Chevytalbert

Hello guys I am in the process of building a 383 stroker and am in need of some advice. I need to know if this setup will run on pump gas.

Apeiron

I doubt it. You're going to be in the neighborhood of 11:1 static compression, that's a tall order for iron heads on pump gas.

TANGO

iTrader: (2)

With the 62 cc heads and the flat top pistons . That 383 will have around 11.1 C/R . Go with a set of 72cc World Sportsman II heads . With this set up you can run 89 fuel . And for a cam the 327/350 #151 Cam was ok back in the day . But todays cams are better . Go with the XE268H cam . It's 224/230 dur at 050 and 477/480 lift with a 110 L/S . This set up should make 430 hp .

Chevytalbert

ok i would change the cam out but i have already bought it. Also if it will not run on pump gas what would it take to make this setup run ok and what kind of hp would i be lookin at with edelbrock preformer rpm intake and edelbrock preformer 750 carb the intake and carb i already had on my old setup so i did not buy a new one

82Five-O

do you have 461 heads? just wondering. Cause i got the same setup as you, only a bigger cam and i run pump gas.

Chevytalbert

Not sure just know that thay are the stock gm heads and that thay are 62cc i can look up the head number later today when it gets light out.

sofakingdom

iTrader: (1)

Why, after all these years of that thing being a worthless POS, do people still allow themselves to be suckered into spending their hard-earned cash for it? And.... that will convince the motor into running better somehow in spite of having that dung in it??

Cut your loss NOW. Take it back to where you bought it and get your money back, or sell it to the next "greater fool" (yes there's ALWAYS one out there, but no, this time it's not me.... BTDT, don't want to go back there). If you can't do that, then just throw that thing in the trash, and chalk it up to just being another installment of the dumba$$ tax. I know I've had to just write off mistakes like that plenty of times. Between you and me, we ought to have enough money in THAT slush fund by now, to throw one helluva party. At least in this case though, it's very very very little money, not enough to get worked up over. A cheap lesson, really.

The cost of a cam is TINY, MINSCULE, INSIGNIFICANT, compared to the cost of driving a motor around that has no power and creates disappointment and sucks on the gas tank like a vacuum cleaner, and THEN buying another one and doing an in-chassis cam swap. Trust me, it's cheeper to fix that mistake NOW, than to put it off until the motor is built and running and driving around and has wasted no telling how much of your money in unnecessary fuel and other parts to try to get it to actually have some cajones, and you just can't avoid facing the grim reality any longer.

What head castings are these? Casting # only please; not "stock", not "350", not "202", not "from a Vette" or even "69 Camaro"; just the casting number, and any machine work that's been done to them.

What's the deck clearance of those pistons in your block AS BUILT? (Like the casting number, the ACTUAL MEASURED value. No, whatever the catalog says isn't adequate...)

Using a 383, .039" head gasket (FelPro 1004 or similar), 62cc heads, 6cc valve reliefs:

If the block is zero-decked: CR is 11.3:1 (not bloody likely)
If the deck clearance is the stock .025": CR is 10.6:1 (not likely, but more so than the above)
If the deck clearance is .045": CR is 10.2:1 (most likely)

As you can see, depending on the machine work that is or isn't done, and the specific details of the pistons, the ACTUAL CR can vary quite a bit. This is the sort of detail that gets "conveniently" left out of calculations when people tell you that their 10.8:1 whatever whatever runs fine on pump regular. Ummmm..... I don't think so..... the laws of physics aren't suspended just for you; there's some other explanation. See my signature for help with that.

More real details about what you actually have, and what you want to do with it, would help point you in the direction you need to go. One thing is FOR SURE though; no matter what you're doing, unless it's a "number-matching" Concours resto on a L79 car, that cam ISN'T the right one for you.

TANGO

iTrader: (2)

We use to run that 327-350 #151 cam a lot back in the 70s and early 80s . And I have seen that cam in many engines make good power . But todays cams will out do that one . But if you want to run that #151 cam and the 62cc heads . Find the thickest head gasket you can .041" or thicker . This will help to drop that C/R down a bit . With this set up you should be still near 400 HP . Or if you want to sell the #151 cam P.M me I have a 327 that will like it . COOL

sofakingdom

iTrader: (1)

See?

