rocketrider93

i don't think the resale value on your car is going to be near as much with a sbc in it as it would with the ls1. anything that has a clean ls1 motor swap done to it has gone up in value. as far as exotic goes, there is nothing more booring than another small block chevy no matter what is topping the thing. if you were to flip the ls1 intake so that your intake was in back of the motor it would look very nice and you would get way more attention in it than you would with another small block. it will save you weight and also fuel mileage. think about the gas mileage differance especially if you are going to drive it every day. you probably get what 15 at the most from an old sbc? if you could get 20 or more from an ls1 that means you would be filling up the tank 25% less of the time you are now. you won't have to worry about heating or the trouble a 400 horse small block can give you as far as reliability. yes if you are looking for easy and low cost than the sbc is your best bet. but if you want to go and turn heads and have something a little more unique do the ls1.

87ssMonte

5k..to spend.. ls6 complete assembled block (low miles).. 2k to 2.5k edelbrock carb, manifold and msd. <$1000.. exhaust less then $100 for cast.. vette, gto, or f body.. accessories(alt. PS Pump, brackets, electric fuel pump (low pressure), hoses, etc) $1000.00 ,should make 400 hp. IF you got time for long tube headers.. 420+ hp..
Tranny... not included..

Mike1234

iTrader: (4)

Thanks for the heads-up PRAY HRD. Sounds like you have a nice power plant, but $12K is more than twice my budget. I have many other upgrades to do to this car.

Mike1234

iTrader: (4)

Hi Pat,

Thanks for the clarification. After my research, I thought I had the weight difference figured out... 100 pounds if the SBC has aluminum heads. Is it really only 60 pounds or so? For weight savings alone, it's not worth bothering with... for my purposes anyway.

So, we're really only talking about upper midrange and top-end torque then? Can't this be improved in the SBC with proper matching/tuning of intake runner length, heads, and exhaust primary length?

Mike1234

iTrader: (4)

Hi Andy1,

Thanks for the gen1 vote. The more I research LSx vs. gen1, the more I tend to agree with your vote. If I had a huge budget, I'd undoubtedly go LS1 or later. However, I've found some really nice strong 383 strokers purpose built to take lots of nitrous for very reasonable prices. I should be able to tune the torque curve to my liking with intake runner length, heads, and header primary length, right?

Mike1234

iTrader: (4)

Thanks for info 'JustDreamin'.

I found a low mile LS1 complete with every little piece including all underhood A/C components for $2700 delivered. I would estimate installation parts/labor at ~$500-1K, plus another $1K or so for a performance cam and good used LS6 heads. This doesn't include a new exhaust or exotic intake. So a fairly basic LS1 swap with a couple of performance add-ons to bump the HP to ~430 could be had for about $4700??? The new induction system will cost $1-2.5K, but that's part of any build cost. The same is true for new headers and exhaust.

What do you think? Given the opportunity above, am I still better off rebuilding this SBC to my specs?

I've been looking into converting this 350 to a 383 stroker, but I can't see any really big HP or torque gains... the torque curve just seems to move lower... not surprising, really... and not what I want. I want this motor to pull very hard all the way to redline. Is the 383's lack of upper pull caused by poor head flow? If so, are there heads properly designed to breathe and make a 383 pull hard to redline???

Mike1234

iTrader: (4)

Resale value, overheating, reliability, and fuel economy... all very good points that I'm hearing often. There must be something to it... and these are all very important.

Is it possible that the SBC's mechanical issues can be cured with a revised firing order cam? I've been reading something about reverse cooling. How important is this, and is it pricey to upgrade the SBC to reverse cooling? Will these two updates solve the SBC's problems?

Mike1234

iTrader: (4)

A complete low mile carburated LS6 for ~$4500 exhaust manifolds included? Will the cast manifolds fit a 260Z? Never mind - it doesn't matter - sounds great!! So... should I start calling local wrecking yards or am I better off sifting through the forums?

67RSCamaroVette

iTrader: (63)

pretty good deal there, i'd pick it up for sure. your price is about right, give or take some. (some people get great deals on parts and service, some dont.)
with that deal, and the intake you want, provided you're willing to pay for it, is leaps and bounds above the SBC, and I say go for it.

Mike1234

iTrader: (4)

For anyone who's interested, here are a couple pics of my fake Ferrari in its current iteration. I don't yet have the car in my possession... it's still in New Mexico... so these images are supplied by the seller. Among other changes, the wheels will be updated to wires and the rear set will better match the flared fenders.


