305 Help

[Dan Juday]

Just for perspective since I'm a 305 tpi guy:

 

4.3 LT1 makes 200rwhp

 

5.0 TPI makes 225rwhp ('90-'92)

 

And the tpi delivers Hefty Bags full of torque way down low in the rev band ( and, yes, runs out of breath at about 4500).

 

MHO, if you have a 305 tpi drop it in and have fun. You can always swap it out for a 5.7 LT1 later.

[jack46]

TPI does not have the tools available like an LT1. Tuning tools are cheap for an LT1, so you can change cams etc. A TPI tune costs more than an entire setup for an LT1.

 

There are no easy choices, but in a nut shell if you stay stock a TPI setup is not a bad choice, if you plan any changes go LT1. A 4.3 is a stepping stone, a 305 TPI is a dead end.

 

As for the 200 vs 225 HP. If you put dual exhaust, 1.6 rockers, and a 3.5" MAF with cold air intake (I used 3.5" mandrel pipe to put filter in front of radiator), retune the motor, then the 4.3 will be close on HP and probably have more torque across the board. These changes would benefit the 5.7 LT1 so NO money is lost. Hell I will even program the ECM for just the cost of shipping.

 

I had a 305 and it was ok, but NO comparison to even a small LT1.

[tfreer85]

Well I definately don't see a 350 Block as a dead end, no matter what FI system you have. There is always to pull more HP somewhere.

 

Block Modifications: Get rid of 265 cid internals

335 stroker kit and bore the block out to standard 350 pistons.

Gear Driven Timing Chain

Electric Water Pump

 

Head Modifcations:

New heads Edelbrock Peformer bare (smog legal)

Manley Undercut Valve Stems

Crane Cam (probably on 230 ish at .50)

Crane Cams Beehive Springs

solid rollers

Roller Rocker Tips

Stud Girdles

Port and Polish

 

Intake Mods:

New Intake (any brand recommendations?)

BBK 58MM Twin Throttle Body

Aftermarket MAF

 

I want the powerband to be in the 2000-6000rpm range, and only 9.5:1 compression ratio since I don't really want to use premium and want to allow for superchargine later. I figure a free/higher revving 327 LT1 would be a good little starter motor since my car has only been in a project state (i.e. I've never driven it). That'd give me plenty of fun, something pretty unique as to engine size, allows me to keep my 6 speed, and have a lot of support in the V8 forum. A 350 or bigger upgrade may be in the future, but I'm in college for at least another 6 years, so its not going to be soon. Also if I can do a lot of mods to on the upper end, if I decide on going bigger (350 or 383) all I have to do is change the inernals which is no biggy. Thanks for all the info guys.

 

Tyson

[DavyZ]

DavyZ' date='

Just make sure it came from either an f-body (Camaro/Firebird) or a Corvette. The L99 was only used in the b-body cars (Caprice, Roadmaster and Fleetwood) and they have iron heads while the f-body and Corvette LT1 has aluminum. Some of the b-bodies had LT1s with iron heads (Caprice Classic/9C1, Impala SS, some Roadmasters and Fleetwoods), they are the ones that will be hard to distinguish from an L99...

Wheelman[/quote']

 

Thanks, Wheelman. I was always under the impression that the Caprices and Impalas came with 5.7L motors, but I may be avoiding that avenue for the motor and just go with the Camaro LT1. The aluminum heads are an added bonus IMO.

 

Davy

[jack46]

Some of the b-bodies had LT1s with iron heads (Caprice Classic/9C1, Impala SS, some Roadmasters and Fleetwoods), they are the ones that will be hard to distinguish from an L99...

 

Only Corvette and Camaros had LT1's with aluminum heads.

 

The blocks are all identical. The aluminum heads are easy to identify, first they do not rust, and do not hold a magnet. All 350 LT1's have 5.7 on the block, and have the number I posted above. An iron headed LT1 is usually cheaper, and once rebuilt to the same specifications will weigh 50 pounds more, but provide about the same hp.

