rezinn

Don and Kevin have my car right now and are telling me it'd be better to change my stock lt4 cam to something beefier, so if anyone has something like a zz4 or similar, please let me know!

BGNCHRS

Comp Cams 266HR-14 is a smidge better.

@ .050"

210int/220exh
.500/.510

Advantage is it has 114 deg lobe seperation so you won't have idle or vacuum problems.

with the ZZ4 or this 266HR-14 you'd better have vortec heads or something like AFR190's to take advantage of the .500" lift.

Just my 2 cents

Barry F

rezinn

Thanks Barry. I had thought that the zz4 wouldn't work great with my tpi setup, but I know that the lorzenzens know their stuff. I've got aluminum L98 heads. I guess I'll have to talk to Don and see what he thinks.

BrandenCali

Well of course your going to need a better cam, having the 350. an find some thing that is going to work for you. The cams I could find you used would be too big for your set up. i guess I will be the new experment with my 236/242 12 lobe. And im trieng this on a rebuilt L98 crank kit. and Vortec Don tricked heads =) rockers an base. With a Super ram an 58 mm billet tb tri y headers dual cat an a mandrel 3" cross flow master 80' and hopefuly some 30lb injectors.

You in good hands with Don go with a good set up for you this time. Get a cam..

BGNCHRS

I didn't say that it wouldn't work well. I really prefer most CC grinds over others but the LThot cam is a good one too.

I don't think the L98 alums flow well over a .450/.460 lift. I don't have flow numbers on those.

Just for comparison, the Vortec heads flow best at no more than .500 lift (un-ported). lets say you run a .530" lift cam with stock Vortec heads, it's like trying to suck air through a straw. Only so much air will go through it no matter how much you try.

Don't over cam your heads is my point.

Don and Kev know what they are doing. use thier knowledge and experience.

Barry F

Dyno Don

iTrader: (7)

His heads are ported so that is not a problem.

However Josh...I waited till 2:00pm the next day and then assemled the motor. It is now ready to go back in the car. I went with your last reply to Kevin ..."I think the LT4 cam will be alright for now" .....

By the way Barry...ZZ4 motors use the heads he has but they are not ported stock. So the ZZ4 cam and 113 heads are a matched combo.

Don>>>

BGNCHRS

It's interesting that GM would choose a dual pattern cam for a head with such a good E/I port ratio (82% in stock form). In theory, a E/I port head with 80%+ works better with a single pattern cam. Of course that is just for the engine performance numbers.

Don, do you agree that the 113 heads and the vortec's in stock or pocket ported form do not really benefit from a .520"+ lift cam in most applications?
It's kind of a general question but I'm sure there are always exceptions.

I have been playing around with 3 hyd roller cam profiles. I find the 113 and vortecs do just as well with a .485 to .510" lift. I also have found for best perf numbers that with most heads under the 80% E/I, benefit from a longer exhaust duration like 275 to 285.

Can you tell I like cam math?

I agree with you that the ZZ4 or LT4 will do just fine with a good set of ported 113's.

Is this a 700R car? what gears?

Have you every used a TPIS ZZ9? I have yet to know anybody that has one in use. I'd be interested in finding a person to see what combo they are running and how well it works. the numbers sure look good with that cam.

Barry F

rezinn

This car is a 700r4 with 3.42 gears. It has a stock vette converter(around 2000rpm stall). Gears and converter done by Don

The LT4 cam is fine for now, I have to have something to do this summer anyway. Any eta on completion?

BGNCHRS

that motor should run real well with that combo. A very streetable motor/chassis combo.

I meet up with the GS3 guys a few weeks ago and met Jaime. He has a 88 Z w/ 383 & dart heads. I fell in love with the sound of his motor. This thing has 272/282 dur (225/234@.050") and .539"int/.565"exh lift. 53 deg overlap. A bit dicey at idle but this thing screams torque.

Barry F

Dyno Don

iTrader: (7)

I just typed a responce to this thread (long) and it told me I wasn't logged in and deleted it.

Oh well, Josh I'll put the motor in Tuesday then I'll have a estimate on time (so many things to fix, so little time).


Barry, you're right on the .500 lift deal.

Don>>>

Auggie

Well, anyhow heres the flow numbers for a stock L98 head w/pipe.



.300 Int = 160 exh = 123
.400 186 140
.500 196 155
.600 199 159

Auggie

BGNCHRS

cool

thanks auggie.

just one more for the set of number for comparison.

Barry f

BTW

What was the flow measured at? 28"?

thanks

89 TA

Barry>
If you met up the guys from GS3 than you met Vince, the last time I checked he was still running his ZZ9. He was running Torquer heads, but he went to trick flows.

89 TA

Barry>

rezinn

Okay sounds good.

Auggie

Yes, 28"

Auggie

ViciousZ

iTrader: (1)

If you're still looking for a cam, I've got this exact cam that I'll be putting up for sale ASAP. I was gonna put it up on ebay, but if you're interested, let me know. It's got about 5,000 miles on it.

Oh yeah, I might add, it's got 114 LSA. Very computer/vacuum friendly.

BGNCHRS

Thanks for the offer. I have a CC264HR12 right now and the ZZ9 I might order to try. The 266 has too wide a LSA for me. I prefer 112.

Barry F

BTW...........how much and why are you changing?