Hello ladies & gents , I'm looking for a "recipie" for an early style z28 302 engine on steroids ! Or a 1970 style lt1 350 on steroids . I have a " correct block " for the 302 & and a 350 4 bolt main block for the lt1 style 1970 engine . I would appreciate any info you guys ( and girls ) are willing to share . Thanks Genaro:D

Steroids????? Do you want an engine or drugs?

Start with a 400 block, bored .030 you're already .155 over the 4 inch block you are working with. That's 326 cubes with a 3" stroke and Eagle makes a crank with 400 mains and a 3" stroke. An ARP studded 2 bolt main block would be more than sufficient for a 3 inch stroke motor. That's where I'd start. Flat top forged pistons and the small chamber head like 55 cc or a 62 cc milled another .030 to drop them to 57cc to get your compression up. Then run a solid roller cam and an 830 annular Holley carb.

no drugs Brett ! Just want a high winding small block for my 69'! I want to use the blocks & parts I have . I'm doing " budget builds ".

read my post about the new UD harold cam in my 302..

alot of guys will disagree with me here... but unless you are using aftermarket heads and intake... you will want an old school grind...

i know from experience that the new stuff works and works great... but the old heads and intake just don't seem to support what the modern camshafts are trying to do.

if you want a high winding 302 that pulls hard from 3500 on up.... the 30-30 is the ticket...
or as i'm about to do, install the old 140 offroad cam...


my DZ302 and 1964 L76 327 Corvette have been test beds for about 4 or 5 different aftermarket cams.... in every single case... i've made the best all around torque and upper rpm power with the GM OE camshafts....

i suspect some of the mid 70s and early 80s Aftermarket stuff will work well too... like the old Blue Racer, or Fireball, or Comp Magnum stuff....

email me and i can go into great detail on what I believe is happening.

thanks

Aaron

Thanks Aaron , I'll use vortex heads (truck ones, they are supposed to flow better than dbl humps) on the 302, I want more hp than the stock 290 hp .what kind of hp & tourque could I expect with the "140"offroad cam upgrade ?

Thanks Aaron , I'll use vortex heads (truck ones, they are supposed to flow better than dbl humps) on the 302, I want more hp than the stock 290 hp .what kind of hp & tourque could I expect with the "140"offroad cam upgrade ?

Im rebuilding my 302 at the moment for my Z and heres what I have thats going back in my car.
Factory # matching DZ 4 bolt block bored .030 over
standard GM 302 crank with .001 bearings
Manley H beam 5.700 rods
Kieth Black 11to1 forgered pistons with speed pro moly rings
Lunati Cam 272/282 mechanical flat tappet / UDHarolds recommend
238/248@50
.485/.503 lift
Bullet cams EDM lifters
186 heads with some mild port,SS valves,headened seats,comp magnum roller rockers. hope this helps abit.
Richard:beers:

thanks richard, is the 302 the same as a 283 crank ? and is the stock compression ratio 11 -1 ?

For 'high winding' and horsepower, keep the stroke short (3.00)... make the bore BIG (aka Dave's suggestion above).. blueprint the parts for weight/size... choose clearances for piston/wall and bearing/journal on the 'large side of the allowable range', .... choose shorter/large dia header tubes will help... give it a high cfm carb... lots of fire...and use VERY STRONG rotating parts..... because it will surely churn some high rpm's and make tremendous HP with the right cam..... :)

PS. you can also use a 350 crank in the 400 block and get 366+ cid of highwinding power .... :)

thanks richard, is the 302 the same as a 283 crank ? and is the stock compression ratio 11 -1 ?

I stayed with the stock 11to 1 with a 3 inch stroke.

is the 302 the same as a 283 crank ?

Yes and no.A 283 forged crank can be used in a 67 and older 327 block to make a 302.The 68 up blocks have larger main bearings so you can't use the 283 crank in them.

Just want a high winding small block for my 69'! I want to use the blocks & parts I have . I'm doing " budget builds ".[/QUOTE]
:noway:

Genaro there are only two ways I'd build a 302 today. One is a correct build for a real Z which would use the correct block like you have. If it's not for a real Z there is not reason to limit yourself to a 4 inch bore block. That said I did not realize you are looking for a budget build. Be careful here, I don't believe a high winding 302 and budget build are a good combination. Like Gary says you need forged internals which are more expensive. There are also a lot of other high quality and more expensive pieces you should have if it's performance you are looking for out of a 302 because these motors need to live above 5,000 rpm to start making good power. It isn't cheap to do if you want it to last. I've owned a few 302s and they don't make much power down below 4000. So you need good gears or it'll be a dog on the street. By good I mean 4.11 minimum, 4.56 or 4.88 are better, but then not street friendly if you drive it much.

