[Streak-O-Lean]

I have an 84 RC with a 318. It was originally a 2bbl and I have upgraded to a 600cfm Edelbrock carb with a Performer intake. I have also upgraded the ignition system. It was rebuilt a little while back and is in good running condition. What difference, if any, would I see or feel if I changed the heads to the later #302 swirl port heads?

 

[Evildriver-3]

It would make an increase in the comp and the burn in the chamber, it should be a noticeable improvement atleast 1 you will feel somewhat since the diff in chamber is fairly good lets say without quoting a book i believe 70cc to the SP 60cc, but i would port them a bit use larger valves and use a nail valve to make a touch more comp

 

[s ǝoɾ]

It would make an increase in the comp and the burn in the chamber, it should be a noticeable improvement atleast 1 you will feel somewhat since the diff in chamber is fairly good lets say without quoting a book i believe 70cc to the SP 60cc, but i would port them a bit use larger valves and use a nail valve to make a touch more comp

i beleive all 2bbl heads are roughly 57-64 cc's. but the chamber design promotes bit more low end and such.

 

[chrysler300le]

The swirl ports are only about 1 or 2 cc's smaller combustion chamber then what you have now. So not a big change in compression. The HP increase from Swirl Port heads would be about 10 hp unless you go with bigger valves.

 

[robo51]

now were does the actual "swirl port" name come from , i have a set here and they dont look swirly.

 

[s ǝoɾ]

the chamber design promotes a swirling turbulenc of air/fuel in chamber causing a more complete burn.

 

[willy J]

can you put the 2.02 an 1.60s in the 302 heads?

 

[s ǝoɾ]

kinda beating the purpose of velocity arent ya? ya you can do it, it has been done with great results. block mods may be needed for 318 thoguh (ie notching) i think a chebby 1.94 or magnum 1.92 would be a better choice.

 

[Evildriver-3]

The valve won't hurt the flow, the port would

 

[willy J]

Joe what do you mean hurt the Velocity?

Ed your saying there is no point steppin up the valve unless i open up the intake an exhaust port?

 

[Evildriver-3]

No im saying opening the bowl and bigger valves isn't hurting the velocity, since it isn't effecting size or port shape

 

[willy J]

so bigger valves are fine. but if i port it i will...............(fill in the blank)

 

[chrysler300le]

Swirl ports get the name from the design of the port not the chambers. There is a Swirl port 360 head that doesnt' have a heart shape chamber like the 318 head. The port creates a swirl and the exhaust side is slightly redesigned to flow better. LA engines are bad for having poor flowing exhaust ports. Going with 1.88 and 1.60 would be a better choice for a 318, unless you want to grind a little on the cylinder wall to unshroud the valves.

 

[willy J]

what do they come in stock sizes on a set of valves for the 302s?

 

[chrysler300le]

stock valve size for '302 head is 1.78in/1.50ex