Im looking to get a set of 918 valve springs for my 94 z but i see in the summit catalog that they are listed for only LS1s is this true or can u use them on LT1s.. Also do you have to machine the spring pockets out for these? thanks.

 

They drop right in just need the retainers to go with them

 

918 so far has been the best drop in spring ever made i prefer the 987s but you have to remove the heads to machine for installation...overall i feel 918s should be considered as (a need to do bolt- on) with 1.6 rockers and such!

 

As already stated, they drop right in. I would recommend also getting the 918 locators, as the stock ones are a real tight fit.

Here are 918s installed on a stock Lt1 head



Thomas.

 

You are supposed to use the locaters by comp. Just be carefull. Those springs can and will coil bind well before the spec givin by comp. I have to build a new engine do to that...

 

I'm running them. Bret Bauer told me what parts I need with my setup, and I bought everything through him.

 

Thats about the only way Id run them. He knows where those springs will coil bind, and thats far before the spec comp gives.

 

how far before? im installing them with a cc306...will i be fine?!

 

Sorry to hear about your engine but I'd like to see some supporting data for the above.

 

Yes.


Jon,

Sometimes they coil bind earlier than the 1.085" spec.

Bret

 

just make sure of your installed height and you'll be fine. i installed mine at 1.75 and I'm fine with my CC306. Used the comp locators with +.05" valve locks.

 

What about changing from the 987's to the 918's? What locators would you need? What installed height to be good at .595 lift??

 

Interesting. Learn something every day....

 

Check out Comps spring chart:



Notice they do not list numbers for the 26918s after 1.15. What is also interesting, is they recommend a 1.80 install height and then say the spring is good for .600 lift. This puts the spring at 1.20, fully compressed.

If you have .595 lift and assume the spring won't perform past 1.15, then you're looking at an install height of 1.745 or larger. (1.15 + .595 = 1.745).

Thomas.

 

Just as you stated. Use the Comp spring seats and 10* retainers with the
+.050" super locks and you should be in the 1.75" installed height range
with a stock head. Here are th PNs:

795-16 steel retainers, or
794-16 titanium retainers
614-16 locks (+.050)
4705-16 spring seats

I would think this setup is safe to .560" lift with just about any off the
shelf hyd roller you can throw at it. Maybe Bret can chime in with a bit
more detail on this.