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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Howdy folks, I was hoping someone could give me some advice on this. What I'm looking to do is take a 350 block with the 1 piece main seal, stuff in the crank and connecting rods from an L99, and cook myself up a Chevy 302. I'll be building this from the ground up. new push rods, rockers, everything. This will ultimately replace the wimpy 305 in my car now. Has anyone here built one of these combinations before? If so, just what exactly could it do? I can't find dynos or anything on this combo. Also, is there any way at all to give this thing a street-able power band? I've read that the real problem with the DZ302s was the Cam, but didn't see any real information proving this. If Ford can make their 302 street friendly, there has to be some way to make a Chevy 302 street friendly.
Why? Are you racing in a displacement limited class? That's about the only reason why you would want a small engine.
A 350 will cost the same to build and will give more bang for the buck. A 383 is roughly the same price and will outperform even better.
If you think your 305 is wimpy, a 302 won't be as enjoyable as a good 350. Screw what Ford does. You're making a Chevy. If you want a Ford, buy a Ford. You can't compare apples to oranges.
Thanks for the quick reply AlkylIROC! Oh believe me, I know what good ole' cubes will give you. I may be young, but I've been around a garage or two
I've got a few reasons for a Chevy 302. 350/383/LS1 swaps are pretty common in 3rd gens nowadays. A Chevy 302? Most people have no idea that even exists. On top of that, a lot of punk kids my age have no idea about cars. "5.0 mustangs are the best cars in the world and fart cans give you an extra 200rwhp". especially in my little town. you outrun them with a 350 and they claim you only won because you have an extra 48 cubes. I think a modernized 302 would be a fun little motor, and by running that setup you keep a few parts around and you could go from a 302 back to a 350 in a weekend. The biggest problem is that damned powerband. peak power at 8K? There has to be some way to reduce that.
Howdy folks, I was hoping someone could give me some advice on this. What I'm looking to do is take a 350 block with the 1 piece main seal, stuff in the crank and connecting rods from an L99, and cook myself up a Chevy 302. I'll be building this from the ground up. new push rods, rockers, everything. This will ultimately replace the wimpy 305 in my car now. Has anyone here built one of these combinations before? If so, just what exactly could it do? I can't find dynos or anything on this combo. Also, is there any way at all to give this thing a street-able power band? I've read that the real problem with the DZ302s was the Cam, but didn't see any real information proving this. If Ford can make their 302 street friendly, there has to be some way to make a Chevy 302 street friendly.
I've looked into this as I was needing to be limited to a 5.0. Matter of fact I have a L99 crank and rods laying around. Think of it this way. Make all things equal between a 302 and a 350(cam, compression, head flow, intake etc) the 350 will still have 48 CI more air moving that WILL make more power. The 302 probably won't be very far behind in PEAK hp numbers but that will partly be due to the 302 will naturally rev higher with the parts being otherwise equal. The 350 will have a MUCH broader power band (ie low and mid speed power) even if it only ends up making a few more horsepower peak. A broad powerband makes a better 'street' engine.
Can a SBC 302 be made streetable? Of course. That's in the cam. DZs did have LARGE cams. It all depends on how it's built.
Don't waste your brain power comparing to Ford. Displacement doesn't make it apples to apples. And a whole lot of SBFs got stroked to 347...wonder why?
I won't tell you not to build a 302, I will tell you a 350 is gonna be faster.
I know a 350 will be faster. Logic also suggests it should also make more torque, making it quicker too. I just think a 302 would be a fun motor, especially when toying with all these 5.0 'stangs around here. Plus, it would make a fun project. When this car's gone, then it's time to work on something with a few more cubes. That being said, I still want to see how one of these combos will hold up before I make the plunge. I've read about all kinds of people building them, but I can't find a single dyno, build sheet, or even video of such a setup running.
Use a desktop dyno. They're relatively accurate. It'll at least give you an idea of the power curve for a given cam and displacement. As far as actually seeing one run there was a guy on YouTube that supposedly had a LT1 302. It's not going to look, sound, or rev much differently than an equivalent 350.
