Engine building...

[Donbecker]

Okay, this isn't too serious of a post, as in I don't have the money to do this right now. Really just wanting some different viewpoints.

For those that don't know, I have a C3 (76) with a SB 350. The car originally came with an L-48 (weak) but I'm not sure if I have the original engine or not.

When I got the car a year or so ago (almost 2), I rebuilt the entire suspension, 100% poly, new heavy duty bilsteins, new big block front coils and a 400+ rear leaf.

Eventually I'm going to need to replace my engine, it is pretty tired. I've thought about rebuilding it, but I've recently been thinking about piecing an engine together over time.

Does anyone know what the front to rear weight ratio is on a C3 (coupe) with a 350 in it? I would love to have the power of a big block but I'm wondering if it would make cornering worse.

Also, I don't think I could deal with a tighter engine compartment.

Which leads to this...

http://www.worldcastings.com/new/feature0307.shtml

It's the world products 'hardcore 454' that makes about 600hp for around $11k.

Yes $11k. No way I could ever get approval from my 'accountant' to buy an $11k engine.

I was looking at the specs on it in my new summit catalog last night and I started just adding up the parts and looked a little high:

2k for the block

1k for the alum. heads

1.5k for the rotating assembly etc etc.

What I'm wondering is, could I realistically save money by doing all the assembly myself?

Is 600hp just ridiculous for a car that I drive daily?

I'm currently running the original 4speed and want to upgrade to the Keisler 6 speed, I think that will make my current engine last a little longer.

[Donbecker]

BTW, one of the cool things about the Motown block is that it is still a small block. If a big block would possibly alter my weight ratio, I think the motown wouldn't.

[Togo]

Okay, this isn't too serious of a post, as in I don't have the money to do this right now. Really just wanting some different viewpoints.

For those that don't know, I have a C3 (76) with a SB 350. The car originally came with an L-48 (weak) but I'm not sure if I have the original engine or not.

When I got the car a year or so ago (almost 2), I rebuilt the entire suspension, 100% poly, new heavy duty bilsteins, new big block front coils and a 400+ rear leaf.

Eventually I'm going to need to replace my engine, it is pretty tired. I've thought about rebuilding it, but I've recently been thinking about piecing an engine together over time.

Does anyone know what the front to rear weight ratio is on a C3 (coupe) with a 350 in it? I would love to have the power of a big block but I'm wondering if it would make cornering worse.

Also, I don't think I could deal with a tighter engine compartment.

Which leads to this...

http://www.worldcastings.com/new/feature0307.shtml

It's the world products 'hardcore 454' that makes about 600hp for around $11k.

Yes $11k. No way I could ever get approval from my 'accountant' to buy an $11k engine.

I was looking at the specs on it in my new summit catalog last night and I started just adding up the parts and looked a little high:

2k for the block

1k for the alum. heads

1.5k for the rotating assembly etc etc.

What I'm wondering is, could I realistically save money by doing all the assembly myself?

Is 600hp just ridiculous for a car that I drive daily?

I'm currently running the original 4speed and want to upgrade to the Keisler 6 speed, I think that will make my current engine last a little longer.

First off - a daily driven 600HP car is NO PROBLEM at all - but a bit of a gas hog i would presume

second - some C3s came with big blocks in them - so that shouldn't be an issue

third - if you thought my engine was expensive - BBC parts are sometimes twice or MORE the price of parts for the SBC - so for just over 10% of what that 454 costs, you could buy the 350 i have! remember? :D

where did you come up with 2K for a block,1K for heads, and 1.5K for rotating asembly?

i have never seen a set of good heads for a SMALL BLOCK CHEVY for $1K much less a big block! you need to reexamine those costs

[Donbecker]

Gas hog isn't too much of a concern, when I first got the car I had the carb on it and ended up getting 13mpg on a good day...I've since converted over to a TPI setup...so I know I need to investigate how to do an EFI conversion...the OEM TPI I am using will definately not work for a 600hp 454.

