kitttransam

I've been debating and searching like crazy about cam choices. I’m just going to get an opinion based on my current and future set up. 89 corvette 355 with flattop pistons, AFR 180 heads with 64cc chambers, Long tube 1 5/8 headers, borla catback, AS&M runners, 58 mm throttle body, Ported plenum, Currently I have a ported stock base but I recently acquired an accel tpi base. So I plan on changing the intake and ditching my current ZZ4 cam. I also have 1.6 IN 1.5EX roller rockers. I’ve been really looking at the 268 xfi cam. But also been considering either the 211 or 219 lingenfelter cams. I mostly daily drive and I live in California. But I do take it to the strip maybe once or twice a year. I know with the xfi cam it’s advertised with 1.6 rockers all around. So I would need to get 8 scorpion 1.6 rockers. Any way throw your opinions at me. At is also an automatic with 3.07 rear gears.

cardo0

AFR heads are hard to beat. So I'm sure you won't change those. I would take a compression test and see what your cranking pressure is now. If you're cranking pressure is below 180 psi then a larger cam may just slow you down.

There are so many cam choices for the sbc it can make you dizzy. But IMHO using a TPI intake makes power peak early and a wider lobe separation angle would help spread that power band out. Which is more desirable with an automatic having fewer gears. And long tube headers amplify this early peak even more. Finding something on a 114 LSA isn't to difficult as I believe Crower lists a few EFI cams for the street like this.

Regardless with those AFR heads I don't think a cam change from the one you have now is going to be drastic unless there is something wrong with the build now. Then again the ZZ4 cam never had as good a reputation as the LT4 Hot Cam as I believe it was a remarkable improvement to install a Hot Cam in the ZZ4 motor. Someone was marketing it as nearly a 50hp improvement though I can't recall who. Bot even 35hp would make it worth it to increase power by 10%.

Good luck and hope this can help.

aklim

What is the Repuiblick of Kalifornia going to let you get away with?

kitttransam

I’m really not worried about California emissions. Place I go to is pretty forgiving as long as all the smog stuff is there. Just past smog about a month ago. Everything I have is smog legal except the cam and throttle body. My Hedmans are legal too. Anyway I was also considering comp 08 305 8 276hr 14 cam. And comp has a carb eo on that one. It’s a little bigger then my zz4.

aklim

Problem I have with the system is that if it works WITHOUT tuning, it so so close to stock, I would consider it a waste of time and money. If it is a wilder cam, it would need tuning.

kitttransam

I have no problem with tuning either. I’ve been getting my tune work done from Scott Hansen mail order and data logging. But I wish there was a place near me that dose dyno tuning. I’ve read about some third gen f body guys doing some tpi work in so cal but that’s 400 miles away from me.

aklim

Dynojet makes dynos. Get them to recommend a guy they sold a machine to in your zip. I haven't had much luck with "guess a tune" but if you have some way to datalog, I suppose that is an acceptable option although it would be my last option. I'd get a tuner. Think of it this way. Unless you are changing heads and cams and intake and headers constantly, you aren't going to tune daily, weekly, monthly or even once a year. I took my car in tow about 5 or 6 hours away once, quite a few years ago. Haven't been back for many years.

ddahlgren

I doubt there is a cam that will have decent street manners pass emissions and do much to change the tuned rpm of a tuned port. I would have saved the money on the base and cam and done an intake that allows 1000 more rpm. The 58 mm throttle body an equal waste of money. The original heads were 58 cc and now 64 cc so a bunch of compression is left on the table there. There is no easy way to get that much back as milling would be 0.040 to 0.050 as a flat mill and then run into intake manifold issues pushrod length etc. I have no idea why sold with such large chambers as they are starting from a clean sheet of paper. Yes it unshrouds the intake valve but there is more than 1 way to skin that cat too. If it was me I would get the compression closer to 11/1 and a better intake and forget the cam.

cardo0

Yeah, he (OP) posted he has new pistons already and 0.030" over for 355" so we don't know where his compression is dd. That's why I said to check cranking pressure now to find out where the motor is at for compression. But ya know whenever I suggest something diagnostic that costs nearly nothing but takes time and patience I get mostly ignored. Measuring chamber, piston volumes with liquid even more so. Owners prefer to spend money first then brag, boast or complain than take the time to do something they aren't familiar with. Yes denial! Pretty much human nature I guess and not trying to flame anyone for that. Just try to put good info out there and hope it takes hold.

aklim

I would agree with you on that. Bang for the buck, intake and headers are your best bet. The 58mm TB should only be used because you are doing heavy mods that will use it or you honestly need a new TB and that is the best price of one. I had someone that did back to back tests with the 58 on a stock system. He actually went SLOWER consistently.

ddahlgren

CC the heads and pistons seems like job 1 to me and get the compression correct and trial fit cam and heads to check for valve clearance to see if milling can fix it or new pistons needed with a small dome. Seems silly to not give the knock sensor anything to do and has to be tuned anyway for that matter. I had thought a stock L98 compression was around 10.5/1 with a very mild cam so a little more cam should easily stand a little more compression.

bjankuski

He has a 355 with flat tops, that will be near 10.5 compression with 64cc heads if it was done right. The 219 superman cam will work well and it was carb approved by lingenfelter. That will always leave you the option of adding the superram latter. Run 1.6 rockers. That combination will net you near 350 hp with the long tube runners and 400 hp with the superram.

aklim

Lets face it. What you suggest isn't sexy at all. I mean, diagnostic procedures isn't as cool as tossing a part at something.

ddahlgren

Then an XT manifold shold do the same for less money and work.

Kingtal0n

I know this is unexpected. But I want to throw this out there.

Many are using stock LS engines from 2002-2004+ to make 600+ horsepower, reliably. There is a stock bottom end reliability list in several places on the internet regarding this. Even the Aluminum block 5.3L is renowned for it's ability to support this power, and I believe it has the record (something like 1k Horsepower on a stock Al engine).

So when I see someone getting caught up with all these expensive parts, difficult combinations (to them), everything seems to be muddled and confusing; I always point out that, you can use a stock engine, most iron versions are $500-$1000, to make almost twice the power you are chasing now.

At that price, you can even afford to keep several spare engines. It also allows you to avoid the machine shops, the waiting, and possible assembly errors. You can put the engine in today and be done etc...

kitttransam

cardo0

Check AutoZone and O'REILLY'S first. The have loaner tools for free (as long as you return them). I have learned my lesson with HF tools. Never, never by a HF tool that needs calibration. I had a HF fuel pressure gauge that would stick mid-range right where I took readings. Also had a HF torque wrench that liked to snap 1/20 bolt heads off at low settings. Just use HF tools that don't require accurate measurement/calibration. I work with power plant instrumentation for a living and can calibrate most anything at work. Don't bother with HF calibrated tools. Just my 2 cents.

Good luck and hope this helps.

kitttransam

aklim

I don't know if you can simply drop an LS engine in. I would think that it would mandate no less than an ECM change and rewire among several adapters.

ddahlgren

the compression is a point low 10.7 makes more sense and the converter means they stole the bottom end torque away with that cam. FWIW good flowing heads don't need a bunch of cam to work well.