Here's the engine... could use some revision... especially the wiring :^)

Mike1234

iTrader: (4)

Hi 67RSCamaroVette,

I was quoting 87ssMonte's LS6 prices :^) Where should I start looking... the local wrecking yards? Or are the forums a better place to search for great LS6/Lsx deals?

'JustDreamin'

Hey Mike....

The 383 (and 400 based motors too) do tend to make power a little lower in the rpm band. BUT, they certainly can and will make plenty of power up top if that's where you want it. All a matter of camshaft & cylinder head selection. 425 to 450 hp out of a reliable 350 or 383 shouldn't be all that difficult. For an example, check out Edelbrock's Crate motors, they've got a 9.5:1 Performer RPM model making 435hp / 435 ft-lbs of torque. Nice thing about that is that Edelbrock has done all the research and dyno testing, all you have to do is buy the matched parts (heads, cam, intake, etc) you don't have to buy a complete motor.

I think reliability should not be an issue in either case. At those power levels, neither the LSx series motor nor the SBC motor will be all that high strung and unreliable (or at least they shouldn't be). If you go carb'd, your tuning will play an important role as to how the driveability and reliability is.

Reverse cooling has a small measureable difference in power output, but not enough for the maintenance headaches. Which is why the LSx and SBC both use conventional cooling. The LT1 used reverse cooling, and it made a wee bit more power, but is tempermental to get fully bleed out, which is why GM dropped reverse cooling. Good aluminum cylinder heads on the SBC are a significant benefit.

Gas mileage probably won't be very different. If you use the same transmission (which means same rpms) and carbs on both (which is what you're talking about) then it really comes down to how well you've got it tuned (carb). LSx motor won't have a 5 mpg advantage, so don't get your hopes up there.

'JustDreamin'

Mike1234

iTrader: (4)

Thanks for the info 'JustDreamin'. I think I'm finally figuring this out.

I must say, I'm receiving many different opinions on these forums. I'm filtering through information which conflicts from one person to another and this can be confusing to an old school dummy like me.

"Do this... don't do that. Can't you read the signs?" The road signs, that is. Am I telling my age with those lyrics? Well... the lyrics... and becoming side-tracked :^) Umm... where was I? Oh yeah... I guess I don't mind being "behind the times" so much as being "behind the eight ball". And you folks are ALL helping me avoid that dam* eight ball. THANKS EVERYONE!!!

To me, again an old school fool, the idea that any given block would make that much difference in performance (other than displacment) is confusing. This doesn't count motors with variable valve timing and cool stuff like that... which is really an upper motor thing, but tied to a given block none-the-less. Not counting VVT and variable intake runners... those sorts of things, I've been taking the performance differences on faith because I don't know nuttin'. I was always told the real differences in motors is tuning, cam, heads, intake/carb (or EFI), exhaust, etc. In other words... flow, flow, flow... more flow. Being basically an air pump, an engine must flow air, right? It can flow well at low RPM's with long intake runners and exhaust primaries... or it can flow well at high RPM's with short intake runners and exhaust primaries. Of course, cam and heads must be matched to everything else. I think we all agree that changing one thing affects everything else. And of course, we're only talking about V8's here... apples to apples, more or less.

With todays' VVT (timing, lift, and duration)... man, that's so cool... and variable intake runner technology taking hold, efficient air flow can be extended. Once variable length exhaust runners are invented... man can we have some fun!!

If I'm off in left field here, please correct this old dummy. I'm just sharing what I learned about a million years ago... and trying to connect it with the new stuff. If different blocks really do make that much difference (all else equal), please chime in and explain why. I like both scientifically aquired data and real-world empirical... even gut feelings are okay.

BTW, please forgive my verbose nature folks. I do realize I talk too much :^)

All above said... old ideas squeezed and puked from my feeble brain... there are still the concerns of longevity, reliability, and overheating.

I still have one thing I need clarified and it involves overheating and harmonic vibrations. Here's the question: Will a revised firing order cam, along with a really good aluminum radiator, high flow fan, H2O pump, etc., correct overheating issues? Will it significantly decrease harmonic vibrations? I've read that the old GM firing order, which is corrected in LSx engines, caused two cylinders to run lean and two to run rich. The lean cylinders overheat, which causes the engine to overheat. Does the revised firing order really help that much?

Thanks again to all. I'm nearly ready to make up my mind. But I need just a bit more shoving in the right direction.

'JustDreamin'

Personally, I don't think the block itself makes that much of a difference. You hit the nail on the head, an engine is an air pump. It all comes down to flow.

