I'm in the research stage of building a 383 Stroker. My machinist tells me that I should run a small base circle cam. I'm currently running a GM 847 that I was planning on using in the stroker. Is there a way to calculate base circle from the cam spec card or do I need to contact the cam manufacturer, Crane, in this case. Apparently the issue is rod bolt to cam clearance. Anyone running the GM847 in a 6.00 h-beam rod configuration. What kind of clearance figure should i be looking for? Also the machinist tells me that the base circle should be no more than .900. Is this a radius or diameter value?

Thanks.

 

It appears to be a trend that customers aren't listening to their engine builder and going to the Internet to find the answer.

If you don't trust what your builder is telling you, move to another builder.

Otherwise the only post that should be made on this topic is your RWHP when the motor is finished.

 

Maybe I wasn't very clear. I do believe what he's telling me, he just didn't know what the base circle of my particular cam was. I didn't get him to clarify at the time whether the value was a radius or diameter and thought someone would know without me having to call him back.

 

My intention isn't to challenge your decision at all. This isn't intended as anything but friendly chat.

If your engine builder is asking you questions on your cam, maybe you want to consider looking for an engine builder that has built high performance LT1s before?

There are many that have had reliable engines from a variety of sources.

 

Dr. Zed I appreciate your input and don't feel threatened at all. My engine builder wasn't asking me questions about my cam, he was recommending that I go with a small base circle cam for clearancing purposes. He wasn't familiar with the base circle of my GM847. He gave me a recommended base circle specification, I'm really just trying to find out what the base circle is on a GM 847 cam.

Thanks for your replies.