Best Cam Upgrade for 87 C4 w/L98

[ARODFX]

I am thinking of buying a Cam for my 87 C4 and wanted to get some info.

Here is my current setup:

K&N air filter (w/Cut Out Lid)
58 mm BBK throttle body
Ported intake plenum and SLP large tube runners
Heads machined and lightly ported. (3 angle valve job and some in/ex work)
True Roller timing chain
Flow master Exhaust and Cat
Relocated Air temp sensor
160 Thermostat
Hypertech Thermomaster Chip
New O2 sensor

The following is what i plan on getting:

Jacobs Pro Street Ignition or Accel 300+ Ignition with Accel 50,000k coil(any suggestions?)
ZZ4 Roller Cam or Higher spec cam if my setup allows (Suggestions?)
Shorty Headers (Y Pipe is new)
1.6 Roller Rockers
Thinking about getting New Heads w/2.02 In-valves 1.60 Ex-valves 64CC chamber.

I want to increase the stock horse power in steps and would like to know what items I listed would show the most gains. Trying to find the best combinations before building the 383 stroker that I want. Any suggestions are greatly appreciated. Thanks!

 

[taegdh]

You really ought to quit the lie stuff, if you want to with the stroker kit and make 383 out of it, just do it, incremental steps will waste a lot of money and time, tearing stuff off the engine now, re assembly, tear do re assembly to go to the next step. Car is laid up... Doing it all at once is the way to go, unless the funds are a problem, then just put it off until the funds are in place...
Plus, every time you tear it down you take the risk of breaking something else.
taegdh

 

[Edmond]

I would skip the Accel ignition system. Those are mainly designed for engines that make power north of the 6000RPM mark.

The 1.6 roller rockers are a given, you should definitely do them.

I agree with taegdh said, you should do everything at once. Taking things apart and putting them back together isn't very good because of the time and the chance that something will break.

But if you do the 383 setup, that would be such an awesome street machine with a lot of torque.

Have you made sure that your transmission could handle the additional power?

 

[tntcorvette]

well depending on your funds and if you are going to do thw work....i can sug. a cam for you.

LPE 74219 cam is a great choice. But if you are serious about a 383, just enjoy the car as is and build the 383 and drop it in.

 

[vader86]

you have no need for the hi-power ignition system until you ditch the TPI-style intake

Only for a Miniram, Stealthram, Modded LT1 intake...would you actually NEED the added boost to the ignition. The Superram is marginal on this point, it may or may not depending on combination. Adding a better coil and good wires, etc is ok but no ignition boxes.

I dont see anything wrong with that plan, but with a TPI-style intake I would look hard at the Accel 211 and TPiS ZZ9 cams. I think the 219 is a bit big for the TPI.

 

[Mad-Mic]

i'll follow Vaders lead and say the 219 cam is made for the SR so i'm not sure if it will live up to your expectations with a LTR setup. ZZ9 is a good choice. maximum lift is in the .520 range or so with 1.6 RR's. if you are running stock heads they will need to be reworked so they can accomodate the lift. if you go with aftermarket heads or get yours reworked and want alittle more cam the ZZ409 cam is a nice cam and with 1.6 RR 's you'll get a total of .555 lift. this is the cam i got but need to get a set of heads before i do the swap.

your 350 stock bottom end, depending on milage, should hold the setup mentioned above. a LTR aftermarket head, ZZ409 cam should put you in the 400fwhp range with 450+ torque range. or mid to high 11's with some traction on a good night at the track

if you want to do the 383 stroker thing it would be nice to a have a completely built lower and bottom end you probably won't gain much on extra hp but gain some on torque. my suggestion would be do the 383 combo if you have more than 50k in miles

 

[ARODFX]

Thanks for the Advice everyone it is very helpful.

I will be buying a block from my local scrap yard and building the 383 stroker from that block. I was thinking of getting the block out of an old police car. My machinist will blue print the block, bore the cylinders .30 over and make the necessary clearances for the Crank. I am looking into purchasing these heads and http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2455987850&category=33617 switching over to the Modded LT1 Intake setup or maybe even going to a carburetor. I will be doing all the RR myself. I am still curious on the cam. I wanted to know a little about the ZZ4 cam and this cam GM #12551142. The specs for the GM #12551142 are duration at .050" lift is 203/210 Intake/exhaust and maximun lift is .467/.480 intake/exhaust with 1.6 rockers and .438/.450 intake/exhaust with 1.5 rockers. The lobe centerline is 115 degrees. Would this cam work on my current setup?