Now, the difference that the block makes is which architechure it locks you into. The LSx platform motors have some of the best head designs ever mass produced for a v8. Factory SBC heads don't flow nearly as well as good LSx heads. But with the SBC, we're not limited to factory heads. Most of the aftermarket heads are really good. And obviously some are outstanding (think 800hp Nextel Cup motors) but they're not really budget oriented.

My personal opinion is that firing order doesn't make that big a difference in thermal management of a streetable SBC. The center two cylinders on both sides tend to run warmer (because of the back to back exhaust ports). I think there are a few good reasons to run the revised firing order, but I don't think mixture control isn't one of them.

Lean & rich cylinders shouldn't really be about firing order, has all to do with intake distribution patterns. Here is where a multiport fuel injection setup is truely superior. You're nearly assured that each cylinder is running at the correct ratio because you're introducing the fuel directly into the intake port. And if you have a lean cylinder (from EGT probes or whatever) you can take specific action to address it (replace injector, lengthen pulses, whatever). There isn't an easy way to do that with a carb, but some manifolds are definitely better than others.

Are you currently fighting an overheating problem with the car? Does the car have a thermostat? Believe it or not, running without a thermostat will cause overheating problems (something about the coolant doesn't stay in the radiator long enough to loose its heat load).

A good adequately sized aluminum radiator, quality water pump, and a well designed air management system will keep it from overheating. Air management system is all of the pieces of the cooling system that get air to flow through the radiator, including fans, fan shrouds, ductwork to the radiator (that hopefully gets you nice cool air and keeps the hot air from the back side of the radiator from coming back around to the front side (called short cycling)). Also need someplace for the hot air to go to (especially a concern if you have very limited ground clearance). Puller type fans work significantly better than pusher type, so stick with them if you can. Because of the cooling system design, the rear cylinders can run hot (water goes in and out of the front). Racers address this with return lines to balance the water flow front to back. LSx and SBC both have the potential for this problem, so there is no magic bullet with one engine family over the other.

I would say address the lean/rich cylinder issue first and foremost. Not only will that cause overheating problems, but it will certainly cause performance, driveability, and reliability issues.

Sadly, none of this addresses your desire for an exotic looking intake system. I think a Hilborn or Kinsler manifold set up for EFI would be cool. Or a lay down style (think old Can Am series) fuel injection manifold converted to EFI would be really neat looking (individual throttle body per cylinder with velocity stack bells basically over the valve covers). If you're electronically inclined, you could run MegaSquirt (a fairly inexpensive DIY fuel injection controller) to control it, and you might even figure out how to do it within your budget. Just trying to make your decision harder by giving you more options to think about.

'JustDreamin'

93Polo

iTrader: (5)

I agree and there are some very clean LSx Z cars out there

http://forums.hybridz.org/showthread...highlight=pics

You can also really clean up a LSx

https://ls1tech.com/forums/showthrea...ht=Grand+sport

rocketrider93

if you were to switch to the lsx you would have some weight difference over and above the 60 -100 pounds discussed earlier and with a car as small and light as that you may feel more of a difference than you think. if you are taking over 100 pounds off the front of the car by changing to an ls1 and you are adding a few pounds to the middle of the car because of the heavier tranny you are pushing your weight farther back and lower for better center of gravity. the sbc is a very good engine. that is why they put it in everything. but that is the reason i would go ls1. hearing about all the hybrid cars on the forum equipped with ls1's makes you think there are a ton of them out there. but i haven't seen one personally. everything i see at the shows has sbc's and bbc's. great engines but old technology. the only reason they are any easier to work on is the knowledge so many people have of sbc's. usually you won't run into too many problems with cooling the chev's unless you are really pumping them out. parade duty makes the sbc pretty warm too. what is the climate like in your neck of the woods? if you live in a hotter area you are definitely going to need the extra cooling equipment. a big aluminum radiator will always help that. make sure you have a good custom fan shroud made for the electric fans and in my opinion i would go for a set of ss or z28 fans. stock fans are almost always better than aftermarket because they were designed for a life of work on 150000 mile cars. the aftermarket hasn't really cought up in terms of research. you can go and get a relay and sensor kit from a speed shop and it has instructions and very easy if you are switching from a mechanical fan. as far as reliability i don't think you will ever make an sbc run as long and hard as an ls1. most of the sbc's i have had have crapped out after 90000 miles while most ls1's are getting into 150000 miles with good maintenance. and fuel mileage is a biggie. at over 3.00 a gallon you have to think about stuff like that while daily driving the car more than if this was just going to sit in your garage and look good.

