90RS305project

i want to put a BiG cam in my 305, something over .500 lift, what do i need to do to make it handle the cam? its stock right now so im starting from scratch, about to change the TBI to a carb.

spurgeon76

I'm not going to get into whether or not it's a good idea too put a big cam in there but you are going to have to upgrade the springs first of all. Probably have to go with beehive springs or get the seats enlarged. Of course you SHOULD get screw in rocker arms with a high lift cam but it's up too you.

Guest

All the TBIs were built with swirl-port heads, so you probably have those. Keep driving those while hunting some 081s. Then drop them off at the machine shop, let them cut the guides down, and cut the spring seats for 1.44" springs.
The 1.84" valves are actually not 1-piece valves, so they're best not combined with really serious springs. You can get stainless 1-piece 1.94" valves machined to 1.84", but most guys just have the heads cut to match the 1.94" valves. This helps flow.
0.500"-lift is not for low-rpm, so you don't want the swirl-port heads, 1.94" valves really won't help those heads. But they will help the 081 heads.
You'll also want the machine shop to pull the pressed studs, then machine the heads for screw-in studs.

90RS305project

lol well i know its not the best idea, but i do plan to build the motor to handle it, 335 stroker in the future...i want performance but im more worried about the sound, what size carb should i get keeping in mind my future plans, and is it safe to bore a 305 .60 over?

Guest

You don't need to go over 0.500" of lift to get either sound or good power results.
You'll find far fewer hassles if you keep it to 0.480" lift. Maybe start with the popular and proven Comp XE268H10?
Just because you have roller lifters doesn't mean you have to stick with them.
The cost of a new non-roller cam-and-lifters is about the same as a new roller cam and reusing your old roller lifters.

gwarren007

iTrader: (1)

Better for carbed application with stall and gears

http://cgi.ebay.com/ebaymotors/Small...item27bb5643ab

90RS305project

Well i guess since i dont know much about how all this works, this video was the start of me wanting to do this project....

http://www.youtube.com/watch?v=ZABvY9PshWE

Guest

So you're gonna let the sound of that person's car decide your build? Even though that owner may have different local laws, and different ideas about driveability, and so on?
Wanting that sound is understandable. But if there's any sort of emissions inspection where you live, forget it.
If you want that sound, but daily driveable, then drive that 305 while building a 350 with a Thumpr cam. That'll be your best bang for the buck.

Saculia

iTrader: (1)

Going over 0.5" lift is not going to do you a lick of good if your heads don't flow any more past that point. There is a lot to consider when upgrading the cam and the rule of thumb is to err on the side of the smaller rather than the side of the larger. I am perfectly happy with my cam, comp xr258hr12, and it is perfectly suitable for TBI applications. That however, doesn't mean that you can just throw it in and hope for the best. Thinks to consider are proper clearances and also computer compatibility if you want to stay FI and then you have to either learn how to tune yourself or have the car properly tunned. Make sure you do your homework first before you decide to do something that may not turn out to be what you expect.

90RS305project

no emission problems here, and definatly switching to a carb. that car is just a basis for what im lookin for...not the exact same...i want the 335 stroker...i want to bore it 60 over but idk if its safe, i want a big cam for the sake of having one...im going to try and make sure the motor can handle what i do, and once i get my roughly 400 hp im going to spray its guts out whenever a race comes up...maybe not too safe but sounds like a hell of a time to me....if it blows...move everything i can to a 350 and restart

gwarren007

iTrader: (1)

If you haven't bought new heads and/or the stroker crank, just build a 350 or a 383 with a more radical cam. You need to build the 350/383 after you get the rest of the chassis ready to support the 400+hp and nitrous. Otherwise you will just be breaking the trans or the rear end.

90RS305project

well as ive said...i want the 335...and i want to begin building it while its in the car, its too slow atm and i want to feel as it gets better, first step is the carb and intake swap...then headers and a cam, possibly different heads at the same time if necessary, im doing a swap from the 700r4 to a t-56 at some point and wont be driving it hard before i get everything together, not lookin to save money so much as build what i want

TNT_Z28

A 335 does sound cool and original... Good luck on your build.

If you take it step by step, some things are going to end up being redundant. I've said it before, it's never as simple as "a cam". You need to account for other mechanical parts that should be swapped such as lifters, pushrods, timing chain. And also the various gaskets and seals; pan and intake gaskets, and a front main seal kit.

