Bird_of_Prey

#1.
ok, some people.. namely 2 mustang guys and one camaro guy.. unfortinatly the camaro guy's the non tech guy who thinks he is.. ya, you know the kind.. but the mustang guys are really helpfull with my car (well.. other then mocking me when something goes wrong.. but they'll help fix it and make it better then b4)
neways.. 302 vrs 305.. advantages of a longer stroke and smaller bore to a shorter stroke and larger bore.. (no, i'm not talking ford vrs chevy... AND I DON'T WANT TO HEAR ANYTHING ABOUT THAT). all i'm curious about is which is better?.. drag it'd be the 302 because of high rpm hp/tq... but for street i've heard that the longer stroke gives the 305 more lower rpm torque.. which is starting to make me rethink about my chevy 302 cid in progress.. either one will have tpi.. and i want both tuned to produce lots of low end torque but still have the capabilities of high rpm.. (just won't shift that high).. and some mild modifications (mild up to the point of getting a different motor) if i wanna make it into a hi rpm hp producer.. (change cam, runners on tpi, tb, heads...) (but not change the block completely.. like, not riping the engine out.. ).. neways.. which is better? ?

#2.. i've also been told that the 305 is hard to make it breath cuz of the bore shrouding the valves(cuz of the smaller bore).. is this true or just somebody who dosn't know what they're talking about?

i just want to make sure of the block i stick into my car over the winter.. i'm at the forks here because my car's getting parked soon so i'll be doing stuff to either the 305 or the 302 soon.

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87 formula
LB9, Automatic
K&N
3" catback v-force muffler
Hypertech preformance chip

87_T/A_LB9

Well, I wasn't really too clear on the true question of your post but I'll point some stuff out.

The 302 is a good race engine because it makes high hp and torque. However, it's like a Hon-duh, you have to rev the **** out of it in order for it to make power. The 302 revs up to 8k or so which makes putting TPI on it kind of like putting a 400cfm carb on a 600hp engine. Just doesn't make sense. If you want to build the 302 you're going to need to go to a carb setup.

Now, the 305 is a better street motor due to it's low end torque but it won't run nearly as well as that 302 once the engine gets revved up.

Conclusion: If you want to build just a daily driver and nothing more, go with the 305. If you want a car with the power to race and still be able to be very streetable, go with the 302.

Edit note: The TPI intake will need to be modified to fit on the 302 heads if you want to use it.

SoCo80p

iTrader: (5)

neather a really fantastic engines, the 305 was just a smog engine fitting in the late 70's threw early 90's birds and other big chevys, the 302 was a circle track engine, 87 has it pretty much right, for a street engine the 305 would be better, for all out racing the 302

smokin87iroc

if you can do it (not sure if its possible) trade in that TPI intake for a LT1 intake and get the 302. that setup would be awesome for power and the loss of torque really won't be noticible espically if you have an automatic and put like a 2800-3500 stall. the lack of low end torque really isn't too bad. look at my friend's 2000 z-28 he put a 3500 stall in it and got some good tires and with just a borla, lid, fast toys ram air, he's running 12.39 @ 109 on a ls1 that doesn't have low end torque. he also pulled a 1.7x 60 ft time on ET Streets.
so if you can, do the 302 LT1 intake
Andrew

Beast5spdGTA

Are you partial to a small displacement engine for some reason. A 350 or 383 will give you all the low end you can handle as well as all the top end assuming you ditch the TPI for something better at high RPM breathing like a mini-ram style manifold or carb manifold convereted for fuel injection.

TPI will not create power above 5500 rpms no matter what you do to it. It won't make power above 5200 rpm no matter what in stock trim either. If you really love the look of TPI check out posts on siamesed bases, it might help upper RPM breathing to an extent.

I know you said not to, but I'm doing it anyways, isn't the chevy 302 and ford 302 the same bore and stroke? Check their combos for driveablitly and top end hp, i don't see why you can't match or exceed anything they build with the 302.

