Stock small-block Chevy connecting rods for the 400 small block came in two lengths, 5.7 and 5.565-inches. Don’t be lured in by the idea that the so-called “pink” rod is a stronger rod. The only thing the pink rods offered was that they were shot peened and Magnafluxed.
Full Answer
How long are the connecting rods on a Chevy 400 small block?
Stock small-block Chevy connecting rods for the 400 small block came in two lengths, 5.7 and 5.565-inches. Don’t be lured in by the idea that the so-called “pink” rod is a stronger rod. The only thing the pink rods offered was that they were shot peened and Magnafluxed. Otherwise, they were forged of the same mild steel as other production rods.
What is the difference between 400 rod and stock 400 rod?
I believe that the 400 rod is 5.565 in length. So the difference in in length is greater. Best pass 8.87 at 150.98 1.212 60'. Sold 3/2018 1970 SS 396 project in progress. Bought 5/2018 usually you can go to a longer rod if your changing pistons, helps side loading, but the stock rods would be fine for what your doing
What was the stroke of the Chevy 400 small block?
As stroke increased from 3.00 to 3.25 to 3.48-inches, rod length remained the same. With the arrival of the 400 small block in 1970, there wasn’t room to maintain the piston compression height that GM desired with a 5.7-inch rod, so the engineers shortened the rod by 0.135-inch to 5.565 inches.
What size heads do I need for a 400cc engine?
The STOCK 70-74 heads, which are 76cc heads, used with 5.7 (350) rods and flat top pistons, will produce about 9.6 comp. DO NOT USE ANY STOCK 75-LATER CHEVY HEADS ON A 400.
How long is a 400 SBC rod?
CHEVROLET V-8 CONNECTING ROD LENGTHSDisplacement Cubic InchesLitersRod Length(inches)350(LT5)5.75.700350(LS1)5.76.0983836.36.0004006.65.56510 more rows
How do I know what size connect rod to get?
A Connecting Rod is measured between the centers of the crankshaft journal bore and the piston pin bore. It can be listed in inches or millimeters. The connecting rod's length will impact Rod Ratio . Also, changing the rod length will require new pistons with the correct Compression Height .
What is standard bore on a 400 SBC?
4.125" bore, 3.75" stroke. Be cautious using the oem 400 block to build a 427.
How are SBC rods measured?
Most automobiles work best with a connecting rod ratio of 1.65 to 1.75....How to Measure Connecting Rod LengthMeasure the inner diameter of the connecting rod's smaller hole using the caliper's inner jaws. ... Measure the inner diameter of the connecting rod's larger hole, using the caliper's inner jaws.More items...
What is stronger I-beam or H-beam rods?
“H-beam is a stronger design when bending stress is considered,” Davis said. “H-beam rods are more difficult to machine, so they are often more expensive. I-beam rods are easier to produce and can sometimes be lighter than H-beams. All other variables being equal, H-beam rods are the strongest design.”
What is the perfect rod ratio?
Rod Ratio: The Math We hear a lot of engine builders shoot for a ratio between 1.5:1 and 1.8:1 on a street motor, with 1.75:1 considered ideal, regardless of application. The most highly developed four-stroke engines in the world - Formula 1 and motorcycle engines - have rod ratios of more than 2:1.
How much HP can a 400 small-block handle?
With our low-compression, power-adder friendly 400-inch small-block easily exceeding 525 hp, it was time for some boost. And that's where things start to get very interesting.
How much HP does a 400 SBC have?
401 hpIn case you missed the story, the best power numbers were gained with a set of GM Performance Parts Vortec heads supplied by Scoggin-Dickey, and even then the 400 small block Chevy managed only 401 hp and 458 lb-ft of torque. We were underwhelmed.
What did 400 small blocks come in?
The 400 saw extensive use in full-size Chevrolet and GMC trucks; K5 Blazer/Jimmy, 1/2-ton, 3/4-ton, 1-ton, and even larger 'medium duty' trucks had an option to be equipped with a 400. The engine was available in midsize A-Body and full-size B-Body passenger cars until the end of the 1976 model year.
What do longer connecting rods do?
Many racing engines use longer connecting rods to help reduce piston weight while having positive effects on torque curve shape and positioning and combustion efficiency. Longer rods typically require shorter, lighter pistons. This pushes the ring pack higher on the piston.
What is the area of 1 rod?
It also denoted just one square rod, or 272.25 square feet (25.29 square metres). The rood also was a British linear unit, containing 660 feet (201.2 metres).
What is the difference between a bent connecting rod and twisted connecting rod?
