i got a l69 305 h.o. motor just how big a cam can i put in it?and not be too big that it hurts performance rather then helps? it rebuilt but all stock it does have a better crank i guess the one was out of stock at gm so they gave me a better then stock one ?oh its a 84 non computer car 4 brl carb thanks
im looking for better performance with a lumpy idle if its possible?

 

You don't want to go nuts. "Lumpy" is way too much for these motors. A litte choppy maybe, but that's the absolute limit if you expect it to run decently.

The factory stock L-69 cam is a little short on duration (not much) but could use a little more lift and a little tighter LSA.

Intake duration around 210-215*, little more on the exhaust and a ~112* LSA is about what you're looking for. HOWEVER.... you must also keep lift under ~.460" or you'll be hitting your reatainers against you guide seals on a stock head.

The Comp Cams XE 256 would be perfect but the LSA is a little too tight at 110*. Fortunately, they make a "computer controlled" version of this cam with a slightly wider 112* LSA under part number 12-256-4. Here's a link to the cam card for it....


Camshaft Specifications


Also, stock valve springs are not going to keep even a mild high performance cam under control in the upper RPMs. You NEED to upgrade the valve springs at the same time. A set of Comp 981 springs will work just fine and drop right into your stock valve spring pockets with no machining whatsoever.

 

thanks for the info bout how much better performance will this yeild i allready run 14.88 in the 1/4 with alot of right wheel spin, lol thats next on the ole checklist

 

Whats your '60? and MPH?

 

So then you don't really need that wider LSA. The 256 is still a good suggestion. You can always use aftermarket springs (definately good idea), and offset locks/retainers to help give breathing room for more lift.
Have you done exhaust, and a better air intake to the motor yet?

Hard to say what time gains you'll see, but I will say, the cam, lifters, springs, is a very good investment, HP/dollar is nice

 

.480"/.500" 238*/248* @ .050 114lsa

hrm...no that's kinda much, that's what i'm running in my 10.4:1 .030 over 305 with ported 113 heads...

214*/224* @.050 .442"/.465" lift 114lsa, that's what was in the first combo, 9.5:1 compression .030 over 305 with stock 416 heads. went 13.03@103.

 

i dont remember 60 ft times cant find my old slips from last summer, but its got full exhaust from stock manifolds to a hollowed cat and a flowmaster muffular the intake is i think the original alluminum gm one, or thats what was one it when i bought it. but i think ill just swap motor before i dump a ton of money into a 305 just to be where a 350 would be stock thanks for all the replys

 

The cam I used when I had my L69 in the car was a Crane Compu-cam 2040.
I noticed a substantial increase in power throughout the RPM range. - And it played nice with the computer!

 

NOVA! I'm itching to see what that 305 will run, find out yet?

 

give me three more days. i just took about 80lbs. out of the car over the last time i was at the track with the 360...and about 100lbs. lighter overall than the last time with the old 305. just got the "good" rearend back in her. this time i put it together with a solid pinion spacer.

track time on friday. i'll post time slips too!

 

I used a Summit brand for my 84 l69.214/224, 0.442/0.465. It worked great and had more power than the stocker.
https://www.thirdgen.org/forums/body...-car-home.html

 

I found an old Car Craft magazine article on the web where they took a 1983 Camaro with the L69 and did an engine build with all of the specs for the heads, intake , cam and exhaust, etc. I'll dig it up and send you the specs.

 

Sir,
Is there any way you can scan that article and post it here on this thread, please . I also believe either CAR CRAFT/HOT ROD magazine did an article as well around that time period on how to build the 305 for performance as well, or how to hop up a Z28 for more performance.

 

http://www.hotrod.com/how-to/engine/...-engine-build/

 

Sorry, I meant the early 80's. But thanks for this link. I did read that.

 

Found it. It was the HOT ROD magazine sept 1982 issue. I will see about getting it scanned for everyone and put it forum. "How to hot rod the Z/28" is the article. I'm just brought it from ebay, and soon as I get it, I will get it scanned for the 3rd gen group.

 

Is there someone in this gruop who would be able to scan this article for everyone to read in the 3rd gen forum? I don't have a scanner, and I would be willing to send copies of this article to get scanned for this group.