You have to clearify you exact needs for this engine/car, expected HP and/or ETs/MPH, like daily driver, pass emissions, vehicle weight, rear end gear/desired stall, etc. Otherwise everyone including me is just guessing with a lot of influence to "our" ideas for "our" cars and not yours.

I plan on going high 13s while remaining stock appearing with emissions stuff and stock heads, stock weight in my 305. If that's all you want, it's easy and many of us can tell you how to do it. If you want low 13s or 12s from that 305 or 302, it becomes a lot harder maybe impossible with TPI.

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14.62@96mph headers, muffler, chip, ghetto stuff, duct tape
89 GTA 305 TPI 5 speed 3.42 gears

Bird_of_Prey

heh.. yeah.. i'm not one for saying stuff clearlly..
k, just a cruiser type car that can keep up with my friends cars.. even beet them.. so i'm guestimating for something that's around 400 + hp BUT, here's where i'm not clear.. i just wanted to know which would be better overall.. and got that answered, TNX!, btw..
ok, it's gonna be turbo so nevermind the intake problem of not being able to cram enough air though the tpi.. cuz there'll be plenty.. but now that i've said that it's a whole new discussion, right?.. yeah.. thought so.. so nevermind the part about the turbos... so..
chevy and ford 302 are the same bore and stroke (FORD STOLE IT... i think..) but they got a different degrees to the crank (from the pistons) so that makes it slightlly different and a couple minor things too.... i think the ford's is a bit wider then chevy's..
ok, like i said.. n/m about ford.. hrmm..
_______________________________________
street application, 1/8 and a bit more racing (with a few 1/4's thrown in for the more serious of us), they all have 5.0's that have about 350 to 390 hp... my camaro and firebird friends all have 5.0's or 5.7's that are in between 240 - 280 hp (5.0) and 310 to 420hp (5.7)
and as you've figured.. i'm a "smaller the cube the better.." but it still HAS to be a v8... so no darkside v6's...
i'm explaining too much.. running on and such..
___________________________________
ok, 302 or 305...
about 350 n\a.. 400+ with twin turbo.. (like 450 or something)..
don't worry about frame integrity and drivetrain stuff.. (other then motor) and suspension and hooking that much hp up on the wheels and such..
just motors.

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87 formula
LB9, Automatic
K&N
3" mandrel bent exhaust,
v-force muffler
Hypertech preformance

Steve R

Solution: Use a 350 crank in a 400 block. 377 cubic inches, low torque, high RPM power, cheap as any SB, and big smile on your face

Tim Burgess

Where do you plan on purchasing your twin turbo setup? As far as I know there are no companies making any form of turbo kit for third gens, so if you find a source there are many on this board that would be interested to know.

305's are often overlooked as worthy of hot rodding - my daily driver '92 Z28 with a TPI (TPIS intake & runners) 305 5 speed runs high 12's on the motor & low 12's with 90 hp NOS & it has over 140K miles on the short block with ported stock GM 305 heads. Also, my '84 Berlinetta with a TPI (stock GM TPI setup) 305 auto runs high 13's. Willie also has a potent 305 setup on his '87 Z that runs in the 12's......

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Tim

1992 Z28, 305 TPI 5 speed, 12.1 sec @ 114.7 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph

Kyle F

Um you dont drop a full seconf off your 1/4 mile times with a Converter, Sticky tires and an exhaust system. SO B.S. and who said LS1s have no low end torque. What are you comparing them to a truck? They have as much as any 305TPI does.

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89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

85transamtpi

I like the idea of a LT1 intake on a 302. If you could get it to work (people here have on 350's) it would scream. DEFINETLY dont put tpi on that 302, you'll end up with a motor that has no low end power and runs out of breath at 4500. If you've already started I'd look into the LT1 intake...and you'd probably be the only one around with that setup.