You can install a small journal 283 crank in a medium journal 350 block using bearing spacers or the special thick main bearings. But then you need better rods than the stock small journal rods, so any money you saved on the cheap 283 crank is lost on good rods as small journal factory rods are pretty weak.

If you build a 326 SBC using a 400 block and an Eagle 3 inch crank those run almost $700 so it isn't cheap either. You can buy a stock 302 crank and use bearing spacers or special thick bearings, but a good factory 302 crank will run more than the Eagle crank.

I think if you want to use your 350 block you should consider building a 355 or 383. Those are good budget builds that don't need to spin to 8000 rpm to run decent like your 302 will need to do. You can get by with cheaper parts as a result.

Not trying to discourage you. But a high output 302 requires some decent and expensive pieces to assemble compared to a budget motor build. The spacer bearings run $200-300 dollars and a good set of bearing spacer will run $100 as King makes the only real good bearing spacers. Manley, Comp Cams and others are all bad choices. They are soft babbit modified main bearings fully grooved, not true steel dedicated spacers like King makes.

Your 383 will also out perform most 302 on the street because most guys aren't willing to put up with the 4.56 or 4.88 gears that the 302 craves to run hard. If you are willing to run 4.88 gears, build in 12.5 compression and can get the gas for the thing it'll show up a lot of bigger motors that aren't geared as well, including big blocks. Been there, done that. But at the end of the day you are better off on the street with a 383 and moderate gearing and compression.

That's not true b/c I beat on my old junk301 for quite a while before I pulled it!

I'm thinking real hard about building another junk292/301/306 depending on cheap piston availability and which of the two sets of heads I use this way again. BUT this time I'm going to balance her, don't like throwing dampers off driving down the road is all.

Flat-top pistons, 6.25" long rods, 3" crank, 50 cc heads and .015" or .020" thick shim headgaskets. (OR domed pistons and 66 cc heads!!)..

750 carb on a Holley 300-36 true high-rise intake and a set of 1.625" dia., 4-tube, long headers.

Cam's going to be a cheap PAW solid lifter cam, their PN 10341 that they did sell for $44.95 +S&H back a while ago.

Spec's per the cam card are:

280/246, 108/106, .498" gross lift and need's .030" lash hot on both sides! I'm going to install 1.6 ratio rockers so she will net out at .501" lift or thereabouts!

D2k say's like 400+ hp easy.

pdq67

i have a 302 (or a 301, whatever you want to call it)

67' 327 block
283 crank
67' (or below) rods
69' z28 pistons
with 462 fuelie heads
cc 280h cam (480 lift, 230* @.050)

I love this thread. Lots of great advice. But 2 run a 302 do I really need 488 gearing? It sounds like I need that kind of gearing to make it work. I just need to know if that is the case because if it is true the motor would need to be built to suit the gearing. Also sounds like that motor would not be streetable? I have 350 or so gears was kind of hard to tell, I spun the tire and it went around 3.5 times for a full rotation, so I would either have to change my rear end or go with another motor. How much $$$$ to build a 301. I found a stock 302 that I am thinking of getting. I would like to compare the price and which motor would be a better option. Any thoughts fellas? You guys are the experts.

Mike I haven't gotten back to your message you sent because I've been busy getting my taxes finished up this week, just getting back to things more fun now.

You don't need 4.88 gears. A lot of guys run stock 302s today with 3.73. I don't see the fun in that. The only reason I would ever build a 3 inch stroke motor is because you can spin it high, and you need to spin it high to make decent power. A short stroke motor with numerically small gearing and a peaky cam makes for a pretty doggy street motor. Now a 383 or 406 with that same 3.55 gear you've probably got would be a great match for a street car.