Bend and Twist A bend in the rod beam results in the centerline of the big-end bore being out of alignment with the center of the wrist pin bore. A twist in the beam throws the big-end bore out-of-plane with the small end.
Who advocated long rod engines?
So far as I know, the best known early advocate of long rod engines was legendary engine builder Smokey Yunick. Smokey's reasoning tracks exactly what TopWrench explained that a longer rod yields a longer Dwell at the top of the stroke when compared to a shorter rod. Persuaded by Smokey years ago, I have for decades run long rods in a series of SBCs, both carbed and blown.
Is piston dwell at TDC a part of thermodynamics?
If anything it would fall under fluid or gas flow dynamics. And piston dwell at TDC is only a small part of it. You're making a decision based on 10 degrees of a firing cycle and there are 710 other degrees that have an impact.
How long is a 400 rod?
The rod lengths available to you range from the short 5.56-inch center-to center length of the stock 400 rod to 6.2 inches of the Scat Premium 7/16-inch rod. So what should you go for?
How big is a 400 crank?
The 400 crank has a larger main bearing at 2.650 inches diameter than all other small-block Chevys. By grinding this down to the 2.450 diameter of the stock 350 crank, the 400 crank will pop right into a 350 block, adding some 28 cubes in the process.
What size bearings are used in a 400 block?
To use them in a 400 block, spacer main bearings can be used. Scats standard forged cranks can be had in a variety of stroke lengths from 3.48 to 4.00 inches at a very economical price. Another brand of crank I have successfully used is produced by K1 Technologies.
What size cranks are available for a 350?
Unlike cheaper (and usually off-shore produced) brands of forged cranks, Scat’s budget forged cranks, as with its cast cranks, go through the same inspection given to its Winston Cup or Top Fuel cranks. These cranks are available in 3.48- to 4.00-inchstroke lengths with the 2.45 main journal sized for the 350.
How much elongation does a 9000 crank have?
After heat treating, Scat’s current 9000 series cranks are in excess of 100,000-psi yield with 6-percent elongation. Although a little more costly to cast, these cranks have a marked advantage in terms of strength and, equally important, are tougher and more ductile than the cast iron used for stock Chevy cranks.
What is the difference between cast and forged pistons?
The basic differences between these two types are related to both function and economies of cost. A forged piston is tougher and often has higher strength at temperature. A cast piston, which usually has a high or very high silicone content, may, depending on the alloy, be as strong but is harder and, as a result, experiences less skirt and ring groove wear. Also a cast piston expands less than a forged one so it can be run at closer clearances for quieter operation. Lastly, in most instances, they are cheaper to make. I intend to walk you through the aftermarket piston maze but before going there it is well worth looking at what your engine may have been equipped with from the factory.
What is ARP on a crank?
What you get here is a cap bolt (ARP) instead of a thru-bolt-style fastener. This means the rod shoulder can be ground the small amount required to clear the cam when a 3.75-stroker crank is used. This rod is also available press-fit or bushed at the pin end and in 5.7- or 6-inch center to center lengths.
How many ports does a 70-74 head have?
If you want to get started with the LEAST AMOUNT OF EXPENSE FOR HEADS, use 70-74 stock 400 heads. The 400 ports are as big as any SB heads and they come with 1.94-1.5 valves. The first upgrade you can do is to open them to 2.02 or 2.05 intake valves and 1.6 exhaust valves. If you have a VERY GOOD head person in your area who will not charge an arm ...
When did Chevy start cutting corners?
In 1975 , Chevy started cutting corners on their heads to save a little weight. In 75 the heads had a second exhaust crossover port added which produced more head heat. And by the late 70s, all SB heads (except the Bowtie heads) were light weight, thin wall castings.
Do SB heads come with rocker studs?
Most SB heads come with pressed in rocker studs. For a cam with .450 or more lift, it is almost mandatory to have screw in studs installed. The reason is because BOTH the bigger lift AND the amount of spring pressure required to handle this much lift will possibly cause the pressed in studs to pull out.
Is a BB head bigger than a SB head?
The BB heads with the the smallest valves and ports (such as a bone stock oval port BB head) ARE STILL BIGGER THAN SB HEADS WITH THE BIGGEST PORTS AND VALVES. You physically CANNOT install a valve in a SB head that is as big as a small BB valve.
stock sbc 350 connecting rod weight?
I am doing some calculations and need to know the advertised weight of a stock rod. I have been told that 615 grams is the average, is this true? Thanks in advance.
Re: stock sbc 350 connecting rod weight?
There's no such thing to me as "average " when your dealing with internal load forces, you want to be dead nuts on when These loads forces go up with the square of the rpm !!