Unload it QUICK, before he changes his mind!!!

chaoz28

well this is probably a retarded suggestion... but depending on your altitude.. why not pump ur local highest octane and then theres this magical stuff called NOSrace octane booster.. im not talkin that little girl octane boost that u buy like outlaw or any of that crap this nos booster bumps 91 octane to 108 octane.. an for 10 bucks a bottle treating 18 gals. its a hell of alot cheaper than going and buying 5 buck a gallon race feul...


that being said listen to what everyone else has suggested move your heads up a few cc's and get maybe a 6al ignition box and a high output coil with some nice plugs and thick wires so you can get rid of that high octane feul with as little left over as possible... this translates to slightly better gas and cleaner exhaust valves and ports

Apeiron

NOS/Permatex Street Formula Octane Booster is about $12, and adds 20 or 30 points to the octane rating of 12 gallons of fuel. A point is "point 1" of an octane number, as in 0.1, so your 91 octane becomes 94 octane at best. http://www.permatex.com/products/aut...et_Formula.htm

Even if that was enough to save you from detonation, at $12 a bottle, and one bottle per tank, if you use one tank of fuel per week, then within a year you've spent $624 which could have bought you a set of heads with larger chambers that wouldn't need any bottled snake-oil.

sofakingdom

iTrader: (1)

EXACTLY!!!

Build the motor RIGHT in the first place; don't worry so much about "what you've already got", because the price of replacing it and doing it right is FAR LESS than the alternatives. Life is too short to move aside dollar bills to pick up dimes, and then go through life dissatisfied with what you've got; especially when it's the work of your own hand that's coming back to hurt you.

chaoz28

wel i didnt exactly put into acount infaltion for the rest of the u.s. round where i live its only 10 a bottle and i dont use the street formula i use this http://www.permatex.com/products/aut...ng_Formula.htm
but like i said using octane boost to compensate for a street driver is a stupid idea but say someone wants high compression and they are just planning on goin to the strip once n a while or weekend rice killing.. 10 bucks for a decent boost plus 91 isnt a half bad way to go.. and then it does depend on altitude Im up in the rocky mountains or damn close to em and i have family with 10-up comp ratios that run 91 for street driving and dont have any problems up here

Apeiron

The racing formula is about $18 a bottle ($17.69 at Summit), for 6 octane numbers of improvement. That brings the payback time for new iron heads down to about 9 months, or within a year you're close to having paid for new aluminum heads.

chaoz28

damn 18 a bottle.. guess racers around here are lucky at 10.50 a bottle..

Chevytalbert

OK i like all the suggestions and it seems like i need to do a little bit of research so i can get everything right. What I need to know is which head and which cam would be the best for producing 450 ~ 500 hp. I was going to try to save the old heads but as i see here that seems not to be the best idea and as for the cam i was able to return it but i don't know what cam would produce the most power. The build I am going for needs to be quick from light to light and I don't really think i will be bringing it to the strip much.

chaoz28

oh so you want to be able to "street race"??? well a set of edelbrock performers they have 72cc chambers but also have the big 2.02 valves so u get the best of both.. also i love my 268h comp cam has great street performance also cranes "energizer" cams are nice but go with the 1500-6k rpm range cam if u choose it...

sofakingdom

iTrader: (1)

What are they?

Cam choice depends on, among other things, the heads you use. Don't get all wrapped up in picking a cam until THE VERY LAST thing. The cam is THE CHEAPEST major component of the engine, and at the same time, the 2nd most critical (behind the heads); you DON'T build a motor around a cam, you build a motor and then choose (or design) a cam to complement THAT MOTOR.

What heads are we working with here?

Don't get all hung up on the intake valve size. Different heads respond differently to that. Some heads you can tell almost no difference at all; some it's crucial.

What heads do you have?

Oh, in case I have forgotten to ask, tell us about your heads. What casting #, what machine work do they have, what porting and by whom, etc.

We need to know about your heads in order to do anything beyond just run off at the mouth about what cams we like.

Did I mention your heads???

Orr89RocZ

iTrader: (20)

hmm i kinda doing the opposite... i had a cam in mind that would make my power goals with the intake setup i wanted to run, and am gonna build the motor around that. But its a two way street, the cam will complement the motor parts/heads i intended to use anyway. Kinda goes hand in hand motor builds and cam selection.



