Home › Forum › Ask A Member › Big Four/460 Crankcase Differences › Re: Big Four/460 Crankcase Differences
On the first motor at top the original 460 parts include the flywheel and timer, the coil and brackets and the switch box. The lower unit may be 460 but I can’t see enough of it to ID. The crankcase looks to be P500. The stacks are aftermarket by Procter. The tank is not 460 but could be either Big 4 or stormboat motor. The driveshaft tube is either 460 or aftermarket by Hubbell for "F" racing.
The second motor has a front freeze plug on the front of the crankcase with the brass plug gone but it is in the position of a big 4 or stormboat motor. It has a magneto ignition so none of that is 460. It has a notched out Speedifour tower to be able to bolt on the "F" powerhead and the foot is either Speeditwin, Speedifour or Big 4. Stacks may be Procter also.
The last motor looks to be a P500 powerhead with a Hubbell lower main to adapt it to a Johnson S, P or V tower and early Johnson lower unit. The powerhead still has the P500 rope plate on the magneto and the plugwire guides on the heads. It does have a WISCO adapter on the vacturi carburetor for attaching the throttle cable and a large float bowl. The tower clamp handles are 1929 only and break easily so take care of them. This motor also has a Johnson S or P tank on it.