IMO you need 4 series gears to get a 302 to perform like it should. I know this irritates people to hear because they are able to drive their cars with 3.73 or 3.55 gears, but there is no comparing a 302 with those gears compared to 4.56 or 4.88 gears. Driven them both ways and it's no fun for me with 3 series gears behind that little motor. Sure it isn't a car that'll be seeing much highway time with that set up, but then again why build a 302? Keep in mind that I also like a tall tire that fills the wheel wells up. I can't stand the factory 26 inch tires with a large gap to the wheel well lip. I usually run a 29 inch rear tire on 68 models. This makes a 4.56 gear behave like a 4.11 with the factory 26 inch tires. So if you keep your short 26 inch tires you don't need as much rear gear either.

That's not true b/c I beat on my old junk301 for quite a while before I pulled it!

Paul I understand and I agree. I've run stock 302 internals but they were always LJ. I ran them beyond 8K all the time, all day long and never ever hurt a 302. I've blown a few 355s trying to run them as hard, usually the rods fail, but it was cast pistons in the last one. Even the $131 a piece 6.0 Bowtie 4340 rods with their 7/16" ARP cap screws didn't hold up to what that motor went through. The big ends were out of round in a short time. You can't hardly buy a stronger rod, so I tend to go overboard on connecting rod strength.

I did run a 331 12.5 motor using 67 small journal rods, but I used ARP Pro-series wavelocs. I think the 67 sj rod was the best choice if you run sj rods. The old 283 rods with the thinner beams and no extra material on the thrust sides of the big ends just scare the you know what out of me when I think of running those to 9K or so.

I'm just trying to set him up with parts that he won't have issues with if it sees extreme hard use. It's probably overkill, but that's the way I'd do it today.

I did run a 331 12.5 motor using 67 small journal rods, but I used ARP Pro-series wavelocs. I think the 67 sj rod was the best choice if you run sj rods. The old 283 rods with the thinner beams and no extra material on the thrust sides of the big ends just scare the you know what out of me when I think of running those to 9K or so.


how can i tell what kind of rods i have?

and about the gears.. whoever had my car before i did, put (or left it stock) 2.73 gears in the rear.. which is probably why the car was so hard to drive

I still have my stock, ordered M-20 and 3.31's under my car and I just rolled my old junk301 outta the hole and when she hit 3,000 rpm, nailed her up to 7 to 7,500+ rpm and then repeated!

Little-bitty sucker turned from Dr. Jekyll into Mr. Hyde right at 3,000! What a hoot!

But I was only running the little-bitty Duntov -097 solid lifter cam in her.

pdq67

how can i tell what kind of rods i have?

and about the gears.. whoever had my car before i did, put (or left it stock) 2.73 gears in the rear.. which is probably why the car was so hard to drive

The very early 283 rods you don't want to run at all. Very thin beams and not much material on the large ends. SJ rods already have small bolts at 11/32", that's why I elected to run ARP pro-series wave loc bolts on mine. The good SJ rods came out on the 327 around 65 and had extra material on the large ends. Look at the side of the crank bore and you should see a couple of pronounced shoulders at the top right and left "corners" of the bore. The old 283 was completely round with no extra material. LJ rods have 4 "corners". You should also see a teardrop of extra material on the wrist pin ends.

Photo below of the late ('66-up) SJ rods - note the "bump" of added material adjacent to the bolt head seat; previous SJ rods didn't have that, and the machined surface of the side of those rods is the same width for its full circumference (no "bump"). :thumbsup:

Thanks John, picture is worth a thousand words. The early SJ rod in the picture is probably an early 327 SJ rod since it has the teardrop at the wrist pin bore. Early 265/283 rods looked the same except they had a small square tab of material extending down instead of the teardrop and the beams were significantly thinner.

Also all SJ rode before 67 had oiling slots at the rod and cap mating surface. It was thought they'd help oil the cylinder walls and cam, but weren't necessary. Some 67 SJ still had these, but many don't. If yours do not you've most likely got 67 SJ rods. Also despite what some think the absence of the oiling slot on a 67 rod does not guarantee it was a 67 302 rod, those rods had a lot of additional work performed on them like magnaflux, heat treatment, shot peening and special attention to the rod cap parting line fit.

"Yes and no. A 283 forged crank can be used in a 67 and older 327 block to make a 302.The 68 up blocks have larger main bearings so you can't use the 283 crank in them."

Fwiw, the early 265 and 283 SJ cranks flanges are round and the SJ 302 has a notch out of it.

