Page 1 of 1

What type of valve springs?

Posted: May 4th, 2014, 5:45 pm
by Jeremy Soule
What type of valve springs are recommended for the Formula First engine? The rules allow any spring as long as it's single coil. There is some rust pitting on the springs one set of heads.... Jeremy

Re: What type of valve springs?

Posted: May 4th, 2014, 7:11 pm
by SR Racing
Depends upon a couple things: If you are using aluminum push rods HD springs (from SCAT etc.) will work fine with the installed height pressure at about 90 - 95 lbs. If you are using the steel or CM push rods go another 5 to 10 lbs.

Re: What type of valve springs?

Posted: May 5th, 2014, 11:44 am
by Jeremy Soule
Thanks Jim,
What are the advantages/drawbacks to the different push rods Alum. vs CM etc.
I've built around 10 race engines in my life, about half were cam in block v-8 engines, some street VW's too. One of the things that attracted me to FST is the viability of racers building their own engines. Out here in the South West we take June, July and August off from racing, so I plan to build my "good" engine then.

Re: What type of valve springs?

Posted: May 14th, 2014, 2:55 pm
by SR Racing
Sorry about the delay in getting back to you. (Been busy in my retirement... :lol: )

On a FST, the stock aluminum push rods flex quite a bit (due to the higher cam lift.) and some have broken. There are some heavier duty aluminum push rods that seem to work ok...

The Chrome are great and won't flex or break, but they are quite a bit heavier. Thus, requiring a bit more spring pressure to prevent float. "If it ain't one thing it's another." :lol:

Looking for some Titanium...

The good thing is that in FST we typically shift well below the 6500-6700 that Vee's do. So float is not as big an issue.