Mild 305 cam

[LukeZ]

Couldn't find what I wanted after a search. Let me also say that I am not a cam expert.

I am looking to upgrade the cam and lifters in my LG4 305. On a Camaro forum, I found these specs for the LG4 cam:

.350 lift intake
.385 lift exhaust
178* dur @.050 intake
194* dur @.050 exhaust
109* LSA

I don't know what a good range is for a mild cam. All I know from various threads is that the stock LG4 cam is garbage lmao. What's the best hydraulic roller cam (preferably a kit that includes both cam and the lifters) for a daily driver 305? I understand it differs for every vehicle setup.

My car is about 3650lbs with me in it. 200R4 auto transmission. 2.56:1 rear end, peg leg. The only thing I have done on the otherwise stock vehicle is an Eddy performer air gap and exhaust.

Thanks

 

[Andebe]

Changing your rear gears will give you more bang for the buck than your cam change. It will be performance you can "feel." Based on what you have described...

 

[Andebe]

Vortec heads would show/feel increase,combined with duals and gears. 305 stands for 3-OH MY GOD WHY WONT THIS GO ANY FASTER-5.

 

[lilbowtie]

You might not like the cam change - with that 2.56 gear your not turning any rpm's and a bigger cam is probably going to hurt your bottom end more than stock.

 

[LukeZ]

Let's say I went with 3.23s some time in the future. Everything else is the same. What cam would be good?

 

[L67ss]

If you go vortec head route make sure to get them from a 305 vortec so you don't lose compression

 

[Andebe]

Basic upgrade...https://www.summitracing.com/parts/...FABUj5nf-FSOMsA7IYjDqFzGoyshuoMN2IaAnYI8P8HAQ

 

[bob64]

305 is a dog , heads don't breathe, so replacing the cam isn't going to help much.
If you want to throw a Cam in it try a RV cam.
Vortec 305 engines had 70 to 100 HP more than a basic 305, so putting on Vortec heads will wake it up, throw a can at it with a max lift of .480 an a bolt up Vortec style intake you'll be looking at around 300 Hp .
You can get heads from a scrapyard cheap, know desire for them.
I just rebuilt a 96 Vortec 240 stock HP added intake, carb an cam an its well over 300 HP.
Your compression maybe be .5 lower with your block but this should give you some ideas.

 

[Wageslave]

As far as a cam goes, you might want to buy more for an RPM range than specific lift and duration numbers. A nasty cam that is made to run 3500-7000 RPM will not do you a lot of good if you don't ever intend to run your engine that fast. I bought my cam with a 1500-5500 operating range. This put me at the low end of the range at highway cruising RPM and the high end came right to my redline (due to factory valve springs). This way, the entire range is usable.

Your intake is a pretty good start, and has an RPM range from idle-5500. It would be a good start to buy a cam that matches this profile and will work well together with the intake. If you already have a good exhaust and a good carburetor you will have a pretty solid runner.

You might want to think of a set of heads for the future, but they are pricey and at that point a 350 short block becomes a more cost effective way to more power. On the upside, everything that you have already bought will transfer over to the new block so no money is lost.


Good luck,

Wageslave

 

[online170]

It's so hard to answer this question without having a runaway build as you can see from the comments above.

I'll try to stick to first hand experience. Firstly everyone is right that the 305 is severely choked and anything you can do to help it breathe will pay back dividends.

An aluminum intake with a spacer if you can squeeze it in there and some headers is a good place to start. You can get these used for about $150 each. I'd also recommend getting a full felpro gasket set as it's cheaper than buying piece parts. That way you have the gaskets if you decide to do the vortec head thing. You are going to need most of the other gaskets for the cam swap anyway.

I would ask what you want to do? ie: Are you after sound or just a bit more performance? But with a "mild cam" it honestly doesn't matter.


I used to have a 78 camaro with a 305 and "mild cam" and that car had the aluminum intake, headers, and a QJ plus the "mild cam". It had a very slight lope at idle, and was still a dog. I would say maybe 200hp to the wheels. A buddy of mine also has a stock 305 with a "mild cam" and it put down 170hp to the wheels in his trans am. He recently invested in a B&M supercharger and 650cfm carb, total price of about $2000 after the ignition upgrade, starter and some gauges. I would say that its making close to 250hp to the wheels now, but way over 300ft/lbs at 4psi. The boost has amplified the torque a ton.

Beyond that, id say you want a split duration cam, where the duration is about 10* or so higher on the exhaust side. Look at the @ 0.050" duration numbers only. I would say you are looking for something in the 227* of duration at 0.050" of tappet lift range. You want almost no overlap, as you cant afford to bleed off any more compression than you have. So stay with a LSA (lobe separation angle) of 112 or numerically higher.

I did a quick search on camquest and the only one i saw that will let you use the stock springs is the 260H and the XT262H with a 212 and 218 duration.

FULL DISCLAIMER:
I have not done any research into what you need to do to make the camshaft "FIT". My recommendations are only based on camshaft behavioural characteristics. Some cams may need you to machine the heads, or a use a special type of rocker (self aligning or not), among other things. Also there is no guarantee that a camshaft will fit based on clearances. If you increase the duration and lift, you may have piston to valve interference, etc etc... Make sure you figure all that out before spending your money.