scat cranks & related info

grumpyvette

Administrator
Staff member

Chevy V8 bore & stroke chart

Chevy V8 Crankshaft Journal Sizes

Here's a list of Chevy V-8 crankshaft journal sizes. All journal sizes are given in "STANDARD" sizes. Your crankshaft may have been cut down in size previously by a machine shop. Make sure your crank will work in the block you have. Blocks were made for each crank main journal size. If you are putting a "small" or "medium" journal smallblock crank into a "medium" or "large" journal smallblock block you will need crank bearing "spacers" or use special "thick" bearings available from aftermarket suppliers.

Chevy Smallblock V8 Crankshaft Journal Sizes


Gen.I, "Small Journal"
265...Mains-2.30"-Rods-2.00"
283...Mains-2.30"-Rods-2.00"
302...Mains-2.30"-Rods-2.00"
327...Mains-2.30"-Rods-2.00"



Gen.I, "Medium Journal", includes "Vortec" 305 and 350 thru '98
262...Mains-2.45"-Rods-2.10"
267...Mains-2.45"-Rods-2.10"
302...Mains-2.45"-Rods-2.10"
305...Mains-2.45"-Rods-2.10"
307...Mains-2.45"-Rods-2.10"
327...Mains-2.45"-Rods-2.10"
350...Mains-2.45"-Rods-2.10"



Gen.I, "Large Journal"
400...Mains-2.65"-rods-2.10"



Non-production Gen.I combination, using Gen.I 400 crank in Gen.I 350 block
383...400 crank, Mains cut to 2.45"-Rods-2.10"



Non-production Gen.I combination, using Gen.I 350 crank in Gen.I 400 block
377..."Spacer" or "thick" main bearings with 350 crank-Rods-2.10"



Gen.II, "Medium Journal", includes "L-99" 265, "LT-1" 350, "LT-4" 350
265...Mains-2.45"-rods-2.10"
305...Mains-2.45"-Rods-2.10"
350...Mains-2.45"-Rods-2.10"



Non-production Gen.II combination, using Gen.II 265 "L-99" crank in Gen.II 350 block
302...Mains-2.45"-Rods-2.10"



Gen.III, includes '97-2005 "LS-1" Corvette, Firebird, Camaro
345...Mains-2.558"-Rods-2.10"



Corvette "ZR-1", DOHC, "LT-5"
350...Mains-2.76"-Rods-2.10"


CID BORE STROKE
262 = 3.671" x 3.10" (Gen. I, 5.7" rod)
265 = 3.750" x 3.00" ('55-'57 Gen.I, 5.7" rod)
265 = 3.750" x 3.00" ('94-'96 Gen.II, 4.3 liter V-8 "L99", 5.94" rod)
267 = 3.500" x 3.48" (Gen.I, 5.7" rod)
283 = 3.875" x 3.00" (Gen.I, 5.7" rod)
293 = 3.779" x 3.27" ('99-later, Gen.III, "LR4" 4.8 Liter Vortec, 6.278" rod)
302 = 4.000" x 3.00" (Gen.I, 5.7" rod)
305 = 3.736" x 3.48" (Gen.I, 5.7" rod)
307 = 3.875" x 3.25" (Gen.I, 5.7" rod)
325 = 3.779" x 3.622" ('99-later, Gen.III, "LM7", "LS4 front wheel drive V-8" 5.3 Liter Vortec, 6.098" rod)
327 = 4.000" x 3.25" (Gen.I, 5.7" rod)
345 = 3.893" x 3.622" ('97-later, Gen.III, "LS1", 6.098" rod)
350 = 4.000" x 3.48" (Gen.I, 5.7" rod)
350 = 4.000" x 3.48" ('96-'01, Gen. I, Vortec, 5.7" rod)
350 = 3.900" x 3.66" ('89-'95, "LT5", in "ZR1" Corvette 32-valve DOHC, 5.74" rod)
364 = 4.000" x 3.622" ('99-later, Gen.III, "LS2", "LQ4" 6.0 Liter Vortec, 6.098" rod)
376 = 4.065" x 3.622" (2007-later, Gen. IV, "L92", Cadillac Escalade, GMC Yukon)
383 = 4.000" x 3.80" ('00, "HT 383", Gen.I truck crate motor, 5.7" rod)
400 = 4.125" x 3.75" (Gen.I, 5.565" rod)
427 = 4.125" x 4.00" (2006 Gen.IV, LS7 SBC, titanium rods)

