Dual valve spring location

[AC sports]

Is it necessary to fit the bottom inner valve spring locator on a dual valve spring installation? The retainer up top locates both inner and outer valve springs without issues. The bottom locator for the inner spring is too thick and I get inner spring coil bind before full lift. My seat pressure and over nose pressure seem ok without the inner seat fitted, but my concern is the lack of solid location of the inner spring. The seat obviously fits around the guide to stabilise the inner. Without the lower seat fitted it relies on the outer springs ID to locate and stabilise. Inner seats are 100' thick, even if I grind them down to 0.040' thick I still only get around 0.030" before the inner spring binds.
I've been told by some I can run double valve springs without a bottom inner spring seat/ locator, and by others never to do so. Thoughts please.
I should say these are isky replacement springs.

[Walter R. Malik]

Is it necessary to fit the bottom inner valve spring locator on a dual valve spring installation? The retainer up top locates both inner and outer valve springs without issues. The bottom locator for the inner spring is too thick and I get inner spring coil bind before full lift. My seat pressure and over nose pressure seem ok without the inner seat fitted, but my concern is the lack of solid location of the inner spring. The seat obviously fits around the guide to stabilise the inner. Without the lower seat fitted it relies on the outer springs ID to locate and stabilise. Inner seats are 100' thick, even if I grind them down to 0.040' thick I still only get around 0.030" before the inner spring binds.
I've been told by some I can run double valve springs without a bottom inner spring seat/ locator, and by others never to do so. Thoughts please.
I should say these are isky replacement springs.

To me ... that totally depends upon the severity of that situation.

[BillK]

It sounds to me like you have the incorrect spring locators. I always have something to locate the bottom of the spring, either an OD cup or some type of ID locator. How about post a couple of pictures of what you are working on ? What type of engine and head ?

[MadBill]

....it relies on the outer springs ID to locate and stabilise...

This implies that the outer is positively located and presumably the inner is a light friction fit within it, in which case the outer will locate the inner.

[AC sports]

Ok. Pic 3 is of the valve train in order.
The 1st and 2nd pix show the location of the inner spring with and without its seat. I want to eliminate the seat for more valve travel before binding. My pressures are fine without it. It's the location or lack if, of the spring that worries me. The lower seat is a nice tight fit around the guide. Without it the inner spring is free to move. Wondering if outer spring od and top retainer are enough to manage the inner spring at high rpm.

[Geoff2]

Machine the centre hole in the flat spacer so that the inner spring locator sits inside the spacer, not on it.

[BillK]

What engine are you working on ?

[AC sports]

Machine the centre hole in the flat spacer so that the inner spring locator sits inside the spacer, not on it.

That would give me an extra 0.040' clearance but I need double that. Also not a good idea as the head is aluminium and it'll dig into it I'm sure.

[AC sports]

What engine are you working on ?

It's a Fiat twincam.

[BillK]

What engine are you working on ?

It's a Fiat twincam.

Honda uses a stepped bottom seat like that on some of their engines. When guys bring me performance springs to install on them they typically have their own locators. Have you asked Isky about it since it is their spring ? If not you might have to do some searching to see what you can find. Ferrea would be my first place to look. They have a lot of import spring seats. You could probably call them with your measurements and see what they have. Their catalog does not show dimensions for the spring seats. Didnt look on their web site.

[AC sports]

Unfortunately I need to get rid of the seat altogether to get enough clearance. Hence my original question, if its sufficient the inner spring just locates on the outers ID. The outer spring isn't restrained on its OD though.....only the top retainer locates both springs.

[BillK]

Personally I would want something to locate the lower part of the spring. Either something around the od of the outer spring or something for the id of the inner spring. Otherwise the lower part of the spring will probably be walking all over the place.

I hate to suggest this but maybe you simply have the wrong spring for what you are trying to do ? Find one that will work with some type of lower locator. Sometimes I have spent hours trying to figure out a valve spring / retainer / locator combination to work. Its part of building performance engines.

[AC sports]

Looking at a beehive alternative now..really no other solution.
Manufacturer replied that it was ok to use them without an inner base. I'm not comfortable doing that.

[6.50camaro]

What are the actual dimensions of spring o.d. and i.d. , and what is the valve guide o.d. Dan

[swampbuggy]

It is always a good idea to buy all of your valve train pieces from One manufacturer.