But yes, cam selection based on heads is most important. we need to know what heads you intend to use and really need to know your deck clearance to calculate compression and make cam choices from there

TANGO

iTrader: (2)

I would build this 383 like this if it's a street / strip car . Fist for the cylinder heads . DART pro 1 200cc 72cc chambers . Still run a good .040 head gasket . And for the cam the XE274H . This camshaft is 230/236 dur at 050 with 487/490 Lift and has a 110 L/S . And for you intake manifold . The Edelbrock RPM will work well . But the Air Gap RPM is better . You will need a hood scoop to clear it . For a carb a Holley 750 D/P . this set up will give you the 450+HP you are looking for . But any bigger cam and you will not have the Vac for your power brakes ! One more thing to think about if you are runnig a 7 1/2 rear end . You may turn it in to Dust !

chaoz28

speaking of turning things to dust.. i think ive said this part on every stroker post and i feel like a broken record...strokers make too much power for f body stock supsension body tiwst will happen with even a mild 383 a better tube torque arm a front strut tower panhards and better chocks and springs all around is a minnimum to keep you windhseilds from cracking (ive seen it with my own eyes and my uncle didnt get it figured out till 3 windsheilds later)

TANGO

iTrader: (2)

Had that problem with late 80s Z-28s and T/As . Frame connectors are a must have . They really work .

89RsPower!

those things will help but the number one main thing as mentioned in the post above is subframe connectors, an absolute must on any f-body making even marginal power. Hell I even think they should be put on bone stock f-bodies.

sofakingdom

iTrader: (1)

Tango's suggestion for heads to buy is a good one.... however I'd like to see what heads the OP has before going any farther, myself. I'm guessing they'r estock, and that if he considers Clevite (Sealed Power) lifters and Pioneer keepers to be significant mods, then they're stock, and he wont' be enthusiastic about biting off on $1200 of heads. But maybe he will. I guess we'll see when he tells us what heads he's got.

Also, the piston part # would be helpful.

Instinct tells me, this motor isn't going to actually have heads with 62cc chambers; even if you look them up on Mortec and it says "62cc". Reason being, if they've had port work done by anybody that knows what they're doing, those 305 heads have had AT LEAST 1.94" intakes installed in them, and the chambers have been laid back about 2-3ccs worth around the intake valve, plus another couple for sinking the larger valves into them. Only way would likely be, if they were originally 58cc heads like 416s or something, and they've bee cc'ed afterdoing as above. But I guess we'll see.

Instinct also tells me, we'll find out that the pistons have not .000", not .025" (stock), but rather, .045" of deck clearance, once they're installed. So what we're REALLY working with here could easily be a 383 with .045" of DC plus 64-65cc heads; which would come out to a very handy and comfortable 9¾:1 CR, although with extremely poor "quench". I guess we'll see. Gotta have the details RIGHT, and then go from there.

chaoz28

actually the best thing you could do to both eliminate body twist from the rear end and wheel hop almost period is convert to leaf springs... its costly and there is no kit you have to do it all on your own but but controll is wayy better i used to lose control down the strip into second in my uncles bird with a 406 fully build.. he got the crazy idea to use oldschool leafs from a nova this thing doesnt go anywhere between gear changes not even a chirp we run almost a full second faster after that. but i do belive im getting off topic now sorry lol

Orr89RocZ

iTrader: (20)

a properly braced frame shouldnt twist to much. subframes and a rollbar will do

89RsPower!

no frame twist with leaf springs? You shoulda drove my 72 nova before the subframe connectors.. lol completely off topic though.. anyway did we ever get those head #'s?

Apeiron

No wheel hop with leaf springs?