Two common, non-factory smallblock combinations:

377 = 4.155" x 3.48" (5.7" or 6.00" rod)
400 block and a 350 crank with "spacer" main bearings
383 = 4.030" x 3.75" (5.565" or 5.7" or 6.0" rod)
350 block and a 400 crank, main bearing crank journals
cut to 350 size

ALL production big blocks used a 6.135" length rod.
CHEVY BIG BLOCK V-8 BORE AND STROKE


366T = 3.935" x 3.76"
396 = 4.096" x 3.76"
402 = 4.125" x 3.76"
427 = 4.250" x 3.76"
427T = 4.250" x 3.76"
454 = 4.250" x 4.00"
477= 4.5" bore x 3.76" stroke
496 = 4.250" x 4.37" (2001 Vortec 8100, 8.1 liter)
502 = 4.466" x 4.00"
557T= 4.5 bore 4.375" stroke
572T = 4.560" x 4.375" (2003 "ZZ572" crate motors)

T = Tall Deck

ALL production big blocks used a 6.135" length rod.

http://www.chevydiy.com/1955-1996-chevy-small-block-performance-guide-crankshafts-manual-part-2/#

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Watch these, they are interesting, and while I don,t agree with all the info in the videos below, watch them all the way thru and see if you catch the few things that are occasionally wrong or done poorly, and yes theres good tips and info




https://www.youtube.com/watch?v=jHeO1h3U4GE

https://www.youtube.com/watch?v=Q3Qm7vRoPKo
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Ive used the clevite (H) in dozens of engines without any problems , (obviously measure clearances and order the correct bearings )
cle-ms829h_w.jpg


http://www.summitracing.com/search/make/chevrolet/engine-size/5-7l-350/engine-family/chevy-small-block-gen-i?keyword=clevite (h) bearing sets

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don,t assume the bearing journal diameters are correct, on any crankshaft,
, ( while they are almost certainly correct on a SCAT crank)
its good practice and certainly smart to measure carefully to be 100% sure, and that youve purchased and matched them to the correct matched bearing set!
it helps a great deal if you take the time and effort to find a trust worthy and reasonably priced local machine shop , and trust me when I say this is critical, and yes, the machinist will seem to point out endless things that should be done to increase durability, or just allow proper component function,and a good machinist will try to guide you in component selection to help avoid mis-matched parts and low quality parts being used, yes quality parts and machine work, ALWAYS COST more than you may expect them too!

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http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/

http://www.ohiocrank.com/chev_bb_shortb.html

http://garage.grumpysperformance.com/index.php?threads/piston-related-info.110/

http://garage.grumpysperformance.com/index.php?threads/496-bb-with-internal-balance.10743/

http://garage.grumpysperformance.co...ng-and-basic-piston-ring-info-youll-need.509/