 

In fact iron heads are better. Why, because you can cheaply put in larger valves and with porting far out flow aluminum. Stock compared to stock, the aluminum win, but iron is more cost effective to change valves.

[jack46]

Well I definately don't see a 350 Block as a dead end, no matter what FI system you have. There is always to pull more HP somewhere.

I said “a 305 TPI is a dead endâ€, that is a big difference.

 

Edit I will assume you weren't trying to aggitate and are simply young and energetic.

 

Modifying a 4.3 is a WASTE of money. I said save money to buy an LT1 later.

 

You can NOT bore a block from 3.75" to 4.00" that is 250 thousands. Blocks are to thin to allow much of an over bore usually ~.060" is maximum.

 

I have not seen a 'gear drive' timing set for an LT1. The LT1 timing chain has a gear on the backside that drives the water pump, and because of this would require an extremely expensive gear set. And the gear set would NOT save enough hp to justify it. Especially with the opti improving the accuracy of even timing.

 

A 230 cam at .050" lift will not pull at 2000 RPM in a 350, they suggest a 2500 stall, and in a 327 the torque won;t start until an even higher RPM. Search for 327 it was a great combination in it's day. Today a 350 is a better bang for the dollar in most peoples opinions.

 

A 52 MM will help if a motor has ~>475. An after market MAF is usually a expensive and is not a significant improvement over stock descreened MAF. The after market MAFs are always available almost new for about half price, and seldom get sold on most Forums.

 

I think a small motor your dad will accept is a better approach than trying to build a large hp motor from small cubes. Get dads confidence and get used to ~200 HP then convert to more power.

 

Good luck

[wheelman]

Jack46,

Don't be to hard on him man, it sounds like he's a young guy with things to learn. I've read the thread and even though he may still have some mis-conceptions about the L99 there is a lot of good info you posted. You haven't wasted your time.

 

Remember back when you first got started and how all the buzz words and gimick things caught your eye. I'm sure you bought into some of that just like all the rest of us did and then learned that most of what you see in magazines and online ads is a bunch of BS. He'll learn, it'll just take some time and if he doesn't then the rest of us got to watch and learn something along the way.

 

tfreer85,

Take a hard look at your plans and make sure you want to put the time and money into the L99. What Jack is trying to say is that the combo your presenting may not be the direction you want to go. Do some research into the differences between the generation 2 L99/LT1 and the generation 1 small block. You'll find that the number of available go fast parts is smaller because alot of things made for a gen 1 engine won't work on a gen 2. Example: Intake manifolds, timing chain sets, cams, heads, cranks, valve springs, water pump, accessory mounts, etc.. Some of these things can be made to work but that adds more expense. Example: The L99/LT1 uses an externally balanced rotating assembly with a 1 piece rear-main seal. A gen 1 SBC is internally balanced and most use a 2 piece rear-main seal, exceptions are 400 and late 80s 305s. The 400 is externally balanced and the later 305s used a 1 piece rear-main seal.

Another example: L99/LT1 is setup to flow coolant through the heads first then the block while gen 1 engines are the opposite. This is why L99/LT1 intakes don't work on a gen 1 engine and gen 1 heads don't work on an LT1. Can they be made to work? Yes. Is it worth the cost? NO!!. All this to say do your research before you make a final decision.

 

BTW: I'd still like to get the rotating assembly (crank and rods) if you decide to move forward with the L99.