Mike1234

iTrader: (4)

Thanks for the links. Those are some nice rides!!

Mike1234

iTrader: (4)

If I lose just 100 pounds off the car, I would definitely notice it. Especially all off the front. The weight loss and redistribution is worth $500 or so to me. I'm not a serious enthusiast, just a middle-age guy who wants to have some fund destroying some inflated Pony Car egos :^)

I don't want to spend $3K beyond what I would updating this SBC UNLESS I'm going to make some very substantial gains. If the gains are truly there, I'll spend the cash.

Having something truly different is precisiely why I bought the '62 Ferrari replica to begin with... (I mean kit car... but "replica" sounds better). It's worth quite a bit more to me in order to have an engine that's very unusual and more Ferrari-esque. But I think the valve covers and induction system are the primary factors there. Very exotic induction systems are available brand new for $1500-3000, depending on how "different" I decide to go.

The original '62 250 GTO had a 3 liter V12 with six dual-throated Webers for a dedicated barrel for each cylindar. The ultimate option is an authentic Ferrari V12 with appropriate induction, but I don't have $30K+ at my disposal to take that route. Too, they are temperamental little monsters. I just want this car to run reliably and be faster than most street machines I'm likely to run across. A late model BMW V12 with new badging is an option, but adaptation is a complete expensive redo. Too, I don't think I can coax anywhere near the same HP out of the BMW as I can the SBC or LSx. I might go for a stock Bimmer V12 adaptation, but probaly not. I really do like to keep things simple... and haulin' A** is just as important to me as the looks.

I'm not likely to mess with parades, but I will be driving in slow bumper-to-bumper traffic fairly often. I live in South Texas and the summers regularly reach 105 degrees F. Plus we're expected to have record highs for a few years. Another factor... I'm adding a hefty A/C to this car so this will affect heating issues too. The previous owner lives in New Mexico and he had to make some changes to overcome heating problems... with no A/C installed.

I'll be sure to install the highest CFM puller type fan I can find and will build a tight shroud for it. The shroud already on the car might be okay though. I didn't know that the aftermarket fans are no good. Are you saying it's a longevity issue... they just wear out? Do you know who makes the most efficient affordable aluminum radiators? What do you think of the high volume electric water pumps? They'll obviously circulate the coolant better in traffic jams but are they okay for highway?

If LSx's are truly lasting 60 percent longer than SBCs for a given build, one could afford to spend that much more for an LSx. But is it possible the SBC's are dying from harmonic vibration caused by the old firing order? Could those SBC's last as long with their firing order updated? Given best build for the money on both engines... excellent heads and exaust, efficient induction systems, intelligent component matching, precise tuning, etc., does the LSx still truly win hands down for performance, reliability, and fuel economy?

Thanks Again!!
Mike

streetk14

iTrader: (2)

Mike,
I'm an old-school SBC guy who just decided to enter the LSX world. I decided to get an LS1 for my '68 Camaro because I wanted to drop weight, gain the driveability of fuel injection, and make good power doing it. Mine is going to have a blower and about 600 flywheel horsepower.

If you are on a budget, an LSX might be hard to do. The car already has a running SBC, so getting more power out of the engine would be the cheapest & easiest route. My car was probably 3400-3500 pounds and was capable of breaking into the 11's with good traction.

The 383 is a very good street motor, and they can be built to rev to 6500+ rpm. But you have a lightweight car, and probably don't need the extra torque (and expense) of the 383.

Just as a reference, my friend had a 66' cobra kit car. It had a 351 Ford small block, T-5 5 speed, and 3.89 posi rearend. It was 2400 pounds and the motor had about 420-430 hp (AFR heads, good cam, etc.). This thing HAULED A@#. Never had it at the track, but definitely an 11 second or faster car if it could hook it up.

If your current motor is in good running condition (ie. good compression, no leaks) you could modify it for a good, streetable 420-430 hp. Stock short blocks are fine. Mine was a 4 bolt block with nothing more than a set of "PM" rods. I beat the hell out of that motor for over 6 years, spinning the thing to it's 6800 rpm rev limit on a regular basis. I never had any problems with the rotating assembly. Here's what I would do :

New Aluminum heads : I have always run AFR heads, and I feel they are one of the best on the market. Their 195cc head will work great for you. If the motor has the stock 8.5:1 compression pistons, get heads with smaller chambers to bump up the compression to 10:1

Hydraulic roller cam/valvetrain: They may cost more than a flat tappet cam, but deliver better power and driveability. They are more durable, too. Something like GMPP's HOT cam works well on the street. I used to have one in my car. It had a nice lope, good idle, and pulled strong to 6000 rpm+. The car actually got decent freeway mileage with that cam.

