vintagewrench
Active member
- Joined
- May 9, 2016
- Location
- Paradise
This B18 crankshaft which is going to be used for vintage road racing on a variety of different tracks and hill climbs after it is ground and re-balanced.
The standard rod journal dia. is 2.135 but it is going to be ground approximately .246" to 1.889" and Carrello connecting rods with a Honda Clevite CB1663 (or possibly a 1.850 Clevite CB1798) rod bearing are going to be used. The grind will remove some weight plus the rod bottom end will be smaller, narrower and lighter and will have only about 380 grams of rotating weight.
Photos found of other Volvo racing cranks show counterweights that have been lightened considerably. I would like to cut down the counter weights here on our heavy-duty lathe (balancing shop does not what to do it because of only having a light weight tool room lathe.) to above the final finished target weight before it goes out to be ground and balanced. This will end up leaving a lot less time spent at the balancing shop and in overall time it can be finished faster this way (spring is on the way). Also will round off or knife edge the weights in the milling machine.
Can anyone give some guidance on how to approach this project and would it be better to narrow the counterweights, which has been done in the past, or take it off of the OD of the weights assuming it can be balanced if it is done that way. Looking to have it run as smooth as possible in the 2500 to 7500 rpm range.
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