If your really planning on stroking ur 305, you would benefit by pulling it and doing all the work at once. That's why it's been suggested to build a motor on a stand while you can still drive ur car as is.

90RS305project

Very understandable, but as it is now its way to slow, wont swing a good donut, and hardly barks a tire from a stop....not workin for me....so as i put more and more into it, it should slowly but surely get to where i want, if its not a good idea to do certain things...then what can i do to get it to ^that point before i take it out and stroke it and what not?....i would love to build a 350 but really its pointless...everyone has a 350...everyone knows what they can do, well all i want is to outrun afew 2000 model ls1's and most mustangs i come across, and if necessary the spray will make sure of that

gwarren007

iTrader: (1)

You can always tell them its a 305.....

90RS305project

I plan on it...cause it will be, i want something everybody doesnt have...im in no hurry to get it finished, i just want the 335...but can i bore it 60 over...safely?

gwarren007

iTrader: (1)

only sonic checking it will tell.

InfernalVortex

iTrader: (4)

There's a lot here I think is a bad idea.

NEVER OVERBORE AN ENGINE MORE THAN IS NECESSARY TO GET THE CYLINDERS ROUND AGAIN. Overboring it more than necessary does nothing except take away potential future rebuilds from it and put you in danger of cylinder walls that are too thin.
A .060 over 305 will get you to... I think... 312 cubic inches... 7 cubic inches... That's it. Not a noticable power difference.

A 335 stroker is a complete waste of time. The cost of a block is pocket change. The money is all in rotating parts and machinework, and a 383 may even end up CHEAPER than a 335. A performance-oriented rebuild of the engine alone can cost you, if you're cheap about it, 2500-3000. A roller 350 block will cost you $50-$200 depending on various things. They're everywhere, they're cheap, and you'll make a LOT more power with a 383 than you ever will with a 335. $100 bucks for a 4 inch bore block next to $3000 you'll have in a rebuild with good parts is nothing.

but if you want to waste your money go for it.

Remember, you'll need to upgrade your exhaust system for a big cam. You'll need heads with larger runners to match the cam's power curve to something your engine can actually use. A cam that big will also mean you'll need to go to much shorter gears in the rear end too. And lets ignore the problem of a stall converter.

If you leave all that alone the thing is gonna be awful to drive, it will nearly stall every time you try to drive it from a stop or come to a stop, etc.

Stick to a xe268 or smaller cam. An xe268 is going to sound ridiculous in a 305 or a 335, and it wont be too unbearable to drive around everyday. It's definitely a medium sized cam, not a small one, but it's still pretty large for engines smaller than 350 cubic inches. Cam size is relative to displacement in case you haven't noticed. A cam that will sound boring and normal in a 400 small block will lope all over the place in a 283.

This is my car with a 355 and an xe262. A cam that's pretty small all things considered. That cam in a 305 will sound pretty crazy. An xe268 is one size higher than the 262.
http://www.youtube.com/kylep133#p/u/5/NZl1_P1VqOo



I had a 350 block before this one that had to be bored .060 over. Got it bored, honed, and put together and this happened after the first time I took it around the block:



I will never touch another .060 over block again. Also, my block is .030 over, it's 355 cubic inches. That .060 over block was 360 cubic inches. Is an extra 4-5 cubic inches worth potentially reducing the integrity of your cylinder walls? If you got a perfectly matched, efficient streetable combination, which you dont seem to care about getting since you seem to be planning on just throwing the biggest cam you can fit into it, you'd lose at most 1hp and 1tq per cubic inch. Throw a K&N filter or set up a fresh air intake from cool outside air and you'll get more hp benefit than that. A good tune up will get you that much probably.

90RS305project

i know a fella with a cutlass with a 350 bored .080 over and it NEVER has problems...i plan to make the motor handle what i do, and everyone has a 383, theyre not that cool....not to mention im not looking for tons of power, if i decide i need more ill replace some stuff and throw on a turbo or something...its not a waste of money to build what i want to have...seems awfully smart to me, i plan on putting as much money into it as i need to make it streetable, besides with gas mileage...i dont plan on driving it all the time anyways, and if it kills the block then oh well ill get another one or build something else, not to mention 350's are EVERYWHERE, and i would like to have the original motor in it as long as possible...thanks for the input but im liking my ideas

TNT_Z28

Lol... That's hilarious.

Look man, I mean no offense by this, but your not listening to common sence and you setting yourself up to learn the hard way. There are reasons so many people run 350s or 383s. Not to be "that cool" but because they want real, practical performance.