peace

Bird_of_Prey

i know this guy (like everybody starts off saying) who used to be a machanic for a speed shop who did alot of imports (i get on his back because of that.. heh) and some mustangs (i got to know him though my mustang friends).. NEWAYS.. he told me he could get a twin turbo setup for my car.. didn't quote me on any price.. and i've been readin' up on it and two turbos off a 2.2 plymouth would work (with some mods) to my engine.. (be it a 305 or 302) and two labarron 2.6 turbo's should work with 5.7's... i'm assuming.. mods again, of course.. didn't tell the machanic tho.. (he's still a machanic.. just left the speedshop and started his own buisness.. misses the speed shop tho.. neways)
oh, and i LOVE the 302 lt1 idea.. cept.. well.. umm... 2002 camaro ss's are comming out with the 302 ls1.. (blah on them).. so it's not going to be that original in a year... (at least they're bring back a 5.0 to put those ford guys in their place).. is it the ss or just the regular z28?.. can't remember.. neways..
377... low torque?.. or is that a typo?.. like it being low end torque.. or is it low torque engine?..
and i've thought about the stroker b4.. but... me and my small cubes...
283 pimped out.. heh.. no.. well.. maybe.. rather keep my 5.0 stickers..
*shrugs*.. i'm just shoting the sh*t with this.. seeing if any new info on 'em (which is better in your opinion and for what reasons) so i can make a more informed choice and have more knowledge..
tnx.

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87 formula
LB9, Automatic
K&N
3" mandrel bent exhaust,
v-force muffler
Hypertech preformance

Bird_of_Prey

oh, just wanted to state this before somebody says it.. plz don't tell me to go read in past archives... did that already...


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87 formula
LB9, Automatic
K&N
3" mandrel bent exhaust,
v-force muffler
Hypertech preformance

RCR

BOP, just to clarify. If a new 302 was brought out by GM, it would have the LS1/6 intake, not the LT1. Therefore you would have a rather unique combo with the converted LT1 and your 302.

Black 91 Z28

Bird_of_Prey said 302s are in the new 2002 SS. I haven't heard of that. I thought they all had the LS1 5.7L in them. Did I miss something here? As for a 302 in a thirdgen I think that would be cool. The 302 in my dad's 69 Z sure screams.

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Stock 1991 L98...for now.

[This message has been edited by Black 91 Z28 (edited November 06, 2001).]

[This message has been edited by Black 91 Z28 (edited November 06, 2001).]

rob231

a while back in a mag. there was a guy that had a 4th gen. lt1 camaro and was trying to make a modern day 302 z-28. so he made an lt1 fuel inj. 302 it made like 400 hp. @ flywheel. sounded really cool and different. i wish i had more info about it. maybe someone on here knows about it and can tell you more.

jwscab

just to add my 2 cents......the 302 LS1 variant was a GM test platform, put in a 2001 z28 and apparently was pretty trick..... The ford 302 and chevy 302 both have the same bore and stroke, the main difference between performance of the two is cylinder heads.(and yes oiling system and overall construction.) The only thing I don't know for sure is the rod length on the Ford, compared to the chevy. As for low RPM tq vs High RPM HP, you're really only talking 20 hp or 20 ftlbs between a 302 and 305 moderately built. The 302 will wind up better becuase the stroke is shorter, and has better breathing becuase of it's larger valves. In a max effort design, the 302 will always outperform the smaller bore 305. That being said, the 305 will benefit more from the stock TPI setup, and the 302 will perform within the limitations of that intake. A 302 could be seriously built with a LTR set-up using aftermarket base, runners and bigger throttle body, since the only thing you are concerned with is airflow, and if you can develop a LTR set-up that flows to 5500-6000 on a 350, then a 302 should flow to 6500. Most of the reason 305's lose high RPM power is that you simply can't get the air in becuase of the shrouded valves and long stroke..... there is an example of a short stroke/big bore engine that was done i think by car craft that actually made a 350 ci engine using a 327 crank and a 400 block(with bearing spacers) that made a very flat 400ftlb torque curve(from about 2000RPM up) using junk gas, and a long rod from a straight 6 ford engine(the rod dimensions happened to work out) with a relatively mild cam to boot, and revved like nobody's business.

branz28

I highly doubt GM will bring out a 302 LS1 many people already have 2002's on the ls1 boards.