 

Wheelman

[tfreer85]

Thank you wheelman for the polite reply. Yes I am a younger guy turning 20 this week. I've taken a couple of engine overhaul classes, but am by no means what-so-ever an engine masters. I know the bare bones about things and therefore don't know what combination would work best. Now jack46, I know you're saying a 4.3 is waste of time and money. I would like your honest opinion if you could only go with an engine smaller than a 350, but was still a V8, what engine choice and setup would you do? I have a budget of $4000, with free block machining because of school. Now let me explain my reasoning (it still may be flawed) behind doing the 4.3 LT1 setup: I see that if do all of the 350 LT1 setup on the topend, that once I get the approval/money do the 350 I won't have a double price new LT1 products. That all I would have to do is swap in the 350 block. As for boring out 250 thousands I didn't think it all the way through and was thinking that the entire block was identical to the 350. I'm asking because I don't know everything and want to know, I learn quickly and don't make the same mistake twice. Since, I've seem to made you mad jack46 I'm sorry, but I have learned a lot from your post and don't feel you have wasted your time. Sometimes I'll accidentaly ask a double question and you make take it as me not listening. I know that can be aggravating. Considering my goals for the car which is nothing extremely radical like Turbo Meister, or Darius. I'm just looking for a quick little V8, that can keep up a little bit. So again jack46 I'm sorry that you feel that way. Again let me know what you would do with a $4000 budget for a V8 engine smaller than a 350 that was smog legal.

 

So you're saying (jack46) don't build up the 4.3 expecting any real hp or build it up for the future 350 LT1 swap correct? I'm not trying to stir the pot or aggravate anyone (I was just trying to say there has to be a way to pull more hp out of a Chevy engine). I've re-read the forum a couple of times. A 350 swap, is pretty much out of the question as I began to crunch some numbers and realize the amount of time (in years) that it would take for convince my dad to do the 350. That being said, I figure a Chevy V8 is my engine choice because of the large number of positives for it. Now I don't have to have FI though I would like to. So I need fair HP from small cubes or at least enough to smoke my friends truck which runs upper 13's.

 

Sorry again jack46, I over read some of the important tidbits when I saw numbers.

 

Tyson

[jack46]

I would get a 4.3 rebuild it use 1.6 roller rockers. Since machining is free I would ‘zero’ deck the block, do mild porting. It should give you >200 RWHP, gets >25 mpg,.and should do a ~14.2 quarter.

 

That is a perfect college car. Will be reliable yet strong at track and great on mileage. Let the remaining money stay in bank and when you graduate then go to what you can afford then.

 

Now let me explain my reasoning (it still may be flawed) behind doing the 4.3 LT1 setup: I see that if do all of the 350 LT1 setup on the topend, that once I get the approval/money do the 350 I won't have a double price new LT1 products. That all I would have to do is swap in the 350 block.

Well sort of. You will swap in an LT1. The harness will plug right to it and the ECM will be reprogrammed. You could use the intake, 1.6 rockers, MAF, Throttle body valve covers, opti spark plug wires, oil pan etc. You would need LT1 long block and injectors to add to above parts. MOST is used on both engines.

 

As for boring out 250 thousands I didn't think it all the way through and was thinking that the entire block was identical to the 350.

External that is true internally no. Also the deck heights I think are different the rod is longer. I can’t find it now but I THINK the deck is higher on a 4.3 so the rotating assembly is not compatible with other blocks. The compression height etc.

 

Since, I've seem to made you mad jack46 I'm sorry, but I have learned a lot from your post and don't feel you have wasted your time.

Don’t worry about it. I wrongfully thought I was being had...many call it trolling and I thought you hooked me not important now and it is forgotten.

 

I'm just looking for a quick little V8, that can keep up a little bit.

A V8 Z will keep up. I think 200 RWHP is a good college car. ESPECIALLY with gas >2.30 a gallon a car that does a low 14 1/4 and gets >25 is a winning combination.

 

$4000 budget for a V8 engine smaller than a 350 that was smog legal.

Small LT1 is way to go. The 4.3 should be reliable and affordable yet allow you to improve it for the LT1 at graduation.

