Piston Head Description

[dmford]

Still trying to find out if I have a H.O. I borrowed a scope and looked at the top on the piston. There is a fish-eye lens type of distortion but the piston does has a concentric ledge approximately 1/3 of the radius away from the cylinder wall. Is this the valve relief? is it probably a H.O piston? It also has a small ~1 " diameter circle in the center of the piston.

Dave

[W2zero]

dm

Here's a link to pictures of 5.0 pistons. http://www.theottoshop.com/budget/te...ry_pistons.htm
It should help you identify the motor. I suspect that you have the generic roller motor like mine.

[Jeb]

I may be jumping into something I don't fully understand, but isn't an easy way to tell a HO from a non-HO, by looking at the firing order?

The 5.0L H.O. has the 351 firing order, the non-H.O. 5.0L has the FE firing order.

Hope this helps.

[W2zero]

Jeb
You are absitively posolutley right about that firing order. It is possible to get all the same lift and duration and such from one of the available Crane cams without the HO firing order but not much point in it. My own opinion on this engine is that it is the generic engine with the cast pistons and the .379/395 lift roller cam and the E6SE heads. It's easier to tell if they still have the upper plenum on the fuel injection so's ya can see which way it is pointed. HO to the right and Non HO to the left. You can put the HO cam in it with max 1.6 rockers and a double roller chain to get rid of that plastic gear and still have a pretty hot and durable engine.

Craig

[dmfconsult]

I have a non-H.O. bases on that link to the piston types... Oh well guess I'm gonna have to git me an E303 cam. Thanks for all your help...

Dave