cheese_kake

Im currently rebuilding my 350 TPI out of my 92" Z28 and Im at the point where Im shopping for a new cam. I want to get a bigger cam but not outrageous. My question is what type of cam came in the car stock. I want to get as close to the stock one as possible as far as the type of cam (ie hydraulic roller, flat tappet)etc, Iam not fluent in all the terms used for cams. Now I know if I change to a bigger cam that I will have to have to tune my prom or chip. So if someone can tell me what came in my car stock and could help me in finding a good cam I would really appreciate it. Thanks.

ME Leigh

It has a hydraulic roller cam. Get one of those.

84z28350

Your stock cam spec'd out at

LIFT---
Intk: .413
Exh: .428

DURATION---
Intk: 202
Exh: 207

Lobe Seperation---
114.5



Your going to want a cam with a fairly large LSA to keep it EFI friendly!

cheese_kake

Alot of the cams Ive seen online say hydraulic, but does that make it a roller? And if I get a hydraulic roller what type of lifters will I have to use? Do I have to use regular 1.6 rockers, or can I use roller rockers. What are my stock lifters ? Finally what is the largest cam I could go without running into vacuum problems, stall converter and gearing , compression ratio ?

84z28350

Theirs a few different types of cams out there and you HAVE to get the right one!

Solid Flat tapett
Hydraulic Flat tapett
Solid Roller
Hydraulic Roller


As for which one you need, what came out of it?...

When you pulled the lifters were the bottom flat or did they have a roller?


You can use whatever rockers your heart desires, so long as your using self aligning rockers if they are needed and they arent going to be too high of a ratio to mash the valve guides.

87TAairlineyard

I think GM went to hydraulic roller cams on all its V8s starting in 1987, so a 1992 350 should have a hydraulic roller, assuming that the engine is original.

Sonix

iTrader: (1)

you should be able to re-use your stock roller lifters if they're not chewed up.

look into comp cams XFI line, I think that's their efi friendly lineup, which means a wider LSA (like 114, compared to a 106 or something). Then pick whichever you'll like based on your driving style, and what else you're doing to the motor. Probably in the mid 210-225 intake duration @ .050.

ResurrectingZ

Just remember to match the cam to whatever heads you have, if they are stock and have the pressed in studs, I wouldnt go too crazy on the cam, also get matched valve springs with that cam. Old valvetrain wont last with a larger cam.

cheese_kake

Right now all the internals on the engine are 100% STOCK, never opened. All the mods I had done were topside. I just pulled the engine today and I was too tired to do anything else so the lifters & cam are still inside. But from what you guys are saying it should have roller lifters, right ? I dont wanna go to crazy I just want decent cam that makes good power and a alittle "lope" in the exhaust note. I have the stock heads and have not been touched except for valve guides and seals about 2k ago. And the extent of work that I'll do on the heads is 3 angle valve job, and maybe new valves and some porting, but most likely staying with the stock heads for some time. Im rebuilding the motor some more performance, but nothing radical because Im 17 and cash flow is minimal when there is any. But thanks guys for all your help I appreciate it. I'll keep you posted as it goes.

Sonix

iTrader: (1)

the almighty die grinder is your friend, porting opens doors I tell ya.

you just don't want a cam too big that you need a bigger stall. Look into comps xfi cams like I said, pick the one that's "biggest cam with stock stall", that'll run just great for ya. Get new springs, and .050" offset locks and you'll be set.

cheese_kake

I checked out the XFI line your were talking about, I decided on CS XR264HR-12, its the best one for my car, and it uses stock converter. I checked out some springs and it seems like the conical ones on there are the best. What are the locks your referring to ? I couldnt find them on the comp site ?

Sonix

iTrader: (1)

conicals are pricey, you should be ok with the comp 981's, but ask the guys at comp, they know best.

the retainer holds your spring to your valve via a lock (also called keepers). You can get them with the notch .050" higher, to give you extra space for more lift. It's cheaper then getting the heads machined.

cheese_kake

Ah I see cool. I also just saw a kit from comp its the XE256H its meant for the TPI cars, and has 112 lobe separation. It comes with springs, lifters and a double roller timing chain and retainers, locks etc all the stuff to put it together for $319.00 brand new from their store on ebay.

cheese_kake

I just purchased a complete kit from COMP CAMS. Its the XE256H Cam with 212/218 and .449/.456 . And it comes with double roller timing chain, roller lifters, ovate valve srpings, retainers, locks etc. All I need now is someone to explain how I install the cam the right way, tune etc.