The Ford Barn

jeepguy1948 · 07-08-2023, 12:25 PM

If you are a purist that believes that everything must be totally stock, please move on…. Here’s my issue; I’m working on a 1951 F-1 that had a fresh .60 over Merc. Motor installed (with Edelbrock aluminum heads) run about 1,000 miles and then parked for 40 years. I am attempting to bring it back to life (I have posted other questions about it here before). I have the motor up and running quite well but I’m trying to get it really “dialed in” something’s were not sorted out when the engine swap was done. It looks to me like the aluminum heads require a longer (more threads) spark plug than the original cast iron heads did (I admit that I could be wrong about this). I would appreciate some advice about a good spark plug to use. Heads are Edelbrock “F8 M 8.5” which I take to mean “Ford V8 8.5:CR? By my calculations, if the heads made 8.5: CR on a 239” motor it probably has about 9.5;1 CR on the current +/- 270” inch motor. Engine currently has a totally stock intake and 94 Holley, stock dist with a Pertronix module, “3/4 race” cam, Red’s headers. The original Ford Load a Matic vacuum advance system is in use and working correctly. I currently have it at 24 degrees TOTAL advance. Spark plug suggestions? And while we are out it: suggestions about jet size in that Holley 94 considering the specs of the motor? Thank you!

07-08-2023, 12:25 PM	#1
jeepguy1948 Senior Member Join Date: Jan 2022 Posts: 721	Question for the guys running aluminum heads If you are a purist that believes that everything must be totally stock, please move on…. Here’s my issue; I’m working on a 1951 F-1 that had a fresh .60 over Merc. Motor installed (with Edelbrock aluminum heads) run about 1,000 miles and then parked for 40 years. I am attempting to bring it back to life (I have posted other questions about it here before). I have the motor up and running quite well but I’m trying to get it really “dialed in” something’s were not sorted out when the engine swap was done. It looks to me like the aluminum heads require a longer (more threads) spark plug than the original cast iron heads did (I admit that I could be wrong about this). I would appreciate some advice about a good spark plug to use. Heads are Edelbrock “F8 M 8.5” which I take to mean “Ford V8 8.5:CR? By my calculations, if the heads made 8.5: CR on a 239” motor it probably has about 9.5;1 CR on the current +/- 270” inch motor. Engine currently has a totally stock intake and 94 Holley, stock dist with a Pertronix module, “3/4 race” cam, Red’s headers. The original Ford Load a Matic vacuum advance system is in use and working correctly. I currently have it at 24 degrees TOTAL advance. Spark plug suggestions? And while we are out it: suggestions about jet size in that Holley 94 considering the specs of the motor? Thank you!