bsmith3163

Ok. I have decided that I would like to build the original L81 motor (100% stock) into a 383 stroker. If you have done this I would like to know everything you feel like sharing. What did u go with? What do you wish that you had done differently? What kind of HP did you really end up with? I mean everything that you feel like sharing. I do not wish re-do any mistakes that I don't have too. My budget is not unlimited but this was originally my fathers car and it will eventually become my sons after I go to meet my maker so the total cost is not the greatest concern. I want to do the build with my son Nate (12) as a father son project. I want to end up with a daily/weekend driver with between 350/420 HP engine with a roller cam and roller rockers. If the L81 is not the best block to use than I would prefer to build a kit engine rather than just dropping in a crate engine so that he understands the difference between a rod and a wrist pin. Any and all help appreciated.

BKbroiler

I converted my L48 into a 383. People here are going to say you need 4 bolt mains, forged crank and rods and high dollar aluminum heads - but you don't. All that stuff is nice and it can't hurt but I am using my 2 bolt block with a cast steel Eagle crank, reconditioned stock rods, with ARP bolts. I do have JE forged pistons. I also have GM Vortec heads, with quite a bit of work in them. This has held up for years on the street and about 200 quarter mile track passes as fast as 12.15, 110 mph.

DucatiDon

I am building one now...see my 383 build thread in the C2 section.

If I wasnt set on building a stock looking sleeper, id have done a crate engine. MUCH cheaper and with a warranty.

I went all forged, 6" rods, internal balanced, roller cam, AFR heads...the works.
11:1 compression, .560 lift cam, Still building it.

You will have to have your stock block clearanced. I had to do additional clearance after the machine shop was done. I had to grind on my windage tray to clear the rods.

What heads do you want to use? How much do you want to spend?

commander_47

You can really save some money if you don't go with the high dollar racing stuff.

It's really up to what your wallet can stand. My build was pretty conservative and it still dynos just shy of 400 hp.

Vortec heads are awesome and for about 400.00 a pair stock they will bolt right onto the 383. Instant 40 hp.

I didn't modify the heads, nor did I get aluminum. I also didn't have any valve or spring modifications and use a cam with .47 lift with no problem.

I opted for strength rather than all out speed. Although I can assure the motor is a monster.

mfeusaf

I just rebuilt my GM crate engine (4 bolt main) to a 383 stroker after a warped crank. It was a breeze. I bought a fully balanced rotating assy with everything and I mean everything included with it for $1,300. everything clearanced perfectly.
have machine shop bore 0.030" over, and clearance the block yourself. the rotating assy I went with was already ground for a stroker conversion.
Here is what I built mine with
1 Set of H860CP30 Federal Mogul Pistons Flat Top Approx Compression Ratio (10:1 With 64cc)
1 Scat/PBM 70002 Cast Crankshaft 3.750" Stroke 1pc seal
1 Set Of Scat I-Beam Floating Rods With 3/8" ARP Cap screw Bolt
1 Set of 2M139.030 Hastings Moly Std Tension Rings
1 Set of King CR807SI Rod Bearings
1 Set of King MB557SI Main bearings
1 Set of Dura-Bond CH8 Cam Bearings
1 Fel-Pro 260-1269 Complete Gasket Set
1 Melling M55HV High Volume Oil Pump
1 PBM 700 Dual Row Timing Set 3 Key.
1 Erson E110040 Performance Camshaft Hyd. (.465"/.488" Lift 224* / 234* at .05 Duration 112 L/C) (Cam can be substituted for for different applications)
1 Set PBM HA817 Hyd. Lifters
1 Set PBM 3000 Hyd. Valve springs ( 1.250" O.D. 110# @ 1.700" 300# at 1.250" up to .500" lift)
1 Set PBM 501S Chrome Moly Retainers
1 Set PBM 205 7 Deg HD Keepers
1 Set Pioneer PE100B Freeze Plugs
1 Allstar Performance 26806 Flexplate
1 Powerbond PB1050N Harmonic Balancer

bsmith3163

What was the cost of the rebuild in the end?

