i have an original l69 with 60,000 on it now, it needs new valve seals and is generally dirty and crappy looking so im looking to freshin it up, i know i should just swap out a 350 but i dont have the cash , plus its a 5spd car and im affraid of adding to much power to that tranny from what ive read.. so what i want to do freshin it up and have a nice sounding engine..i'll never race it , just a cruiser, i would like to replace the cam, maybe differant heads, and an intake.. im hoping for a little lumpy to the cam. so if you could steer me in the right way it would be much appriciated...

 

One of comp cams thumper cams can give you a nice sounding car and still keep good vacuum

 

Don't bother with the intake or the heads. Neither of those things is limiting the CAR'S performance.

The Thumpr cam will probably slow it down. The XE262 is a MUCH better choice.

They make the quarter car wash for that. Pick yourself up about 4 or 5 cans of Gunk Engine Bright, or the store brand that's the same thing (diesel fuel in a spray can) on your way there. Take a can of WD-40 with you just in case, for the inside of the dist cap and such if it gives you trouble afterwards. Park the car in the bay, let the motor cool down for 10 or 15 minutes, take the air cleaner off and set it aside and do these same things to it separately. Soak everything down thoroughly with the cleaner, making sure you get it on ALL surfaces; not just stand there and squirt the top, but also underneath from the front and sides, up in the tunnel around the trans, the firewall behind the motor, the front suspension and steering, the K-member, the rear end housing, etc. Wait about 5 minutes, soak it again, wait about 5 minutes, soak it with the "engine wash" if the have it or "pre-wash" or "tire cleaner" if they don't, wait about 2 minutes, blast the crap out of it. Don't point it at the distributor cap or any of the sensors. Give it a try, it'll amaze you.

Best single mod you can do is chassis-specific HIGH QUALITY headers; not, just the cheeeeeepest thing you can find that it's still not quite illegal to print "headers" on the box. SLPs if you can find em, Edlebrock TES are OK if not near as good. Whatever you get, have em ceramic coated, it's a HUGE improvement in every way.

It likely needs new exhaust as well. Get a stock replacement cat such as a Catco and one of the better 3" cat-back systems. Avoid "custom" exhaust like the plague.

LCA reloc brackets will help with the wheel hop.

 

WOW , thanks for the info sofakingdom, thats what i was looking for , the engine is pretty clean .. just the paint on it looks like crap. do they make headers with the A.I.R. tubes? the emmissons police up here are bad. so the xe262 is the best cam ,.. will it have a lumpy sound to it..??

 

Forget the XE262, try the HE268.

 

Forget either of them, they are a bit much for the computer controlled carb, HEI and ECM to deal with. You want to keep duration around 210* and the lobe separation fairly wide. On the cheap, the base model Edelbrock Performer cam is a noticable upgrade (also sold under the Summit house brand cams part number K1102). Little more lift, little more duration, slightly tighter LSA and I know from personal experience the computer controlled stuff can handle it. Might not sound like much of an upgrade but it boosts the torque curve a noticable amount and even makes a little more top end power. You don't even need to change out the stock valve springs if you don't want to (a drop-in upgrade to a set of Comp 981 springs is advisable, though).

LUMPY CAMS ARE NOT FOR THIS MOTOR. You gotta play within the rules of what the computer can hancle or it'll run like crap everywhere. Anything with a noticable lump to the idle won't be happy working with the ECM. If you want to go further then forget about emissions compliance and build a real ***-kicker (i.e. ditch the 305 completely and build to your budget). Don't try to bolt the computer controlled stuff on top of an ***-kicker because it won't work well.

A set of shorty headers and a complete cat-back exhaust (Hooker makes a set of bolt-in headers and Y-pipe and even has options for emissins-legal air tubes). Honestly, a complete exhaust upgrade from the headers to the tailpipe will make a bigger difference than a cam swap in a near-stock engine.

