Do big valves require big springs? 2.3 lima

[Sevensecondsuv]

I am thinking about putting oversize valves in my head since I've gone so far with porting it and the valves are now the limiting factor. Can I keep the stock valve springs or do I need bigger ones? Cam will be an A237. Engine management will be stock ford EEC-IV.

 

[Maverick]

Big cams require big springs. Since you have an aftermarket cam it wouldn't hurt to run some stiffer springs. Especially if you plan on winding it, it help keep the valves from floating. Don't go to big on those valves, your likely to hurt your bottom end torque.

 

[Sevensecondsuv]

Ok. I've heard the A237 with stock springs results in valve float occuring at an RPM in excess of the rev limiter on the stock EFI. So I'm thinking I don't have to worry about that.

Right now my circular exhaust ports are about .25" larger diameter than my exhaust valves. The valves I'm looking at are 1.89" intake and 1.59" exhaust.

Also, I'm not too worried about bottom end torque seeing as how it's going to be 10:1 compression.

 

[Dave R]

I don't think I'd bother with heavier that stock 'turbo' springs. Especially if your going to be living with the stock rev limiter. I also am not sure that your going to see much of a difference with the bigger valves.

 

[Sevensecondsuv]

You should see what we've done to the head...

Then again the chances of me ever remembering to take a digi cam out to shop is slim to none. Besides, before we'll work on the 2.3 again, we've got to finish putting my buddy's 700 HP EFI 521 (formerly 460) back into his '87 F-350 with 37" tires...