92 Octane 496 Build

Mark Bradley

Da guy in Newbury
If things go well this will be all the relevant details on my 496 build including the dyno results and specifics on the parts used that make a difference.
Some of you may recall my concern about the RPM accuracy but the curve really tells the story.
=====================

The photos attached in order are:
- Brodix HV2017 manifold.
- NGK7 plugs with ~300 miles.
- Dyno pull comparing the different air cleaners.
- Salad bowl (red line on dyno).
- Custom drop base (black line on dyno).
- Stainless Works headers

BTW: at ~4000RPM and up the motor pulls less than ~1/2” of vacuum. Even with the low profile air cleaner.
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Motor
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Block & Rotating Assembly
- 0.60 over 454 4bolt
- 4.310in Bore x 4.250in Stroke
- 4340 internally balanced crank (1500hp rated)
- Eagle H Beam Rods with 7/16" ARP 8740 rod bolts (850hp rated)
- Mahle forged +18cc Pistons
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Heads
=====================
Brodix Race-Rite 26°
P/N 2061003sscc
CNC 115cc chamber (10.2:1CR)
Compression check = 150 PSI/Cyl
2.250 intake & 1.880 exhaust
Lift/Flow @28"H2O
.200/160/113
.300/224/147
.400/280/179
.500/321/203
.600/340/221
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Cam components
=====================
- Cam (XR294HR) .571/.593 & 294°/300° w/110° lobe separation
- Short travel hydrolic rollers (15854-16)
- Ultra Pro Magnum XD 1.8:1 rockers (1828-16)
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Induction:
=====================
- FiTech MeanStreet fuel injection (Modified to 940cfm)
8x62lb injectors.

- Brodix HV2017 manifold
- 2.5” drop base with 14x4 K&N filter
=====================
Ignition:
=====================
- Pertronix III module (in original distributor & Rev limit set at 6900).

18° initial & 38° total all in by 2500 rpm

NGK7 plugs (gaped at .035)
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Exhaust:
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Stainless Works CANV679

2" primaries with 3.5" collectors.

3" stainless exhaust, X pipe & mufflers
=====================
 

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thank you for posting the details and parts info
btw that cam, has a

242 int/ 248 ex duration at .050 lift ,
if you are going to compare specs,
which is close to ideal for that application
if the truck sees any appreciable street drive time

, but in my opinion, .. a smidge conservative, if its only used for racing
in that particular application, I think I would have selected
BTW if your 496 -540 displacement BBC combo includes an engine with at least 10:1 compression and a cam with at least 240 duration at .050 lift, and oval port heads, youll almost always find a single plane intake has some advantages over a dual plane intake.
https://www.holley.com/products/intakes/single_plane_manifolds/parts/7620
7620_2[583x].jpg


if only used for racing, and with the more radical cam, and boost the compression to about 10.9:1 Id select a 4.11:1 rear gear
https://www.howardscams.com/hydraul...-502-mark-iv-3400-6800-howards-cams-120345-08

If your building a 496 stroker BBC ,
DO THE MATH THINK IT THROUGH AND ASK QUESTIONS
you should be looking at oval port heads in the 265cc-300 cc port size range
ideally, compression ratios for common pump ,street octane fuel ,would work best with about a 10.4-10.8:1
cams in the 235-245 duration at .050 lift and lift in the .580-.650 ranges generally in a hydraulic roller on a 108-110 lsa


http://garage.grumpysperformance.com/index.php?threads/sellecting-cylinder-heads.796/

http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

heads

TRICKFLOW
http://www.trickflow.com/egnsearch.asp? ... 4294867081
http://www.trickflow.com/customerservice
1-330-630-1555 • 1-888-841-6556

BRODIX
http://www.brodix.com/heads/heads.html
479.394.1075

DART
http://www.dartheads.com/products/cylinder-heads
Dart Machinery; 248/362-1188; DartHeads.com


AIR FLOW RESEARCH
http://www.airflowresearch.com/
https://www.airflowresearch.com/cylinder-heads/bbc-magnum-24-cylinder-head/

toll free: 877-892-8844
tel: 661-257-8124

Patriot Performance
Patriot Performance; 888/462-8276; Patriot-Performance.com


RHS
http://www.racingheadservice.com/rhs/cylinder-headshtml
Toll Free: 877-776-4323
Local: 901-259-1134

EDELBROCK
http://www.edelbrock.com/automotive_new ... main.shtml
Edelbrock; 310/781-2222; Edelbrock.com

BMP (world products)
http://www.theengineshop.com/products/cylinder-heads
Tel: 631-737-0372
Fax: 631-737-0467

BUTLER PERFORMANCE
http://www.butlerperformance.com/products/cylinder_heads/cylinder_head_labor.html
866-762-7527

BLUE PRINT ENGINES
http://www.blueprintengines.com/ind...sb-chevy-aluminum-cylinder-heads-cnc-machined
1800-483-4263

PRO-FILER
https://www.profilerperformance.com/
937‐846‐1333

https://www.billmitchellproducts.com/world-cast-iron-26degree-269cc/



“Quality is like buying oats. If you want nice, clean, fresh oats, you must pay a fair price.
However, if you can be satisfied with oats that have already been through the horse ...
that comes a little cheaper.”


