lunati 496 BBC engine build-up

grumpyvette · Mar 21, 2009

heres an interesting bbc build in a magazine article

http://www.chevyhiperformance.com/tech/ ... index.html

viewtopic.php?f=53&t=9986&p=38689#p38689

Westech Performance 496 Chevy Big Block Build - A Monster Is Born
Shopping Cart
DESCRIPTION PN PRICE
AFR Cylinder heads (complete) 2101 $2,485
ARP Head bolts 135-3703 $70
COMP Rockers 1.7:1 Pro-Magnum 1320-16 $318
Intake pushrods (8.580-inch) 7906-8 $88
Exhaust pushrods (9.470-inch) 7757-8 $136
Camshaft 11-825-9 $328
Lifters 888-16 $501
Adjustable billet timing gear 8110 $214
Two-piece timing cover 271 $258
Spacer VH311 $20
EDELBROCK Victor Jr 454-R manifold 2902 $225
FEL-PRO BBC gasket kit 2805 $124
GM Gen VI big-block 12561353 $1,200
HOLLEY 1,000 cfm 80513-1 $740
LUNATI Rotating assembly EA496FMTD $4,380
Crank 4.250
Rods 6.800
King rod bearings CR849HP
King main bearings MB5147HP
Wiseco 48cc pistons WISK238A6
Wiseco rings WIW100F8-4310-5
MILODON Oil pan 30955 $304
Oil pump 18760 $68
Oil pump pickup 18201 $57
MSD Distributor 85561 $253

Dyno Chart
RPM LB-FT HP
3,500 579.7 386.3
3,600 579.6 397.3
3,700 583.0 410.7
3,800 587.1 424.8
3,900 589.6 437.8
4,000 591.2 450.3
4,100 593.8 463.6
4,200 597.8 478.1
4,300 602.7 493.5
4,400 607.7 509.1
4,500 614.3 526.4
4,600 621.5 544.3
4,700 629.9 563.7
4,800 637.0 582.2
4,900 642.1 599.0
5,000 645.5 614.5
5,100 649.2 630.4
5,200 653.2 646.7
5,300 656.8 662.8
5,400 658.3 676.9
5,500 657.8 688.8
5,600 656.0 699.5
5,700 653.8 709.6
5,800 651.8 719.8
5,900 650.2 730.5
6,000 648.1 740.4
6,100 644.9 749.1
6,200 641.2 756.9
6,300 637.7 764.9
6,400 633.3 771.7
6,500 627.6 776.7
6,600 619.1 778.0
6,700 611.5 780.1
6,800 602.2 779.7
6,900 593.2 779.3
7,000 583.8 778.1
Average torque 623
Average power 625

Sources
Air Flow Research
877.892.8844
airflowresearch.com ARP
800.826.3045
arp-bolts.com
Comp Cams
800.999.853
compcams.com Edelbrock Corp.
310.781.222
edelbrock.com
Fel-Pro
248.354.7700
federal-mogul.com Holley
270.782.2900
holley.com
King Engine Bearings
973.857.0705
kingbearings.com Lunati
662.892.1500
lunaticams.com
Milodon
805.577.5950
milodon.com MSD
915-857-5200
msdigntion.com
Westech Performance Group
951.685.4767
westechperformance.com Wiseco
440.951.6600
wiseco.com

filmjay · Apr 2, 2009

This is what you should do to that recently acquired 454.

grumpyvette · Apr 16, 2011

IVE built at least a dozen 489-496 bbc strokers and the longer 6.385" rods, vs the stock 6.135" rod length and larger counter weights on the 6.385" combo make the whole deal easier to clearance and balance,Ive always preferred a tall deck 427 block over a production 454 block, the problem is both in initial cost and transporting it once you find one and have it purchased in most cases, if your local ID swap a short deck 454 block for a tall deck 427 block in less than a heartbeat, as I find they are significantly better blocks to build a 496 stroker with, but it hardly makes sense to spend a great deal of time and effort if the cost factor becomes a burden, your better off with a DART aftermarket block with its larger bore and thicker casting and a block thats not 30-40 years old,at some point, that you can easily use to build a 540 bbc,and that points a lot lower cash value than most people realize

