 mile trap speed).

Tim H

I said when I have a hot street car, I never said this was one of those at all.
I didn't know the mid 7s was so hot?
I did it in a 72 Nova with a 2 bolt main I built in my garage with a set of factory 375 hp heads, 501/292 comp cam, gear drive, 750 DP Holley, RPM style intake, $54 HEI, Summit headers, 3500 stall and 373 gears.
It ran 7:78 with 9 inch slicks and open headers. I really guess thats the upper 7s if you look at it, sorry.
This impresses/satisfies me so I use it as my guide line to run faster or slower.

63mako

[QUOTE=Tim H;1580601376]I said when I have a hot street car, I never said this was one of those at all.
I didn't know the mid 7s was so hot?
I did it in a 72 Nova with a 2 bolt main I built in my garage with a set of factory 375 hp heads, 501/292 comp cam, gear drive, 750 DP Holley, RPM style intake, $54 HEI, Summit headers, 3500 stall and 373 gears.
It ran 7:78 with 9 inch slicks and open headers. I really guess thats the upper 7s if you look at it, sorry.
This impresses/satisfies me so I use it as my guide line to run faster or slower.



You like playing games but the questions on these threads are serious. These people need real advice based on the experience of the members here. When you throw out the BS you have been giving in this thread and many others some of these posters are actually going to take your recommendations seriously as they don't know better. You would have this guy pull his cam and replace it with almost exactly the same thing. If you can't give sound advice either because you really don't have a clue or your playing some ignorant game in your own mind best off not posting. It is not helpful to the other forum members and gains you no respect.

Tim H

What does it matter what I tell them when you guys come on here and tell them exactly the opposite of what I say when I know for a fact about what im talking about from experience and all you tell them is paper back results.
Whether the L82 and a 470/270 cam are close, the duration is more and the lobe separation 110 and that will make a difference.
I was being conservative to help out by not spending tons on other matching parts but just upgrading and getting good results.
You guys try to undermine my advice so I just return the favor and will continue until you see that street and track results are more real than a dyno that not all of us have sitting next to the latte machine so get used to it.

billla

Tim, no one here is "undermining" your advice. We disagee with your advice, and where we do we state clearly why. Your only response is that we're wrong, that we're bench racing snobs that don't know anything about the real world, and then you flavor it all with being a smart-***. All of us build engines and have real-world experience, as you do. We've also invested in learning HOW and WHY engines make power or don't to help us be better builders. You use the dragstrip to try stuff, we use design information, testing AND the real world to do designs and builds.

Most of my builds are GEN I SBCs around 1-1.2 HP/CID. Mako, gkull and others are experienced on very high HP/CID builds that I don't work with enough to offer solid advice on. There's a bunch of guys here that do BBCs that I have near-zero experience with. We disagree regularly - yet we seem to do it openly, honestly and without any personal nastiness. I respect them even when I completely disagree with them, because I recognize the different experience and expertise - and I am always learning.

Getting combative about your advice when someone doesn't take it, or others disagree with it, doesn't really help your credibility. The OP and others can pick what advice they want to listen to - so post your information and move on...rather than just beating up anyone that disagrees with you.

Not sure if any of this will help, but I've said my piece

Tim H

I don't answer big block questions either because i don't know anything about them only owning 1 70 402 engine, I like the SBC and thats what I stick with.
Really, believe me when I say I read every word you guys write and have used lots and lots of it, especially the revelation of the direct vacuum to the distributor thing which I now do.
But I wouldn't seriously tell someone something I have either done it or seen it done so I know it either works or don't work.
just like my 76 now had a 600 carb on it and went to a 750 and it ran 100% better yet if you punch in the numbers I should be running a 570CFM but my real world testing proves street wise I am way more happy with my choice so I try to convince people of what I have done and it works.
Yet you could put it on a dyno and prove me all wrong but it runs just fine???
You drive a car on the street more than on a dyno or at least some of does.
My vette runs really good with the cam/ heads( I don't like the heads but haven't changed them out yet) I have on the street, put it on a dyno and you WILL show me different but what can I do?
I like big cams, I build engines around the cam so I know I have the sound.

Little Mouse

Tim H
You have not used an 850 dp holley on a 383 with a wide ratio 4 speed and 280s rear gearing. Yet you came on C3 pauls thread told him to do just that. Paul has better sense then that. I see you run a vacuum carb.

Had an 850dp on a 454 that could turn 7500 rpm fine for that. Not some sub 6000 rpm 383 with zero for gearing.

Putting an " old tech slow ramp " magnum cam of the same duration lift with tighter LSA in place of his L/82 old tech cam would not even be worth the cost of the gaskets to do the job.

To the op start making changes elsewhere not your cam.

Tim H

Keep digging everything I said for the last 12 years because its alot so good luck.
I run a 750 vacuum carb because its my favorite carb and im going to experiment with the adjustable secondary pod to see if its worth it, plus this car is a street car only so a $275 carb will do me way better than a $500 carb.

I tell ya what more stupid is adding 1.6 rockers to anything instead of changing out the cam, its a lazy way to think your doing some good with less work.