Ran into one of the first, and im sure not last, set backs of the final assembly.

Maybe some of you engine/math gurus can help shed some light because its a bit blurry to me.

Turns out the valve springs i have, are no good to use with the cam i have due to "coil bind"

The Valve springs are Brian Tooley .660 lift platinum springs with Ti Retainers.

-Spring specs are 155 lbs @ 1.780", 380 lbs @ 1.180", 400 lbs @ 1.130, coil bind @ 1.070"

The Cam is a Flowtech Cam

-.614" intake lift, .601 exhaust

Heads are untouched 243s of a TBSS.


Anyone run into this problem ? I thought the BTR springs were drop and go ?

 

1.78" installed height minus 1.13" is .650". I don't see what the problem is unless your installed height is different than 1.78"

At 1.78" installed height, you would have .096" before coil bind.

 

Pardon my lack of knowledge on this stuff, but why are you subtracting 1.13(400lbs spring height) from the 1.78?

 

Im guessing the 1.13 is just to show you where 400 lbs of spring pressure is.

What you need to be concerned about is staying .050" off of coil bind, which would put you at 1.12". And from an installed height of 1.78" minus 1.12" (Coil bind + .050) you get .660 useable lift from the springs.

 

What I got from my phone call with BTR. I spoke to Nick, and he was super helix and informative.

1.780 = installed spring height
1.070 = Bind
.614 = Cam lift

1.070+ 0.614 = 1.684.

1.780 - 1.684 = .096

Aka... perfect fitment

HOWEVER.

Took a ride to my machine shop after work to check out what they were talking about. Sure enough, "availabe" spring height with supplied BTR valve seals, 1.700. That is .080 off BTRs averted hieght.

Something is up.

 

What is the free height of inside and outside spring?

 

That I'll have to grab from the shop tommorow. Maybe I got the wrong springs in the box ? Anything is possible.


My machine shop will be calling BTR tommorow as well.

 

The stock heads I have worked all set up in the neighborhood of 1.78". Are you sure they didn't put a double seat on the springs or install some shims? I am assuming this is an umbrella seal with a separate seat?

 

Yes, Seperate seals and seats.

WITHOUT the BTR valve seat, hieght is 1.760

 

Just heard back from the shop, it was a measurement error.

 

Do they have the correct measurement?

 

time to find a new shop

 

The shop that NEVER makes mistakes hasn't opened yet.....

 

When I had my heads reworked I had the same issue. At the same time frame I read a thread here about where your measuring from when using BTR springs. I was fortunate enough to get Brian on the phone and the issue was resolved immediately.