I know that there were some with big blocks, but (and I may be wrong) my impression was that the big blocks were much bigger than the small blocks. I hate the lack of room in the engine compartment, and going with this block I was thinking would not increase the engine external dimensions too much...

Since it is still a small block, all SBC chevy stuff fits it. The only thing that would be different would be intake and exhaust manifolds (if someone knows better, chime in and let me know!)

It was late, let me look up some prices and post what it actually says in the catalog.

Maybe I grabbed the prices for the bare heads?

[Donbecker]

Okay block 2.5k

Engine Block, Cast Iron, 4-Bolt Mains, 4.125 in. Bore, 2-Piece Rear Main Seal, Chevy, 400, Each

5/21/06 $2,419.95

Still needs to be bored out to 4.25" (they don't sell one bored out that size)

Heads are $900 each, complete (man I'm 0/2)

World Products Motown 220 Cylinder Heads

Cylinder Head, Aluminum, Assembled, 64cc Chamber, 220cc Intake Runner, Ford, 289/ 302/ 351W, Each

5/21/06 $899.95

Rotating assembly is 2k

Rotating Assembly, SBC 454, Internally Balanced, 4.250/ 4.000/ 6.00, Scat Or Eagle

5/21/06 $2,049.00

So we're here:

2.5 - block

2k - heads

2k - assembly

= 6.5

So we have around 4.5k left.

[Togo]

Okay block 2.5k

Engine Block, Cast Iron, 4-Bolt Mains, 4.125 in. Bore, 2-Piece Rear Main Seal, Chevy, 400, Each

5/21/06 $2,419.95

Still needs to be bored out to 4.25" (they don't sell one bored out that size)

Heads are $900 each, complete (man I'm 0/2)

World Products Motown 220 Cylinder Heads

Cylinder Head, Aluminum, Assembled, 64cc Chamber, 220cc Intake Runner, Ford, 289/ 302/ 351W, Each

5/21/06 $899.95

Rotating assembly is 2k

Rotating Assembly, SBC 454, Internally Balanced, 4.250/ 4.000/ 6.00, Scat Or Eagle

5/21/06 $2,049.00

So we're here:

2.5 - block

2k - heads

2k - assembly

= 6.5

So we have around 4.5k left.

a 400 is still a SMALL BLOCK

which i doubt bu reading the bore - a standard 350 has a 4.0" bore, and my 383 block has a 4.125 bore (i think) but with a longer stroke crank

unless it is a bored 396

big block engines are as follows

396, 402, 427, 454

small blocks are

302, 305, 327, 350, 400

and those heads - are FORD HEADS!

[Donbecker]

right, but the motown block is not a stock casting. They changed it around so that you can bore out to 4.25" and still have .200" on the walls.

So it's a small block, yes, but it has the actual displacement of a big block.

bore 4.25" x stroke 4" = 454, right?

The heads I meant to grab were these:

World Products Motown 220 Cylinder Heads

Cylinder Head, Motown 220, Aluminum, Bare, 64cc Chamber, 220cc Intake Runner, Chevy, 302/ 327/ 350/ 400, Each

5/12/06 $799.95

$800 apiece, they come with valves, but I'd need to get the rockers and the rest.

Just an FYI, I know the basics around engines, just have never built one from scratch before.

If I say something totally outta wack let me know, as I'd love to learn how all this stuff goes together.

[Donbecker]

Just re-read your 400 comment... they don't sell the block bored to 4.25, I'd have to get that done... but the block I referred to from what I understand is the same block that they use in the crate engine in the first post. Make sense?

[Togo]

Just re-read your 400 comment... they don't sell the block bored to 4.25, I'd have to get that done... but the block I referred to from what I understand is the same block that they use in the crate engine in the first post. Make sense?

i guess it makes sense somewhat - so you aren't actually talking about buying a BIG BLOCK - you are talkinag about buying a small block with big block displacement.