cams

lunati
http://www.lunatipower.com/

ISKY
http://www.iskycams.com/

BRODIX
http://www.brodix.com/heads/heads.html

ERSON
http://www.pbm-erson.com/store.php?catId=327
http://usaperform.com/-c-154_206.html


CROWER'
http://www.crower.com/

KINSLER
http://www.kinsler.com/page--Home-Page--13.html

HERBERT
http://www.dougherbert.com/

DART
http://www.dartheads.com/products/engin ... big-blocks

CRANE CAMS
(I did a ton of business with the old crane cams, Ive not yet built a firm background with the new company but so far they seem competent)
http://www.cranecams.com/?show=technicalhelp

http://www.jonescams.com/2006catalog_002.htm
Ive heard good things but never used these guys

ELGIN
http://catalog.elginind.com/download/PROSTOCK.PDF


are some other companies Ive had nothing but good results from
CROWER
http://www.crower.com/media/pdf/chevrolet.pdf

CRANE
http://www.cranecams.com/uploads/catalog/Crane Cams Master Catalog.pdf

ERSON
http://www.pbm-erson.com/UserFiles/Documents/Catalogs/2013 erson catalog.pdf
http://usaperform.com/-c-154_206.html

HOWARD
http://www.howardscams.com/howards2015.pdf
https://howardscams.com/c-1268612-camshafts-and-cam-lifter-sets.html

HERBERT
http://www.herbertcams.com/herbert-cams-cam-kits/

ENGLE
http://www.englecams.com/downloads/2010_engle_catalog.pdf



that 4.25" stroke crank and 6.385" connecting rod = 8.51 inch combined
remember 1/2 the stroke or 2.125" is used here,
on a 496 4.25: stroke crank
combined with rod length and deck height
td425.png

http://garage.grumpysperformance.com/index.php?threads/427-tall-deck.15267/


http://garage.grumpysperformance.com/index.php?threads/tall-deck-options.14678/

http://garage.grumpysperformance.com/index.php?threads/427-truck-tall-deck-engine-mods.14632/
BBCbott.jpg

with a 9.8" standard deck block that requires a 1.29" pin height piston pin
with a 10.2" standard deck block that requires a 1.69" pin height piston pin

yes the piston can be slightly lower or above the deck,
and yes different head gaskets can be used but ideally you want about a .040-.042 quench
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
and yes blocks tend to measure about .020 over the listed deck height until machined
to level or square the deck surface
 
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It was built as a driver. I have hopes of seeing a track some day but that is a maybe.
The trans is a TKO600 with 3.31 and 27” tall tires.
Some more detail...
Additional Images of:
- Brodix heads with CNC combustion chambers.
- Advance curve associated to the specific springs and the advance attributed by vacuum advance.
I have a light spring set and a heavy spring set... heavy springs shown.
- I did a bit of work to my distributor to yield the total distributor advance I wanted.
- Cam spec card.
 

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Nice photos and details about the engine ! ...... And pretty much all in one place !
 
Nice photos and details about the engine ! ...... And pretty much all in one place !
I took the recommendations from Grumpy of an “all in one place” post.

This is the first build I have done for myself.
I am so grateful for the feedback from this forum and as a result of applying that feedback I seem to have made the correct decisions for my purpose.

The torque curve is so broad it makes driving her is a blast...
 
yes all too commonly guys go out and build an engine that might be near perfect for the race track,
that would be a total P.I.T.A. to live with on the street.
youll have a good deal of fun with that truck! congrats
 
yes theres a great sense of satisfaction in doing something well,
especially when you get it done and the results are impressive.
 
How can I tell if I am leaving power on the table?
I’m not looking to make the power at the risk of reliability but it seems like my 496 is a little underwhelming.
Don’t misunderstand... I’m impressed but if I take the reported 459 at the tire and multiply by 1.14 to 1.18 for drive line loss it comes up at 523 - 541hp.
That is only ~1.1hp/ci.
I’m thinking I should be 1.2 to 1.3 without too much effort.
 
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the most obvious, reason is lower compression but thats good for pump gas,
I don,t know what your fuel/air ratio was during the dyno, but it should be near 12.5:1 at anything much over 4600 rpm, and at closer to 14.5:1- 14:1 at idle up to about 3500rpm where it starts to transition richer,
I'd also like to know the exhaust backpressure reading in the header collectors at with the exhaust hooked up,4000, 5000,and 6000 rpm

Static compression ratio of 10.2:1.
Effective stroke is 3.08 inches.
Your dynamic compression ratio is 7.67:1 . thats a bit lower than ideal
Your dynamic cranking pressure is 154.23PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of PSI is 7.65 :1.
btw


your engine looks like a great candidate for a wet nitrous 100-300 hp plate system
https://www.jegs.com/i/Nitrous-Express/744/30040-10/10002/-1
 
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I completely agree with all your math as I have used the various calculators to come up with the same.
It is what it is....
cheers.
 
As for the back pressure...
I’ll work on getting that since I have an extra O2 bung on the drivers side that is immediately after the collector in the 3.5-3” reducer.
 
Tying things together... I posted on another thread the results of an 850 mile trip I took.
Average milage was 16.2 although on the last leg of the trip I decided to really push the economy practices. The last 156 mile leg was 21.88MPG.
After reviewing my logs I can see the average manifold vacuum for the last leg was up by 2.5” and that allowed my vacuum advance to pull in more timing at cruise. That put me at ~50° of total advance with the average AFR at 14.65.
 
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