Black 91 Z28

Ok. I knew about the test 302 LS1. Here's a page if anyone wants to check it out. http://www.camaroz28.com/articles/302camaro/index.shtml 435HP@6000 RPM.

Bird_of_Prey

i was watching tv.. (yes, i know they lie alot on there).. and on one of the car show's, can't remember which... they said they were bringing back the 302 for the camaro's final year...
neways..
that page was interesting.. too bad i don't have an aluminum block.. heh..
302.. lt1.. hrmm..

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87 formula
LB9, Automatic
K&N
3" mandrel bent exhaust,
v-force muffler
Hypertech preformance

mtccl

Chevy is offering the 302 in the Camaro SS in this last year of production as a tribute to the original 302 SCCA racers. 302 LS1 with modified LS6 Corvette heads producing 375HP.

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87 TA, 305 TPI, Custom CAI, ACCEL 8mm wires,ACCEL Super-coil, ACCEL Plugs, JET TPI Airfoil, Cherry Bomb Muffler
"35 yr old helo pilot
with a cool new toy my 17 yr old son wants" The Phoenix Project..click to see my project car
Trans Am stuff and GIRLS, GIRLS, GIRLS!!!!!

smokin87iroc

if you want timeslips i can get them for you and if you want you can come watch him run. take it or leave it. he has 2.73 gears so the stall helps him a ton. it was about 20 degrees cooler but that doesn't count for but what 2% increase in hp (1% for every 10degrees i might be wrong on that). i could say the same thing about just cutting your wastegate and bumping up fuel pressure dropping a second off a turbo 3.8 but it happens. why not just accept it. why post bs on a board? thats not gonna help anyone!
Andrew

[This message has been edited by smokin87iroc (edited November 07, 2001).]

PETE

iTrader: (1)

1st generation 302's gave up alot in the cylinder head design.the ford heads are a much better design than the gm heads were up until the 18* ad sb2 designs.i assume that this will be a double duty car mostly street some strip........that in mind a steep set of gears is a must and that 700 tranny isn't worth the trouble.the rpm drop from 1st to 2nd will only **** you off when you realize you just dropped out of your powerband of that 302.i would go with a 406 it may be slightly more to build than a 383 but would kill that 302 in any form.if you are into the smaller engines just to be different go with a supercharged long rod 327.it'll force feed it to give you some low end tourqe for the street plus the longer rod will flatten the curve out a bit so that rpm drop of the 700r4 wont hurt as much,and it'll be able to breathe at higher rpms and you can use a smaller gear for the street...........


just one man's opinion...............

Ed Maher

wow smokin, you took the words right out of my mouth. Leave it to a turbo buick guy to disbelieve the awesome potential of the LS1 cars. Don't worry about him, i as well as many other people who don't have our heads in the sand know what a vigilante on an LS1 does.

[This message has been edited by Ed Maher (edited November 07, 2001).]

Bird_of_Prey

what does a vigilante on an LS1 do?

tranny would either be a th400 or a t56 depending on which engine and the way it's set up (t56 for the 302, i was thinking.. keep it high in rpm's)
so... ford heads are better, eh?.. umm.. whouldn't chevy make some aftermarket heads that are just as good if not better then ford's?
i'm starting to like that lt1 idea more and more.. stick the 305 tpi into a S-10.. have that for pulling around stuff (snomobile, atv, (car trailer..?).. or my friends' car trailor neways.. ).. tpi = low end torque.. hrmm.. good for pullin.
or sell off tpi to pay for some stuff..
tnx everybody for the information.

