My buddy is trying to sell me a cam for my car, great condition with 2500 miles. .480I .510E, 112LSA, can't remember the duration. Anyone have any experience or recommendations with this cam?

 

the zz4 cam works well with tpi, does alot better than the stocker, thats for sure.

 

I went .35 faster in the 1/4 and gained 3mph with the ZZ4 cam and 1 5/8 headers.

 

Will my stock heads need machining, I know I need diferent valvesprings..

 

valve guides need to be machined to handle the lift.

 

I didnt machine my stock 91z28 heads. I just replaced the springs and retainers with my heads still on the car. The retainers were the shorter ones that came stock on the corvette d-port heads and so were the springs. I think they were the orange color coated springs.

 

hmm. the retainer should be hitting the guide at around .480 lift, but if you got it to work with those parts thats pretty cool. actually good to know, i have a zz4 cam to throw in another car, now i know i dont have to get the heads machined.

 

Ya I was told the same thing that the stock heads would only take .500 lift but I figured .01 isnt much so i tried it and it worked! Just have to have the shorter retainers. The stock ones wont work they are to long. The cam has been in there for about 10 years and havent had any trouble from the valve train.

 

Anyone got a part number for the spring set and the retainers set??

 

Thats pretty weak if you ask me...

 

So whats your point? Thats what I seen as a gain some might get more some might get less, like I said whats your point? You must be just another forum troll always trying fing something negative to say. Whatever dude have a nice day!

 

My point is You Changed From a Stock L98 Cam and stock L98 Exhuast manifolds to the ZZ4 cam And Headers, and Got a gain that you could expect from Just the Headers or Cam alone.

If I was you I would be very dissapoint, and It dosent stand as a very Convincing arguement for how great the ZZ4 Cam works w/ TPI.

Thats My Point, and Im sticking To it.

As far as the retainer Hitting the guide, Several people on this site have measured the Max lift w/ stock guides and retainers to be in the .470-.480 area, Like justin Said.

I sure as hell wouldnt try to Run More than that w/ Stock Heads.

 

So exactly what else do I need to buy other than the cam to make this work?

 

You Need to buy Springs to handle the lift,


Your also going To have to Have your Valve Guides Machined Down to Accomodate the .474/.510 lift w/o retainer/guide interferance.

Thats going to Involve removing the heads, and Costs Will Depend on What Shop you Take Them to.

I know redZ28 Says his worked fine Without any machine work, But Considering the Interferance has been measured to occure at approximately .470" Lift @ Valve, I wouldnt personally Test it.

 

Ya And I think it was measured with stock retainers and not with the d-port retainers which are shorter! How else would it have worked with mine?

 

IMO trying to run near/over 0.500 on stock heads, short retainers or not is not something to be taken lightly. Not saying it won't work, but there is the chance it won't. You'd definitely want to measure it before you actually committed and ran it. And you should probably have a contingency plan for if/when a rocker stud pulls out. 0.500 and pressed in studs is rolling the dice for sure...

 

I ran a .480/.505 Isky cam at 1.65 rocker ratio for about 15,000kms in an L03 motor. I did this using stock heads with pressed studs. I replaced the factory springs with Comp Cams conical springs rated for .550 lift -- I did not have to modify the heads for these springs they fit the stock location.

The car was a daily driver and I had zero problems and trust me I beat on that motor. I think the lift was .505 and .525 after the 1.65s were factored in.

REDZ28 IMO a .35/3mph gain is pretty good for the cam and headers. Not sure where Bort62 is coming from ? We had a local guy (92zeddar) with the hot LB9 setup throw on the SLP headers and collectors (NO camshaft upgrade) for MEGA $$$ and to our horror at the dyno shop it showed a whopping 7hp (as in seven horse-power) gain from 2000-5500rpm... pretty disappointing eh ? For that kind of coin...

IMO the ZZ4 cam is making you alot of power. Thx for posting the info I'll be checking out the same mod for my winter build-up.

RP.

 

Thnx palric. I dont think Bort knows where hes coming from either!

 

Thats pretty Pitiful, I would wager something else was Wrong.

Ill get back to you later as to why 3.5 and 3 mph from a cam and Headers Install is a little less than I would expect, and Why.

 

I cant wait to hear the expert Bort show some more of his infinite wisdom. Also My car has ran a best of 13.11 at 101.6 with alot less mods then alot of people have here so I would say I did a good job with the mods I have. Im sure your car runs 10s right Bort?

 

I have to agree a little with Bort62, with just headers alone I gained a solid .3/2 mph.

Hey REDZ28 nice time you got there, can you tell us a little about your setup?

