THE TRUTH ABOUT 318's:
They were never designed or intended to be powerful engines.
They were designed and intended to be "The Peoples Engine".
Make enough torque to move LIGHT DUTY 3000-4000 lb. cars, trucks and vans.
Their weakness is built in.
Their weakest points are:
Camshaft....no production 318 EVER had more lift than .380" Lift.
Compression.....most 318's have a compression ratio beween 8:1-9:1.
Induction......318's almost never got more than a 2 barrel carb.
Now if you look at a 318 from the standpoint that it is JUST an engine....all of those weak factors can be overcome.
Notice how I never said a 3.91 bore is a limiting factor....nor is the 3.31 stroke....the infamous 340 shares the same stroke....but the bore is 4.04".
Like others have stated, there are pistons available to bump the compression into the Hp friendly 9.5 - 10:1 range, and ideally they should be on more peoples list....but I understand that by the time you BUY a set of custom pistons for a 318, you really should have built a 360....but I also understand the reasons people like to build 318's....they are EVERYWHERE....cheap replacement.
To build a hot little 318, there is no better recipe than the one published by HotRod Magazine. 406hp for cheap.
That, is the truth about 318's.
And if you want more truth...a Forced Induction 318 is a great idea...the factory compression is already inline, you just need a camshaft and some induction...if it breaks there is another longblock ready to go (like Hotrod says) on every street corner.
:cheers:
They were never designed or intended to be powerful engines.
They were designed and intended to be "The Peoples Engine".
Make enough torque to move LIGHT DUTY 3000-4000 lb. cars, trucks and vans.
Their weakness is built in.
Their weakest points are:
Camshaft....no production 318 EVER had more lift than .380" Lift.
Compression.....most 318's have a compression ratio beween 8:1-9:1.
Induction......318's almost never got more than a 2 barrel carb.
Now if you look at a 318 from the standpoint that it is JUST an engine....all of those weak factors can be overcome.
Notice how I never said a 3.91 bore is a limiting factor....nor is the 3.31 stroke....the infamous 340 shares the same stroke....but the bore is 4.04".
Like others have stated, there are pistons available to bump the compression into the Hp friendly 9.5 - 10:1 range, and ideally they should be on more peoples list....but I understand that by the time you BUY a set of custom pistons for a 318, you really should have built a 360....but I also understand the reasons people like to build 318's....they are EVERYWHERE....cheap replacement.
To build a hot little 318, there is no better recipe than the one published by HotRod Magazine. 406hp for cheap.
That, is the truth about 318's.
And if you want more truth...a Forced Induction 318 is a great idea...the factory compression is already inline, you just need a camshaft and some induction...if it breaks there is another longblock ready to go (like Hotrod says) on every street corner.
:cheers:
