valve lift

this is just a curiosity question but what is the stock valve lift for a 1977 chevy 305

this is just a curiosity question but what is the stock valve lift for a 1977 chevy 305

Depends on what that 305 was installed in at the factory. Most of them are in the .380 range.

According to Melling, the only cam used for 305 in '77 "sports" .372" intake and .409" exhaust lift (1.5:1 rocker ratio), with 189/202 deg duration @ .050" lift, on a 109 LSA. NOTE: No "HO" version for that year.

Pretty wimpy... (:-

Jim

the 305 is in my 77 monte, im thinking about putting a summit cam in, http://store.summitracing.com/partdetail.asp?part=SUM%2DK1102&autoview=sku

what kind of power increase can i expect with this cam everything else is stock except i put a stock 4bbl intake and a rochester quadrajet ( it originally had a 2bbl)

You would experience a bit of a power increase in the mid-range. Maybe a little "up high", but without upgraded exhaust and intake, minimal.

You would have better results with a modern cam profile, rather than the generi-grinds offered by mail-order companies. We usually recommend Comp XE series grinds for "pump gas" street engines. They seem to be the hot lick today. For one in the "parametric range" of that Summit grind, go for XE256H. Bump it up a tad with XE262H, which is our most popular seller for "stock" engines. In a 305, it's a genuine performance cam, and will have a slight "lope". It will be okay with the stock torque converter.

FWIW

Jim

Edelbrock Performer would be a good intake for your application, as well. And yes, use the Q-Jet with it.

i plan on running daual exhaust through cherry bomb mufflers

without a catty converter

with the llow compression these engines had and the small peanut ports these heads had and the crappy highway axle ratio these vehicles had you would be much safer with a stock 350 replacement cam from your local auto parts store

bene here done this already

most recently in the stock original LG4 4bbl 305 in the 85 elky and we opted for a stock 350 cam and had the block done at the machine shop and it had to be bored out .030 jkust to be able to rebuild it and it runs STRONG


didnt do anything to the heads although some porting and 1.94 should ahve been put in but it was not my engine i was in charge of disassembly and reassembly and reinstallation

even with the crap 2.73 axle it runs very strong and smooth

perfectly

surprisingly so

dont go overboard with the cam selection especialyl if everything is stock and the axle ratio is crappy

you wont get to the RPM range to even use much more of a camshaft than stock and it will be doggy


good luck

My entire point about using the modern cam... You would be amazed at how much stronger your "elky" engine would run with one of the smaller XE grinds versus ANY factory grind. Factory grinds are "safe", but also a complete set of compromises. The XE series is at its best in lower compression applications. The smaller grinds aren't "rowdy" like a stereo-typical "hot cam". You're absolutely correct about over-camming an engine. None of those I suggest would do that. Trust me... (:-

Jim

bottom line is you're dealing with a mostly stock 305.

and you want to run loud mufflers too. perhaps you're interested in doing some burnouts and jumping on it whenever, nothing wrong with that, but it's never going to be a serious performer in reality.

for any stock/daily driver/everyday streetable racer out there, the best advice is moderate compression, moderate carburation, stock to mild cam grinds that produce power at lower rpm's, and headers.

ok thanks, i decided to go with the summit cam
http://store.summitracing.com/partde...2&autoview=sku

and summit long tube headers throught turbo mufflers, no catty converter

also i have a rochester quadrajet replacing the original rochester dualjet

other than that the engine is all stock

anybody have a guess on what kind of power my 305 will put out with these mods

thanks

ok thanks, i decided to go with the summit cam
http://store.summitracing.com/partde...2&autoview=sku

and summit long tube headers throught turbo mufflers, no catty converter

also i have a rochester quadrajet replacing the original rochester dualjet

other than that the engine is all stock

anybody have a guess on what kind of power my 305 will put out with these mods

thanks
that Summit link was bad, what's the cam spec's? lift/duration/lobe centers?

also, what are your goals for this car/motor? what do you want it to do? my feeling is you are looking for more than you will find regarding performance with this project.