Thanks for the information Aliceempire, I appreciate it. Who knows if that was a 302 or not, but if it was, at least I have video proof it won't blow on the first start. I'm going to check out one of these desktop dynos, I'll post the results once I'm done, if that'll interest anyone.
If this really is a 302 then this is it running. Hot Rod had an article in 97 with one, comparing 67 to 97....http://www.ebay.com/itm/Hot-Rod-How-Tos-Special-Section-September-1997/250784588234?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D32933%26meid%3D34e0e12574f8431e838a899a50bdcfe0%26pid%3D100011%26rk%3D2%26rkt%3D2%26sd%3D121681613003I have this book in front of me, They took a LT4 and destroked it. 302 was 350HP @6250 and the 350 LT4 was 330HP @5800. Rev that 350 to 6250 and I bet it's more than 350HP..
Last edited by aliceempire; 08-09-2015 at 05:45 PM.
Thanks for the help! Did they only destroke the LT4? That's certainly not bad for a 302, but my guess is the torque numbers on it were a "tad" bit worse
I had to re read it. They built two. Both LT4 headed, hot cammed, 11ish to 1 compression, 1 3/4 long tube headers. One efi, one 750 holley. Carb'd 411hp @6250, 372tq@4750 on a engine dyno. EFI'd 350hp@6250, 335tq@4250. They don't give a whole lotta details. GM Motorsports engineer Mark McPhail was behind the creations.
Mother of god. The torque at those ranges is good too, given the displacement. a 750 carb though? A bit much for such a small engine, I'd think. Though if I recall my readings, those DZs came with 780s on them. Silly GM. I'll have to buy a copy of that issue and read the article, see what all I can pull from it. If there's one thing I've learned, it's do your research before you start slapping stuff together.
This is kinda day dreamers build. No way would u want to push a 350TH auto with that 302. A 5 or 6 sp with steep gears yes. Im sorry but if using an auto trans i would look at stroking the motor not destroking it.
I considered a LT1 destroker when living in California due to smog restrictions and small pipe shorty headers were all that were legal. Kinda rather have a smaller motor with higher VE than a larger displacement with lower VE that chokes on itself. The optimum lobe sep angle for smaller displacement engine is wider also and using a wider LSA will allow greater duration cam before it becomes un-smoggable and/or a difficult daily driver. I was thinking a 5 ltr with at least 280 duration HR cam and a manual OD trans could be a fun daily driver and still get good fuel mileage.
Some specifics for that GEN II small block crank.
The rod weights are not known and unless u can get one of those 6.18" powder metal rods to weight and compare. But the balance could be expensive so get your piston and rod weights straight before u spend your money or even waste your effort. U could probably find an L99 block (baby LT1) in a junker impala, caprice, roadmaster or junk yard for next to nothing.
Next is the crank is a casting not a forging. If u plan for greater than 7000rpm then u should look for forged and forged in a 3" stroke one piece main seal i think is over $550 - i think Eagle sells them (that and the 3.25" stroke cranks in 1pc rms).
Another problem is keeping compression high enough w/o using domed pistons. U need really small chamber heads and pistons with minimum vlv cutouts to keep compression high for a large duration camshaft.
Thats all i can think of for now but the small block chevy has soo many options it always keeps ya dream'n.
"5.0 mustangs are the best cars in the world and fart cans give you an extra 200rwhp". especially in my little town. you outrun them with a 350 and they claim you only won because you have an extra 48 cubes.
The mustangs also have a big weight advantage over a Camaro. Shove an extra 500+ pounds into the Mustang and see how well it performs.
The 302 Ford will always be better than a 305 Chev. Bore make HP. Stroke makes torque. The 305 has a small bore.
302 makes torque? The same bore but longer stroke of a 327 makes more torque. Stroke it even more to a 350 and it makes more torque. Punch it out slightly and stroke it even more and make a 383. A 302 torque band is pitiful compared to the other engines.