 

Free mods, 3.42 gears, under drive pulleys, 50 psi fuel pressure, 12 degrees timing, Ram air, 160 stat, head light covers for better aero, zz4 cam, 1 5/8 headers, air foil, slightly ported plenum, Aluminum 88gta drive shaft, dyno max super turbo and no cats. Trans pac shift kit. Its a 1991 z28 350. went 14.24 bone stock with no traction when I bought it in 91.

 

My car must really suck then. I put on headers and SFC's and only gained .10 and 2 mph. Nuttin at all on the 60's. I gained more MPH with a $4 piece of dryer hose for a CAI.

 

Hrm... I put on SLP 1 5/8" headers on a stockish L98 and while it only made 210 HP to the rear wheels, my ET went from 14.33 to 14.07 with me driving it, and 13.86 with another driver.

After I put in a ZZ4 cam and L98 Corvette heads, the ET dropped to a best of 13.24 @ 107.18 MPH. The RWHP jumped to 282. But, I have a manual trans and its not a direct comparison to an automatic.

 

The ZZ4 is a good cam for a stock type TPI setup. My slightly warmed over 350 will be getting one after I get the T5 swapped in and some headers put on.

As for HP gains... there are ALOT of factors here...More power / torque almost always means more problems getting the power to the ground, especially of the line.

Also, what about tuning? Did you burn a new chip for your car after you added the headers and the cam? How's your exhaust after the headers? Stock?

There are NO set results for mods to these engines. EVERY engine reacts differently to even the same mods. As Kevin pointed out, driver skill has alot to do with it as well.

Also, the driver and track conditions have ALOT to do with the Et's and MPH as well.

Was that run above sea level? Was the temp / humidity high? Was the track hooking good? Lots of wheel spin?

Did you bump up the fuel pressure to the motor? Etc Etc Etc...



For an UNTUNED mod, the cam and headers put down some pretty stout numbers IMHO.


As for running this cam with stock heads, every stock GM head is different, so measure the clearance yourself. Check for bind, some companies also sell springs that don't need modification and will handle the lift.

I've run .500+ lift cams on stock pinned stud heads plenty of times.....twice did I have any trouble, and coincidence or not, those two times I was too lazy to check the clearance out.

It's all about what the overall plan for the engine is....


Sure, you add headers to a TPI 305, and it gives it a boost...but when you turn that 305 into a 350, it's technically a bigger boost. Also, some later TPI cars had some decent flowing exhaust manifolds from the factory.


Just my 2 cents

HTH
I plan on using a ZZ4 grind in my 350 TPI pretty soon, and I plan on using the stock iron L98 heads. But hey, that's just me.

 

I forgot to add this.......

Not factoring ANYTHING else in, that .3 improvement is roughly 30 HP gain. Now add @ 20 percent to that for drivetrain loss, and that's roughly a 40 HP gain from an untuned cam and header drop in.......

 

Hey I am pretty happy with my setup.. 2.225 60' and 14.5 in the 1/4 at 96.87 now I am pretty sure that if I got some more traction I could get my car down to 14.1 or so... Not bad for a set of headers and pulleys...stock chip aswell.. I have seen alot mor people spend more to get alot less!!

I too am going to be using a ZZ4 cam for my swap sometime in the future.. I put a 1.5 rocker on the exhuast valve at .510 lift and I couldn't se it hitting on stock valve retainer and no grinding on valve guilds!! BUT it was super close!! So where do I get these low profile retainers??

 

Well So far two people have surfaced without me even doing any digging to back up my claims, both supporting my point.

Depending on What your mods are, That may or may not be a decent time, its definately not astounding.

There are several Guys on this board Running simialr times with the Stock L98 cam, So while Its a repsectable time, Its not Like your some wonderful *** of tuned port knowledge. There are plenty running as fast and faster than you with completely stock longblocks.

And No, My car does not run 10's. You got me there.

It is a Lg4 w/ Some work done to it and it runs alot faster than most LG4's on this board ( with the exception of maybe 2? )

But its still slow as hell, IMO. And besides what the hell does my car have to Do with anything ? Most of the time All having a fast car proves, is how fat your Checkbook is.

Mine is anorexic.

What is your Raceweight ? A L98 W/ headers and Zz4 cam should make Quite a bit more power than an Lg4 w/ XE262H and Stock exhuast manifolds, wouldnt you agree ?

Then Why are you only pulling 102 mph traps when Ive trapped 99 in My Lg4 ? Thats 3 More mph and with the most generous of calculations, 30 More horsepower.

Ever seen a Lg4 Exhuast manifold and 1-3/4" Ypipe ? Its got even less girth than some parts of some Peoples bodies...