BIG DIFFERENCE!!!!!!!

the torque you will get from an actual big block would be INSANELY high, but with the same cubes in a small block, will be MUCH lower - why? i don't exactly know, but i'm sure it has something to do with rotating "mass" as obviously big block parts are larger and heavier - i could be wrong, but that's probably the easiest way to describe it.

not to mention, on a true big block, your intake would be useless, because it wouldn't fit, not because it isn't capable of supporting 600 HP!

i may not be an expert, but one thing my old man taught me while he was still on this planet was that big block chevy motors will break the bank - so stay away from them!

[Donbecker]

totally agree with you about the big blocks, and I am certain my 86 OEM TPI won't be enough.

As a side note I once heard that the OEM TPI was actually designed for 305's and scaled up to work with 350's. Also heard that at most I could use it on a 383.

So that is definately a major hurdle. With my current setup in the car I could get the fittings to run with a carb for awhile if needed. I've heard that engines should always be broken in with a carb, even if they are destined for EFI.

I believe that an actual big block would have more torque, the crate in the first post is rated at 600 horsepower and 585 foot pounds torque on pump gas...which works for me.

[Togo]

totally agree with you about the big blocks, and I am certain my 86 OEM TPI won't be enough.

As a side note I once heard that the OEM TPI was actually designed for 305's and scaled up to work with 350's. Also heard that at most I could use it on a 383.

So that is definately a major hurdle. With my current setup in the car I could get the fittings to run with a carb for awhile if needed. I've heard that engines should always be broken in with a carb, even if they are destined for EFI.

I believe that an actual big block would have more torque, the crate in the first post is rated at 600 horsepower and 585 foot pounds torque on pump gas...which works for me.

even it it would be enough, it still wont' fit, it is a small block manifold, on a big block with big block heads - so it would not bolt up

or are we still talking about the 400 small block?

[Donbecker]

ah, well I was always talking about the 400 small block bored to 454...

takes all small block parts.

I did a quick check and was only able to find a couple of intakes that would work... no prices and I'm guessing they'd be really pricey.

[Togo]

ah, well I was always talking about the 400 small block bored to 454...

takes all small block parts.

I did a quick check and was only able to find a couple of intakes that would work... no prices and I'm guessing they'd be really pricey.

you might be good with holley stealth ram - it's kinda tall, but should fit under your hood just fine - as it won't fit under a stock C4 hood. and they are about $280ish

[Donbecker]

The crate comes with a 1050 dominator.... as in 1050 cfm.

but I think that includes the secondaries open all the way? So primaries would be 525?

Going here: http://stealthram.com/flowcomparison.html

You can see a comparisons between the stock GM TPI and some others...

They state that the stock flows around 200, the holley is 275, 300 with mods.

Heading here: http://www.arizonatpi.com/products.html

They show the Accel Pro Ram 1200 (as in 1200 cfm) as the only thing for a small block pushing that much power.

$2.6 with the computer: http://www.sdpc2000.com/catalog/4332/produ...tion-System.htm

I already have an EFI setup I can convert...so besides the tb and intake, I would need injectors, the rails, probably a new fuel pump and lines, and an adjustable fuel pressure regulator.

[sloryde]

The T.P.I. setup is low revving (unless you get an aftermarket setup like accel or others). That being said it would work well to get 383 stroker as it is a stroker with relatively low cubic inches. Get a reasonable comp. ratio like 9.5:1 and a higher lift (relatively speaking) cam with a short duration. This setup would have lots of torque and not have to be revved high. Perfect for T.P.I. as stock setup is only good to the low 5k r.p.m.anyway. With a torquey low R.P.M. setup you wouldn't need a bottom end that would break the bank as you won't be revving that high. It would probably get decent mileage as you wouldn't need to use low gears to stay "on cam". Joe

[92ZR1Wannabe]

Just re-read your 400 comment... they don't sell the block bored to 4.25, I'd have to get that done... but the block I referred to from what I understand is the same block that they use in the crate engine in the first post. Make sense?

i guess it makes sense somewhat - so you aren't actually talking about buying a BIG BLOCK - you are talkinag about buying a small block with big block displacement.