Overdrive transmission: I'm not sure what you said was in the car, but an overdrive trans will make the car much better overall. I had a Tremec TKO 5 speed in my car. The low 1st gear made for great acceleration, and the 5th gear overdrive kept the rpms down on the freeway. If going automatic, a beefed up 200-4R may be a good choice.

Induction system: Unfortunatly, most of the "exotic" systems are expensive and don't perform as well as a single 4-barrel manifold. If you want the bling factor, then by all means. An Edelbrock performer RPM or RPM air gap is a great all around manifold, and is cheap. There was an article in Hot Rod a few years back where they tested a 475 hp small block with a bunch of induction setups (tunnel ram, dual quads, crossram), and besides the massive Edelbrock street tunnel ram, the single carb performed much better. Just some food for thought.

Hope this helps you a little, lot of information out there to soak up. I switched my mind about 10 times before I decided to buy my LS1. Let us know how if you have any more questions.

-Andy

Mike1234

iTrader: (4)

Hi Andy,

This is a very well articulated argument for modding the current SBC since my budget is a big factor. Like you did Andy, I'm teetering on the edge with this and, just as I feel myself falling one way, another post pulls me back

From what I understand, the pistons are cast flat top 10.5:1 hypereutectic. Of course, the "build sheet" made no reference to real CR as affected by the heads... no info about the heads at all. To tell the truth, I'm a little afraid of this engine because the so-called build sheet is evidence that the builder had no idea what he was doing. I would hate to do a nice job re-doing the top just to spin a bearing, lose a rod cap, or have a rod damage the block. Yeah... the more I think about it, if I keep this SBC, the more I think I should do a complete rebuild.

If I opt for a rebuild, I want to leave some options open, such as adding a centrifugal SC. Stronger parts will cost more money. Does this affect your opinion?

I think you're right about the 383. From what I'm reading... and I'm interpolating the real issues here...to gain any real HP from the extra CI's a 383 offers requires much more than just a 400 crank. Apparently, even very good aftermarket heads are near their limits with a 350 at 6500 RPM. It takes some truly kick-a** heads to flow a 383 at 6500 RPM. These are much costlier than heads that'll flow well enough on a 350. Then there's the cost of crank, etc. I think your right about the torque issue too. Why bother if all I'm going to do is melt the tires? In other words, a really good 383 could easily cost $1K more than a really good 350 and I'd gain no real speed. Is this right, or am I bonkers?

Yeah... I do like the Cobras. I've missed some really good deals on some too... very nice completed kits in the $16-18K price range. And these were the "asking" prices. Of course, when I find these, they're alreday sold

AFR heads seem to be very popular. I'll research these and do some price checking. Assuming I "don't" yank the bottom apart, I guess I'll have to run a compression test, then measure the head chamber sizes to determine what new heads I should buy. I guess that's as good a method as any. I think the compression has to be tested with the engine warm and running at or near the upper RPM limit though, right? BTW, have you heard anything about the new 3-valve SBC heads? I'm sorry... I can't remember who makes them.

A new build will definitely include a roller cam, full roller rockers, and maybe a roller timing set too.

An OD transmission is one of the first updates. The TH400 has to go. I've found a local shop that'll build a strong 700R4 and install it for $1600 plus the cost of shortening the driveshaft. They'll mod the gearing for cost of the parts. They'll guarantee it for a year and unlimited mileage with no questions asked. I wonder if they'd give me a deep discount for advertising their business on this fake Ferrari?

Yeah, the exotic systems are pricey... up to $2500+. If I can find a truly reliable system, I'll opt for one anyway. Vintage Speed has a retro-styled modern EFI system with three dual throat throttle bodies with velocity stacks for $2600 and it comes complete with a Megasquirt controller. It looks pretty nice and it should perform well. I've heard of modded Hilborn and similar systems. There are some very interesting modern or modern-ized systems out there. I just have to find one that has the exotic looks... and can perform well too. I realize that "simpler is better" and I generally live by this rule. I just need to find that right compromise... sort of like this Fake Ferrari

Yes, this helps a lot, Andy. Like you say... there's a lot of information to soak up and I just need to keep reading until I can come to a decision which I'll never doubt nor regret... or will I?