drifter-x

Did the search for the cam thing, but I couldt find what I want.
I read on tbichips.com that the 305 tbi can rev 6k+ w/ a cam and valve springs. This possible w/o losing power brakes? I do the handling thing, so I cant afford to lose those. I realy want those revs tho, what are the chances of a cam giving me both?

Also, I was wonderin if I had reached the 200hp mark yet.
I have the Ultimate TBI mod, flowmaster 3'' american thunder exaust system, no cat, custom CAI, timing, tbichips.com stage 1, 170* thermostat.

My lil bro's gettin a Mustang GT (prolly a Fox), and I just wanna make sure he wont be out runnin me so bad, thats y I want the revs, so i can put short gears in it.

Thanx,
Chris

Dewey316

yes with the right valve train, and the right parts, you can get TBI to make power at 6k. not exactly sure what you are asking. typicly with the computer controled cars, you dont' run the huge radical overlap cams that cause the power brake issues.

200hp eh, what are you 1/4 mile trap speeds? that is the real tell tail sign.

kfoley

It's possible to have both. You might want to upgrade the TBI, or at the bare minimum do the unltimate TBI mods. Pick a cam that makes peak power at 5500rpm and you should be good to go. If you want cam recommendations, give me some more specs on the car.

LedZep

iTrader: (22)

what if you had a bone stock 305TBI with flowmaster exh on an 89 Formula what cam would you recomend for good power and sound?

drifter-x

I just want to know if there is a cam that will allow my car to rev that high w/ the valve springs and not kill the streetablility and brakes so that I can use 3.73 gears and not top out at 90mph. Big power isnt what im worried about, I only need 200-250. I want the revs and enough power to get it into the uper RPM.

Ive never had it on a track. Or even raced it on the street to give something to compare too.

drifter-x

Its a 5-speed. It already had the ultimate TBI, custom CAI, tbichips.com stage 1, 170* thermo., and 3'' inch pipes where the cat used to be back. Ill wait to get an intake manifold till the time i get the cam so i can get the Performer RPM airgap. The car only has 60k, so its pretty solid still. I want as heavy RPM as possible
Thanx

kfoley

For that I'd go with something similar to the 204/214 grind. Summit pn SUM-K1102. It'll give a more pronounced exhaust tone and make good midrange power.

kfoley

I'd go with a 214/224 cam (or something similar), Summit pn: SUM-K1103. It'll pull all the way up to 6 grand, idle fairly smooth, pull plenty vacumn for the power brakes, and keep good midrange power. You'll need new valvesprings too. Look on ebay for a set of Z28 springs/retainers, they go pretty cheap. Also go to the parts store and get vortec valve stem seals, they came on 96 chevy trucks with vortec (350) motors. You will also need valvespring shims since you will lose the stock exhaust valve rotators. You'll need to shim the exhaust springs up .100" since the pocket is cut lower. It should be one of each size shim stacked up to make .100".

If you would rather use Comp Cams stuff I'd reccomend the XE 262 cam and 981 springs w/ matching retainers. It will be a bit more exspensive than the Summit stuff though...

drifter-x

I do realy want the Comp stuff, but the Summit pieces have a great price. Are they not as good a grind or quality? I know alot of that is paying for a name, but if the summit's are inferior, I aint gonna buy em'.

Also, I just looked on ebay, there are valve springs that handle .550" of lift, and .600" of lift from Precision Racing Componets, those what your talkin about? Which ones?

Dewey316

the cam i am putting in, is 210/218 .492 .492 112, it should pull to 6k (the cam designer said to shift at 6400 on a 305 with this cam).

also, for the stock cam guy.

i'm selling a 206/216 .447 .447 112 cam. PM me if you are interested.