[tfreer85]

Okay Jack46. The 4.3 Longblock is all that I would be getting. A rebuild kit I was just quoted for around $500. What is your opininion about new heads with mild porting? (I'm thinking Aluminum to save weight for a not as powerful engine). Do the LT1 intake, a 52 MM Throttle body, stock MAF. I wouldn't be doing a longblock LT1 for used parts because the cheapest I can find is $1500 and I'd rather spend a little more for new. Do the 1.6 Roller Rockers like you're saying. I'd do a painless wiring system, and a reflashed ecu. What do you think about for camshaft degress around .50? (included in the rebuild kit). I don't even know what trolling is, so I'm sorry you thought I was hooking you. This should still allow for a little bit of money left over to go else where in the car. Thanks a ton for all the very useful info.

 

Tyson

[tfreer85]

Well I found something thats explains quite a few differences between the 4.3 LT1 and the 5.7 LT1. http://www.automotiverebuilder.com/ar/ar99928.htm

 

Tyson

[jack46]

265 - The 265 rods are 0.240" longer than the ones in the 350. Both blocks are the same height, but the stroke for the 265 is 0.480" shorter, so the rods have to be longer to make up for half the difference. These rods can be identified by the single, raised dot on both sides of the shank.

I thought the decks were different, but they are not,

 

I was just going to give you that link it has good information.

 

The 4.3 Longblock is all that I would be getting. A rebuild kit I was just quoted for around $500. What is your opininion about new heads with mild porting? (I'm thinking Aluminum to save weight for a not as powerful engine).

Save the money for your LT1 the 4.3 won’t give enough hp for different heads to justify the money. If you want performance get a Camaro Cam. YES a stock camaro that will be a nice increase probably get the engine to pull much higher yet be driveable with a standard shift.

 

Do the LT1 intake, a 52 MM Throttle body, stock MAF. I wouldn't be doing a longblock LT1 for used parts because the cheapest I can find is $1500 and I'd rather spend a little more for new.

4.3 will do FINE with stock Throttle body. When you upgrade to 350 get it bored to 52 it costs ~$130.

 

Do you mean new LT1 I didnt follow. I would get a new opti spark, used injectors cheap 19, 22, 24 cheapest you can find. MAF from a Camaro.

 

Do the 1.6 Roller Rockers like you're saying.

If you use a stock Camaro cam no need in fact will hurt the 4.3. With that cam simply use stock rockers buy rollers when you put in an LT1 that way you will get matched to the new LT1 not what you used on old engine

 

I'd do a painless wiring system, and a reflashed ecu.

Cheaper to convert one from an Impala or Caprice can get the harness and ECM for ~$150 and a few hours and you will have it converted ‘sweat’ equity.

 

What do you think about for camshaft degress around .50?

In 4.3 stock Camaro 202/208 .450/.460..

LT1 224/232 on 112 LSA with .508/.524 is what I run in my Z. Pulls hard yet very streetable even in an automatic.

 

Now you mentioned Smog I don’t have to deal with that soo...IF you have to then I would probably do a regrind and have it custom ground probably 198/210 .450"/.460" on a 112 LSA. That grind is basically between a Camaro cam and the iron headed cam. You could try smogging with stock Camaro cam it might pass. To change is not bad in a Z. Pull radiator and take cam out front.

 

Now with all that was said, PRICE alternatives! Not just motor now, but later upgrade. TPI 305 then 350 could be an alternative.

 

Good luck

[jack46]

PS forgot to also say the 4.3 requires smaller combustion chambers so heads that work with 4.3 would be BAD on a 350. The CR would be WAY high on 350 for heads that are right for a 4.3

 

I just ran it on desktop and Camaro cam should gain close to 20 HP and pull to 6000. It is just an indication not totally accurate. But on small engine the Camaro Cam is BIG. In fact if you had an automatic I would say too big for street.

[80LS1T]

Just wanted to give a little info on the timing chain set up....

 

If you run an electric water pump like you want you can run a regualar small block timing chain or gear drive. However a gear drive set up might cause "false" knock and cause the PCM to pull timing, which is deffiently not good.