DucatiDon

Depends if you go cast or forged......
My forged internal AFR build is running almost $6k

Cast should be much less.

jb78L-82

I just rebuilt my OEM L-82 into a 355 with:

OEM block bored .030
JE Forged pistons/rings-9:1 compression pistons
OEM reconditioned forged rods
OEM reconditioned Forged crank
AFR 180 64 CC aluminum heads
Howards roller cam kit-Lifters/pushrods
New Hayes clutch kit
OEM L-82 aluminum Intake
Reused Shorty headers
New Harmonic Balancer
New Fuel pump
New Oil Pump
Reused L-82 oil Pan
ARP bolts
Reused Holley 4175 carb
Reused GM HEI distributor
New Wires/plugs
New Motor mounts
Reused Stewarts Aluminum Water pump
Reused Dewitts Aluminum Radiator
Resurfaced the OEM flywheel
Felpro Gaskets
I had the short block assembled by the builder and did the rest myself

Total cost $6,000

mfeusaf

I had right about $2,000 in my build. That's including all parts and machining. But I did all the work besides boring it 30 over. I also had the machinist dip the engine. I reworked the heads myself. I also installed a edelbrock performer intake manifold and flowtec long tube headers and a summit bolt kit.

DucatiDon

Check your local Machinist but here is what these services run in Cali:

Clean and mag block $75
Bore and Hone $15
R&R cam bearings $60
Square deck $100
Align Hone $125
Balance Rotating Assembly $125
Check bearing clearances $80
Wash and prep block $175

Thats $800 just for the basics before any parts.

Rings and bearings $280

Thats $1k using all old parts. If you bore you need pistons ($400)
Havent even included any gaskets yet....

Intake gasket $15
Rear main seal $40 I use the high end one.
Timing set $80
Oil Pump $80
Head Gaskets $90
oil pan gasket $25
Timing cover gasket $12
exhaust gasket $15
Fuel pump gasket $5

Thats another $400

And you likley want new camshaft, and lifters as well as plugs and wires....

Roller cam and lifters and rocker arms plus pushrods +/- $1000
Flat tappet and stamped steel are much cheaper.
So, $2400 for a roller cam upgrade with your reconditioned factory junk.

Want heads??? Add another 800- 2k
A cast rotator can be had for about $900. Forged for about $2k
Plus a generous supply of lubes, chemical cleaners, bolts, etc.

Going cheap with all new bits I just dont see it for less than $5k. unless you use a flat tappet, cast internals, and iron heads.

Rebuild and recondition..no new parts $1500

Rebuild with retro roller $2500

Rebuild with new (iron) heads and roller cam $3k

Rebuild with roller cam and aluminum heads $4k

Do the math for pistons, rods and crank.

A 383 will add about $1000 for the rotator if you go cast....$2k for forged.

Makes a crate look very appealing.

jb78L-82

The problem with crate engines from the cheaper ones to GM factory crates like the ZZ4/ZZ5 etc is that they are cheaper dollar wise in most cases but there are lots of compromises that are made in those engines along their builds. Will those engines work well in most cases? Yes, of course but are they made with the highest quality, durable, performance parts? Almost universally no. Take this as an example, no commentary on the actual company:

http://www.blueprintengines.com/inde...base-bp3834ct1

So what we have here is a 383 with the following parts:

Cast Crankshaft
Hypereutectic pistons
10:1 compression
Aluminum heads-Blueprint performance?
Flat tappet cam-.480/.486 lift, 229/230 duration
No Harmonic Balancer

Cost $3,400 plus shipping ($600?)=$4,000 Not a bad deal BUT several places for improvement.

Forged Crankshaft instead of cast-I reconditioned my forged L-82 crank in the my 355 L-82
Forged Racing Pistons instead of hypereutectic Pistons-I used 9:1 JE Forged Racing pistons/rings
AFR 180 64CC aluminum heads in my build instead of Blue Print heads
Roller cam instead of flat tappet cam-I used Howards roller .525/.525, 219/225 duration

When you start adding the cost up for the better parts (and performance) for the $3,400 crate motor, the cost is going to be over $6,500 with the better parts. Yes, you do get a warranty and it is easier but if you compare apples to apples, the crate motor most of the time is more money especially if you go with a GM crate 383-$6,500 plus shipping and even then the parts are not the best you can get doing the build yourself.