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/#post-60300

http://garage.grumpysperformance.co...-displacement-street-engine.10961/#post-48359

http://garage.grumpysperformance.com/index.php?threads/tall-deck-big-block-related-threads.10391/

http://garage.grumpysperformance.com/index.php?threads/which-496-bbc-engine.12291/#post-60423

http://garage.grumpysperformance.co...g-block-head-comparison.319/page-2#post-56649

http://garage.grumpysperformance.com/index.php?threads/build-a-496-stroker-bbc.101/#post-49427

http://garage.grumpysperformance.com/index.php?threads/block-choice.10472/#post-43984

http://garage.grumpysperformance.com/index.php?threads/scat-cranks-related-info.10930/#post-47993

http://garage.grumpysperformance.co...apless-top-piston-ring-sets.10555/#post-44980

http://garage.grumpysperformance.com/index.php?threads/block-prep.125/page-2#post-58033

http://garage.grumpysperformance.co...-on-the-cheap-well-to-start.11739/#post-55365

http://garage.grumpysperformance.com/index.php?threads/what-big-block-is-it.11655/#post-54494

http://garage.grumpysperformance.com/index.php?threads/scat-cranks-related-info.10930/#post-47993

http://garage.grumpysperformance.co...-15-years-later-after-long-term-storag.10443/

http://garage.grumpysperformance.co...g-block-pushrod-guide-plates.4596/#post-52034

http://garage.grumpysperformance.com/index.php?threads/build-a-496-stroker-bbc.101/#post-49427

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/page-2#post-49183

http://garage.grumpysperformance.co...-calculators-and-basic-math.10705/#post-72061

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

http://garage.grumpysperformance.com/index.php?threads/picking-a-cam-for-street-strip-496-bbc.13384/

http://garage.grumpysperformance.co...-car-craft-magazine-big-bang-big-block.10830/

http://garage.grumpysperformance.com/index.php?threads/striders-540bbc.1356/
 
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Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member

YES READING LINKS WILL HELP A GREAT DEAL
http://garage.grumpysperformance.com/index.php?threads/thrust-bearing-wear.619/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68861


http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

http://garage.grumpysperformance.co...ed-holes-in-bearings-shells.10750/#post-53298

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-44530


http://garage.grumpysperformance.com/index.php?threads/which-torque-wrench.342/#post-10864


SKIPPING READING THE LINKS IS GENERALLY GOING TO BE A MISTAKE
http://www.superchevy.com/how-to/engines-drivetrain/4380-bearing-clearance-info/

https://www.chevyhardcore.com/tech-...ies-measuring-and-setting-bearing-clearances/

https://www.chevydiy.com/pre-assembly-guide-build-chevy-small-block-engines/

http://knowhow.napaonline.com/know-notes-measure-engine-bearing-clearance/

https://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/cl77-1-205r.pdf

http://www.superchevy.com/how-to/engines-drivetrain/0707ch-main-bearing-clearance/

https://www.enginebuildermag.com/2013/03/bearing-clearances/

https://blog.k1technologies.com/how-to-check-bearing-clearances

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http://www.homedepot.com/p/Powerbuilt-23-Piece-Ball-Joint-U-Joint-Service-Kit-648617/203120548?cm_mmc=Shopping|THD|G|0|G-BASE-PLA-D25T-Garage-Automotive|&gclid=CM7-rI-e-tQCFUa4wAodcnEHfg&gclsrc=aw.ds

https://www.summitracing.com/parts/ATI-918999/?image=large


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blueprint engine blocks
https://www.jegs.com/v/Blueprint-En...brand&storeId=10001&catalogId=10002&langId=-1

DART BLOCKS
http://dartheads.com/product-category/big-block-chevy/blocks/

world products blocks
https://www.billmitchellproducts.com/engine-blocks/

G.M. performance
https://www.gmperformancemotor.com/category/LS196.html
https://www.summitracing.com/parts/arp-100-9942/overview/

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one factor I find rather annoying is that every time I price out tools, I purchased years ago , or need to replace worn out tools,
, the price has increased a great deal, Ive purchased dozens of tools over the decades,
and yeah, occasionally lent those out and its seems like a great many never get returned or get returned with broken or missing parts.
yeah I'm well aware of inflation, but its still a bit of a shock when a tool you purchased a decade ago now lists for 2-3 times what you originally paid.

