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Discussion Starter · #1 ·
Well, I finally decided on a motor. I have a brand new ZZ454 on the way. I also scored some new Harland Sharp 1.8 rr's off Ebay to kick it up a little. I thought this would be an easy install, until someone told me I oughta check my piston to valve clearance. Is this really necessary? Is anyone out there running this combo? I'd rather not pull the heads on a brand new motor.

I kinda figured I might have to check out the valvetrain geometry (which I've never done). How do I go about this? Do I need a pushrod length checker?

TIA
 

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You might as well just throw the valve springs in the scrap bin. They are very marginal with even the stock parts. I recall a magazine article from a few years ago. Adding roller rockers to a 454 or 502 crate engine cost HP because the heavier rockers pushed the valve springs into goofy harmonics; they couldn't control the valve properly anymore.

You will need adjustable pushrods to verify contact pattern between rocker and valve tip. Common to need different length pushrods when using aftermarket rockers.
 

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Tim,

You should be OK with everything. The ZZ454 has the upgraded heads (aluminum of course, but heavier duty springs, lighter valves, and adjustable valvetrain). You will probably not be able to use the stock valve covers b/c the RR's use polylocks which will not allow the valve cover to sit down. Here's your chance to get a nice set of tall chrome covers. As far as piston to valve clearance, you have plenty. I checked this with my 454HO (same shortblock as yours), and I know that you have more than enough clearance.

All you need is the valve covers and your good. My guess is that your motor will like the 1.8 b/c the cam that you have doesn't have that much lift to take advantage of those heads. But in any case, you'll be close to 500HP w/those rockers.
 

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Discussion Starter · #6 ·
Thank u, Vince. I thought this would be an easier way to get a few more ponies than changing cams. Did u start out with my cam. I'm wondering if it sounds bone stock, or does it have a little lope to it ( I hope). I thought of upgrading cams, also. But, I know I have to swap out those lifters for lift over .570, which is kind of cost prohibitive right now with everything else that I need. I don't know why I included EVERYTHING when I sold my sb:sad:

That's quite a setup you've got there. What kind of pwr do u think your putting down with that cam? What kind of carb ru running?
 

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Tim, I actually am converting my 454HO to ZZ454 specs and then some. The heads I have are new ZZ502 heads - same as yours except these have 2.25 intake valves vs. your 2.19's (which won't make any difference BTW).
You'll be please to know that the .600 lift cam I'm running is with factory lifters. This cam was ground in such a way that the lifters are in the same postion as stock. I'll bet that I coulda ran the .625 lift version w/absolutely no issues, but it was too big in other ways. Funny thing is, Joe (GRN69CHV) let me borrow a .577 lift cam for trial fit purposes and it let the lifters drop low - that would be as low as I would go with that brand. So basically it all depends on the manufacturer as how large a base circle they run. But, I had valve to piston clearance issues :mad:

Motor still being put together, but I'm looking for 525+HP. I'm going to run the recommended 850 Holley vac sec, maye 870 Avenger. I got a ZZ502 heads, distributor, intake, carb, and starter. Everything but the 502!

Enough about me - yes, your motor will have a nice mild lope you'll love it. Don't worry about cams just yet - with close to 500HP and well over 500ftlbs of torque you will be happy for a long while!

But when your ready, the Comp XE284 XE288 would be killer in that motor! No lifter issues and probably no piston/valve issues either.
 

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Discussion Starter · #8 ·
Thanks a lot, Vince. You've been a lot of help!! I'm relieved to know I don't have to pull the heads off to install these things.

Keep me posted on how your build goes..........and I will do the same:beers:
 
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