Drifter -- Look at more than the lift capabilities of springs, the spring pressures are really going to determine if it will work for you or not. the springs i have are 115#/340# springs.

kfoley

The Summit stuff is good quality, I've used them on all my motors. You just can't beat the price, especially when you're on a budget and they're comparable to brand names. The Comp Cams stuff is generally the newest technology and higher quality than the summit stuff, but unless you're racing the difference is minimal. As for the springs on ebay, the ones you would need are the .550 lift ones. Here's a link to an auction: http://cgi.ebay.com/ws/eBayISAPI.dll...category=33617
They're 110# seat and 325# open which will work great for the cam I suggested.

Nebu

why can you loose your power brakes with a too big cam?

kfoley

If you're running a big cam with lots of overlap it won't pull enough vacumn to operate the power brakes. That doesn't generally happen until the 235-240 duration range though. Even then you can add a vacumn canister that will store enough to operate them.

drifter-x

Ok so I'm gonna get the Summit SUM-K1103 cam/lifter set, valve guides, the springs off ebay, and an Edelbrock performer RPM. That all I'll need to get this to work?

Also, I was thinkin' will they have to take the heads off to do the valve springs? If so, I was thinkin about gaskets to put them back on. Does anyone make thinner ones that will up the compression? I've heard about this with import stuff, but never on a sbc. I already use 93 octange fuel, so thats not a problemb.
Thanx

kfoley

You'll also need valvespring shims for the exhaust springs. You can replace the valvesprings with the heads on the motor, but it's a bit more difficult. You'll need an adaptor for an air hose that will screw into the spark plug to keep the valves from falling down. If you choose to pull the heads, you can get steel shim head gaskets that are .015" thick. If you use those grab a can of copper gasket spray and spray both sides of the gasket before you put it on. Those gaskets are Fel-Pro p/n 1094, and go for about $19 each. It'll raise the compression a little less than half a point.

BronYrAur

iTrader: (1)

Aren't those Summit cams non-roller? If he has an LO3 he would want a roller cam with similar specs to that cam.

kfoley

The summit ones are flat tappet. I didn't realize he had a roller block. If you want to go with a roller cam it's a whole different setup... Let me know

drifter-x

I'm assuming its roller. Thats what I've always been told about the L03, its a '92. Sorry Will I have to convert it to the flat tappets, or do they have make the roller cams that run those RPM?

Dewey316

get a roller cam, you will be much happier with it. all the 87+ CAR blocks were roller.

i would suggest comp 264HR-12

summit part # CCA-08-501-8

Specifications:
* Advertised duration: 264 intake/269 exhaust
* Duration at .050 in.: 212 intake/218 exhaust
* Gross valve lift: .488 in. intake/.495 in. exhaust
* Lobe separation: 112 degrees
* RPM range: 1,200 to 5,200

note the RPM range is figured on a 350, typicaly add about 1k rpm to get the range on a 305

kfoley

Sorry I didn't catch that earlier...

Dewey is on it, that's the cam I would suggest as well. It'll rev to 6k no problem.

You'll need much stronger springs though (than a flat tappet setup anyways). Use the ones Comp reccomends and the matching retainers.

BronYrAur

iTrader: (1)

Hey Dewey and Kfoley do you guys think at the point he's at though (i.e. basically stock) it would be beneficial to run a cam like that with those stock heads? Wouldn't a cam like that kill some low-end power which would normally be made up for in the upper rpm range but with those swirl port heads the upper range would also be killed would it not? I would think a cam swap like that would necessitate a new set of heads too, at least some TPI heads.

Dewey316

a set of TPI heads, and a 4bbl manifold would be the ticket with those heads.

yes, that is probably a little more cam than the stock heads would like. i guess when people start talking about making power at 6k, than the stock heads would be long gone. i really don't know what the actualy flow limitations of the stock heads are, with the right cam in them, they **might** be capable of power at 6k, but it is doubtfull. the real key is going to be the exaust, its much easier to get air into the engine, harder to get it out. a good free flowing exaust is a MUST for trying to get power.

kfoley

I agree with Dewey. You can also port the TPI (or Lg4, L69) heads too for more power. Sitting Bull has a great thread about it. You'll definitely want to get rid of any part of the stock exhaust, it's really restrictive. Headers and a good 3" catback should do nicely. I would look at the Performer RPM for an intake and a Holley, Edelbrock, or modified QJet (no computer controlled models) for a carb.

drifter-x

I'll eventualy have World Class heads, and im putting a proformer RPM intake on it with the cam. Headers will be the next addition after the cam.