Heads..... there is exactly ONE set of performance-oriented heads available bolt-on for a little 305. The Trick FLow aluminum 305 heads. I haven't used them personally but they look like a real nice upgrade for not outrageous bucks. I would stretch to buy them before I would put any serious money into the stock ones. Vortecs shaved down to ~58cc to maintain compression would be another alternative but the upgrade isn't cheap when you factor in all the otehr things you need to change (valvetrain differences, intake differences) and definitely not emissions-compliant.

One thing I should mention here is that the computer controlled stuff doesn't care much about how much displacement is under it. Sounds weird, I know, and a very different situation than an EFI motor, but since it's a computer controlled carb system it mostly cares about the CAM, not about how many cubes it's feeding. You could build a mild 350 to similar specs and it wouldn't mind at all. What it WILL mind is a lumpy bastard of a cam- it just doesn't have the programming to deal effectively with that.

 

Damon is right!

60k miles ain't nothin' on a small block Chevy!
The 84 L-69 was in its day a hot motor and GM put a few tricks in it!

My L-69 has 157,000 miles and purrs like a kitten!
It has never been touched or modified and I'm sure it has lead a hard
life with 6 previous owners and had 130k when I got it 5 years ago.
It was a NC rust free car all its life till I got it and now it sleeps winters.

Clean up the motor compartment and ride and enjoy!
As far a valve stem seals mine needs them also and it "puffs" oil on hot
starts. A new set of the umbrella seals will cure that issue!
They will be a nice winter DIY project.

 

If it's just a cruiser, then why bother doing anything to it. The factory already did an ok job by adding the aluminum intake and a cam from the corvette.

http://www.chevyasylum.com/tech/L69vsLG4.html

It's a flat tappet cam, so you gotta run oil with ZDDP in it like AMSoil, Royal Purple, Redline or Edelbrock oil or you are just wiping the lobes.

I'd start with headers. Just go with Dyno Don's and switch to a dual cat set up. You'll need high flow cats like Random, Vibrant, or possible the magnaflow spintec (I believe that's what it's called. Basically you're trying to find 2 cats that will flow 1000 cfm as the catalytic converters are the restriction in the exhaust system after the manifolds. You can do this by getting 2 cats that flow about 500 cfm each.). Hooker also makes a street header, but it only comes with a single cat set up so you'll run into that restriction again. Both headers come with air tubes and you should pass emissions.

Start with the headers and dual cats as you can move that to a 350 later when you finally realize that the small bore causes valve shrouding problems and you'll have to move up if you want 350-400+.

Otherwise...if you're going to stick with the 305...just port the intake and heads. You can spend a lot of money on new heads/intake but at the end of the day, there really isn't anything that great for the 305. With less than a 4 inch bore you are choking the air through the motor and the stock rods will stretch and snap if you mis-shift and spin the motor above 6500 rpm-which can happen more easy in a manual.

With all the machine work involve just to rebuild the 305, it would have been better to spend it on a 350 but since we've gone over that, and you're aware of the limitations of the small bore we can now move onto the cam. It's a low mileage motor but the cam lobes have probably worn after close to 30 years. This is more certain since the EPA made all the oil companies remove ZDDP from their oils in 2006.

Try the Isky 256 supercam. I had this in my LB9 305 TPI and I loved it! It was great on gas, it is really good off the line and they have a specific part number for the 305 with a 108 LSA. It's really overlap that matters more so than a wide LSA. This cam on a 108 LSA would have about 40 degrees of overlap which is just right for a little more power than a strict towing/RV/mileage cam.

If the smog police are really bad and you need a C.A.R.B approved cam, look at Comp's high energy stuff. I would NOT go with their 240H unless you are strictly looking for mileage. The Comp 252 has about 32 degrees of over lap because of the 110 LSA so it's not as powerful as the Isky 252 on 108. You would have to go with their 260H to get the same 40 degrees of overlap. On the plus side you would get more lift. If you had the clearance, you could even run the comp magnum roller rockers (I always use the 1.6 and check the push rod to make sure that the lengths are ok as sometimes you need to correct the geometry.). But, sometimes I see the Comp 1.52 rockers packaged with push rods at a reasonable price and they are way more accurate than the stock rocker arms.

