LT11996

I have the same LE cam in my z28. Lloyd recommended me Lunati dual valve springs for the cam so that's what I'm running with 1.6rr's. Still haven't fired the engine yet but hopefully will this week once I get new pushrods in. Do you happen to have any videos of the car idling with that cam? I can't find anyone running it

v8vette84

Thanks a lot for your help. Under the spring is the "seat or locator" I'm guessing? Do the shims just go over that or do I need to pull up that seat and put the shims under that? It was on the heads when I got them.

lt1-xjs

How did you measure the installed height ? I don't think a 1.9 can be achieved without longer valves and cut spring pockets, recheck that. The 26918 spring setup at 1.740 won't handle .580 lift. Marginal maybe. Although the newer redesigned springs are rated for .625 lift.

v8vette84

Let me check my phone and videos I have to see if I have one. I'm sure I have at least one....

hrcslam

Not sure, I haven't used shims before. I'd put them where they'd fit best. And I meant 2-.060" and 1-.030" shim from the measured 1.9".

v8vette84

I measured that height with a valve spring installed height micrometer. I put it in place of the spring and read what the dial showed. The micrometer only technically read to 1.8" but based on the complete rotation past 1.8" I got 1.900". The heads have been ported so I have no idea if they have any other work. I bought them used from another guy.

v8vette84

I held the valve up with air and then took the spring retainer and locks off. Put the micrometer in then put the retainer back on and the locks back in and opened up the micrometer until it took up all the slack.

v8vette84

I just looked up the tool I bought and it states for most 4 and 6 cylinder engines. (Did not see that when I ordered it) But it looks exactly the same as the "Fits most V8 engines" model. The only difference being how far it actually opens up. The one I have is 1.4" to 1.8" and the "V8" one is 1.6" to 2.1" I can't imagine that makes all the difference.....

http://www.proformparts.com/product-...ategory_id/170

http://www.proformparts.com/product-...ategory_id/170

I have seen that some are beehive specific. I wonder if that is an issue... Why would they make them different though? Then a normal valve spring height micrometer won't work properly... makes for more confusion if you ask me.....

bufmatmuslepants

iTrader: (3)

Lets get some new track times now at 6800rpm shifts!

v8vette84

I will once I figure out if I used the correct valve spring height micrometer.... I might have to call Proform to see what they say.... Unless someone knows for sure...

lt1-xjs

Can you measure the outside diameter of the bottom of the spring ?

bufmatmuslepants

iTrader: (3)

1.74-1.76 is still within the 1.4-1.8 checker you have, you don't need the v8 one. You'd only need the v8 one if your install height requirement was over 1.8. It sounds like the issue you were having like hrc said was too large install height causing too little pressure causing valve float at high rpms. If at 1.74 you have too much lift and will bind your 918s are not going to work, but you need to check coil bind on the 918s at your lift with your rocker ratio. I still would suggest a dual springs that's not so close to being maxed out, but if you can shim the 918s to 1.75 height and you find that you still won't bind, it should be fine. Just start shimming. Don't buy another tool.

v8vette84

Ok will do, thanks! TO check for coil bind all I have to do it turn it over and see if the spring hits itself or the valve guide? Or is there another way I have to do it? How much clearance do I need between the coils to compensate for when they heat up?

v8vette84

Here are 2 videos I took of the exhaust. In the daylight is without cats, the night time video is with cats. Not the greatest quality but you can kinda hear the idle.

v8vette84

Outside diameter comes in around 1 5/16th" or 1.31". It's not exact as I used a tape measure but seems to line up with Comp cams specs for a beehive. I bought them new myself through summit.

v8vette84

Does this matter? I just realized I never installed the suggested locators. There are locators on there now but I have no idea id they are correct or not. Does it matter at this point?


These are the suggested locators from Comp.
http://www.summitracing.com/parts/cca-4705-16

Here are the locators I have been using...





Picture of the head without the locator.


With locator.


P.S. yes I know the valve seal is missing, I took it off to get the locator off.

v8vette84

I'm sure sure if it really matters which ones but I was just going to shim it.... I mean I already know how far off I am. If I get different locators that do the same thing then I'll just get a different height and have to buy different shims. At least that's what I think anyways.

lt1-xjs

I saw that when I went back through the post. You said you bought the heads used and installed the 918's yourself. What springs were on the heads before, and what retainer combo and spring cup did you use for the 918 install ?

lt1-xjs

Those are the stock locators. I run those also. Did you measure the spring height with that installed ?

v8vette84

Yea those were installed when I got the 1.900"