 

[47fleetline]

I would recommend a Competitions Cam XR258HR (in 258 / ex 264 deg @ seat, lift in 488 / ex 487) or a XR264HR (in 264 / ex 270 deg @ seat, lift in 487 / ex 495).


These cams produce very good torque and good HP according to the Dyno Sim software.

 

[vader86]

The ZZ4 will work, but its not enough different from the stock cam for you to notice anything major. I would also not want it at all with a LT1 intake, its too little.

A happy medium is what you want, I know the ZZ9 works with short-runner intakes well, and it works with the LTR well. If you only wanted to this once, I would go with it.

 

[tntcorvette]

The ZZ4 cam will work with your setup, but it will not give your setup the most potential versus other cams that will behave the same as the ZZ4 in terms of idle, vacume, etc.

Remember the ZZ4 block with the fast burn heads will do 385hp and that is with a carb intake. Granted those are good numbers you can get more power with a different cam.

I run a miniram II with a custom ground comp cams hyd. roller cam that is 224/230 with well over 1/2" of lift on both sides on a 112 lsa.

I still think the 74219 cam is a better choice for you if you are serious about doing the 383 because you will need to buy another cam when you do the 383 versus the ZZ4 cam. The LPE 74211 cam is more towards the long runner engine and the LT1 setup so I guess you cant loose with the 74211 cam if you do the LT1 conversion. LPE gets good numbers with the 350 LT1 packages....something like +400hp & +400 torque at the flywheel. Their LT1 383 packages use the 74211 cam also and make over 440 hp and around 430 tq at the flywheel too.

I am not familiar with the GM 434 casting sbc heads in the above link. I think most people use the 113D port heads from the later '87 or so and up corvettes.

I'de proabbly pass on those heads.

 

[tntcorvette]

I would recommend a Competitions Cam XR258HR (in 258 / ex 264 deg @ seat, lift in 488 / ex 487) or a XR264HR (in 264 / ex 270 deg @ seat, lift in 487 / ex 495).


These cams produce very good torque and good HP according to the Dyno Sim software.

is that a flat tappet cam or a hyd. roller cam? I belive the '87 block has a hyd. roller cam.

 

[vader86]

87 does have a hydraulic roller, and '128 heads.

'113 started in 88.

I believe the '434 has a raised runner, 15 degree setup

 

[ARODFX]

What cam can i put in my L98 now, that will give me more horsepower using either the stock chip or my Hypertech thermomaster chip? I want to get my current engine up to 300+ horse.

 

[Mad-Mic]

What cam can i put in my L98 now, that will give me more horsepower using either the stock chip or my Hypertech thermomaster chip? I want to get my current engine up to 300+ horse.

you don't need a cam to achieve 300+ hp until you want to get in the 350+ range.

do the TB Bypass, Cut air lid/K&N filter, new front Y pipe with NO pre-cats, high flow cat, muffler eliminators, crank pulley, MAT relocation sensor, a full tune up and an Accel SuperCoil and that should put you over 300 hp.

i used a HP calculator and with my ET i put out 348 hp to the crank and 290 at the rear wheels. by the MPH it was 330 at the crank and 280 at the rear wheels. i will find out soon when i dyno the car to see what it is doing but i think that is pretty close to the HP i'm making with my mods list that i described above except the crank pulley and the MAT relocation sensor.

personally if i was to swap cams i'd do the upper end also. heads, intake work, cam, and a set of long tube headers. you will only notice about 20 hp with the ZZ4 cam swap if that with stock TPI and stock heads.

 

[tntcorvette]

87 does have a hydraulic roller, and '128 heads.

'113 started in 88.

I believe the '434 has a raised runner, 15 degree setup

15* heads? Wow....pretty much a race head only huh?


Pretty cool! Are those heads iron or aluminun? They look iron.

 

[vader86]

What cam can i put in my L98 now, that will give me more horsepower using either the stock chip or my Hypertech thermomaster chip? I want to get my current engine up to 300+ horse.

You dont need a cam to get 300.

You do have to pick something to go with future mod plans if you only want to do it once. If youre staying with TPI-style, then Accel 211 or TPiS ZZ9 or something with similar specs to those. If youre going with a modded LT1 or Miniram, then you want something with more duration and the ZZ9 is what I call 'entry-level' for the Miniram. Once you get a Miniram, there are other things youll want to modify, like the rear gear ratio and probably the transmission. Understand, youll probably have to modify one or both of these (eventually) no matter what route you go.