Many pieces of advice posted above would save you time and money. But the wonderful thing about America is its a free country and you're free to build a motor as you see fit.

five7kid

iTrader: (14)

Different engine built by a different company with a completely different casting. You can bore 454 blocks out .125" easily - that doesn't mean you can do it to a 305.

A 335 is about 48 cubic inches colder. They're neither hot nor cool (neither are they original).

So, you just want to spend money?

Simple fact is whatever you put together, it will be different than what anybody else has. For instance, I don't know anyone else who has an '82 Berlinetta with a 2000 SS LS1 and T56 with silver exterior and grey interior, 9" rear end, 3" DOM driveshaft with 1350 U-joints, Covan instrument panel with Autometer programmable speedo and fuel gauge, AMSOIL air filter, and no ground effects or spoiler.

Perhaps you know someone with an '82 Berlinetta with a 2000 SS LS1 and T56 with silver exterior and grey interior, 9" rear end, 3" DOM driveshaft with 1350 u-joints, Covan instrument panel with Autometer programmable speedo and fuel gauge, AMSOIL air filter, and no ground effects or spoiler, though...

IROCyou86

I too had the desire to be original with my 305 but as much as you want to stick out with your kick-*** underdog/underbored engine, it's not realistic. You can still make it fun. My plan is to get a 305 roller block, use the stock heads but cut them out for 1.94/1.60 valves, port/pollish,MILD cam, domed pistons, and my edelbrock performer intake manifold w/ my rebuilt q-jet. I'm going to wait till something breaks in my engine and will rebuild it with these parts +new lifters/pushrods/ gaskets/anything else that needs refreshment. Most of these parts I already have/can aquire from the pick'n pull for cheap making a regular old rebuild much more fun and way less expensive than drastic measures to make a 305 stroker. If i got 250ish HP/300ft/lbs out of a 305, I'd be jazzed!

The 305 I have now which is relatively stock besides headers/MSD dizzy still hauls *** and chirps tires. If you want 400 HP+ please don't ask this of a poor economy 305.

InfernalVortex

iTrader: (4)

1. 350's and 383's may be "everywhere" (I think there are lot more thirdgens with 305s than 350s, but that's just me) but they're still gonna be faster. And cheaper.

2. So you want a giant cam 305 that's streetable and cheap and different? You need to evaluate your needs and desires and then figure out what you need to get there rather than work backwards from an engine of predetermined parts.

3. Not only do you put yourself in danger of cracking cylinder walls and losing block integrity as a whole, for the sake of an extra 4 cubic inches, you make it more prone to overheating at the same time.

4. Dont bother with throwing on turbos. They require a lot of knowledge, research, tools, ability, and creativity to get them to work properly. An engine that works well with a turbo will not work well naturally aspirated, and an engine built to be naturally aspirated is usually not going to work well with a turbo either. You need stronger internals, and you need specific dynamic and static compression ratios and they have different demands from their fuel delivery systems and camshafts than naturally aspirated motors. A turbo thrown onto an engine as an afterthought can work, but youre very limited as to what you can do and you still have to be very careful about what you're doing.

90RS305project

i was never really lookin for cheap, just lookin to see what id need to do it, and ^ that above about the turbo is why i said i would replace parts in the future that i may need if i was to get one. everyone puts down the 305 but GM did a test on the 305 to 350 comparison and with approximatly the same upgrades the 305 pulled 372 hp and the 350 pull 395 hp, not to sure on the torque but numbers dont lie, and i dont need more hp than that...long as i can spin tires from here to forever...everyone knows the 350 is cheaper and better and blah blah, why does everyone insist on reiterating it? i know it...just like you do...but i want my car to have the original motor in it...although in all honesty wouldnt mind to have a 400 sbc...but idk bout all that

torque_is_good

then ask your parents to buy you a new Mustang 5.0

honestly, you are all over the map with respect to what you want


you've been given advice from others based upon experience. If it's not what you wanted to hear then so be it. When asking advice from people who have ACTUAL experience you may not like the answers but as you leave your early teens and enter into your 20's and beyond, you will realize that it makes FINANCIAL sense to benefit from the experience of others.