 

I am running a CSI electric water pump and a Cloyes double roller timing chain. I forget the part number but Im sure you could find it by doing a search in the Chevy V8 forum.

 

 

Guy

[tfreer85]

Okay well, after a whole lot of research, I'm going against the 4.3L LT1. Parts are harder to find, there would be a lot of custom work involved to pull any amount of decent HP out of it. What I'm looking at now is a complete 2000 4.8L Chevy truck engine. I have one in my other truck, and it pulls nice and hard through a large rpm band while still being a relatively small cube V8. I'm guessing since I want to upgrade to the T-56 I'd have to use one of the newer models that came with the LS1. I've got some more researching to do about it and I'll keep everyone updated with what I find out. Jack46 thanks for the patience and help.

 

Tyson

[jack46]

Make sure and understand the imapct of smog. ALL 96 and newer cars are OBDII, and expensive to make changes to, also harder to 'fool' the smog tests with ANY modifications.

 

I misunderstood I thought dad was making you go mild? LSX is a good setup good luck

[Guest SupraGuy]

Hey, you could always get the 350 LT1 and run a custom 3.00" stroke crank (4.00 x 3.00 = 302"). I believe Eagle makes one for that application. It sounds like your old man is thinking in terms of cubic inches dictating horsepower. If you went with that combo you would have a modern day 302 that could handle more power than just about any 350 on this message board.

[tfreer85]

Hey, you could always get the 350 LT1 and run a custom 3.00" stroke crank (4.00 x 3.00 = 302"). I believe Eagle makes one for that application. It sounds like your old man is thinking in terms of cubic inches dictating horsepower. If you went with that combo you would have a modern day 302 that could handle more power than just about any 350 on this message board.

You hit the nail on the head. Okay so since your saying jack that the newer OBII would be harder to smog thats out then. SupraGuy do you by chance have a link for it? I'm over at a friends house so I can't do research right now.

 

Tyson

[jack46]

To program an LT1 you need:

 

1. Tuner cat and definition file ~$90 (or LT1 Edit I personally prefer Tuner cat ut research both, but LT1 edit is locked to one vin as I understand).

http://www.tunercat.com/tnr_desc/do_tc.html

 

2. Cable ~$90, I use AKM others available

http://www.akmcables.com/ic.htm

 

Then you can tune and load programs for yourself.

 

3. Collection program is TTS datamaster from

http://www.ttspowersystems.com/index.htm

 

Or you can simply have someone program ECM for you, like PCMforless. I do NOT have OBDII, I was told it is harder because it is more restrictive and programs to alter OBDII are I am told almost twice what I showed above.

 

Do the research, and make sure this is true.

[jack46]

As for a 302 making more hp than a 350, they make LESS torque and hp except at HIGH RPM, and are basically a DISASTER for a street motor. It is unique and if you want unique fine, but build cubes if you want power.

 

A 302 is also EXPENSIVE because the cost of pistons, and Chevy quit building them SUPPOSEDLY because of smog problems so NOT valid for a Ca build. Search 302, 327, 350 etc it has been debated MANY times. The crank in the 4.3 has a 3.00" stroke. BUT I have not heard of anyone destroking an LT1, simply no need. Also remember the LT1 rotating assebly is lighter.

 

here is a recent debate of 327/350

http://forums.hybridz.org/showthread.php?t=103152&highlight=327

 

LT1 opti is NOT reliable for high RPM. So you will need a different system than the opti, and the ECM will not handle HIGH RPMs needed to make a 302 viable so it is simply impractical in most SBC and ESPECIALLY an LT1.

 

To put it in a few words there is NO substitute for cubes. Smaller cube engines require HIGH RPMs for the same HP, and a 350 LT1 makes good power to ~6500. Most INCREASE cubes to 383 in an LT1, but with Ca smog ASK BEFORE you start building. Try to get a ruling from Ca smog if possible.

 

CA smog is STRICT and not forgiving so ASK people that KNOW Ca SMOG.