 

[tntcorvette]

you don't need a cam to achieve 300+ hp until you want to get in the 350+ range.

do the TB Bypass, Cut air lid/K&N filter, new front Y pipe with NO pre-cats, high flow cat, muffler eliminators, crank pulley, MAT relocation sensor, a full tune up and an Accel SuperCoil and that should put you over 300 hp.

i used a HP calculator and with my ET i put out 348 hp to the crank and 290 at the rear wheels. by the MPH it was 330 at the crank and 280 at the rear wheels. i will find out soon when i dyno the car to see what it is doing but i think that is pretty close to the HP i'm making with my mods list that i described above except the crank pulley and the MAT relocation sensor.

personally if i was to swap cams i'd do the upper end also. heads, intake work, cam, and a set of long tube headers. you will only notice about 20 hp with the ZZ4 cam swap if that with stock TPI and stock heads.

I do not think those bolt on parts will gain ~70hp at the flywheel. TPI cars run great in the 1/4 due to the low end torque and narrow power band.

In all honesty you do not need a cam to get 300 flywheel hp but the stock TPI has to go. You will need at least a set of high flow TPI runners (Arizona Speed & Marine), high flow intake manifold (accel), ported TPI Plenum, 52mm throttle body, cut lid & K&N, modified maf sensor, full length headers, chip and i'de upgrade the ignition system. Personally i've had bad luck with MSD 6A units as I fried 2 ignition coils and eventually the MSD 6A itself. I now run my car w/o the MSD 6A and I know it was connected correctly.

Proabbly a set of high flow mufflers too. If you want to challenge your wrench skills purchase a Accel SuperRam system and slap on a 58mm throttle body to compliment it versus a 52mm with a TPI style setup.

The SuperRam makes great low end torque and moves the hp peak up versus the stock TPI style setup, but it is a pain in the ass to install. Definetly replace everything below (egr, injectors, etc) before you install that intake because you will not want to do it again anytime soon.

Anyone know if LT1 style shorty headers will bolt up to the L98 front y-pipe? I heard that they will but i've never done it so who knows.............

 

[Mad-Mic]

I do not think those bolt on parts will gain ~70hp at the flywheel. TPI cars run great in the 1/4 due to the low end torque and narrow power band.

In all honesty you do not need a cam to get 300 flywheel hp but the stock TPI has to go. You will need at least a set of high flow TPI runners (Arizona Speed & Marine), high flow intake manifold (accel), ported TPI Plenum, 52mm throttle body, cut lid & K&N, modified maf sensor, full length headers, chip and i'de upgrade the ignition system. Personally i've had bad luck with MSD 6A units as I fried 2 ignition coils and eventually the MSD 6A itself. I now run my car w/o the MSD 6A and I know it was connected correctly.

Proabbly a set of high flow mufflers too. If you want to challenge your wrench skills purchase a Accel SuperRam system and slap on a 58mm throttle body to compliment it versus a 52mm with a TPI style setup.

The SuperRam makes great low end torque and moves the hp peak up versus the stock TPI style setup, but it is a pain in the ass to install. Definetly replace everything below (egr, injectors, etc) before you install that intake because you will not want to do it again anytime soon.

Anyone know if LT1 style shorty headers will bolt up to the L98 front y-pipe? I heard that they will but i've never done it so who knows.............

87 vettes came with 245 hp so your only looking at 55 more hp. this is my mod list and i can pull C5's on the top end with a stock tranny/stall/TPI/2.59 gears. you don't need a SR and a bigger TB is pointless on a stock longblock. once you do the SR and heads and cam setup the chokepoint isn't the TB it's in the MAF unit if your exhaust is done.

 

[tntcorvette]

well lpe rec. that all s/r motors from 350 ci and up with the s/r intake use the 58 mm throttle body. I belive this is so because of the large plenum volume. The s/r plenum is about 2x a big as the tpi plenum.

I did not know the '87 came with 245 hp....my bad!

The maf sensor is not that big of a restriction. It really isnt. But opening it up via cut screens and cutting the heat sinks is a good for more air flow.

Where are you shifting in the 1/4 mile? Around 5000 rpms or such?

 

[Mad-Mic]

Where are you shifting in the 1/4 mile? Around 5000 rpms or such?

i was shifting at 4900 rpm but she seems to be pulling to around 5300 rpm before i feel a drop off. rrubel was with me and i winged her to 5500 rpm and i asked him if he felt a drop off and he said no.

i will know shortly when i do some dyno tuning in the next few weeks.