I'm not lookin for power with this car, it's a drifter. I need RPM to keep the tires spinnin, and i want 3.73 gears for the jolt and torque. There is gonna be a time gap between the cam and headers/heads to build suspension, so I need something that'll work with what I have, but be usable w/ the heads and headers.

kfoley

I'd use the XR264. It will work with what you have now and you won't have to replace it when you do the heads.

Dewey316

something i just thought of

the stock heads aren't going to take the lift unmodified. .495" lift he would need to have the valve guides checked, and likely machined. and i doubt the studs will hold.

25THRSS

I believe it was dyno don who flowed his stock tbi heads and he only got something like 148 cfm on the intake side out of them IIRC. He said they didn't even change much from .400 to .450 lift and .500 made hardly any differenct if any I recall. The stock heads aren't worth a crap. Putting in a cam like that on stock heads would be worthless. I believe the heads on our cars are just as much a handicap as the dinky cam is, if not worse.

Pablo

iTrader: (1)

DONT DO ANYTHING UNTIL YOU GET HEADERS


Any other mod will be a waste of time.

buzz12586

I would love to get my 305 TBI to rev up to at least 5-5.5K. Having it stop pulling at like 4K sucks.

25THRSS

drifter-x

So, I cant get 6k rmp out of the stock heads at all? I know I wont be making alot of power, but I dont need power. I dont WANT power. I want RPM. I know I need power to get up there, but 200 is good.

BronYrAur

iTrader: (1)

Why?

drifter-x

Drifting. I need RPM to keep the tires spinning, and to be able to use the 3.73 gears for a torque-jolt. Until I get the suspension built, power is more of a danger than a help.

kfoley

You can rev them up to 6k (depending on springs), you just don't have the flow at that rpm to make power.

drifter-x

Ok, I've been looking for heads, and I'm gonna buy some used 350 heads. Unless..... I can get a set for free from a carbed 305 out of a firebird. I can afford to get them worked somewhat. Will they work on my car, and be worth it? I'm getting a carb intake anyway, so I will just purchase one for the older engine, if need be.

Thanx,
Chris

Dewey316

what casting number are the 305 heads?

chevypower

If I pulled the heads I'd have 1.97 intake and 1.55 exhaust valves put in. I don't think the stock heads are worth putting any more money in them than doing that. But that would help with your RPM's. Any larger and I think youd just be shrouding the chambers, but you can go as large as 2.00 intake and 1.60 exhaust. The 2.00in/1.60ex workes good on Vortec's with a mild port and polish in a 305 though, thats the size that come in the aluminum Vortec heads, now theres a hot ticket for a 305. If I was going to try to pull all I could out of a LO3 thats what I'd use, with some different pistons to get the compression up around 10.5/1 to 11.0/1. Maybe the 670cfm Holley 2bbl TBI and a RPM Air Gap intake. That just may hang right there with that Rustang. My '84 F41 5.0L HO ran nose to nose(won a few, lost a few it was a toss up on the best traction, but always close, real close) with late 80's to early '90's 5.0 GT Rustangs. The LX 5.0's always seemed to pull harder. With only a Flowmaster muffler, a 650cfm Q-jet with all emmisions crap removed and a deep drive crank pulley.

drifter-x

What trucks and cars came w/ vortech heads? Any vin stuff to look for?

Z28GEN3

i believe anything vortec you have to use compatible parts, like the intake it needs to be vortec as well.