TANGO

iTrader: (2)

My 1972 Nova was a much better car after the Subframe Connectors . So was the 77 T/A and the 78 / 79 Z-28s . GEN II F-body car also need to have them . My Dad had a brand new 80 Z-28 T-Top car . We in-stalled them the very first week he owned that car .

flyitlikustolit

hey Sofa, Ape - I think the BS is getting knee-deep in here. in the mean time, to the OP - check Craigslist and E-bay. I got my World Sportsman II's on E-bay for 700... angle plug, 72cc chambers, 2.08/1.60 valves. they're pretty good heads for the money. there are better aftermarket, but there are a lot worse too. they're pretty affordable, and you can buy them bare or assembled. grab a set of those, your choice of block (I stepped up to a 4-bolt main for my latest build) and whatever rotating assembly you're using, and then come to us with numbers. I recommend, if you intend to spend money, do it in 2 major places on this build: good Aftermarket heads (be it World, AFR, Dart, Brodix, etc.) and a hydro-roller cam. better for longevity. that's my .02

Chevytalbert

OK guys I have done some research and found the head casting number is 462624 these heads have had some work on them but it was done by the previous owner and I am unable to get in contact with him to find out what all he did to them. However the valve sizes are 1.94 int and 1.5 exh and as of now i am unsure what the cc is because i have look at like 10 different places and all of them say different stuff. The springs in the heads are double and the valves are stock replacement sealed power valves. I will not be able to afford a new set of head yet but will end up with a set of World Products Sportsman II 72cc heads. What cam should I use with these heads that will still work ok with the new heads when i have the extra cash flow.

Chevytalbert

Deck clearance is .045"

OK guys I have done some research and found the head casting number is 462624 these heads have had some work on them but it was done by the previous owner and I am unable to get in contact with him to find out what all he did to them. However the valve sizes are 1.94 int and 1.5 exh and as of now i am unsure what the cc is because i have look at like 10 different places and all of them say different stuff. The springs in the heads are double and the valves are stock replacement sealed power valves. I will not be able to afford a new set of head yet but will end up with a set of World Products Sportsman II 72cc heads. What cam should I use with these heads that will still work ok with the new heads when i have the extra cash flow.

Orr89RocZ

iTrader: (20)

anything like the xe268 like above mentioned or setup to the xe274...always a great grind. i prefer the larger grind for a 383

flyitlikustolit

I agree. it's what i ran in my last 383 until i wiped a lobe. word to the wise - break it in using Rotella. Havoline doesn't have enough zinc in it anymore.

sofakingdom

iTrader: (1)

Casting numbers!!!! OK!! Now we're getting somewhere.:barf: Sorry.... {as he cleans out his keyboard}

An EXTREMELY familiar head, unfortunately. It doesn't get much worse than that.

Those are not 62cc; they're 76cc. http://www.mortec.com/castnum.htm They're arguably the worst of the worst from the 70s smogger era. They're one of the parts responsible for those 165 HP wonders with 350 CID that GM turned out so many millions of. If you can get the S2s used, definitely do so, ASAP. On the other hand, if you're thinking about buying those new, don't; you can do considerably better, for about the same money.

So:

383, flat tops, 6cc valve reliefs, "down in the hole" .045", .039" head gasket, 76cc chambers:

8.9:1

I don't think you'll have any trouble even with pump regular.

That super-low compression makes that 151 cam an EVEN WORSE choice. Sell it to TANGO since he has the right combo to use it, and get yourself something that matches the rest of YOUR combo. I'd suggest not going any bigger than the XE268; the XE262 might be a better choice, in fact, especially with the light duty stock-replacement valve springs (probably not "double", but rather, single with damper... stock ones have that too... if the thing in the middle looks like flat ribbon, it's a damper, not a spring). Check their OD: stock is 1.25", the next step up is 1.45". If you want to go bigger on the cam, get whatever springs the cam mfr recommends, for going with their particular cam. For either of those 2 XEs it would be Comp 981 springs with the retainers and keepers to match (DO NOT use the stock ones).

TANGO

iTrader: (2)

Do not use them 624 Heads ! They are the worst 350 Heads of the Late 70s and 80s . They are very thin and most likely they are cracked . If they have new Valves and springs . Fine just strip the good part and trash the castings . Buy the sportsman II head that guy has . And if that 151 Cam is un-used Sell it to Me I have a 327 that will Love it COOL

Orr89RocZ

iTrader: (20)

with an iron head you can use a steel shim gasket.. like the felpro 1094 i think it is.. rubber coated .015" thick. that will give you much better quench and compression. it will seal just fine if both surfaces are flat and clean. People have used them on aluminum heads too.

if you had somewhere in the 9's to 1 compression that bigger cam would be better...but your quench height still stucks with .045 in the hole.

Chevytalbert