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87 formula
LB9, Automatic
K&N
3" mandrel bent exhaust,
v-force muffler
Hypertech preformance

PETE

iTrader: (1)

the way ford heads were designed they were a better idea.they don't have siamesed exhaust ports(cylinders 3&5 and 4&6 on a small block chevy)kinda like the big block chevy's and they are arrainged differently.by doing so you eliminate the restricted confines and create a better path for the exhaust to leave the cylinder.the new ls1's heads have this design along with cathedral intake ports.what in the world are you thinking?"the ls1 has no tourqe"if only i could package the stuff your smoking i could buy everyone on this board a new ls1 f body.the indivdual runner length was shortened(compared to the 3rd gen)to provide the ability to supply air at 6300rpms.if you notice they didn't shorten them all that much,so that they can still produce mid range grunt.the reason it worked so well was the fact that the heads are so amazing they make up for any compromise in runner length.most new ls1 f body's with a good exhaust and a vigillante would hit mid to high 12's no problem.

smokin87iroc

thanks Ed

Andrew

branz28

What does a vig. conv. do for a LS1 vehicle? If i am correct compared to the yank converter (all on the same vehicle in identical weather +/- 1 or 2 degree's) It gave better 60 ft times but the yank gave better topend mph? What does a converter in general do for the LS1 vehicles? Well many of things, since most of them like the 3500 yank Super Thrust converts it takes anywhere from 2 tenths to 5 just depending on traction and what rear gearing they had to begin with and for a few it was 2.73. Which makes it a nice improvement for them. This is also where many LS1 owners decide SFC's and LCA's are their next mod. Hopefully that answered your question.

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR
-Gutted Air Boxes

Z03Z28

No one is putting a 302 in a f-body or anything from G.M,it was just John Moss
and his crew testing some idea's.It wouldn't make sence to replace a 346 with a 302.If
you had the choice what would you buy???
It would cost them more to make that kind
of power with a 302 and get it through EPA
It just wouldn't happen.

Black 91 Z28

FYI. The Chevy 302's didn't have siamesed exhaust ports (if you're talking about it in the sense of the exhaust joining up and then exiting the head). The 3&5 and 4&6 cylinder ports exit the heads next to each other like they do on L98 heads. I think you were just trying to say that the exhaust exits like on a big block head. I don't mean to affend, just thought I'd clarify.

PETE

iTrader: (1)

maybe siamesed was the wrong word.the design of the standard gm head put the exhaust ports of the 3&5 and 4&6 cylinders together whereas the ford/big block chevy and ls1's valve train is oriented differently.instead of E,I,I,E,E,I,I,E(standard chevy head)the ls1 design is E,I,E,I,E,I,E,I.it allows greater flexibility when designing an exhaust port.as well as decreasing the chance of detonation because now the cooling system can do a better job without having to worry about that excessive heat building up from those cylinders(by far the hottest area of the head).no offense taken

jhainer

if i remember correctly if you do a search on google for the 350 chevy should have built this motor comes up
nevermind i will save you the search
http://purplesagetradingpost.com/sum...%20engine.html

cuisinartvette

Put a real good head on the 302 the LT1 intake with a little love done to it, some compression and a solid roller. Jim Grubb Motorsports collaborated with Mamo a few years back and got over 500hp with one I beleive it used a ported crossram intake, too. Strong runner

Those 302s as they were back in the day were real dogs. They had absolutely NO torque at all. You really had to spend time tuning them, longtubes and a deep gear before they felt like something. Fun little motor when you get them right though.

jhainer

I know this was a old thread but i was thinking. building the modern day version of the 302 . but with the TPI now for all that know the tpi probably won't breath enough for it. use the newer style vortec heads and it might turn out to be a nice little motor that revs high and might be alittle fun. bolt it up to the t-5 put a gear in and see what happens. I was reading hot rod made one with after market heads and a roller cam and got 500+ hp and 400 ft lb out of it now that was with a single plane and i think it was a 780 holley Just thinking out load here.

midias

Why is this 11 year old argument coming back?

