AFR205 valve spring

[mr408]

Hi all ,I mean g'day mates ,just wondering what you guys think about the afr205 valve springs , im building a 408w ,the cam is going to be the comp cam solid roller xr280r 242/248@50 608/614 lift im going 11.3.1 comp are those valve springs okay for that cam, any help would be appreciated , i don't plan on going over 6000-6200rpm im using the rpm air gap.
cheers chris.

 

[oh9mustang]

The springs will work, but the pushrods, rockers and retainers wont live in a 600 lift world. Are you using the AFR heads? Why are you building this engine.
didgeridoo

 

[mr408]

Hi ,yes i will be using the afr heads , im building this engine cause i hurt the old 351 and needed new pistons and crank so thought what the hell might as well go 408 , as for the cam its the one i had in the 351 , worked fine with no issues but the old donk had the cast iron heads so i bought a set of afr205's i was just curious about the valve springs on the heads , i thought maybe they would be to much spring for that cam , im sure there rated at 225 lb on the seat , the comp cam web site does not list the seat pressure for the valve springs mated to that cam, thats why im asking the question
cheers chris.

 

[10secgoal]

The springs aren't too much for a solid roller. You just need to make sure the pressure are right open, and you aren't going to have a coil bind problem.

 

[oh9mustang]

11.3 compression, You have a source for some very high octane fuel?
If not you should think about a shorter cam and 9 to 1 s with a Turbo or a blower, It will live longer.

 

[mr408]

Thaks for the replys , we have plenty of 98 octane pump fuel here so 11.3.1 comp with alloy heads will be no problem , i ran 10.6.1 on the old donk with the cast iron heads with no pinging issues, I'm not keen on the turbo or blower idea, but thats me, and ive already got the heads with the 58cc chamber , our plan was to build a motor which will drive nice on the street and every 3-4 months take it to the drag strip for a blast , i don't think that cam is to big for a 408 and should have good manners on the street ,with the rpm air gap and a BG 750 , i don't drive the 68 every day ,its a weekend warrior, afr state that the valve spring is good for up to 700 lift , so i suppose they should do fine.
cheers chris