rbat

I am ready to start my 383 rebuild next week. I have a lot of research and am trying to put it all together. I would like to get advice from people who have done this. Simple tips on the do's and don'ts from experience

I have a L-48 with TH400 auto, 3.73, performer manifold, ac, dual exhaust (no cats). The tranny has been rebuilt, engine compartment is finished and waiting for the motor

thanks

weimer20

Do you have any particular questions that you would like answered?

cottoneg

My engine from Golen:

Block: GM 2 piece block modified to accept a roller cam, thermally cleaned and Stainless Steel Shot. Inspected by MPI process. Decked, bored, honed with torque-plates and pressure washed. Clevite cam bearings and pioneer brass freeze plugs installed. 4-bolt main caps with ARP main studs

Crank: Eagle 4340 Forged Steel Crank

Rods: Scat 4340 forged steel, 6” length, floating pin.

Pistons: Mahle Forged with anti friction coating

Rings: Mahle low drag plasma rings

Bearings: Clevite H-series Main and Rod Bearings

Core Plugs: Brass Pioneer core plugs

Lifters: Comp Cams Hydraulic Roller

Pushrods: Comp Cams Magnum

Valve Springs: AFR 1.250”

Rocker Arms: Comp Cams Pro Magnum Full-Roller, 1.6 ratio

Timing Set: Cloyes True Roller

Timing Cover: New factory

Oil Delivery: Melling high volume pump, pickup tube and HD Drive

Oil Pan: Canton 6 quart Road Race

Harmonic Balancer: Fluidampr Harmonic Dampers

Gasket Set: Fel-Pro Performance

http://www.golenengineservice.com/sp...383_450lb.html

Head Bolts: ARP

Gordonm

Make sure you clearance the block properly. If not things start to contact other things and it does not go well from there. I spent about 5 to 7 hours clearancing and making sure nothing would hit at 7000 rpm. Other than that it is pretty much standard assembly.

billla

These discussions start with budget, power targets and trans/gear information. With your TH400 and 3.73 gears (sweet) you're looking to make power a little higher in the RPM band...so cam choice is going to be key.

In general, there are a couple of key points:

1. Buy a balanced rotating ***'y. Piecing together a 383 from different parts is expen$ive and takes more time.

2. Don't buy anything until your design is done. There's not a quicker way to end up with parts that don't work together than getting antsy and buying stuff right out of the gate.

3. Buy the best heads suitable for your performance goals you can afford. Heads make power - so this is probably the single most important decision.

4. The machine shop is your friend - make sure you have a good one and that they'll MAKE TIME to give you advice...and then listen to them.

Should be fun

63mako

Gordon didn't post this link so I will. With Billa good heads are the key to power. If you are planning a 450 HP street build with 6000 RPM redline which is what I would be shooting for with your driveline these are awesome heads and rockers at a great price.
http://forums.corvetteforum.com/c3-p...r-rockers.html
I would go hydraulic roller and really like the Mahle powerpack pistons. I would not even consider an externally balanced rotating assembly. Callies compstar makes a good, competitivly priced crank and rods if your going forged and the quality of machining is second to none. I think CNC Motorsports has a kit with these components.

Gordonm

The reason for it is that I should have them sold. I have a buyer who commited to buy the heads and rockers. So pending the funds arriving at my house they are sold. They are a great set of heads and produced excellent power. Heads are where HP is made so that is why I am going larger.

BLOCKMAN

Becarefull of the prebalanced kits as we have not seen them very close and one crank was off 32 grams on one end, The pistons were in a sealed box and the rods were all sealed in plastic so I could not figure out how they weighed the parts.

Becareful of the external balanced cranks as there seems to be some issues with breaking the snouts off on the cast cranks.
http://www.nastyz28.com/forum/showthread.php?t=164465

http://www.pacificp.com/forum/viewto...8d105315551ca3

billla

Definitely agree that the pre-balanced kits are rarely right on - every one I've used has always required a quick touch...but this is way cheaper than ending up with completely mis-matched components that take hours to balance or worst case...Mallory.

The parts in the balanced kits I've had from Eagle and Scat are VERY tightly weight-matched...always within .5 grams.

I'd bet cash money on any broken crank that the balancer was wrong and a harmonic developed

LFZ

If anything....spend the extra dough and go with a roller cam. With todays technology and dependability, I'd stay away from the flat tappets on high performance builds.

Billysvette

go look at my post about internal and external balanced engines,i made some mistakes,it might help you out.Bill

MotorHead

I never looked at your post but I've had both in high HP applications and done correctly the externally balanced motor is fine. I do find my new internally balanced 427ci to be very smooth though, could just be I spent twice as much on quality parts though.

Good advice above, definitely go with a roller cam if you can swing it.

I buy my heads bare and populate them myself I don't like throwing out the springs that come with pre assembled heads as how heil do they know what cam I;m running ? And then spending another 200 bucks on springs. "Spring are for solid roller cam" which one ? the one with .700" lift or the one with .500" lift

Also the heads if bought assembled they should be disassembled anyway and everything checked from valve guide clearance to valve seats sealing properly, there's a dozen or so checks a good machinist can do

Balancing is very important and should be done by someone who knows what they are doing. You want it smooth all the way to redline. All your parts should be gone over by a qualified machinist.

And finally the most time you are going to get talking to the machine shop owner is when the money is still in your pocket. So take a list, he will sit with you and answer questions for however long it takes to the money out of your pocket

rbat

sorry for being too vague.....I am putting together the plan before I buy anything, so I am a little more specific with the questions below, oh BTW the gears may be the next size (350??)