BIG DIFFERENCE!!!!!!!

the torque you will get from an actual big block would be INSANELY high, but with the same cubes in a small block, will be MUCH lower - why? i don't exactly know, but i'm sure it has something to do with rotating "mass" as obviously big block parts are larger and heavier - i could be wrong, but that's probably the easiest way to describe it.

not to mention, on a true big block, your intake would be useless, because it wouldn't fit, not because it isn't capable of supporting 600 HP!

i may not be an expert, but one thing my old man taught me while he was still on this planet was that big block chevy motors will break the bank - so stay away from them!

Hot rod mag once did a great article where they built a 427 CI small block , and a 427 CI BB and ran them down the track in the same exact cars, all things equal.

The small block was faster , made a tad less power , but the weight savings was enough to make the difference.

Unless of course you wanna buy a alum. BB

[Desertdawg]

A big block chevy CAN be assembled from readily available parts that weights close to or even less than a small block using expensive options like an aluminum block and heads,intake,water pump, etc.......but lets look at the more common style combo with an IRON block and aluminum heads, intake, water pump. you'll be about 80lbs-90lbs heavier than an iron small block combo, but what do you gain for that extra weight?

first you gain much better flowing heads,larger stronger rotating assembly and potentially at least a larger displacement, and better engine cooling, a wider head gasket seal area between the cylinders, and generally significantly more hp at the rear wheels if both engines are built to a similar hp per cubic inch level of power.

lets look at that!

lets assume your sbc corvette weights 3500 lbs and has a 383 stroker based on the common 350 block, producing 470hp

a similar big block stroker would be a 496, this gives you a 113 more cubic inches, if both engines make about the same 1.23 hp per cubic inch that small block makes the big block will make about 608hp but the car would weight approximately 120 lbs more, yet the small block with 470hp is pushing 7.44 lbs for each hp, the big block combo even thought its 120 lbs heavier(engine plus accessories) has only 5.95 lbs per pound to accellerate...........approximately a 20% advantage, now both engines can be made larger, or more powerful but the ratio and potential advantages only get slanted even more in the bbc favor

[Desertdawg]

"settle a myth for me -- what would gas mileage look like for a properly tuned bbc in a lightweight car like the c4 -- some of us still have to drive to work"

a big block with a driver that puts his foot in it regularly will use significantly more fuel....but drive for economy, seldom getting the engine over about 3500rpm and the difference between a performance sbc and a similar hp bbc is just not that great, it takes a certain amount of fuel air mix burnt efficiently to produce a certain amount of hp REGUARDLES of the engine size, its very common for a properly tunned bbc to get 17-20mpg or better when geared correctly and driven conservatively, with a manual or OVERDRIVE transmission, ESPECIALLY on the highway.

the problem is most guys with a big block under the hood DON,T DRIVE CONSERVATIVELY, if you do the math a 454 spinning an average of 3500 rpms burns exactly the same volume of fuel air mix as a 383 thats spinning an average of about 4150rpm....and theres no comparison in the tq produced, the big block properly built wins, better designed cylinderheads and a larger bore makes the cylinders and ports on a bbc superior

"Why not just stay with a nicely built small block? "

with a iron block,aluminum heads,intake and water pump the difference in weight between a bbc and a sbc is less than 100 lbs, closer to 70 lbs actually,

heres a bbc C4

http://www.3cinc.net/index.html

now I know you did not really ask, this question exactly,but this would weight LESS that the factory sbc engine ,you might want to look at this, its a rough idea still needing careful parts matching checks, before finalizing , its for a serious race only application, and at this point the combo needs tweaking, if anyone can post a picture of the DD DYNO power curve Id appreciate it as I can,t POST that PICTURE

