I plan on getting rid of the cam I am currently using.
I have searched around and seen that alot of people use LT1 cams for their TPI's.

I want to make sure than the LT1 is what is best for me though.

I am running #128 Aluminum Corvette heads and 1.6 RR's

Will the 1.6's make the LT1 too agressive? Also if not would I be able to use these #128's without any machining to run LT4 hotcam?

The thing is I actually have an LT1 cam sitting around, just wondering if it would be a waste of time.

 

that cam workes great on TPIs. ive seen a C4 with SLP runners and ported stock base with edl performer heads out of the box with that cam run 12.9s
but i dont think that the stock press in studs would hold up to that lift. that guy said he had 1.62 RR, from who? i dont know but yea that cam is great. he was shifting out at 5300rpms with a 700r4 and 308 gears.

the stock LT1 cam would work good too, but anything is better than the stock TPI cam.

 

if your running the stock L98 cam and switch to the LT1, you'd be lucky to pick up 10hp. its nearly the same cam! add 1.6 rockers to the L98, and you have the same lift as the LT1 just about.

i think its a waste of time to put that cam in. a better bet for cheap is the ZZ4 cam. it works well with TPI.

LT4 hotcam would be abit much for TPI but probly make decent power once its tuned right. the TPI crate motor from scoggin dickey runs that cam and vortec heads with edelbrock TPI stuff, it makes about 360hp.

but LT4 hotcam isnt designed for the TPI. it works best in LT1 intake shorter runner setups.

i'd search for something else if your gonna do a cam swap. gonna have to keep it near .470 lift and not any higher. cuz i think stock springs are only good to .500 on those heads.

 

I have to keep in mind that I am running 1.6's.... so it changes things.
I thought the ZZ4 and LT4 were pretty much the same. Guess I should research that too.

So you think the zz4 cam is a better choice for #128's with 1.6's?

 

zz4 on 1.6's will bring the lift up really high, and exceed stock springs. you'd need to setup the heads to work. i think even on 1.5's the lift wil be too much.

other than that its a good cam for TPIs. makes decent power and doesnt require i whole lot of tuning.

what would be really beneficial tho is to upgrade all the stock TPI stuff and run a good TPI cam like zz4 or LPE 211/219 grind. anything in the that range seems to be a good tpi cam. others tried bigger cams like 224/230 with success.

 

I really do not think the springs are stock... I did not rebuild these heads they were done for me. They look beehivish. I will try and take a valve cover off the day after tomorrow. I will be out of town tomorrow. I will even take a picture.

ZZ4 cam is .510
with 1.6 RR is .544

in other words I need to find out what my heads can handle.

 

zz9 cam seems like it would be a good choice 212/226

lots that stick with TPI seem to have good success with it.

 

that would help to find out what u got so you can tell what u can get! lol

 

simply taking a picture will not tell me what springs I have. Is there a way to measure them while on the car?

 

The ZZ-4, LT-4 and LT-4 "HotCam" are all different. In order of mild to wild they would be: Stock LT-4, ZZ-4 and LT-4 Hotcam.

 

just for arguments sake.. my car is very similarily modded to yours. I've got #113 aluminum L98 corvette heads with 1.6 roller rockers and a LT4 Hotcam jammed into a lil ol' 305. It is a pretty aggressive set-up.. still streetable but pretty wild. .525 lift in/ex. It can be a bit challenging to drive a 5-spd through town with lots of stop and go traffic.. it wants to surge at low rpm because of the lopey idle.

A lot of tuning and I've still havn't got it running right, but it is to the point where I'm happy with it. I've got the idle smoothed out quite a bit and I no longer have stalling issues.

Yes, it would be more mild in a 350... a bit more tame. I think it would be a bit easier to tune it in a 350 as well, but I'm not certain. I found my powerband has changed from the stock LB9 cam. I used to have power off idle to about 4000rpm. Now the power kicks in around 1500-2000 and is still pulling hard up to 5000rpm where the TPI starts to choke out. I can burn rubber pretty easily well into 2nd gear and chirp into 3rd w/ 3.42 rear and crappy tires.

I'm hoping to improve my top end, I've recently purchased a TPIS bigmouth intake, SLP runners, and a heavily ported plenum... everything ported and port matched to each other.

Check my vbGarage for some idle/lope vid links.

 

Go with the zz4 cam if you would like a mild non-lopey engine. I would not recomend the LT4 hot cam in a tpi car unless it is full of aftermarket parts. I have it in a tpi. I think that it has too much torque downlow, below 2,000 RPM. I have a 245 series tire and can not give it much throttle at a take off with out spinning the tires. It is annoying. I personally think the cam is only put to full use in a TPI if it is a larger runner base that is ported and siamesed.

 

i am runnnig the ZZ4 camshaft with stock heads and a ported TPI ( edlebrock runners and base ...runners siamesed 4" . Ported and siamesed plenum aswell. car started right up I didn;t miss any of the down low TQ I lost either.