heres the catalog
http://www.scatcrankshafts.com/downloads/14scat_catalog_10-13.pdf

http://www.scatcrankshafts.com/rotating-assemblies/rotating-assembly-product-search/
Phone: 310 370 5501

http://garage.grumpysperformance.co...market-4340-connecting-rods.13321/#post-72048

http://garage.grumpysperformance.co...a-scat-rotating-assembly-be.11495/#post-52962

http://garage.grumpysperformance.co...haft-journal-surface-finnish.2728/#post-72042

http://garage.grumpysperformance.com/index.php?threads/types-of-crankshaft-steel.204/

http://garage.grumpysperformance.com/index.php?threads/rod-bolts-rpm-vs-stress.341/#post-68856

http://www.scatcrankshafts.com/rotating-assemblies/rotating-assembly-product-search/

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

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68850
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It looks like they use eagle crank and rods, which are a common name brand,
I've seen several guys buy and install those cranks and have friends that have used eagle rotating assembly's without issues,
but having compared them side by side with SCAT, ID PREFER SCAT,
the machine work quality and consistency was noticeably more precise on the two 383 sbc cranks,
I compared on the SCAT crank

How A Stroker Crankshaft Affects Piston Speed and Inertia.
Print Email
WisecoLogo.png
SPONSORED BY
Wiseco


001wiseco-piston-speed-k1-stroker-crankshaft.jpg


An intense look at mean piston speed, inertia, and controlling the massive, destructive forces at work inside your engine.

Engine builders have long calculated the mean piston speed of their engines to help identify a possible power loss and risky RPM limits. This math exercise has been especially important when increasing total displacement with a stroker crankshaft, because the mean piston speed will increase when compared to the standard stroke running at the same RPM.

But what if there was another engine dynamic that could give builders a better insight into the durability of the reciprocating assembly?

“Rather than focus on mean piston speed, look at the effect of inertia force on the piston,” suggests Dave Fussner, head of research and development at Wiseco Pistons.

Let’s first review the definition of mean piston speed, also called the average piston speed. It’s the effective distance a piston travels in a given unit of time, and it’s usually expressed in feet per minute (fpm) for comparison purposes. The standard mathematical equation is rather basic:

Mean Piston Speed (fpm)=(Stroke x 2 x RPM)/12

There’s a simpler formula, but more on the math later. A piston’s velocity constantly changes as it moves from top dead center (TDC) to bottom dead center (BDC) and back to TDC during one revolution of the crankshaft. At TDC and BDC, the speed is 0 fpm, and at some point during both the downstroke and upstroke it will accelerate to a maximum velocity before decelerating and returning to 0 fpm.

002wiseco-piston-speed-k1-stroker-crankshaft_2.jpg

As the piston races from bottom dead center to top dead center, for a brief moment, it comes to a complete stop. This places tremendous stress on the wrist pins. Shown, these Trend pins are offered in various wall thicknesses depending on the application.
002wiseco-piston-speed-k1-stroker-crankshaft-300x200.jpg
The mean piston speed takes the total distance the piston travels during one complete crankshaft revolution and multiplies that by the engine RPM. Piston speed obviously increases as the RPM increase, and piston speed also increases as the stroke increases. Let’s look at a quick example.

A big-block Chevy with a 4.000-inch-stroke crankshaft running at 6,500 rpm has mean piston speed of 4,333 fpm. Let’s review the formula again used to calculate this result. Multiply the stroke times 2 and then multiply that figure by the RPM. That will give you the total number inches the piston traveled in one minute. In this case, the formula is 4 (stroke) x 2 x 6,500 (RPM), which equals 52,000 inches. To read this in feet per minute, divide by 12. Here’s the complete formula:

(4 x 2 x 6,500)/12=4,333 fpm

You can simplify the formula with a little math trick. Divide the numerator and denominator in this equation by 2, and you’ll get the same answer. In other words, multiply the stroke by the RPM, then divide by 6.