I am looking for a budget build that is 350-400 hp which is drivable and dependable (does this sound reasonable?)

will the rest of the drive be ok with this HP and TQ

will the 2 bolt main be ok

i want to stay in the rpm range of the performer (0-5500 rpm)

should i rebuild the Q-jet or get something else, if so what

will the double hump head be ok, they are milled which reduced the chambers from 64cc to 60cc

if not, which heads are the best bang for the buck

which kits are better (I am currently looking at eagle and scat)

should I go with the long or short connecting rods

which roller cam is the most aggressive that will provide enough vacuum

I have a good shop to build and balance whichever kit we get

BKbroiler

My 383 might be similar to what you are planning. Check my signature for details, but other things not described there are: 5.7 (short) rods - reconditioned & ARP bolts, 2 bolt mains, Performer intake, Eagle cast steel crank. You might want to upgrade your heads. I would estimate HP as about 350, at the flywheel.

jackson

rbat:
Still not clear, but seems you already have L48 block & 60cc double humps & plain performer intake & qjet & 3.73 gear & th400 ... seems you're planning for 400fwhp 383 BUDGET BUILD.

• next higher common gear sizes 3.55 & 3.42.
• regarding strength only; suggest you don't need forged crank nor forged pistons nor any H-beam rod for your indicated goals.
• whenever practical, avoid KB/UEM/Silvolite branded cast-hyper pistons; they're common in kits.
• 2-bolt is AOK here.
• keep & freshen qjet.
• hyper pistons Sealed Power p/n H890CP (1.425"ch, -23cc dish).
• any cast crank (scat, eagle etc) is strong enough here. However, by the time you get cast balanced right, cast can become as expensive as forged (forged crank often easier to balance).
• any 5.7 rod (scat 3/8" capscrew I-beam p/n 3-ICR5700).
• felpro 1094 head gaskets.
• above'll put you right about 9.4:1 scr.
• lotsa cam choices; plenty hydraulic FLAT tappets can reliably take above 383 to 400fwhp. Neither roller rockers nor roller cam are needed.

rotating assemblies available either balanced or not balanced; nothing in between.
Have your local shop balance. Locals cannot continue to help you unless you help feed them more than scraps. At least give locals a chance at pricing out crank, rods, pistons etc.

If you spend a bit more, you can go w/ forged pistons Sealed Power p/n LW2620F (1.125"ch, -21cc dish) that'll bump scr to about 9.6:1; they'll require 6" rods (scat p/n 3-ICR6000).

?Are you personally doing the clearancing, prep & assembly?

*sealed power-fed mogul-speedpro scr calculator
http://www.power-21.com/federalmogul...lculator4.aspx

billla

You're not being vague - you're brainstorming Design is an iterative process, you create a general design and refine it...this is the right way to do it. There are a ton of options.

However, you do need to set a budget - without this there's no driver for hard decisions.

400 HP from 383 CID is less than 1.1 HP/CID - easily achievable. Assuming you want to keep your stock, reworked heads this is a very reasonable target.

Your drivetrain is fine for this much power. If the trans is tired, then it's worth putting an overhaul on your calendar. You will want a torque converter upgrade.

2-bolt main is fine up to about 450HP with ARP studs, which will require an align-hone.

Your performance rebuilt Q-Jet will be fine for this power level and displacement.

I strongly recommend Scat over Eagle; I've personally had too many Eagle products arrive far out of spec on their cast products. If you're confident that you're not going to use a power-adder later, a cast crank and hypereutectic pistons is fine. For a daily driver, I'd stick to the 5.7 rods over the 6.0 rods - there are benefits to a longer rod, but at these power levels it's very little.

The heads set the parameters for the cam - if the camel-humps haven't been ported, they max out between .450 and .500 lift...so a cam with more lift than that provides no real benefit. If there was a single place to think about investing, this would be it. However, with no budget there's absolutely no way to give head guidance...and if you really only want to make 400 HP you can get pretty close with your existing heads. I agree that in this power range the spend for a retrofit roller isn't really giving you much return for the $$$.

A caveat: all the above is predicated on using most of what you have to hit the power targets you've outlined - and with no budget. Providing a budget will allow discussion of what you COULD achieve for power levels and much better guidance on design.

rbat

Quote:

The heads set the parameters for the cam - if the camel-humps haven't been ported, they max out between .450 and .500 lift...so a cam with more lift than that provides no real benefit

.
My heads and intake manifold will be ported to match

Quote:

Providing a budget will allow discussion of what you COULD achieve for power levels and much better guidance on design.

I am trying to keep it as reasonable as possible without compromising reliability, but have enough gains to justify stroking over a 350 rebuild. I am looking for the most power for the buck and still maintain drivability and reliability
My local shop will be ordering the parts as well as the complete rebuild and machine work. They will be balancing ANY kit I go with to be safe

thanks for all the help so far, the more you know, the more you realize you don't know

billla

Don't bother intake matching at this power level - it's just not worth it. Cleaning up the bowl and the short radius are about the best thing you can do (or have done).

rbat

How much HP/TQ am I gaining by stroking (compared to the same build components @ 355 ci) and are ther any other advantages.
Just want to make sure there is a gain for the added expense

rbat

Thanks for all the replies. The heads I have were decked too much.
Sooo, now I need heads too :drunk: . I want to stay with the old style outer parimeter valve cover mounts and really don't want to deal with buying used. Any sugestions for the best heads for the money. Looks like I may be priced out of the stroker now,
thanks again :thumbup: