Vendor Heads: IS3 vs ZZP S4

[GTPpower]

Been looking at some of the vendor heads lately, and there have been a few sets of IS3 heads being sold cheap on clubgp. Also, Leander was kind enough to send me some pictures of his fresh ZZP S4 heads.

Here is what each vendor claims:

Intense

• .005" milled for flatness
• Bronze valve guides installed
• Manley Severe Duty SS Valves 1.90" intake, 1.57" exhaust
• 1.8" Spring install height
• Manley Titanium retainers
• Fully Polished Combustion Chambers

Pictures of what Intense says they look like:

What they actually look like:

A set of lightly used IS3 heads:

It's obvious that the last set has been sitting for awhile, but that aside, they both look like crap, and nothing like Intense says they do. Combustion chambers look untouched to me.

ZZP

• 1.89" intake, 1.55" exhaust valves.
• Factory-hardened exhaust seats left intact. No need for special fuel additives!
• Viton valve seals
• 1.80" installed spring height
• 4 angle intake valve seats
• Full radius exhaust valve seats
• Less than .005" taken off

What ZZP S4 heads actually look like:

That is what I would expect a $1500+ head to look like.
Just thought I'd post this, because Intense heads seemed to be lacking the work for the price tag included with them.

Click to read more...

 

[Mike K]

Intense was sold a few years back and does a fraction of the business they once did so I would assume (and it's just a guess) that they changed suppliers for heads at some point, the work changed and their website didn't. If I was an enthusiast and I'm being honest, there's just no reason to use them. Their stuff was out-dated in 2005. I can only imagine how stagnant it's become now that new R&D is most likely really limited if not altogether nonexistent.

The first picture looks CNC'd while the actual product looks to be done by hand and you can see the rough cast surface in the combustion chamber so no, that doesn't appear to have been touched though carbon build-up can sometimes look rough. Ask them to see if it chips off... lol

Here's a third CNC'd option that's awesome and inexpensive, for the heritage.

W Body Store CNC Heads

 

[ktraver97ss]

:jayz:

 

[Bob Kazamakis]

Mike K and the wbody store ftw

 

[GTPpower]

Intense was sold a few years back and does a fraction of the business they once did so I would assume (and it's just a guess) that they changed suppliers for heads at some point, the work changed and their website didn't. If I was an enthusiast and I'm being honest, there's just no reason to use them. Their stuff was out-dated in 2005. I can only imagine how stagnant it's become now that new R&D is most likely really limited if not altogether nonexistent.

The first picture looks CNC'd while the actual product looks to be done by hand and you can see the rough cast surface in the combustion chamber so no, that doesn't appear to have been touched though carbon build-up can sometimes look rough. Ask them to see if it chips off... lol

Here's a third CNC'd option that's awesome and inexpensive, for the heritage.

W Body Store CNC Heads

You should talk your shop into doing a more extensive port job with some bigger valves. I hate having to buy stuff from ZZP.

 

[Mike K]

There's just no money in it any more. For us to set it up and have a run done and it would probably take us years to move a run of 10. We barely sell any of the CNC heads as it is. There was a shift about 5 years back where people really started to go turbo instead of piecing together supercharged builds and that was good for ZZP and no one else.

 

[1quick]

There's just no money in it any more. For us to set it up and have a run done and it would probably take us years to move a run of 10. We barely sell any of the CNC heads as it is. There was a shift about 5 years back where people really started to go turbo instead of piecing together supercharged builds and that was good for ZZP and no one else.

Make a turbo kit and take some sales back

 

[ktraver97ss]

I have a test car for ya, have James mock one up on his new pricks, have them manufactured in china, and put this smilie stamped into them.

 

[GTPpower]

Mike, do you have any pictures of the ports on your heads? I either need to get a set rebuilt for my 01, port them myself, or buy a set somewhere. And, like I said...I don't like to buy from ZZP.

 

[Turbocharged400sbc]

the is3/4 heads i tossed on the riv were full cnc down to the chambers so its probably that they cut costs/corners...at least they did hit the area's where the valves are shrouded

 

[TwistedSoundCo]

My impala can be donated for a turbo kit fitment as well.

 

[Handsome Jesus]

those first heads aren't anything like they describe. no bronze guides or anything. cray

 

[Larz01]

My heads look more like the zzp ones posted. Had a shop do them, which outflowed both vendors, but price tag of $1800 for port/valve work is hard to look at when used turbo kits are this.

 

[Larz01]

What percantage gain was made over stock (intake/exhaust) for the two heads posted GTPower?

 

[GTPpower]

What percantage gain was made over stock (intake/exhaust) for the two heads posted GTPower?

I don't know. I don't have any flow numbers from them.

I think it's a good idea to take advertised flow numbers with a grain of salt anyways.