(4 x 6,500)/6=4,333 fpm

With this simpler formula, we’ll calculate the mean piston speed with the stroke increased to 4.500 inch.

(4.5 x 6,500)/6=4,875 fpm

As you can see, the mean piston speed increased nearly 13 percent even though the RPM didn’t change.

003wiseco-piston-speed-k1-stroker-crankshaft.jpg

Reducing piston weight plays a huge role in creating a rotating assembly that can sustain high rpm. The seemingly insignificant gram weight of a piston is magnified exponentially with rpm.
Again, this is the average speed of the piston over the entire stroke. To calculate the maximum speed a piston reaches during the stroke requires a bit more calculus as well as the connecting rod length and the rod angularity respective to crankshaft position. There are online calculators that will compute the exact piston speed at any given crankshaft rotation, but here’s a basic formula that engine builders have often used that doesn’t require rod length:

Maximum Piston Speed (fpm)=((Stroke x ?)/12)x RPM

Let’s calculate the maximum piston speed for our stroker BBC:

((4.5 x 3.1416)/12)x 6,500=7,658 fpm

By converting feet per minute to miles per hour (1 fpm = 0.011364 mph), this piston goes from 0 to 87 mph in about two inches, then and back to zero within the remaining space of a 4.5-inch deep cylinder. Now consider that a BBC piston weighs about 1.3 pounds, and you can get an idea of the tremendous forces placed on the crankshaft, connecting rod and wrist pin—which is why Fussner suggests looking at the inertia force.

“Inertia is the property of matter that causes it to resist any change in its motion,” explains Fussner. “This principle of physics is especially important in the design of pistons for high-performance applications.”

004wiseco-piston-speed-k1-stroker-crankshaft.jpg

When the connecting rod is lengthened, it provides a softer transition as the piston changes direction. The longer connecting rod also reduces the compression height of the piston and can help pull weight out of the rotating assembly.
The force of inertia is a function of mass times acceleration, and the magnitude of these forces increases as the square of the engine speed. In other words, if you double the engine speed from 3,000 to 6,000 rpm, the forces acting on the piston don’t double—they quadruple.

“Once started on its way up the cylinder, the piston with its related components attempt to keep going,” reminds Fussner. “Its motion is arrested and immediately reversed only by the action of the connecting rod and the momentum of the crankshaft.”

Due to rod angularity—which is affected by connecting rod length and engine stroke—the piston doesn’t reach its maximum upward or downward velocity until
about 76 degrees before and after TDC with the exact positions depending on the rod-length-to-stroke ratio,” says Fussner.

005wiseco-piston-speed-k1-stroker-crankshaft.jpg

Stroker cranks such as this forged LS7 piece from K1 Technologies, are a great way to add displacement. However, when the stroke is lengthened the piston must accelerate faster each revolution to cover the larger swept area of the cylinder wall.
“This means the piston has about 152 degrees of crank rotation to get from maximum speed down to zero and back to maximum speed during the upper half of the stroke. And then about 208 degrees to go through the same sequence during the lower half of the stroke. The upward inertia force is therefore greater than the downward inertia force.”

If you don’t consider the connecting rod, there’s a formula for calculating the primary inertia force:

0.0000142 x Piston Weight (lb) x RPM2 x Stroke (in) = Inertia Force

The piston weight includes the rings, pin and retainers. Let’s look at a simple example of a single-cylinder engine with a 3.000-inch stroke (same as a 283ci and 302ci Chevy small-block) and a 1.000-pound (453.5 grams) piston assembly running at 6,000 rpm:

0.0000142 x 1 x 6,000 x 6,000 x 3 = 1,534 lbs

With some additional math using the rod length and stroke, a correction factor can be obtained to improve the accuracy of the inertia force results.