Corvette Dream engine, the ideas to get 700hp before the giggle gas injection,AND not to exceed 6000rpm, maximizing power from 3000rpm-6000rpm is the concern, I don,t want to change the bore/stroke or cylinder heads feel free to point out potential problems its still a rough draft idea at this point , its similar to other engines Ive built but with several new part designs and yeah its only going to see 115 octane not pump gas

TALL DECK 4.5 bore Block #083111

http://www.worldcastings.com/docs/05_cat_pg7.pdf

heads #020750-4 ??.345cc

http://www.worldcastings.com/docs/05_cat_pg23.pdf

intake single plane dominator style

http://www.worldcastings.com/docs/05_cat_pg27.pdf

crank 4.375 stroke

http://www.dougherbert.com/chevy-4340-forg...tml?cPath=1_359

solid roller cam

http://www.dougherbert.com/8620-billet-rol...?cPath=83_84_87

roller lifters

http://www.dougherbert.com/catalog/product...oducts_id=10117

rockers

http://www.dougherbert.com/catalog/product...oducts_id=12702

pistons

http://www.kb-silvolite.com/forged.php?act...etails&P_id=399

RODS/ 6.8? eagle

http://www.jegs.com/cgi-bin/ncommerce3/Pro...240&prmenbr=361

dominator carb, 1150cfm

http://www.jegs.com/cgi-bin/ncommerce3/Pro...189&prmenbr=361

500hp nitrous direct port injection

http://www.jegs.com/cgi-bin/ncommerce3/Pro...771&prmenbr=361

oil pan

http://www.jegs.com/cgi-bin/ncommerce3/Pro...756&prmenbr=361

yeah, its a 14:1 cpr 555 bbc, yeah the pistons are .058 out above deck ,unless machined, if the decks at minimum, they will be custom fitted or replaced with custom made, but the vettes handling would be improved over stock and the corvette should easily run respectable times

[Donbecker]

Dude that was EXACTLY what I was looking for.

One thing in the second post that is REALLY interesting is "maximizing power from 3000rpm-6000rpm" as getting the power band / rpm range as wide as possible would be awesome for minimizing shifts in autoX which is eventually what I'd like to do.

[Desertdawg]

Have you been autoXing yet?

I think you may be heading in the wrong direction if you want to build it for autox, big HP numbers are not necessarily faster on an autox course. The first thing anyone will tell you is "Fast is between the ears, not under your right foot" which means you need to learn to drive what you have to go fast.

If you build a monster for the autox and then try to learn how to drive it, it's going to bite you and your times will not be competitive. I have been a few times in my almost stock 82, and my times are pathetic compared to some of the little 4 banger imports running with other rookies driving, I am still learning how to keep my measly 200 hp under control in the corners without the rear leading the way.

You would be better off spending your money on suspension and tires long before you go looking for 400 hp...

[Donbecker]

tires yes, suspension is pretty good...as far as it can be without spending big bucks and buying a welder.

Haven't autoX yet, might do it in a couple months after i have a little $.

[Desertdawg]

It's really cheap to autox, heres the link to the next event...

http://www.azsolo2.com/details/event20060429.html

There is also another one about mid May that I was thinking of going to, let me know if your intrested...

I would suggest going with your vette the way it is now as long as it's safe and reliable, you really don't want a monster to learn in.... Tires would be the very first thing to upgrade. The last time I ran, I really felt I was at, or close to the limit of my street tires...Plenty of 4 wheel drifting, and one stupid spin...

[Donbecker]

I'd like to go, but I have the cheap firebird seatbelts in it, and the upper part where they attach doesn't let them move freely.

I really would hate to get down there and have them turn me down for the tech thing, else I'd go....

Wait that's a different one, I'll have to look into it tonight!

[Desertdawg]

You may have been talking about "track days" where you get to run on the race tracks with lots of rules for passing and such. Autox is where you run around the cones in a parking lot...

Autox to me is 100% safer for mr and the vette...

[Donbecker]

yeah I think that would be the best thing, as I don't have a backup car.