Crank Scrapers for 6G72?

[nodoze]

that and knife edging the crank reduces weight substantially ffwd.com does have a service for knifing our cars , i got my crank for my dsm project from the took 8 pounds off !

[akotten]

that and knife edging the crank reduces weight substantially ffwd.com does have a service for knifing our cars , i got my crank for my dsm project from the took 8 pounds off !

Wow, that is a LOT of rotating mass!

[IPD]

does knife edging work on v engines?

[BaadVR4]

Knife edging the counterweights works on all engines, but there are trade offs. While the crank loses weight when knife edged, balancing is more difficult and a fair amount of weight is put back on in the form of Mallory metal. The Mallory metal/installation is also costly. In the end, the advantage of knife edging is primarily the reduction in windage from the sharper edge.

[J_Parker]

I think knife edging is by far a more effective method or windage reduction, but it costs A LOT! IMHO, I wouldnt go that far with it unless I was building a high power F-1 engine. As far as I know the weight of the rods and pistons must be reduced to balance the whole rotating mass properly to keep the total mass down with the first hack of the knife edging, unfortunately that would compromise the strength of our rods If I had the funds to experiment with one of the engines I have in my shop, I would try to create the lowest possible rotating mass and try for very high RPM numbers, I think hitting ~10,000 RPM with a 6G72 would be something to bragg about

[J. Fast]

Can you also shave more weight off the crank if you add cross drills to the journals? Sounds like there's some good mods out there to preserve engines and keep the oiling. Kinfe the crank, add scrapers, and add cross drills. In to hear some info on someone who has any of these modifications.

[J_Parker]

I wouldn't cross drill the oil passages on our cranks, to me that's just asking for a problem in terms of snapping. I think however increasing the diameter of the jets would be beneficial, but might require a more efficient pump to supply adequate oil pressure to the system. Not only that, cross drilling a crank is usually done in a low RPM engine such as a diesel. When you reach a higher RPM the oil will begin to be centrifuged and supply less oil to the rods/bearings. The way the oil supply in our engines works is the main bearings are very pressurized and from that pressure the oil is fed through the crankshaft out into the rod bearings, etc. With a cross drilled crank the oil supply to the mains is needed to be increased significantly to feed both holes.

[IPD]

whatever steve 68 says, i'd believe the opposite. just to be safe.

[J_Parker]

Steve... STFU&GTFO, there's a link in the original post that shows that there is indeed a fucking scraper for our engines. You just proved everyone's point that you know nothing and just throw out senseless information. The second gen cranks are not cross drilled, I have one sitting in my shop as we speak and I stare at it every day...

[J_Parker]

Umm... Nope, you got me Steve, I have no idea what cross drilling is... Hey, I have an awesome idea, can you write us all a book on how you got so awesome and knowledgeable?