Turbo mufflers are always a sign of class on the street, you won't be sorry for choosing Turbo mufflers.

i wouldn't be looking for much power overall, but you will get a boost from the right cam, carb, and headers.

if you really want to build some power, you need cubic inches or you have to go radical (with small motors) with things like compression, cams, heads, etc, all of which make affordability/everday driveablity difficult.

what intake manifold are you going to use?

a 750 cfm QJ is an excellent carb, but it's too much CFM for that motor, but if you already own one, you can try it. with a mostly stock 305, i'd go with a 600-650 cfm carb.

the cam specs are

Intake Duration at 050 inch Lift:224Exhaust Duration at 050 inch Lift:234Duration at 050 inch Lift:224 int./234 exh.Advertised Intake Duration:282Advertised Exhaust Duration:292Advertised Duration:282 int./292 exh.Intake Valve Lift with Factory Rocker Arm Ratio:0.465 in.Exhaust Valve Lift with Factory Rocker Arm Ratio:0.488 in.Valve Lift with Factory Rocker Arm Ratio:0.465 int./0.488 exh. liftLobe Separation (degrees):114

as for my goals, i just want to be able to stomp on it and go, and be able to do burnouts whenever i want

the intake is a stock intake off of a 350

the carb is a stock quadrajet off of a 77 chev 1/2 ton truck

i am planningon using summit long tube headers and summit turbo mufflers

thanks for the help

That's a pretty "rowdy" cam for a 305. Too much duration, IMO. It will be a stone until about 3,000 or higher. you can "help" it a little by advanvcing the cam timing 4 degrees (use the "advance" slot on the crank gear). It won't "like" a stock converter, either.

I know it's cheaper than the Comp I recommended, but you get what you pay for! XE256H or XE262H would be a MUCH better choice.

Q-Jets are "self-adjusting" regarding CFM. Max flow would never be realized with a mild 305. ALL Q-Jets from '74-on are 800 CFM. The secondary air valve controls the total amount of air at WOT.

Jim

well said Mr. Pbody, i conqur on everything.

you can't just throw a cam in and make it a street racer. everything is part of a "system," if you modify one variable, it can adversely effect another.

that cam would kill your bottom end/launching/tire burning ability unless you ran at least an aftermarket torque converter. and ideally, you really need more compression ratio too with a bigger cam, especially when you have none to start with.

also, what gear you running? probably a 10 bolt with 2 series or low 3 series gears in the back. not the kind of gears you need with less bottom end from a small motor and a bigger cam.

the reality is, you have to learn somewhere, and even if the current project doesn't live up to your expectations, you are going to learn a LOT about engines and working on them, knowledge that will transfer completely into the next performance project you, whether it's a small block or big block.

with a small 305 and low compression cast pistons, a stock QJ intake with a new cam and headers, you can't hope for much, but it will be better than stock.

a daily-driver with a 305 and stock tranny/rear end needs bottom-end torque more than anything. you need a good intake as well, do some internet research on Edelbrock Performer intakes and 305 engine projects and you will find a lot of good stuff.

and, if you start throwing converters and gears and stuff like that into the mix, now you are starting to build a more serious street car that becomes more like a race car and less like an easy to drive and maintain daily driver.

if this is your first performance project, i'd build it around a Performer intake, headers, and a low end/torque enhancing cam that will help you fry the tires off the line better and give you quicker acceleration from a dead stop or slow cruising speeds. the car will run a lot better and you will have a lot of fun.

if you do this project with low-end power in mind, you'll learn a lot and have a lot of fun and that's what's it's all about.

sorry, that was the wrong cam

the duration on mine is 204/214
and the lift is .420/.442

thanks for the input

any guesses on power output

oh and yes this is my first project, im 16 and biulding it in auto class

i dont want a serious street car, just somethin to have some fun in ( its my first car)

the gears in the rear are 2.73 in a 10 bolt rear end

thanks again for all the help

ive learned alot on this site since ive joined

mr.pbody, would you still recommend advancing the cam timing with this cam, if so how do you do it?

That cam is a lot more "reasonable" for such a project. Stock valve train is adequate with it.

Advancing or retarding the cam timing is accomplished by moving the cam in relation to the crank, either forward or back, in crankshaft degrees. Most current "double-row" timing sets have three key-ways cut into the crank gear. One is in the "stock" location and refered to as "straight up". One is 4 degrees advanced and one is 4 degrees retarded. There are some high-end sets out there with 9 key-ways. Extraneous for this application.

Advancing the cam will make the events occur SOONER in the cycle (relative to piston position). Retarding will make them occur later.

For the most part, advancing will lower the RPM range wher the power curve begins and peaks, retarding will raise it. Again, this is all relative to the position of the piston at the time the events occur, and compared to "straight up".

It is common to confuse ignition timing and cam timing. I now many good technicians that are not engine "specialists" that have a hard time grasping it. The reality is ignition and cam timing are pretty much independent of each other, except the need to re-adjust ignition timing if you change cam timing (moves the distributor gear).

With rear gears that "tall" (lower, numericly, higher as a "ratio"), a higher-than-stock stall converter is a very bad idea. It may give a bit more "grin factor" when playing, it will raise the stall speed (where the fluid coupling achieves "lockup") above the necessary "cruise" RPM. This will inject a tremendous amount of heat into the transmission fluid, seriously shortening transmission life, and EAT fuel!

Jim

would you still recommend advancing the cam timing for the cam i have?

does the stock gear have the 3 keyways?

if it doesnt, is there still a way to advance the timing to help the cam along?

also, the operating range for the cam is idle to 5000 rpm, should i still advance the cam timing and lower the power curve

i want to be able to do burn outs and stomp on it whenever

Stay with the cam MFG recommended intake centerline for cam timing when you degree in the cam.

I agree with Maxwedge. I also discourage the use of cars for "showing off". If you want a fast car for competition, that's one thing. If you just want to do burnouts and make noise, consider learning the drums or the guitar...

I often get the request: "I want a motor that "sounds good"...I don't really care if it runs good" (makes power) I have yet to figure out how to build a good sounding engine that doesn't run good, too....

Jim

in agreement with Maxwedge and MrPbody, do not advance the cam. forget about advancing the cam. install it "normally," and follow the break-in proceedure EXACTLY as stated in your instructions.

i can see this see two ways. one is the general wanting to sound loud and smoke the tires to impress the ladies at some gathering hole, which is within the realm of the average dumbass trying to get laid.

the other is a young kid doing his first performance project looking for answers about streetable performance.

providing lux really is who he says he is and really is 16 doing his first project, he's got a lot of learning to do (and i mean that in a good way).

it takes time to understand mechanics and it takes time to be in positions where you can afford certain parts/projects. the joy is in the journey. let's face it, if you have an 8 second street car that runs on pump gas, where else is there to go? the 7's? how much fun is left in that project?

taking a 15 or 17+ second street car into the 12's or 13's for the first time is a blast, that's probably where you are going to have the most fun. when you start going faster/ramping up HP, you have to start ramping up maintenance, $$$, and time. a 305 in a Monte Carlo is a good project to start with, my take on the whole thing is to have fun with it and learn solid mechanical skills, not expect too much, but enjoy the reward if you do it right and select the right parts.

and if you choose the wrong cam, you can always buy another one with a different profile, right? the most important thing for now is to get wrenching time under your belt, just turn the wrenches, and when you make a mistake (and you will make mistakes - it's ok), just learn and move on.

idle to 5,000 RPM is what you need to focus on from the sound of things, especially as a first project. before you start rapping motors over 7,500 RPM, learn how to make power in them for easy, everyday driving first.

hey man, just wondering, hows your project coming along?

pretty good, the fenders are almost done (lot of metal replacement) door is off and starting to cut out the rust

the engine is goin back together with a summit cam, headers and 4bbl carb

the floors are all redone and the trunk will be started soon