Crank Radius÷Rod Lenth

“Because of the effect of the connecting rod, the force required to stop and restart the piston is at maximum at TDC,” says Fussner. “The effect of the connecting rod is to increase the primary force at TDC and decrease the primary force at BDC by this R/L factor.”

For this example, the radius is half the crankshaft stroke (1.5 inch) divided by a rod length of 6.000 inches for a factor of .25 or 383 pounds (1,534 x 0.25 = 383). This factor is added to the original inertia force for the upward stroke and subtracted on the downward movement.

006wiseco-piston-speed-k1-stroker-crankshaft.jpg

Both the crank on the left and right are at the same point in their respective rotations. However, the piston on the left will have to travel much faster to reach top dead center at the same time as the piston on the right.
“So, the actual upward force at TDC becomes 1,917 pounds and the actual downward force at BDC becomes 1,151 pounds,” says Fussner. “These forces vary in direct proportion to the weight of the piston assembly and the stroke to rod length and they also vary in proportion to the square of the engine speed. Therefore, these figures can be taken as basic ones for easily estimating the forces generated in any other size engine.”

007wiseco-piston-speed-k1-stroker-crankshaft.jpg

As the piston reaches top dead center on the exhaust stroke, there is no cushion of compression to help slow it down. Instead, the connecting rod takes the full brunt of the force which pulls on its beam and tries to separate its cap. Quality connecting rods are paramount to a high-horsepower, high-rpm engine.
“We know a common measure used for many years to suggest the structural integrity danger zone of a piston in a running engine is mean piston speed,” sums up Fussner. “As the skydive instructor told his student, it’s not the speed of the fall that hurts, it’s the sudden stop. And so it is with pistons. So rather than focus only on the mean piston speed, let’s decide to also consider the effect of inertia force on the piston, and what we can do to reduce that force. And if that is not possible, make sure the components are strong enough to endure the task we have set forth.”

This article was sponsored by Wiseco. For more information, please visit our website at wiseco.com
a considerable enhancement too any wet sump oil pans efficiency to oil control can be made ,
through the fabrication of a semi circular perforated
sheet metal, oil control windage screen welded above , the oil control baffles in the oil pan,
located about 1/8" out from the crank assembly rotational arc,

you can weld tabs to bolt the screen into the oil pan making it a removable component. (use fine thread bolts and nyloc nuts) or weld it permanently into place
look carefully at the linked pictures below

READ THE LINKED THREAD
http://garage.grumpysperformance.com/index.php?threads/building-a-custom-wet-sump-oil-pan.65/


https://www.industrialmetalsupply.com/Products/perforated-sheet#1

https://www.industrialmetalsupply.com/perforated-steel-sheet/pss164848375

Perforated-Metal-421x295.jpg

I generally buy 12" x 24" sections of perforated 16 ga to start a windage screen project , but salvage yards at times have old scrap computer cabinet doors with perforated metal doors that can be purchased cheaply as a good source

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it would be rather useful to find a cost effective high volume oil pan and matching oil pump pick-up matching your particular application before jumping into the purchase of related parts,
don,t blindly grab your credit card and start purchasing parts think things through, measure accurately and you'll find you save yourself a great deal of wasted time and effort
fabricating a custom built windage tray like this if properly done will more than likely be cheaper AND more effective than many you could purchase
I generally use perforated steel, stainless or mild steel, galvanized or aluminum can,t be safely or easily welded into a steel oil pan, with the common mig welder, galvanized won,t weld easily and gives off toxic fumes, you can,t weld aluminum to steel
I generally buy a 12" x 24" sheet like this and make a poster card board , pattern and tape it with duct tape in the oil pan to test fit before I cut the metal ,that way I don,t screw it up before I start to cut and fit and weld it into the oil pan, the cost will generally be under $20 an oil pan
one more in an endless list of reasons to buy a decent welder in their garage shop


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yes one more in an ENDLESS LIST OF REASONS TO OWN A MIG OR TIG WELDER



 
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