ironhead88

I'm having thoughts of buying a ZZ-4 cam #10185071
With 208 deg of intake @ .050"
Anyone out there using that?

Tuned Performance

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sofakingdom

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Exactly... that cam was MEANT to go along with a Holley 4-bbl.

zman1969

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I used in my 383 on a 87 and it passed the dyno emissions when it was tested sounded stock IMO

sofakingdom

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Yup, it probably would sound basically stock, in a 383. It'd be more likely to be noticeable in a 350 but still only just barely.

ironhead88

I see - I thought that the ZZ-4 was an LT-1 option
I was thinking LT-4, I guess
Sounds good though - This will be going into a 327 with retrofit hyd roller system.
About 9:1 CR Iron heads
Thanks

sofakingdom

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The ZZ4 is not particularly related to the LT1. (or for that matter, "LT-1", whatever that might be...) It was a crate motor sold over the counter starting in the late 80s or early 90s (sorry, can't recall when the ZZ3 was replaced by the ZZ4) by GM at stealerships and other outlets like Summit, consisting of a L98 short block (638 block originally then later 880, a 350 w/ very slight dish pistons) and 113 heads (aluminum, 58ish cc, the same ones used on the Vette version of the L98), with an Edelbrock Performer intake that had a bowtie cast into it in place of the "Edlebrock" logo. And of course, that cam. The ideal carb for it, in my personal experience, was the Holley 6210.

In fact, it was sold as part of a "kit" upgrade for the L69, which included a chip and some E4ME calibration parts tailored for it and some other things specific to the L69. It was at least 49-state legal in that trim, maybe even 50-state.

Yes of course you will definitely need the retrofit hyd roller system in any actual 327. Although if the way you went about it was to downgrade a later-model 350 short block to fewer CID, it's entirely possible that you could build the lesser, lower-output motor that could use the factory roller system, although to create this downgraded setup would cost more than building it for the full potential of the original ZZ4 at 350 CID. Wouldn't be a very sensible thing to do even though "possible". Like so many things, "possible" does not necessarily translate automatically to "A Good Idea".

Tuned Performance

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sofakingdom

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The ZZ4 cam can be used with the "retrofit" (some of us prefer to think of it as the "original" ) roller system, but you have to use a nylon cam button, and carve it down to fit within the smaller bolt circle on the front of the cam. You also have to use a factory-roller cam sprocket and some sort of spacer to take up the thickness of the factory roller cam retainer plate, which can be as simple as taking an actual retainer plate and grinding off the "ears" where the bolt holes are.

Yes; BTDT.

Tuned Performance

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sofakingdom

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AFAIK the chains themselves are the same within a given brand, but to be safe, the smart thing to do would be to buy it as a full set. You'd need the factory-roller timing set.

The cam length is the same, because the block length is the same. That's why you can freely install a flat-tappet cam into a roller block, just like GM themselves did in many short blocks such as L05 (same 638 or 880 casting as the ZZ4 & L98). Everything is the same, at that level. The thing that's different, in addition to the cam bolt pattern, is the back side of the cam sprocket. The roller sprocket is .050", or whatever it is, thinner. The thickness of the retainer plate which I can't recall off the top of my head.

The roller bolt pattern is smaller because the retainer plate extends into the radius of the cam journal about 1/8" or so. The bolts in the older-style bolt pattern would interfere with the roller retainer plate. Then since the bolts are so much closer together, the usual cam buttons such as the fully roller ones won't fit down among them. That's why you have to use the nylon type and carve it down. You can take a cylindrical grinder and make 3 appropriate divots in the nylon quite easily.

Tuned Performance

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ironhead88

It's Impossible to explain using words. It seems to make things more confusing.
But if you have the actual part in hand you can see that there is some swap-ability.
A new timing gear with a smaller diameter front is needed

Orr89RocZ

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ironhead88

I get what you're saying.
I have a storage area that has an assortment of old parts... All Chevy small block
Including a 327 balanced assembly that I could put into a roller block with an adapter which is also sitting there on one of my shelves
Or I could put that balanced crank assembly into a 4 bolt block and use some retrofit roller lifters that I know are in one of those boxes somewhere.

I wouldn't buy new parts and do that, but it ought to be OK for a car that I commute in that will hopefully burn 87 octane gas and get good MPG as well

Thanks for the info

Tuned Performance

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sofakingdom

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Yup, you can sometimes drill and tap the block, but not all have a smooth machined place where the bolt holes need to be. Sometimes it's as-cast. Esp older blocks.

ken5

Here are some specs. For future F-Body DIY. Better late than never.