Trying to learn about this is like having your teeth pulled.
Does anyone have any sites I can go to, to learn about this subject?
I'm in the planning stages of an engine build and I have several interrelated theories that I have developed and I am stuck on figuring out what grade of fuel works with what combo.
Basically I want to build a long rod, stock bore/stroke, small runner, high port velocity, small valve engine. But I can’t decide on the better compression ratio. I have 2 compression ratio options I’m considering.
First I have the static compression ratio of 9.25:1 with a dynamic compression ratio of 7.93:1 with my cam specs and rod length being figured into the equation.
Next I have the considerably higher static compression ratio of 10.76:1 with a dynamic compression ratio of 9.2:1 with the same cam specs and rod length being figured into the equation.
What I can’t tell is what kind of fuel the higher compression setup would require. Several factors need to be divulged to offer a glimpse into my madness.
My engine plan is quite simple. I plan to take a low mileage 302 from a mid 90’s F150 and build this engine. Starting in the oil pan it will have a high volume (not pressure) oil pump so it doesn’t create drag buy building too much oil pressure, but pumps a lot of oil. Next up will be a balanced and blueprinted rotating assembly consisting of the following – factory crank, Eagle 5.40” rods and Keith Black Forged pistons for this combo. This assembly will go into the block that will be align-honed and squared/decked to zero deck height for this combo. I considered a main girdle, but since rpm’s will be limited to 6000, I don’t feel it would be needed. However a windage tray will be employed.
The cam for this engine will be a B303. The cylinder heads will most likely be Thumper ported E7TE’s with Crane 1.7:1 bolt down roller rockers. I am leaning toward the thumper ported heads for the high velocity small ports and valves it offers.
The intake will not be EFI. It’ll be a Demon 625cfm mechanical secondary carb on a Weiand Stealth intake. The intake will be port matched to the heads and there will be a 1” (possibly open) carb spacer as well.
For ignition I plan to utilize a MSD billet Ready-to-Run distributor and a MSD coil. No ignition box is needed and it’s accurate to 9,000 rpm. Plenty capable for my planned usage.
For added protection and increased cooling, I also plan to use pure propylene-glycol coolant in a low pressure, high volume system.
As an alternative I am also considering a slightly more costly AFR 165 headed engine that is the same, except it would be .030” over with the 58cc version of the AFR165 giving 9.73:1 compression and 8.33:1 dynamic compression with the same cam and rod specs. And it would of course have stud mount 1.7:1 rockers instead of the bolt downs that the E7TE’s use.
My goal is to run on the cheapest pump gas possible, while making as much power as possible.
Does anyone have any sites I can go to, to learn about this subject?
I'm in the planning stages of an engine build and I have several interrelated theories that I have developed and I am stuck on figuring out what grade of fuel works with what combo.
Basically I want to build a long rod, stock bore/stroke, small runner, high port velocity, small valve engine. But I can’t decide on the better compression ratio. I have 2 compression ratio options I’m considering.
First I have the static compression ratio of 9.25:1 with a dynamic compression ratio of 7.93:1 with my cam specs and rod length being figured into the equation.
Next I have the considerably higher static compression ratio of 10.76:1 with a dynamic compression ratio of 9.2:1 with the same cam specs and rod length being figured into the equation.
What I can’t tell is what kind of fuel the higher compression setup would require. Several factors need to be divulged to offer a glimpse into my madness.
My engine plan is quite simple. I plan to take a low mileage 302 from a mid 90’s F150 and build this engine. Starting in the oil pan it will have a high volume (not pressure) oil pump so it doesn’t create drag buy building too much oil pressure, but pumps a lot of oil. Next up will be a balanced and blueprinted rotating assembly consisting of the following – factory crank, Eagle 5.40” rods and Keith Black Forged pistons for this combo. This assembly will go into the block that will be align-honed and squared/decked to zero deck height for this combo. I considered a main girdle, but since rpm’s will be limited to 6000, I don’t feel it would be needed. However a windage tray will be employed.
The cam for this engine will be a B303. The cylinder heads will most likely be Thumper ported E7TE’s with Crane 1.7:1 bolt down roller rockers. I am leaning toward the thumper ported heads for the high velocity small ports and valves it offers.
The intake will not be EFI. It’ll be a Demon 625cfm mechanical secondary carb on a Weiand Stealth intake. The intake will be port matched to the heads and there will be a 1” (possibly open) carb spacer as well.
For ignition I plan to utilize a MSD billet Ready-to-Run distributor and a MSD coil. No ignition box is needed and it’s accurate to 9,000 rpm. Plenty capable for my planned usage.
For added protection and increased cooling, I also plan to use pure propylene-glycol coolant in a low pressure, high volume system.
As an alternative I am also considering a slightly more costly AFR 165 headed engine that is the same, except it would be .030” over with the 58cc version of the AFR165 giving 9.73:1 compression and 8.33:1 dynamic compression with the same cam and rod specs. And it would of course have stud mount 1.7:1 rockers instead of the bolt downs that the E7TE’s use.
My goal is to run on the cheapest pump gas possible, while making as much power as possible.