How To Build A 525ci Big-Block - Big-Inch Punch

How to Build 1,700-Plus Horsepower with a Blown 525ci Big-Block

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Under pressure

RPM PSI (before cooler) PSI (after cooler)
4,500 11.12 8.76
4,600 11.72 9.13
4,700 12.29 9.55
4,800 13.01 10.02
4,900 13.5 10.41
5,000 14.2 10.83
5,100 15.05 11.26
5,200 15.75 11.73
5,300 16.44 12.15
5,400 17.39 12.62
5,500 18.07 13.25
5,600 18.98 13.85
5,700 19.79 14.5
5,800 20.67 15.06
5,900 21.63 15.65
6,000 22.61 16.39
6,100 23.58 16.92
6,200 24.53 17.62
6,300 25.53 18.27
6,400 26.6 19.09
6,500 27.66 19.79
6,600 28.85 20.5
6,700 29.74 21.34
6,800 30.99 22.08
6,900 32.01 22.89
7,000 33.35 23.69
7,100 34.41 24.35
7,200 35.49 25.09
7,300 36.33 25.3

Shaft-Mount Rockers

A shaft-mount rocker system’s job is to provide valvetrain stability in the upper-rpm range; however the added benefits can also result in a gain in horsepower by minimizing movement. While that may seem fairly obvious, we also learned that T&D Machine Products offers a variety of options to custom-fit any combination. Once we spelled out our goals, T&D recommended that we add the following options: First, the spring oil holes (PN 0720), measuring 0.040 inch and placed on the bottom side of the rocker. During the lift cycle, it’s constantly oiling the springs, helping to extend the spring life. The second option was the needle bearing tips (PN 0731); these feature 23 needle bearings in the roller tips and are recommended for high-lift applications and for endurance. Lastly, the steel rocker option (PN 0727); these are built out of billet chromoly, offering minimal fatigue with incredible strength in a lightweight construction. If you’re looking for a set for your mill, it’s definitely a good idea to call T&D directly.

1112chp 28 O  How To Build A 521ci Big Block Shaft Mount Rockers 8/31

525 Buildsheet

Displacement 525
Bore x Stroke 4.500x4.125
Compression 10:1
Rod center-to-center 6.385 inches
Piston Deck Height 1.332 inches
Chamber Volume 119 cc
Rod Bearing Clearance 0.0028 inch
Crank endplay 0.010
Piston Ring endgap Gapless top, 0.028 second
Main Bearing Cap Torque 110 ft-lb (moly-lube)
Rod Bolt Torque 70 ft-lb (moly-lube)
Head Bolt Torque 80 ft-lb (moly-lube)

Parts List

MFG

PN

ITEM

Aeromotive, Inc. 11107 Billet Hex Drive fuel pump
ARP 235-4302 Head studs
235-5603 Main studs
400-7614 Valve cover studs
400-1212 Header bolts
435-1902 Oil pan studs
230-7004 Oil pump stud
334-1401 Timing cover
430-3201 Water pump
430-3504 Starter bolts
435-2101 Intake bolts
400-2401 Carb studs
430-7401 T-stat housing bolts
430-1701 Distributor stud
135-2501 Damper bolt
135-7901 Oil pump drive
200-2902 Flexplate bolts
230-7303 Torque converter bolts
Brodix 2038116 BP BB-3 Xtra 380
HV 2000 manifold
COMP Cams 11-000-9 camshaft
948-16 springs
739-16 retainers
611-16 locks
518-16 seals
8996-16 Endure-X solid-roller lifters
8531-1 (8) 9.350-inch, pushrods
8512-1 (8) 8.550-inch, pushrods
6200 beltdrive
Component Drive Systems Call geardrive system
Dart 31273344 Big M Sportsman Block
Federal Mogul C141M main bearings
C87200CHA rod bearings
Fel-Pro 10751 (2) head gaskets
1275 intake gaskets
1412 exhaust gaskets
1884 R oil pan gasket
17936 valve cover gaskets
Holley 80496 950 hp
Moroso 20403 oil pan
22163 high-volume billet oil pump
25970 dipstick kit
38361 Oil pan stud kit
MSD 85551 Pro-Billet distributor
Lunati B2Custom 4.125-inch stroke blower series crankshaft
6385FM 4340 I-beam rod set
T&D Machine Products 3128 shaft-mount rockers
The Carb Shop Call blow-through modifications
Total Seal, Inc. CT9190-255 TNT piston rings
Vortech Engineering Call V-28 123 supercharger

Pressure Loss?

If we had one issue, it was not having a large enough air-to-water cooler. Since our geardrive was spinning the Vortech V-28 123 at its maximum recommended rpm, we were expecting to see boost levels at around 35 psi. Only, this wasn’t the case, and we were seeing 25 psi at best. To locate the pressure drop, we placed boost sensors before and after the air-to-water cooler and found an 11-psi difference. Interestingly, we were averaging 30-40 hp per 1 psi of boost, which tells us there’s a good chance we can still gain anywhere from 330 to 440 hp with an appropriately sized cooler. We’re pretty pleased with the results for the time being, but you can bet we’ll get our hands on the bigger cooler and see if our theory stands true. CHP

Sources

Lunati
662-892-1500
www.lunatipower.com
Brodix
Mena, AR 71953
479-394-1075
http://www.brodix.com
Comp Cams
Memphis, TN 38118
800-999-0853
http://www.compcams.com
T&D Machine Products
Carson City, NV
775-884-2292
http://www.tdmach.com
The Carb Shop
Ontario, CA
909-947-3575
CustomCarbs.com
Vortech Engineering
Oxnard, CA 93033
805-247-0226
www.vortechsuperchargers.com
A.R.E. Performance & Machine
Simi Valley, CA 93065
805-583-0602
http://www.areperformance.com
Total Seal Inc
Phoenix, AZ 85027
800-874-2753
www.totalseal.com
Dart Heads
Troy, MI 48084
248-362-1188
http://www.dartheads.com
Component Drive Systems
(888) 388-0249
www.cachassisworks.com
Steve Morris Engines
(231) 747-7520
www.stevemorrisengines.com

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