jhainer

well i did a search on google and this thread came up. read it and i think it would be a nice thing to try . I always do things outside of the box like built a 2.8 back in 1995 put a bunch of money into it. 30 over at the time there was 3 cams went with the middle size cam roller rockers double roller timing chain high volume high pressure oil pump edelbrock 2 piece intake holley carb. headers msd into the 700r4 with a shift kit and a mega shifter. was it a nice motor yea was it a 350 not even close but a very nice motor none the same. motor was painted chevy orange bought edelbrock valve covers and air cleaner for it. by the time i was done i had about 3000.00 into the motor. everything was new except the block and it was fresh machined the heads were redone with a 3 angle valve job. I like to dare to be different. like a big block with a t-5 behind it. if we all thought the same thing and did the same thing all our third gens would be black like ford did with the model something. ther eis a reason gm made the 302 for racing and to fit the rules it turned out to be a nice motor take a look on youtube you will find a few of them and they sound down right nasty. yea i can cookie cutter a 383 or drop a 355 or 350 in it and get teh same ole sound of everyother third gen out there. or i could put alittle time effort and of course money into a motor build do it correctly and see where it takes me who knows but atleast it would be better than a 305. bore size is bigger so ther eisn't the issues with valve clearance the stroke is smaller so it would rev faster, and would rev to the moon . and with todays heads better than the original fuelies they put on them back in the day. you can get better numbers out of them. this isn't just a hey I'm 19 and i have an idea I'm 41 with the money to do it the time to do it and the know how to do it. How many people in this site can say they have done a complete rebuild on there camaro and the only things they have paid someone else to do is mount tires and rebuild a carb. I would bet not to many. I probably could have rebuilt the holley but i wanted it set right back where it was when they got it. that wasn't meant as a dig to anyone cause i know there is alot of guys on this site that do there own work. but ther are also guyson here that have nothing to say other than do a search and thats garbage. if i listened to everything people have told me the current project of mine would have been junked and not getting paint in the next week. they would have scrapped the car. but I paid $500.00 for the car bought a parts car for $750.00 sold parts off of the parts car and kept what i needed and got every dime back on teh 2 cars bought so right now the car has been free even the new paint was paid for in parts. tap the key it starts up no problem.everything works everything is in the car emissions everything the cigarette lighter even works. I went and bought wheels for it and caps for my old wheels and spent a few hrs each to polish them and it should be a very nice z28 when done. total i will have about $300.00 into it. minus labor. and if i sell the other set of wheels the car would be free other than labor. so what i am saying is this the forums are here to read and learn bounce ideas off and get opinions. the fact that it's a old thread doesn't matter it's the topic that i was searching. and if i creatd a new thread asking questions someone would have told me to search it which i did and i would end up back here posting anyways. Now I think a 302 might be a neat little project and maybe with more research i might look into doing it.
I have already found the small journal 327 and 283 which is a good start for the short block the reasearch i still need to figure out is the pistons and rods from what i have read the rod length is alittle gray area i have hears 5.7 and something like 5.95 ?? not sure i read it this morning and its been a long day. as for heads i found a new set of alininum heads for $1000 and i have an extra tpi setup and in reading an looking up info it looks like you can port and clean up a tpi enough to flow better than the aftermarket tpi units. so research is where this project is at at the moment. Hence the search and finding a 11 year old post about this topic

Nelz

#1.) Correct. 302=HP up top like a Honda. 305=TQ low, like an 80's TPI Camaro
#2.) True. The Bore shrouds the valves thus 1.94 is all you can use

Don't buy bigger runners for the 305. The engineers designed the TPI for the 305. The 1.47 diameter is tuned for a 305 with a 268 advertised cam to make peak torque at 4000RPM.

If you are punching out the stock block 0.030 over to a 310, stick a 280 advertised single pattern cam on a 110 LSA. Use 1.6 comp roller tip rockers with beehive springs and check the valve to piston clearance. The bore may limit the amount of lift you can use. Port match the stock runners and intake to the heads. Port the heads. Use th diagram for the 30 degree valve seats from How to Build Max Chevy Horsepower 2009 by David Vizard and buy his cam from Lunati. Make sure you specify you have a late model roller block when you order a roller cam. Get a dual cat exhaust system along with 1-5/8 long tube headers.
Compression needs to be 9.5 or more.

Voila! Budget 5500 RPM TPI with good torque for the street.

If you are set on a 305/302, that's the combo you need. The machine work costs as much on a 350 or 383 but if you are bent on doing it....

The intake is tuned along with that Cam and motor to make peak torque around 3850 RPM, you should be catching the 3rd harmonic wave. The 1-5/8 long tubes are the correct headers for that motor.