My '66, 283 that I got off my Nephew has a SJ 302 crank in it. And my old junk301 had a round cranked '55, 265 crank in it.

I threw the 265 rods away b/c like John said, they are too flimsy to use. I hunted in my Buddy's steel scrap metal pile until I found 8, thicker rod and piston assemblies out of I don't know what 283 engine.

And another fwiw, imho, the early 265 rods are a whole like the lo-po 262/267/305 rods!!

GM probably had the original 265 rod forging dies still on the shelf so used them again!

I say this b/c forging dies are so dammed expensive that unless they flat wear out or break, they are not pitched!

At least NOT in the Refractories, (aka, Firebrick making), Industry!

pdq67

And another fwiw, imho, the early 265 rods are a whole like the lo-po 262/267/305 rods!!pdq67

Interesting thought Paul, you may be right. The 262 V8 only put out 110 horses so it didn't need much of a rod. They did take a ton of abuse though, probably in part due to the short 3.10 stroke. I replaced 6 TH350 trans, a rear end and a torque converter behind one, but never hurt the motor! Sad only rated 110 hp since the straight 6 had 105 hp and actually was quicker off the line than the 262.

I almost bought a 265 from a friend back in 82. But as soon as I saw it had no oil filter or provisioning for one I dropped that thought. Must've been a 55, I think that was the first year and didn't have a filter. But man those rods are skinny beams!

Dave,

There's been rumors for years coming down from the north that GM Canada tried to use cast-iron rods in the very 1st 305's. I have never been able to verify it myself, but one guy has posted here on the three Boards somewhere at sometime that, (I think???), he said he saw/handled(??) some cast 305 rods.

Am I glad this didn't pan out, (IF it's a fact??), for use in the lo-po smaller engines!! Can you think about what kind of a disaster this would be if cast rods got into the hi-po and bigger SB engines!!!!!!!!!!!

I don't even trust the powder-rods!!

pdq67

Am I glad this didn't pan out, (IF it's a fact??), for use in the lo-po smaller engines!! Can you think about what kind of a disaster this would be if cast rods got into the hi-po and bigger SB engines!!!!!!!!!!!

I don't even trust the powder-rods!!

pdq67


Paul I'm damaging 4340 7/16 ARP capscrew Bow Tie rods, I can't imagine a cast iron rod in any motor. Sure sounds like a bad idea. Maybe it was an experiment before they came out with the PM rod. Kind of like the weak casting oil pumps they specified be built in the 90s. I bet a couple pulls to 8K and the cast iron rod and your block would be history.

wow ! thanks for all this good data fellas ! i appreciate the help ! it may be less expensive to buils the 383 that was my plan b !!! i just wanted a hi winding motor im torn between using a m20 4spees trans or a 700r4 i understand the 383 is not a hi rpm motor combo . decisions decisions........

thanks guys i appreciate all your assistance, may be cheaper to go the 383 route, word the 383 is not a hi rpm motor & i should prob use an automatic w/ that combo . may have to sell my m-20 4speed

"I almost bought a 265 from a friend back in 82. But as soon as I saw it had no oil filter or provisioning for one I dropped that thought. Must've been a 55, I think that was the first year and didn't have a filter."

Right, my '55, 265 had the optional top mounted can oil filter on her!

I want to say it plumbed into the back oil gauge hole by the Dizzy and road-draft tube and the little-bitty 1/4" pipe plug that's right above the timing cover and to the right a schosh!

It worked fine but was a general mess to change the filter as well as wipe clean each time!

pdq67

Genaro you won't like the 302 with an auto trans behind it. Tried it with a TH400. The TH400 shifts into 2nd gear around 6K and the little 302 is just starting to make good power at that point. Also it needs a very loose converter and on the street that's not always the best deal. My brother tried this as well on one of his 12.5:1 302 motors. He ran 4.88 gears and kept breaking his ST10 BW 4 speeds. So he went TH400, but used a 4500 stall converter and full manual valve body. It worked great, but not something you want to drive daily.

I like the high winding SBC myself, but you can't go wrong on the street with a good 383. It'll be cheaper to build, and you don't have to spin the heck out of it to make power, so you can probably run less expensive parts that won't be subjected to real high rpm and all the problems that are associated with it.

Paul I was aware they had an option filter can. It's good to know that at least GM recognized they needed something, although it sounds like it was a pain to service.