weberflorida

iTrader: (2)

Hey is anybody running a ZZ4 cam in there Tbi? And if so is it the same as a LT4 Hotcam?

Thanks

BronYrAur

iTrader: (1)

I just swapped one into my car, specs are in my sig. It's not the same as a HOT cam at all.

ZZ4:
Duration @.050 208/221
Lift: .474/.510

LT4 HOT cam (IIRC)
Duration @.050 218/228
Lift .525/.525

The ZZ4 runs nice, noticeable idle, strong low end, good midrange. Haven't been able to feel the top end yet...

weberflorida

iTrader: (2)

So how do you like the ZZ4? I mean I see them on ebay all day for like under a $100. I think that is a really good deal for a good roller cam.

DM91RS

moved ...DM

Crusin' 1980's

What Exactly would need to be done so that the 305TBI motor could accept the higher lift on the ZZ4 cam?...shaving the heads? Cut the Valve Guides?...what else would need to be done? Is it computer tunable?

weberflorida

iTrader: (2)

Looks like Bron has already done it brother. I would probably just get all the insight via him. I am definitely trying to the get the same info. LOL!!

BronYrAur

iTrader: (1)

I got some 081 heads at the same time. But to accept the cam and make sure I was safe, I had the pockets opened up and used larger diameter valve springs. Cut the valve guides for clearance and I'm actually using retainers that provide a little more clearance.

For tuning: I mapped out a completely new timing chart. I had tuned a chip really, pretty good after the intake, headers and holley 670. I'm using that but I have a lot of flat spots and it falls on its face at anything over 4k RPM.

Tuning is key with this, it idles very good right now with my new timing curve and much changed VE tables. It idles solid with a small lope at about 725 RPM. Just to put it in perspective, I have a Prominator with switchable bins. My new calibration idles steady and drives pretty smooth, I switch it to a stock calibration with the only changes being BPW constant changed for the injectors and it falls on it's face at idle and dies and almost floods out when i try to drive it.

Stock chip WILL NOT work AT ALL with this cam, that is why tuning is so necessary. It took me about 5 minutes to rough out a basic timing curve and about 5 chips of datalogging a while back to rough in the fuel, and it drives smooth.

weberflorida

iTrader: (2)

That is awesome. I really need to learn to chip burn. I have the winaldl cable and am about to start learning to read the datalogging then try to step up from there.

kidcamarosc

hey BronYrAur, ive pretty much got the same exact setup as you except I have World SR Torquers and I think I have the same 8746 ecm. Ive been struggling trying to tune my rich idle and have taken alot of fuel out. Have you had any trouble with this? Seems overlap might be a problem. Also I am failing the forced knock test everytime I go WOT, it will throw a code on me and kill my timing. Have you had any kind of issue with this also??

BronYrAur

iTrader: (1)

Nope I haven't had any issues with the tune really, I just got my idle to almost match stock LO3 idle. If you want to take a look at my .bin, I don't mind.

I have bigger problems though. Got some clanking going on, and some missing. Pulled a valve cover, turns out I pulled a stud about 1/4" out of the head. Aint that a bitch.

weberflorida

iTrader: (2)

OMG!! That sucks man. You got to stay off that thottle just a little. LOL!!

BronYrAur

iTrader: (1)

Yep, I should have just gotten screw-ins while the heads were getting machined. .474/.510 lift and bigger higher seat pressure springs were not a good combo with press-in studs.

RBob

iTrader: (1)

Ouch, that'll ruin the day. I've pinned studs with the heads on the car. A magnet and vacuum cleaner will keep the chips cleaned up. Should be able to hammer the pulled stud back down before pinning.

Just another option for a fix.

RBob.

BMmonteSS

Another option is to get a set of the screw in studs that Mr. Gasket sells, they havea shoulder instead of a full hex so you can tap the head and install without machining. You have to very carefull because the intake studs go into the intake runner, and it's impossible to do without droping some shavings. I got the proform stud puller/ alignment tool and did it on the car with the intake pulled and rags stuffed around the valve and a shop vac running. The alignment tool is a must have, you'll never tap them strait without it.

With that said.....DON'T BUY THE MR. GASKET STUDS. Their chineseum junk. I broke a stud, don't know how. I'm running 120 on the seat and 290 open at only .468 lift on the intake and I snapped a intake stud. It was high cylcle fatigue, as in it slowly started to crack at the thread root and finally snapped off. When I went to drill the stud and use a thread extractor, the stud drilled super easy, almost like cast iron. Hardened fasteners aren't supposed to drill easy. So they must have totally screwed up the heat treat on that stud.