Just the addition of the edlebrock 1-5/8" TES and Dual Cat Ypipe Made such a huge SOTP differance in my car, It feels like a differnt combo all together. I could not belive it. I was and still am kicking myself for Not making that my first Modification, and it always will be in the future. Performance and Cast manifolds are mutually exclusive, In my book.

Car Craft picked up 30 flywheel horsepower with the addition of Headers to a Stock Lg4.

It stands to reason that with the increased Breathing demands of My Cam in the Upper RPM ranges (4500-6000 rpm) where the stock LG4 Manifolds and Ypipe Perform so Terribly that I could have gained even more than That.

So thats very likely, going to set me at approximately a Similar Trap as you, 101-102 mph ( wich I fully expect )

So with your 50 more cubic inches than me, and better flowing heads Your turning the same hp#'s As a Stock headed 305.

I would Say your combo is Down on power, personally. I think you need some attention to Tuning and to Detail To fully realize the benifits of what you have done. Either that, or You have some signifigantly mismatched parts.

And that is why I don't think that .35 and 2-3 mph out of a ZZ4 cam Swap + headers on a otherwise stock L98 Is very impressive.
I would Personally expect more than a Half second gain when properly Tuned.

 

They are the stock retainers for the corvette D-port heads. Bort 13.11 is better then most with more done to thier engines then mine and I had 1.73 60ft time, thats pretty good also the mph is kinda low but not by much.. So im happy with it. When I get my 383 done and running 11s im sure you will say how it either doesnt run that fast or people go alot faster with the same stuff I got. Your opinion is not worth much judging by alot of your posts in this forum that are totally wrong. But keep guessing and ill keep doing!

 

I know I may have started a war but someone please just give me the number of the person I can reach to get these short retainers....

 

I don't even have to say anthing, this thread Says it all...

https://www.thirdgen.org/techbb2/sho...hreadid=111706

Multiple accounts of stock cammed L98's running faster than you.

So How am I wrong ?

Where are all these post on here That are so Wrong ?

Go ahead and build your 383, and run your 11's and feel like a big man. I don't doubt you can do it. Dosent take anyting special to do so. Personally I just turned 21 and Have other things in life demanding my time and precious little money than big buck engine builds. I don't have that defaulted child support money laying around to spend at will.

Ive got a whole lifetime ahead of me for that, and am in no rush. Right now Ill stick to school so I can get a job where I tell people like you what to do.

But thas beside the point. This poor kid asked How well the ZZ4 cam acted with TPI, and you gave a response.

I Clearly stated that I thought your experiance was atypical, and was not a good indication of the results he could expect, and provided evidence (via others experiances) to back up my claims.

You Turned to personal insults. Typical.

52 posts on this board and your already picking fights. I give you about another 2 weeks before you get frustrated, exposed and leave forever to return to your life of being a local talking head in the car scene, continually blowing nothing but hot air.

You think your a big shot on here? Wow you ran a bottom 13 with a weak MPH in a modified L98.

You and about 10,000 other memebers.

You know a few friends with "fast" corvettes that actually don't own them anymore and just like to talk about how fast their car's "were"

Just surrounding yourself with fast people dosent make you Mr Know-it-all. I imagine ive wrenched faster Car's than you have, but it dosent really matter.

Weather your tightening valve covers on a 1500 hp 8 second turbo buick or on a 16 second L03, unless its your car and your experiance and your knowledge wich cumulated into the end product, it dosent mean ****.

SO want me to tell you some stories about my "friends" and their fast cars they actually still own ?

Maybe then I can convince you I know what im talking about.

 

Im not going to waste my time responding to your misinformed ramblings. You wouldnt have said so much if I wasnt right. So think what you want. Considering Ive been working on cars as long as youve been alive I guess I dont know anything! I dont know how Ive become an ASE Mastertech with my obvious lack of automobile knowledge. Maybe in the next few years you will learn some reading comprehension and actually understand what people are writing and then you could have an intelligent response that includes all the facts. But I too have a life, so Im not going to waste anymore time pointing out your incorrect statements. Fastcarjoe.. Call your local Chevy dealer and ask for the corvette D-port retainers and springs they should work, they worked for me. Also replace your valve seals while your there. Good luck dude! P.S. you didnt start anything Bort is just mad because Myself and other people have proved him wrong about alot of things the last few weeks!

 

PS. I'm an ASE master certified L1 Porssche Technican at a dealership. I value all of your posts and thank you for your input. I will measure all the necessary retainer to valve guide clearance as instructed and hopefully I don't have to pull my heads but I won't crash any valves, be sure of that,