There is no free ride in life and holds true for the crate engine purchase…..

DucatiDon

Hey Jb..on a side note...how do you like that cam in your 355?
Do you have a sound clip?
Idle vacuum?

jb78L-82

Hey Don!

63Mako asked me the same recently and was going to make a go pro video this weekend but had a crack develop in my boiler so that took precedence although I did have the car out yesterday for gas….

Have about 700 miles on the L-82 355 now and probably is it for the winter now but the engine is AWESOME. The Howards roller .525/.525, duration 219/225 LSA 110 pulls like a freight train from about 3,000-6,000 RPM (I shift at 6K but still pulling hard) with the AFR aluminum heads. I have a slight oil leak at the back of the pan which I suspect may be the rear main seal although the builder for the short block says he thinks it is the pan/gasket and will fix gratis soon or in the spring. I am thinking of replacing the GM HEI distributor since it is old and the weights hang up occasionally and the Holley 4175 650CFM needs bigger primary jets (63's right now but probably closer to 67-69's) and probably a bigger secondary metering plate (going with an adjustable pro form secondary block with idle jet screws) but other than those issues all good so far. The drivability is perfect with no stumbles, hesitation etc and no detonation on 89 octane gas-none.. The idle quality is equal to the stock L-82 cam and zero issues with vacuum-brakes or lights. Looking at the engine from afar it looks like a stock L-82 unless you spot the aluminum AFR's….

DucatiDon

Yes, so my 383 will have a bigger cam 230/230 .56/.56, but i suspect the bigger cubes should tame the came...to being similar to your 355... you used AFR 180cc heads right?

I think the 180s were a good choice fo rthe 350...if you recall I put 195s on my L82..and a slightly smaller cam than yours..and i was underwhelmed.

jb78L-82

yes, AFR 180 64 CC….10.2 compression with the JE Racing Forged pistons

63mako

I believe at the power levels your looking for an internally balanced cast scat 9000 crank rotating assembly would be fine. I would recommend 4032 forged pistons and balancing at a local quality shop. I believe AFR heads are a bargain. You can get them setup with the right springs and the high Intake/exhaust ratio and aluminum allow you to run less duration especially on the exhaust side. This makes for less overlap, more power, more streetable, better idle and vacuum. You get power without sacrificing manners. Square deck and 0 deck the block and use a Felpro .039 4.125 gasket
http://www.summitracing.com/parts/fe...make/chevrolet
http://www.summitracing.com/parts/sc...make/chevrolet
http://www.summitracing.com/parts/af...make/chevrolet
http://www.summitracing.com/parts/cc...make/chevrolet
http://www.summitracing.com/parts/cc...make/chevrolet
You likely have the 2.87 rear gear ratio so if your keeping the stock drivetrain this limits the things you can do compression and cam duration. 383 helps this a lot.
This combination will get you a solid 425 HP, great bottom end, midrange, pull to redline and work with everything else well. It meets your goals, will probably run on regular fuel. 9.5 to 1 compression and be durable long term.

63mako

1 3/4 Headers, true dual exhaust, performer intake and good 750 vacuum secondary carb needed also.

mfeusaf

http://www.motorsportsunlimited.com/383-master-engine-kit-with-1pc-rear-main-seal-hydraulic-roller-camshaft/
This might be a good low cost option

63mako

He has a 2 piece rear main engine. All the 383 externally balanced kits with cast or hyper pistons are cheaper. Externally balanced SBC started in Low RPM 400 truck engines. They really are not the best option for a performance build. You get what you pay for. You can buy a cast externally balanced rotating assembly for $700 or a fully forged internally balanced for $1500-$3000 and up. Depends on budget, intended use, durability, power and RPM goals, personal preference and experience. You will see $3000 SBC crate engines and $10,000 SBC crate engines. Stay away from Eagle crank, rods and KB hyper pistons.

Silvertone

I think you could reach your power goal with a stock 350 block, crank and rods. Choose some hypereutectic pistons that will work with your cam in terms of compression. Add good heads and plumbing and you'll do fine. I did a 383 crate motor only because I wanted to find the simplest way to reach 500 lb/ft.