But other than that, you still might not see a good return on your dollars. I would start with the headers with a dual high flow cat set up as you'll gain a lot of the horsepower there without opening up the motor. And you could transfer that to a bigger motor later. I would start there and see if you're ok with that. You should already be in it for $800-1000 with Ceramic coated headers (Make sure you get ceramic because if you install it properly, they'll last you up to 10 years usually.) You'll probably only gain 20-40 horsepower here realistically. Maybe 50 if you're lucky, but I'm thinking about 20 minimum. If you want horsepower for cheaper there is always NOS!

Otherwise I would just leave the motor and get a K&N air filter. If it's a cruising motor and you've got tough smog police, without a power adder its hard to find HP with a 305 on the cheap. If you're good with a grinder you can port heads. Try following along with Standard Abrasive's head porting kit instructions as they use a 305 head for their example. But you can also ruin Your heads too. http://pirate4x4.com/tech//billavist...0Abrasives.pdf

 

Or if you're really tight on money, just take your die grinder and port match the exhaust manifolds (you only want to port the sides and tops of the exhaust manifolds and not the floor/bottom to prevent reversion), get the standard abrasives DIY porting kit and port the heads and a set of carbide cutters from summit. (You can just get a set for iron for the exhaust manifold or if you're really tight on money you can try using the cutting stone that is provided in the porting kit.). Port the exhaust manifolds, heads, and intake. You can then take your heads to a machine shop and have them give you a 3 or 5 angle valve grind. At this point you're probably $100 in on carbide cutting tools and maybe $300-600 in on machine shop labour. Switch to 1.6 magnum roller tip rockers for $150ish. You could stay with the stock cam if it's still good. The 1.6 rockers will give it more lift but you'll probably have to get different push rods and check the piston to valve clearance and retainer to valve clearance and maybe change out your valve springs. At that point you're probably about $1000 in without tearing open the whole motor. And you've probably gained about 30 horsepower. Oh, throw in a high flow cats (I can't remember if your car has the single cat or dual, bit if you're on a budget and stay with a single high flow cat) you may gain another 5 horses.

 

hey NELZ , bravo for the reponse here.. i really appreciate it.. lots to absorb there, but i think you yhave talked me out of doing anything to the 305.. the smog police up here arnt bad, they way it works is IF you get yanked by them..which i have to admit is very rare, ive only seen them once in 4 years , they only do a visual inspection to see that all the original equipment is hooked up and there.. there is no tail pipe test..so its all about appearance.. my neighbour is a motor builder.. he offered to do a 350 4 bolt main for me for around $2000, so no sence in spending $1000 on the 305... the only reason i was thinking of doing the 305 is that if i make HP with a motor then i need to repklace the T5 because i keep reading about them being junk behind anything bigger that a 305, then the rear end should be done too.. so i saw it as a snowball effect happening.. then it gets pricey, i would really just like a nice lumpy sounding engine with a nice dual system..im just after "hot rod" sound...i could careless if it could smoke the tires..there to dam expensive now with the C6 rims anyways...so thanks again ..i think im much clearer in my decision to go with a 350...or maybe a 383... oh ..see there i go again...LOL...
kevin

 

We all eventually replace the T-5. The rear end is usually ok. But you're gonna be driving any rebuilt motor easy while it breaks in and the T-5 only breaks if you're power shifting. So technically, you can wait for the T-5 to blow up first. I have a steel Lakewood bell housing to protect me from any shrapnel (I don't want to lose a foot or leg because of a piece of the clutch flying up into the interior.)

I'm building a 383 and putting it behind a world class T-5 but I'm driving it until I break it, then I'll dump the $2500-$3000 for a T-56 or whatever.