Nobody has piped in about the old 302's running around the road course at 8000 rpm yet. That's great for a race engine but sucks for street use. Your street operating range barely gets over 3000 rpm. Depending on cam grind etc, typical operating range usually peaks around 6000 rpm or less for a street engine. Putting around at those lower rpms you either need a torque engine or a transmission with enough gear ratios to multiply torque at the bottom end to get you moving quicker.
It's your engine, your car. Build what you want but don't expect miracles or have high expectations because you wanted something different.
The L99 came with 5.94" rods, and according to one fella who claimed to have built one of these motors, The factory L99 rods work perfect. he did pull a book that stated the rods, pistons, and cranks were interchangeable between the L99 and 87 and up 350s, I'm assuming the L98s. I'm definitely not aiming for 7K plus rev range. I'm hoping to find the right cam to give this combo a more street friendly power-band. As for the TH350, I was a bit skeptical at first, but my Uncle, who swears by these things, claims that if I do go the 302 route a good set of low gears should take care of things. 3.73 or lower. I'm not going to argue with a man that built one, bolted it up to a 502, and made over 400 passes on it without hurting it. If he has that much faith in them, I suppose I should too.
You're certainly right about that AlkylIROC, mustangs are a lot lighter. Especially the fox bodies. A GT fox weighs in around 3200 pounds. Notchbacks are lighter yet. My TA? 3408. I've seen videos of those DZ 302s. Wow, were they screaming. I'll definitely be using a more streetable cam if I go the 302 route. Get that powerband adjusted. I'm certainly not expecting 1000rwhp and 1200 ft.lbs of torque. What I am looking for is a motor that will move the TA better than the 305. Right now I could probably peddle my bike faster than the car will go, and my chain's broken. All I want out of it is to outrun a few of my buddies' mustangs, pull up beside them, and tell them it's a CHEVY 302. I'm sure I could get that out of the 302. Once this car's gone, I'm definitely going with a 350 or maybe a 400 in my next one, but right now it's time to play around a bit
i've always wanted to do this... i'm usually more of a torque kinda guy, but there's just something about an engine that you can shift at 8000rpm that sounds magical to me... i almost did it when i had my 71 Nova and the LT1 out of a 94 Caprice that i parted out. i was going to get the L99 crank and rods and the HOT cam kit, maybe with some LT4 heads and put something like 4.56 gears in it.. i was also thinking of going twin turbo on it, because why the hell not?
but there is no reason why you couldn't cam it for bottom to mid range torque and have a decent running car that would be faster than the lazy 350's that they were putting in cars in the 80's. i do know that those 5.0 powered Mustangs were plenty fun to drive and had decent torque with a 5 speed, but the craptastical heads that they used choked them down so they couldn't make power up high..
I've always wanted to build one of those.
One thing that no-one has mentioned, is that it takes less air to fill 302 cubes, than it does to fill 350. So you don't have to have monster head's for it to work well. A cam with less duration & lift will help make power at a lower rpm, but if you're building this to "play around " , then the smaller cam kinda defeats the purpose of the build ( & just slightly better performance than a 305.... is not going to make you feel better ). I say, decent ported head's , cam, intake that will optimize the power & rpm with a 780 or even an 830hp carburetor ( the Rochester that the '67 model came with, I believe was an 850 cfm carb.)
Then gear the car to use that power band.
Thanks for the reply Novaderrik! My uncle once told me you can make any motor do anything, if you've got the $$$. I'm sure that's an exaggeration to some extent (if you can push a 170 straight 6 to 1000rwhp, I wanna know how) But I'm sure a chevy 302 can be set up as a nice little street motor, and for a reasonable price. Like AlkylIROC said, you can't compare a ford motor to a Chevy motor, but I'm sure if Ford's top engineers figured out street-ability on a 302, A young kid and a bunch of SBC gurus can figure out how to do it to a Chevy 302.