DM91RS

Thanks BM for the Proform tool review. I was going to buy one to do mine with.

The GM stud pkg part number is 12371058 if you're interested in using those. That stud is for NOT using guide plates which is what you want if using guided rockers. IIRC they were about $15 when I purchased them. SDPC price today is $20.

I hope that these are good studs for the task. I've got a ZZ4 cam with around 510/544 lift with the 1.6's IIRC.

Hope that helps and back to "the Glen"

BronYrAur

iTrader: (1)

Thanks for the information guys. I've got to do this quick now, I parked the car for the weekend, I'm kind of fed up with it.

I don't know if I should pin the studs then, or if I should get those studs with the shoulders and try to tap and install them. What's the consensus on it? I'm not sure what the best route would be. The way my luck is going something would go wrong tapping them and I'd end up with shavings in the intake runners.

Thanks
Jim

BMmonteSS

If your not going to pull the intake to tap the heads, don't even try it. The pinning method works great, especialy if your just wanting to get it back on the road. Just knock that stud back down and stick a pin in it.

BronYrAur

iTrader: (1)

Well, I don't really mind pulling the intake, I'd do it if I need to. I'm just afriad with the pinning method that I'll crack a stud boss trying to drill through it.

BMmonteSS

naaa, cast iron is like drilling through playdough. The hardened studd is a little fun, but doable.

BronYrAur

iTrader: (1)

Quick question, can that GM stud package 12371058 be used in lieu of the cheap Mr. Gasket ones? Are they also studs with a shoulder that do not require machining? That is how I read the above posts, but I want to be sure. I'm going to order them and do the screw-ins. Thanks guys.

DM91RS

Take a look see.........

http://www.sdpc2000.com/catalog/979/...r-Stud-Kit.htm

I have a set in front of me and they have a flat bottom but since I have not installed a set yet I cannot answer the question about any further machining than drilling and tapping for the 7/16" threads. IE: they may have to be spot faced on the top of the boss. Wished I had a definate answer. Maybe someone who has done this will chime in. But it seems that if Crane and Comp make the tools to cut the valve spring seats down with a drill this should be ez.

BMmonteSS

Those won't work without maching down the stud boss. You have to machine a good bit off in order to clear the hex. That's whey the Mr. Gasket stuff works without machining, there is no hex to get in the way. If you look at your heads now there is very little room between the bottom of the rocker and the stud boss.

This is whey I suggested pinning them like Rbob said. much easier and will work fine.

BMmonteSS

You need these

BMmonteSS

and this to do it without machining.

BronYrAur

iTrader: (1)

Thanks BM, I had a feeling they wouldn't work with the hex on them. It just seems like it would be easier to tap them and install the screw-ins while the heads are installed. It seems like it would be very difficult to fit a drill in there and get a good straight angle into the stud boss with the drill, to pin them. That is my main concern. I wish another manufacturer made those studs with the shoulders on them.

DM91RS

Thanks for the info guys........thats why I could not give a definate answer since I have not done them yet. My heads will be off when I install mine.

This did not sink in my thick skull either.........

BMmonteSS said........ [Another option is to get a set of the screw in studs that Mr. Gasket sells, they have a shoulder instead of a full hex so you can tap the head and install without machining ]



DM

RBob

iTrader: (1)

When pinning studs there is a fixture to aid in the drilling. The pic is a setup I purchased years ago. Uses a 5/32" x 1" roll pin. The drilling is done from the top side of the head (intake side) and goes through the stud. Today, I'd even use a short flex drive for the drill bit. That will help prevent snapping off the bit due to angle.

One thing I ran into not long ago, is that GM has now 'wacked' the bottom of the stud during manufacturing. This puts a raised ring on the bottom of the stud. Causes two items: one, it makes it that much more difficult to pull out (strips the threads as you try to pull it), and second, can easily break off the head boss.

If you really want to make sure of what is done. Pull the heads, strip them down and have them machined for good screw in studs.

I went to pinning studs after rolling the Mr Gasket shoulderless studs across a glass plate. Wobble city.

RBob.

BMmonteSS

Chineaseum !!! Sorry I just wanted to use that word again. Really stay away from them, they really aren't worth it.