 

I too run the LT4 hotcam but I have a mildly built 355. I'm using ported/bowl blended 081 heads with "beehive" springs and Crane race gold 1.5 rockers. Brings the lift to around .492/.492 which is still good for a TPI engine. The duration has already been said with 218/228. Right now, with my stupid flowmaster, it sounds pretty mean. But once I put my custom Bullet setup on there, I'm sure the cam will come alive and sound a bit more lopey. Power wise, it wants to haul *** off the line and just fly through the gears only bad part is I'm using a stock converter. Once I change that out....

Right now, my 2nd gear pull is CRAZY and I only have a stock base which was port matched to my head work, stock runners and ported plenum. I have AS&M runners on the way and I'm going to port my base to match those. We'll see what all that does when the 2800 stall goes in.

 

demon, you just runnin plain hypertech chip? how does the tune feel?

 

Like crap, lol

It needs a custom tune. I just threw the hypertech in to get it running this year so I could drive it. Idle needed to be changed a bit, fuel pressure juggled around. For the most part, it runs fine. It's being dyno'd on saturday so we'll see what my car does the way it is right now, hypercrap and all.

 

Would you recommend the LT4 hotcam with the 113 vette heads? I am looking at 113 heads with a zz9 cam...bit more mild and broad powerband, i just figured a LT4 hotcam is a little too much for TPI. If you could do it over again would you stick with that cam or what?

What kind of springs did you use with those heads also?

Thanks.

 

If you have map based metering I could send you a copy of one of my engines .bin files.

 

zz9 seems to have a better design more suited for TPI style intakes. its a modded/improved zz4 cam which was designed to work with the alum L98 heads and the zz4 crate motor. good power can be made from that cam. LT4 hotcam likes LT1/miniram stuff

 

what are the specs on a zz4 cam...i cant find it?

 

zz4 is something like 208/221 .474/.520 i think. not a bad TPI cam..that big split duration does help on stock heads tho

 

You think it's worth changing my cam from the LT4 to something like a ZZ9 or a custom one from Thunderracing? My engine is getting etec heads and a vortec intake next season...

 

The LT4 hotcam with 1.6 roller rockers is a good setup in my opinion with 113 heads.. I've got no complaints with it now I've been doing some chip tuning. Heck you could run it with the stock chip (I did for a while) but you just have to watch your rev's else it'll stall when you push in the clutch. The power band starts a little higher then I'd like, but for me its not a daily driver. If my car were a daily driver I'd probably would have liked something a little more tame.

If I could do it again... hum.. I'd probably change the induction system.

Funny you should ask, because I am doing it again. I bought a L98 350 engine which I'm going to reuse the cam and roller rockers. I'll reuse the 113 heads until my AFR's arrive (unless they show up on time!). I've also bought a new induction system which consists of a tpis big mouth intake, slp runners, and a heavily ported plenum. Everything is bored, honed out, and port matched to each other. Should be an interesting comparison and I should see a really nice seat of the pants increase in performance.. from the engine, induction, and heads.

So what do you think I'll break first.. my 9 bolt rear end, or 5 speed?

 

the 5 speed FTL

 

Thanks for the info..im prolly gonna go with whatever cam i can get a deal on...but for heads im pretty much set on alum vette 113 heads. Lemme know when you sell em

As for the rest of the drivetrain...kiss the 5 spd goodbye lol and no sticky launches for the 9 bolt and i think itll last awhile.

 

Hey I started piecing the hotcam kit together one piece at a time.. first I bought a cam, then I bought the GMPP springs (good for .525 lift). Eventually I ended up buying the whole retail kit from summit racing and I resold the cam. I still have the springs..., if your interested shoot me a pm.

 

Okay, Here is an update.

I did some research, sorry it took me so long. I popped off my valve covers and wanted to make sure what I had is what I had you know... since I did not build these heads myself. They are diffenately 1.6 RR's and the rocker studs are screw in type not pressed in. However I cannot tell if the springs are stock...

They are not beehive like I thought, they look like normal springs but just because they look like same ol same ol they might not be. Is there a way to tell while the springs are on the car?

So far I have chose to do the LT1 cam to upgrade my L98 cam.

L98 cam is 207/213 Dur .415./ .430 lift 117 Lobe

stock 93-94 LT1 Cam (the one I have) is

230/ 208 .450/ 460 116 lobe

Now since I have 1.6 RR's the lift will be

.480/ .491 which is right at/ slightly above recommended lift for stock 128's

the question is... how do I find out if they are stock guides and springs?

Another reason, I wanted the LT1 cam is because I have been reading that they are a good combo with nitrous.

 

I believe the only way to be certain is to take a spring off and measure it with a spring compressor gauge. I have an extra set of LT4 hotcam springs (good for .525 lift) if your interested, they're the normal shape (not beehive) and they're marked with a green stripe. Do yours have a stripe or anything on them marking them that way...

 

I could by the best springs in the world but it will not change the fact that the guides will have to be modified to accept higher lift.

 

guides... which guides?? When I did my engine I bought the LT4 Hotcam kit from summit. It came with the cam, springs, locks, retainers, and 1.6 roller rockers. While I was in there I replaced the valve seals, and all of this on aluminum L98 heads. I definatly changed the cam and lifters which gave me a much higher lift, and the springs to accomodate this.

What guides are you referring to?

 

guide plates only aline the push rod, thats why you selfalining rockers.

 

show me which springs you used again?