yes it possible to use the standard rods but their fairly short at 6.135" and counterweights clear the piston skirts far better with the slightly longer 6.385"rod length
most effective combos have about a 10:1-10.5:1 cpr ( for street strip engines) and a cam with a reasonably tight 106-108 LSA and lift over .600 and duration in the 245-260@ .050 plus range.
Id suggest keeping the dynamic compression around 8:1 for a street driven car intended to operate on pump high test gas and keep the coolant temps under 190F, so get a high capacity water pump and a decent large radiator, because with the extra hp you generate more heat!
you can obviously boost the compression ratio and go with a more radical cam duration on a race engine where street manors play less importance than brute power
obviously your parts selection needs to match the application and gearing, but a 489-496 has a great deal of potential, basically the bore and stroke are similar and the resulting displacement size makes the better flowing large oval port (280-290cc) (best for street)and smaller rectangle port heads (305-325cc)(better on a more radical combo) with a decent intake and roller cam really work well. and the piston speed maxes out at or below the rpm range (6000rpm-6500rpm) where really expensive valve train mods are usually required, most 496 BBC engine get by just fine with good heads, roller rockers and a rocker stud girdle.
be aware that not all oil pans clear the longer stroke and in an ideal world you'll have a BAFFLED 7-8 quart oil capacity, a windage screen and an oil cooler on the car.

https://www.enginelabs.com/engine-tech/engine-blueprinting-how-to-check-piston-to-valve-clearance/

after reading thru the thread Id just want to state a few points

(1) software dynos can be useful but don,t even think the actual predicted hp/tq numbers will be exactly accurate

(2) no hydraulic roller cam in my experience is worth a damn over about 6400rpm compared to a decent solid roller cam, but on a street car mid range torque is far more useful

(3) guys commonly make the mistake on big blocks of selecting a 112-114 LSA ,with a good deal of duration, big blocks are UNDER VALVED, and a tighter 106-108 LSA and slightly less total duration almost always works better

(4) try and get your dynamic compression in the 8:1 range and your quench down in the .038-.044 range

(5) on a 468-496 bbc a 290cc oval port heads fine on a 540 Id be inclined to select a 315-335 cc port head,.

(6)both the intake and header design have a very pronounced effect on your effective head and runner flow rates, a tighter LSA can benefit from the more efficient flow during overlap

(7) a strong ignition and controlling both the advance curve and fuel/air ratio is critical.

main_page=calculators&zenid=823ce2c9e2ffa691864d832c10107df0

the best solution from a performance perspective is to do the required calculations to select the longest length connecting rod and the lowest weight piston,
of a decent design that will reduce the reciprocating mass significantly more.
the tall deck has a 10.2" deck height, a good dual plane aluminum high rise intake manifold will tend to provide the best compromise if you use a low compression and mild cam duration,
while it might seem like a waste of time, now, reading the links and sub-links will provide a good base to work from, later and save you a great deal of wasted time and money
you have a choice, you can slap the components you own together, now and live with what you have built regardless of the results , or you can put some real thought into making the result perform and carefully select parts and significantly boost power... yes that routes more expensive up front, but in the long term it tends to get better results and cost LESS.
common BB CHEVY piston compression heights are
1.270"
1.395"
1.520"
1.645"
1.765"
remember the blocks deck height, minus the piston pin height minus 1/2 the crank stroke will equal the required connecting rod length
OR
the blocks deck height, minus the connecting rod length, minus 1/2 the crank stroke. will equal the required piston pin height

if you wonder why I suggest using SCAT (H) beam style cap screw connecting rods vs stock or most (I) beam designs this picture should show the increased cam to connecting rod clearance

notice the pin height in the pistons pictured above allow a longer or shorter connecting rod length

heres a selection of commonly available big block chevy connecting rod lengths

https://www.uempistons.com/index.ph...e=deck&zenid=823ce2c9e2ffa691864d832c10107df0

https://www.uempistons.com/index.php?main_page=calculators&zenid=823ce2c9e2ffa691864d832c10107df0
1.765 compression height, pistons in standard 9.8" deck block, a 10.2" tall deck requires a longer connecting rod
most likely a 6.535" aftermarket connecting rod

threads you should read through carefully,and the sub links in them are below,
the tall deck block is put to much better use building a 496 with a 4.25" stroke and a .060 over bore and 6.385" connecting rods