90RS305project

uhh actually i asked for specifically what i wanted to know...and for the most part its just been blah get a 350 blah...and finance isnt the issue, moneys no problem...i want to build what I want, not what you guys think i should, and my man im 20 years old im in the army and i have plenty of time/money to do this and make it work...as i said I WANT THE ORIGINAL MOTOR...guess that doesnt make sense to any of you guys, but its plain english, so thanks for the attempts at changing my mind, ill just go about this myself

InfernalVortex

iTrader: (4)

Original motor doesnt mean anything to the value of the car unless you have a highly optioned car. If you had a 1LE T5 305 setup or something to that effect, you'd want to keep the original block because they're rare combinations.

You have an RS. The originality of the block will never be a concern to anyone except perhaps yourself.

Have fun tossing away your money. My 355 will be faster and cheaper than your 335.



Your original question, what do you need to do to make a big cam (.500+ lift) work? Here's a list:

1. You need new heads. A big cam on those swirlport casting cylinder heads will make that car into a complete dog. It will have valve timing for a 2500-7000 RPM power band, and the cylinder heads tuned for a 1000 RPM to 3000 RPM power band. End result is the car wont make power in any range.
2, You'll need screw in studs, preferably 7/16s of an inch diameter
3. You'll need some stronger rocker arms. I suggest some of those Comp Cams steel lightened rockers. I think tehy call them Pro Magnums or something? Aluminum ones iwll work but they fatigue over time and will need to be replaced on a regular basis
4. You'll need better valve springs to handle that high of lift without coil bind. Talk to a machine shop about this when you get your heads setup for screw in studs unless you buy decent aftermarket heads that have them already. Springs for that kind of lift also wear out and you'll need to change those out every once in a while.
5. Get a decent double roller timing chain set.
6. You'll need to get your TBI re-tuned or go to a carbureted setup. Removing the factory fuel injection will lower the value far more than putting a non original 350/383 in the car, btw, which, if its a well-built engine, will increase the value.

Optional but highly recommended:
7. Get a looser torque converter to handle the changed power curve or it's gonna be awful to drive.
8. Get some shorter gears, 3.42s or 3.73s are recommended. While you're at it change over to a posi carrier in your rear or else it will never, ever, hook.

There are ways to make 305's with big cams work, but it's gotta be a matched combination. The main fudge factor is whether you're going to go with a roller cam or a flat tappet cam. Im not sure what the pressure limits are for the factory roller setup. .500ish may be okay, but .530+ you may want to consider getting some linkbar lifters, or go flat tappet, which has a whole can of worms of drawbacks, the advantage being cheapness.

torque_is_good

1: the advice you sought, and were given, took into account cost/benefit. You are free to ignore the voices of reason and experience.

2: still a pup but apparently you don't need anyone's advice or experience

3: thanks for your service but that has no bearing on the topic

4: nope, and as you mature and begin to understand things such as cost/benefit it won't make sense to you either. Right now, the term that comes to my mind is impetuous

90RS305project

Oh, because im not looking for cost/benefit...i happen to have done a lot of studying on this and there have been several 305's built that were very fast and very streetable...ive seen quite afew running down into 11's in the 1/4 and quite frankly i need nothing more than that...i want the original motor for the sake of having it, not for resale purposes...sure its cheap to build a 350 and you get more power but thats not what im lookin for, i can get all the power i need out the 305, have a certain shock value to it, and i already have the motor so why buy another one...i know i can get them cheap but you guys act like i havent read the MILLIONS of debates that trash the 305...I want it for the sake of seeing what itll do, stroke it...bore it out...throw a nice carb/intake...good heads...lunati built a 343hp 305 without boring it at all, still using stock heads...and it was streetable, why couldnt i just do alittle more and have alittle more power and be set?

InfernalVortex

iTrader: (4)

Because if you do that to a 350 block you'll make 400-450hp. More displacement = more streetable. If you'd rather have a slower car for the sake of shock value thats your prerrogative.

It's awesome to put some money into a 305 and see what you can do with it, because they CAN be made very quick. But at the end of the day the valves are still gonna be shrouded and you'll always be leaving volumetric efficiency on the table. To me once you start stroking and boring it's time to move on. Matt Walter had himself a daily driver 305 that did 12's. But his definition of a daily driver is a bit different than others. He had some tall gearing and a very loose torque converter and that car was set up to hook at all costs, and it worked out very well for him. That car is now doing 10's with a 6.0 LSX, and the cost of a 6.0 truck engine and 4l60e really isnt that much more than your 335 with fancy heads and cam etc.If you want to be different in addition to a money is no cost attitude, go LS.