VG33E red line

[fiveoneO]

I'm currently planning an engine swap for my 510. I have it narrowed down to a couple of engines. I was wondering what the stock red line is for a VG33E?

[datzenmike]

Should not exceed a sustained 7500 RPM. This is a piston speed of about 4,000 feet per minute. 4,000 FPM is the limit for producing g forces during acceleration and deceleration that can be experienced by stock internal parts, rods, piston pins and rod bolts, before they begin to stretch and fail. This assumes perfect bearing clearances, adequate oil supply and parts in good condition. You can briefly exceed this but there is an element of luck involved.

 

Using on line calculators I get the deceleration of a piston and rod at over 1,100gee at 7,500 RPMs. This assumes that the distance from start to stop is linear but it isn't. The piston deceleration is highest as it nears TDC and is not constant. A one kilo (I'm sure that they will be much higher) piston and rod would experience 2,200 pounds of deceleration 125 times a second. 

 

 

[fiveoneO]

Thanks you datzenmike. I was hoping to build something that had a power band up to around 7000 rpm, and it sounds like the bottom end will handle that. 

[datzenmike]

The red line is based on the 4,000 feet per minute piston speed. The 83mm stroke crank would be rolling down the road at 45.45 MPH at 7,500 RPMs. The formula is Red line = stroke in inches X RPM /6 or 83mm = 3.27" X 7,500 = 24,525 /6 = 4087. A little over so 7,340 RPMs for an exact 4,000 FPM. Don't go much over 7K and you'er fine.

 

The shorter the stroke the higher you can rev and have the same piston speed. A longer stroke travels farther in one turn and if RPMs remain constant it has to travel faster