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Mystery Rockers
A call for help from the knowledge base that is ClubCobra.
I recently took my cobra to an open practice to give it a run and to commence the sort out phase. I thought that the engine could have a bit more go and suspected that the cam was a little mild, putting the verniers on the springs to measure gross lift confirmed my suspicions (.425in :( .291ex :eek: looks too small to be real:confused: ) However, while pulling the rocker cover I struck by the nice golden rocker gear - which upon inspection revealed the inscription "CRANE 407R" - on the top flat area, no other markings to be seen. Naturally I hopped onto the Crane Cams web site but could find no reference to any model 407R - does anyone know what i've got. The engine is old - 289w and was sitting in someones shed in the kit for years, also has an obsolete inlet manifold that Holley was able to give me info on - so I'm guessing that the rocker gear is out of date too. thankyou in anticipation LoBelly |
I would have to look ar an older Crane book on the rockers, but I can tell you that cam is either worn or it is the weirdest cam I've ever seen. The lift on the intake looks about stock but the exhsuat, which on a Ford should be a little more, is less than stock. Makes me wonder if you have a stock cam that is worn out.
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thanks for that Woodz - my suspicion is the same on the exhaust - only measured the one (in mm) and then worked it out later - should have measured more, but I suppose the bottom line is that a new cam is in order.
id be grateful if you can get the older Crane book out - I suppose the key part is the ratio, the rest doesnt matter but it might give me an idea to the quality of the other components (cam notwithstanding) ta LoBelly |
I can't help you with the catalog numbering but if you are attempting to find the ratio, here is how to do it. Use your calipers. From the side view and in one straight line, measure from the center of the pivot to the center of the pushrod hole. Do the same from center of pivot to the center of the roller tip axle. Divide latter measurment by the first; it should work out to be very close to 1.6 which is Fords standard ratio unlike Chevrolets which is 1.5. Sometimes the ratio is actually stamped on the rocker arm.
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