trigger_andy
Well-Known Member
- Joined
- Feb 3, 2006
- Messages
- 469
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- 154
Hello all,
I hope Im not going over old ground here although I feel I will be but I have done some research and thought Id throw it out here and see what the experts think.
I have a '73 340 coming over from the US to the UK in the next month or so and will have that rebuilt to some spec but that will be a project that might take a year depending on funds. In the meantime I have an 318 running smoothly although I feel its underpowered even for a 318. I dont know what mods its had other than its got a 1406 Edelbrock Performer carb and Edelbrock Performer intake. (I have a 1405 calibration kit coming for the carb regardless what I do)
The 318 has standard 2843675 heads but I have a set of 4027596 360 heads and I fancy having ago at porting them and fitting them to the 318 as a small side project. Ive done my research on porting and Im itching to give it ago, if I bugger it up no loss really.
From what I gather the 2843675 heads chamber volume is 67-68-5cc with a minimum recommendation of 60.1cc. The 4027596 heads I believe have a capacity of 71cc so to keep even the same crappy CR I'll need to lose 3-4cc. Ideally Id like to up the CR but as Im not wanting to spend much money on the 318 as I have the 340 coming over in a few months.
So I guess my question is how much can I mill off the 4027596 heads and they will still be usable and a performance upgrade over the 160cmf 2843675 Heads? From what Ive read this head will need 0.0043'' off the head to drop one CC and I'll have to Mill 0.0095" from the intake surface for each 0.010" milled off the deck surface of the head.
Will the Edelbrock Intake and Carb still be usable? Obviously it will be jetted and the springs and rods changed to suit.
I doubt getting 2.02" valves installed will be worth it on an otherwise stock 318 and I also presume unshrouding the Heads will be of much benefit either? (all things planned on the 340.
Thanks in advance for the feedback.
Andy
I hope Im not going over old ground here although I feel I will be but I have done some research and thought Id throw it out here and see what the experts think.
I have a '73 340 coming over from the US to the UK in the next month or so and will have that rebuilt to some spec but that will be a project that might take a year depending on funds. In the meantime I have an 318 running smoothly although I feel its underpowered even for a 318. I dont know what mods its had other than its got a 1406 Edelbrock Performer carb and Edelbrock Performer intake. (I have a 1405 calibration kit coming for the carb regardless what I do)
The 318 has standard 2843675 heads but I have a set of 4027596 360 heads and I fancy having ago at porting them and fitting them to the 318 as a small side project. Ive done my research on porting and Im itching to give it ago, if I bugger it up no loss really.
From what I gather the 2843675 heads chamber volume is 67-68-5cc with a minimum recommendation of 60.1cc. The 4027596 heads I believe have a capacity of 71cc so to keep even the same crappy CR I'll need to lose 3-4cc. Ideally Id like to up the CR but as Im not wanting to spend much money on the 318 as I have the 340 coming over in a few months.
So I guess my question is how much can I mill off the 4027596 heads and they will still be usable and a performance upgrade over the 160cmf 2843675 Heads? From what Ive read this head will need 0.0043'' off the head to drop one CC and I'll have to Mill 0.0095" from the intake surface for each 0.010" milled off the deck surface of the head.
Will the Edelbrock Intake and Carb still be usable? Obviously it will be jetted and the springs and rods changed to suit.
I doubt getting 2.02" valves installed will be worth it on an otherwise stock 318 and I also presume unshrouding the Heads will be of much benefit either? (all things planned on the 340.
Thanks in advance for the feedback.
Andy