I think the most important key here is the right power band. Everything I've seen regarding DZ-302s suggest that not only was the power band too high, but it's also a very narrow band. I'm not too sure if a "LT1" 302 will have such a narrow band, but most likely that will be the case. Set the band too low, and you lose valuable "top end" that you would usually have with a 350. Too high and you run like a chainsaw. Find the mid point and you're going to lose some low end torque, but you'll have a very street-able SBC. The idea is to find a cam that will allow you to have as much low end as possible, while still maintaining top end power at say, 6-7k. The factory gauge in my TA tells me the crappy 305 TBI that used to be in the car topped out at 6k, so that would really be the number to push for.
If anyone else has any information that can help nail this one, it would be appreciated. I'm new to the forum and just recently started getting into the mechanical end of cars on my own, so any little bit helps. Thanks in advance!
Thanks rb85TA! Right now a lawn mower's got more performance than my 305. The only thing not factory on the motor is the rebuilt Quadrajet. My uncle learned how to really ramp up those carbs from a local guy that used to sell them to drag racers back in the day for $1K a pop! I'd say that's a nice return on a junk yard carb. I'd say I'm making a real wimpy 150 horse MAYBE, and I'm sure that's not to the wheels. I can't even lay rubber if I stomp on it from a dead stop. My 87 with the TPI on the other hand, that would lay some down!
The reason for the smaller cam is, this hunk of tin is my Daily Driver. For now at least. Running 8k may be fun, but fuel doesn't just come out of the ground. hehe. I'm sure even with a smaller cam that one of these motors can be made fun, but it will take some playing around to figure out which one's gonna do it. I have Dyno2000 now, if anyone here uses that particular desktop Dyno. If someone does and can show me how to correctly set up all the numbers, I'll run through the various cam profiles and see which one seems the best. Comparing the 302 to the 350 set up the same would even be simple, since all I'd have to do is change the stroke in the program.
Put 4:11's in the rear & a gearvendors overdrive on the back of that th350 trans. Set compression @ 11:1 (using aluminum head's, 2.02-2.05" int. & 1.6 "exh.) A hydraulic roller version of the DZ302's cam& 830hp carburetor. ... then run it for all its worth☺
If you really want to know the difference between the Ford 302 & the DZ302, look at the bore & stroke of both.
If just want to play with it, then play... but as a daily driver & a play toy, just build the 350... it'll work better for a dual purpose vehicle. JMO
It basically turns your 3spd auto, into a 6 spd. It bolts on in place of the tail shaft/ housing at the rear of the tranny. It's not exactly cheap, but they're used from daily driving to towing to all out racing.
To my knowledge, both are 4.00" bore and 3.00" stroke. The difference is the rod length, with Chevy's being 5.7" and ford's being 5.090". The big reason for a "street" 302 for me is there is a lot of punks in 5.0 'stangs around my little town that think they're untouchable. Smoke them with an extra 48 cubes, and they claim you got a bigger engine. Dust them in a Chevy 302, which none of them will even have known existed, they'll be dumbfounded.
On top of that, Everyone and their cousin has a 350/383 third gen. If I was going the bigger better route I'd rather stuff a big block in it just to keep it interesting. My next one I'll definitely do a 350 tpi just to keep it period correct. This one's a $1k car. It's getting abused
Alright, so I used Dyno2000 to try and replicate the l98 350 and the 302. Here were my results. Both engines have the exact same specs, minus the stroke. If anyone notices issues with the setup, please let me know and I'll correct it accordingly. I'm still learning how to use this nifty little gadget. The first set is the 302. The second set is the 350 combo.
My uncle said the same thing, Build a 383, slap some custom covers on it that say 302. Simple. But to me, that's cheating, especially what I want it for. I want to show 5.0 stangs that they aren't the hottest thing around. Anyone could tear a 302 apart with a larger motor, but a Chevy 302 smoking a ford 302, that's sweet. I could tell them all it was a 302, and the morons would believe it too. But in my heart, I'd know I done fibbed.
Nice rides by the way. Since I was a young lad (Well a younger lad anyway) I've had a soft spot in my heart for pontiacs, especially the TAs. That black formula is awesome! After I'm done foolin' around with the 86, I'm going to settle down with either a nice 89 TTA or a 91 GTA myself.
Well, you can also take a std. Bore 350, bore& hone it .020 over with the 3" stroke. .. gives you 304.6 (305)cid. Then, really blow their minds when you fly by them @ 8k ��
O.O Yowzers. Chevy 305 done the right way. According to Dyno2000 (if I'm using this darned thing right) It wouldn't work too much better than a 302 with the same configuration (Of course boring itself doesn't net any real gains) But it does kick a real 305's hiney. There's an idea...
You just want to say your engine has different numbers on it and you're going to do it regardless of whether it actually makes sense from a practical or financial point of view. so have fun losing to more people than you would if you had a 383. If being able to say "I only lost because i have x amount less cubes!" is something you enjoy doing, go for it.
I dont get hte whole "I want to be different" thing. If you want to be different, put a turbo Iron duke in it. Put a RB26DETT in it. Put a 2JZ in it. THat's different. None of those are a good idea, but neither is a 302. Having a smallblock chevy that looks identical and costs the same as all the other faster smallblock chevy's and is slower isnt really bragworthy. It's been intentionally sandbagged because you want to make number claims that arent power numbers, then go for it.
It would be like me going to the autocross and putting really expensive bicycle wheels/tires on my car, because it's "different".
Originally Posted by Reborn756
O.O Yowzers. Chevy 305 done the right way. According to Dyno2000 (if I'm using this darned thing right) It wouldn't work too much better than a 302 with the same configuration (Of course boring itself doesn't net any real gains) But it does kick a real 305's hiney. There's an idea...
Because that's what a 302 is. A 350 with a 3" stroke. Repairing out of round cylinder walls by boring them out .020" and adding 2 cubic inches isnt going to change anything. THe only way to get a real 302 then is going to be to buy a brand new engine block if the extra 2 cubic inches matter that much.
Have fun beating 305's for 383 money.
Last edited by InfernalVortex; 08-10-2015 at 05:37 PM.
I may be new to the game, but that doesn't mean I haven't been in garages all my life. I know what a 350 can do. I know what a 383 can do and I know what a 502 running a dominator carb and cam2 can do. To be different, I would go with a chevy motor over that japanese crap and the pontiac V6 simply because of reliability. There's a reason the SBC block design hasn't changed much since the late 60s. It's a proven design. On top of that, 350 parts are significantly cheaper. All you need for this is a L99 crank and connecting rods. A skilled mechanic with the proper tools could convert between a 302 and 350 at will over the course of a weekend. Price is debatable. Keep it factory junk yard parts, and you'll have a cheap 302. Go with new internals like I intend to, yes, the prices are going to just about match a 383 build. From what I've seen, between the 350 and 302 built the same way, there is actually very little difference in performance. The main thing is the 350 usually pushes out ~30 ft.lbs more torque, and it has a much more realistic powerband. Is the 302 not the greatest idea? of course not. Is it a cool idea for a project car? I don't think any of us could honestly say it's not cool. Like I've said before, my next one will have a more appropriately sized motor in it. This is just going to be fun. And I'm certain that some factory 350s from the 80s will eat this thing's dust. Smog crap really killed 80s performance, making my goal a whole lot more reachable.
I want to show 5.0 stangs that they aren't the hottest thing around. Anyone could tear a 302 apart with a larger motor, but a Chevy 302 smoking a ford 302, that's sweet. I could tell them all it was a 302, and the morons would believe it too. But in my heart, I'd know I done fibbed.
To be fair, if you win they'll still think you had a 350. If you lose, they'll think they beat a 350. Though I agree with you, I like having 5.0 Liter H.O. decals that are truthful.