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/

http://garage.grumpysperformance.co...g-block-head-comparison.319/page-2#post-61658

http://www.maliburacing.com/patrick_budd_article.htm

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck-bbc.14451/

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/#post-60299

http://garage.grumpysperformance.co...-displacement-street-engine.10961/#post-50668

READ THESE
http://garage.grumpysperformance.com/index.php?threads/540bbc-335cc-afr-head-combo.10627/

viewtopic.php?f=53&t=5563&p=16836#p16836

viewtopic.php?f=69&t=170

viewtopic.php?f=57&t=4701

viewtopic.php?f=69&t=3153

http://maliburacing.com/patrick_budd_article.htm

viewtopic.php?f=54&t=64

viewtopic.php?f=52&t=319

viewtopic.php?f=54&t=2187

viewtopic.php?f=54&t=4576

grumpyvette · Dec 2, 2011

here are the details of this build.

496 4 Bolt Main,
10.2 comp,
Mahle custom modified dome pistons,
.238 @ .050 hyd roller,
"probably similar to this
ERSE119849-47
specs>> 3000-6000 298Â°/306Â° 238Â°/246Â° .548"/.548" .584"/.584" 108Â° "
AFR 265 heads, http://www.airflowresearch.com/index.php?cPath=68_111
RPM air gap intake.

grumpyvette · May 1, 2012

HEY GRUMPY, HOW DO I CHANGE MY 454 into a 496, what parts are required?

if your planing on building a 496 which is basically the big block version of a small block 383, its done by swapping to a .25" longer stroke crank , 6.385" connecting rods (which are .250" longer than the stock 6.135" rods) and using .060 over bore pistons.
Ive always preferred a tall deck 427 block over a production 454 block, the problem is both in initial cost and transporting it once you find one and have it purchased in most cases, if your local ID swap a short deck 454 block for a tall deck 427 block in less than a heartbeat, as I find they are significantly better blocks to build a 496 stroker with, but it hardly makes sense to spend a great deal of time and effort if the cost factor becomes a burden, your better off with a DART aftermarket block with its larger bore and thicker casting and a block thats not 30-40 years old,at some point, that you can easily use to build a 540 bbc,and that points a lot lower cash value than most people realize

a stock 454 has a 4.251" bore and 4" stroke and uses 6.135" connecting rods
a 496 stroker uses a 4.25" stroke crank, USUALLY 6.385" connecting rods to clear the larger crank counter weights and a .060 over bore piston at 4.310" bore
you calculate displacement
bore x bore x stroke x number of cylinders x .7854= displacement
4.31 x 4.31 x 4.25 x 8 x .7854=496

youll also find that the larger displacement and longer stroke tends to favor a slightly tighter LSA and about 10 degrees more duration than a similar 454 would use.
for hot street use, in lighter weight cars like camaros and novas with manual transmissions Ive had good results with a the 250-260 duration cams on 106-110 LSA and either large oval port or small rectangular port heads
obviously compression and rear gear ratio must match the combo used

Junkman2008 said:
Hey Grumpy, you always hear that headers give you more horsepower. How does that work and what formula can you use to determine the horsepower gain that a given set of headers may bring?

that questions a bit like asking how good a girl might be in bed based on the color of her hair brush, yes theres a mathematical formula , in fact several, but theres a whole bunch of factors that determine the results, like cam timing, compression,cylinder head flow, back pressure,engine displacement , header primary and collector length and diameter,exhaust temps,etc.
the more back pressure the exhaust system beyond the header collectors has the less effective the headers will be, but if you have a low restriction exhaust and a ram tuned intake with a matched cam timing, a tuned header can in some cases produce gains in excess of 60 hp.
as a general rule Id say your safe expecting a 25-40 hp increase in peak hp from good long tube tuned headers over stock cast iron exhaust manifolds that come on most passenger cars, but with properly matched components on a high compression engine more can be gained.

READ THESE

http://victorylibrary.com/mopar/header-tech-c.htm

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=495&p=613#p613

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=1303

viewtopic.php?f=56&t=572&p=35352&hilit=rams+horn#p35352

http://forum.grumpysperformance.com/viewtopic.php?f=56&t=185

http://www.chevydiy.com/chevy-small-block-engine-guide-exhaust-systems/

I find this graph very useful, it shows stock corvette exhaust manifolds vs headers on the same 496 BBC engine dyno test

lunati 496 BBC engine build-up

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