That's what I expected out of those torque curves. It takes the 302 500rpm to still not reach the 350's peak hp. On the street, average numbers need to be high to be fast. I wish Desktop dyno showed those. Anyway, point being, it'll move, but won't idle as well or move as fast as the 350 that the Ford's think they got beat by.
Last edited by aliceempire; 08-10-2015 at 06:03 PM.
I agree, something like that it would take a lot of convincing that it's only 302 cubes. Those charts are with the LT4 HOT Cam, factory L98 heads and at 10:1 compression, dual plane manifold and a "quadrajet" set at 600 CFM. So almost factory except the cam. I don't know a whole lot about cams yet, so I'm not sure how mild the HOT LT4 is, but I'm sure a milder cam, and possibly a different head setup would adjust this a bit more. This is all "dynoed" with small tube headers and mufflers, which my car will have when I do a swap. Could anyone give me any insight into some heads and cams I could sub in? And how high compression can you generally run on 87 octane? I read somewhere that pump gas can run usually up to 11:1, but I'm assuming that's 91 octane or better
I agree, something like that it would take a lot of convincing that it's only 302 cubes. Those charts are with the LT4 HOT Cam, factory L98 heads and at 10:1 compression, dual plane manifold and a "quadrajet" set at 600 CFM. So almost factory except the cam. I don't know a whole lot about cams yet, so I'm not sure how mild the HOT LT4 is, but I'm sure a milder cam, and possibly a different head setup would adjust this a bit more. This is all "dynoed" with small tube headers and mufflers, which my car will have when I do a swap. Could anyone give me any insight into some heads and cams I could sub in? And how high compression can you generally run on 87 octane? I read somewhere that pump gas can run usually up to 11:1, but I'm assuming that's 91 octane or better
Qjets were 750 and 800 cfms, depending on model. My Pontiac has an 800 for example. Vortec heads would be the easy option. Likely best bang for the buck. You could find used aluminums too if you're hunting. LT4 hot cam isn't 'very' aggressive but in a streetable 302 it kinda is. Not all that terrible.
Carb'd and 87 octane...ouch....9.5ish compression maybe less, touch more with aluminum heads. Based on mid 80's LG4's were 9.5to1. But that's with a smaller bore, therefore less detonation prone. With a LT4 hot cam you may need more than that. 11to1 is safe-ish with aluminum heads and fuel injection, specifically sequential.
Thanks for the information aliceempire. My uncle told me Qjets were fairly large carbs, but from the factory they would put a tab on the air valve, which "limited" CFM. He said that's the only way engines like the 305 could handle the Qjet. One of his buddies actually told me a story about his son accidently snapping that tab off his factory 305 camaro when he rebuilt the carb. Washed the rings real quick. I'll make a few adjustments with the 302 graphs and post them quick as a comparison.
My uncle told me Qjets were fairly large carbs, but from the factory they would put a tab on the air valve, which "limited" CFM. He said that's the only way engines like the 305 could handle the Qjet. One of his buddies actually told me a story about his son accidently snapping that tab off his factory 305 camaro when he rebuilt the carb. Washed the rings real quick.
Never heard of such a thing. I've had several apart and properly adjusted. Including my 77's. I do know that Pontiac in the late sixties bent a peice of linkage to prevent the secondaries from opening all the way on the Ram Air II's...maybe IV's...for Firebirds but set them to open all the way on GTO's. High Preformance Pontiac had a great write up on it years ago.
The problem is, that you want a 302/305 sbc... to beat a 302 Ford. ... like a stout 350/383 would, but have the same or similar rpm band / drivability.
It's kinda like wanting to have your cake & eat it too.
Just doesn't happen, in most cases.
Building a 302/305 isn't necessarily building a loosing engine, like some say. It simply means running it harder ( much higher rpm) to get the win.
A generic single turbo 302/305 would be more suitable for the conditions your wanting it to perform under, but then they'll say you won because of the turbo.
Reality is, winning is winning & whining is whining!
When they cry because "you only beat me because X", look at them & say..... weather it's by an inch, or a mile... WINNING IS WINNING!
Or, no need to be jealous, You to can put a bigger engine in your car. Smile & walk away
Mother of god, I made a few adjustments and let me tell you, Good ole' CompCams 260HR made some very noticeable adjustments. The powerband may be a tad low on it. I'll play around a bit but it looks like a cam in the vicinity of the 260 HR is the real winner here. This also has SFI on it, but that didn't make too much of a difference. Compression is still 10:1, and the heads have been changed to Vortech.
It'll be hard rb85TA, but there has to a combo that will get us where we need to be.
LOL, don't get me wrong. ... I like it ( the idea of it), but being on a budget & building something that makes sense over wants or cool ideas. .. is what experience teaches you.
& in the end, the "COOL " things. ... really are what you make them.
Cool is a loose term to me, because my idea of cool & yours, can be COMPLETELY different. ... ya know.
Very true. Cardo0 in post 12 gave the best advice possible in this situation. L99s are like the 305s of the mid 90s. There's a hundred in every scrap yard and no one want's em. So L99 cranks and connecting rods for VERY cheap. Should be able to find good one piece seal 350 blocks cheap too. Essentially, with a good bit of hunting and luck, I could track down the building blocks for this little sucker for 200 or less. Not too shabby
302[edit]
In 1966, General Motors designed a special 302 cu in (referred to as 5.0 L) engine for the production Z/28 Camaro in order for it to meet the Sports Car Club of America (SCCA) Trans-Am Series road racing rules limiting engine displacement to 305 cu in from 1967 to 1969. It was the product of placing the 283 cu in 3.00 in. stroke crankshaft into a 4.00 bore 327 cylinder-block. The 1967 302 used the same nodular cast-iron crankshaft as the 283, with a forged-steel crank that was also produced. This block is one of three displacements, 302/327/350, that underwent a crankshaft bearing diameter transformation for 1968 when the rod-journal size was increased from the 2.00 in. diameter small-journal to a 2.10 large-journal and the main-journal size was increased from 2.30 in. to 2.45. The large-journal connecting rods were thicker (heavier) and used 3/8 in. diameter cap-bolts to replace the small-journal's 11/32. 1968 blocks were made in 2-bolt and 4-bolt versions with the 4-bolt center-three main caps each fastened by two additional bolts which were supported by the addition of heavier crankcase main-web bulkheads. When the journal size increased to the standard large-journal size, the crankshaft for the 302 was specially built of tufftride-hardened forged 1053-steel and fitted with a high-rpm 8.00 in. diameter harmonic balancer. It had a 3/4-length semi-circular windage tray, heat-treated, magnafluxed, shot-peened forged 1038-steel 'pink' connecting rods, floating-pin in `69, forged-aluminum pistons with higher scuff-resistance and better sealing single-moly rings. Its solid-lifter cam, known as the '30-30 Duntov' cam named after its .030/.030 in. hot intake/exhaust valve-lash and Zora Arkus-Duntov (the first Duntov cam was the .012/.018 1957 grind known as the '097, which referred to the last three digits of the casting number) the "Father of the Corvette", was also used in the 1964-65 carbureted 327/365 and F.I. 327/375 engines. It used the '202' 2.02/1.60 valve diameter high-performance 327 double-hump `461 heads, pushrod guide plates, hardened 'blue-stripe' pushrods, edge-orifice lifters to keep more valvetrain oil in the crankcase for high-rpm lubrication, and stiffer valvesprings. In 1967, a new design high-rise cast-aluminum dual-plane intake manifold with larger smoother turn runners was introduced for the Z/28 that the LT-1 350 1969 Corvette and 1970 Z/28 engines were equipped with until the Q-jet carburetor returned in 1973. Unlike the Corvette, the exhaust manifolds were the more restrictive rear outlet 'log' design to clear the Camaro chassis's front cross-member. It had a chrome oil filler tube in the front of the intake manifold next to the thermostat housing from 1967 to 1968, and the first year unique chrome valve covers that had Chevrolet stamped into them without an engine displacement decal pad. In 1968 the engine had the chrome covers, but without the Chevrolet name, that had air cleaner breather and PCV valve grommets. In 1968, a chrome 14.00 x 3.00 in. drop-base open-element air cleaner assembly on a 780cfm vacuum secondary Holley 4-Bbl carburetor. A 'divorced' exhaust crossover port heated well-choke thermostat coil was used to provide cleaner and faster engine warm-up. Its single-point distributor had an ignition point cam designed to reduce point bounce at high rpm along with a vacuum diaphragm to advance ignition timing at idle and part-throttle for economy and emissions. Pulleys for the balancer, alternator, water-pump, as well as optional power-steering, were deep-groove to retain the drive belt(s) at high rpm. In 1969, the 302 shared the finned cast-aluminum valve covers with the LT-1 350 Corvette engine. Conservatively rated at 290 hp (216 kW) (SAE gross) at 5800 rpm and 290 lb-ft at 4800, actual output with its production 11:1 compression ratio was around 376 hp (280 kW) with 1.625 in. primary x 3.00 secondary tubular headers that came in the trunk when ordered with a 1967 Z/28, and associated carburetor main jet and ignition timing tuning[citation needed]. In 1968, the last year for factory headers, they had 1.750 in. primaries x 3.00 secondariesour . A stock 1968 Z/28 with the close-ratio transmission, optional transistorized-ignition and 4.88 gear, fitted with little more than the factory plenum cowl cold-air hood induction and headers, was capable of running 12.9 second/108 mph 1/4-mile times on street tires.
note close ration 4 speed 488 gears etc.
If you want bragging rights on the stangs, why not just build your 305? AFR makes heads , flat tops and a cam headers and some low gears 5 speed should be able to take the average 302 Stang.
The biggest reason for not wanting to build the 305 is that parts are more expensive. The block will need machined. It's just not worth it. While most of you will argue that a 302 shouldn't be worth it either, it's still worth it to me to build up a fresh 302 than the 305. Plus, since the 302 will use a newer 350 block, parts will be plentiful and cheap. I could actually probably build a 302 cheaper.
Exactly. Build any size SBC and call it a 302. What's to say that 302 ford is still a 302?
You need to change your race attitude. Best race motto is "Race your own race" When I'm in my race car sitting on the starting line, who or what's beside me doesn't matter. All I care about is which car launches first so I can time the tree. Someone asks me who I beat or lost to at the end of the race and I usually reply "I think it was a blue car". How much power some other car makes means nothing. No matter how much money you spend to try and beat someone else, somebody else will just spend more.
As mentioned above, build a 302 to beat a ford with a 302 and if you win, they say you have a 350. If you lose, they say they can beat a 350 no matter which engine you have under the hood. If you want to beat them, build a bigger engine. If they want to beat you, that forces them to do something better to keep up with you.
Drop in a Grand National V6 turbo and go beat them.
I hate to be "that guy" but I would never spend money & time to build a nice motor just to outrun another. There will always be fools talking trash just like there will ALWAYS be a faster motor out there no matter what you buy or build. That's just life. Ignore the fools, build a motor YOU will be happy with and enjoy. Don't get caught up in the local bull... it will only waste your money and get you in trouble.
Sorry for the soapbox... best of luck in whatever you build
That's kind of the reason I want a 302. It's unique. I can almost guarantee there are no 3rd gens with a 302. 350/383/LS1s are extremely common though. I'd have the only one, until I sold it of course. it would be more potent than a 305, fun to drive when I figure out which cam will get the power band exactly where I want it, and would even do ok in the street class at our local drag strip. I've thought about both this build and a 454 (VERY cheap to build around here as well) and I'm really leaning towards the 302
I could change the stickers rb85TA. wouldn't that be something, seeing a 3rd gen with 427 or 454 or 502 stickers!
08-09-2015, 03:37 PM
