As of right now this is what I have done.
K&N, 1.6 roller rockers, TB-bypass, EM long tube headers, no cats ( not required in MI) Corsa's and a chip from PCM for less..

Right now I'm working a crap load of hours at my main job and I have a lot of work going with my business I run from home ( 70 - 80 hours a week between the two) I have a wedding to pay for in April but after that I will be able to put some of this "extra" cash to something fun. And of course I would love to put it to the car.

I dynoed it at the Cruise-in this year and it showed only about 10hp over what it "should" be stock. I know that my 1/4 mile times are not what they should be either. The car ran high 14's stock and now I'm running mid 13's NA and mid to low 12's on the N2O.

What would be the best combo for me to do without punching it out to a 383 or anything like that. If I have the time, money and energy I would like to do a full rebuild but I don't see that happening just yet.

What heads, valve size, chamber size, cam, TB would you guy say I should run?

I think I could pull some more HP out of her with a good Dyno tune but I'm greedy and want more.

 

LT4 hotcam of course, just portmatch the heads and intake, dont spend money on bigger heads when porting can do as well or better for less $$$.

 

NOT!!!!! I have nothing against the hotcam, and it is a proven winner. But.......there are plenty of off-the-shelf cams that are sooooo much better than the LT4 hotcam.

If you're looking for a great package give Lloyd Elloit (www.eportworks.com) a call/email. His combos are second to none.

 

 

So you guys are saying not to really change the heads but just match the ports from head to intake? No bigger valves?

I was looking at getting a cam that's a lttle more agressive then the LT4 Hot Cam.

 

If I were doing the car myself, and didnt need to worry about emissions or near-perfect drivability or noise or the like....I would probably go with CC306.

Depends on your power goals if you actually will need bigger or better heads than what porting can do for you.

 

I would like to see 400+ at the crank. I would like to keep it drivable though.

 

Look on my site at Nathan Plemons' results

 

I just did the exact thing you're looking at. I will try to find the thread I started, it was full of awesome information. Member 500HP gave me a perfect recipe for 400 chp.

My car is done (except for an annoying spark knock I can't figure out), should easily be north of 400 at the crank.

I went with a pretty aggressive cam, but other than that it's probably about the same mods as what you'll want.

I'd guess (doing a lot of the work yourself) you're looking at $3K total.

 

Yes I do all my own work.
I would love to see what parts you have.
I was thinking of going as high as 5K on this but 3 would be better, then I could add in the D44 too.

Thanks, I forgot all about that site.

 

http://forums.corvetteforum.com/show....php?t=1195485

 

500HP's post, pasted from my old thread:

Recipe for 425 to 450 CRANK HP:

Corvette 350 LT1 with flattop pistons. (Stock components will work)

LT1 Alum. Heads that flow over 260cfm/intake, 190 cfm/exhaust. (Pretty easy to achieve through CNC or hand porting by a pro)

1.75" Full length headers with dual 2.5" exhaust and hi-flow mufflers.

Relatively large camshaft with at least 236 degrees of duration @ .050" and .550" to .585" lift, depending on the ported head's limit. (With no emissions and decent exhaust this can be a single pattern cam with 110 or 112 degree LSA)

52mm or larger throttle body with modified air filter assembly.

24lb to 30lb injectors, depending on who programs/tunes your PROM.

.029" headgasket to get 10.75-11.0:1 compression, depending on final combustion chamber size after head porting/milling.

MSD 6A or 'bigger' and a full-size coil for top end spark energy.

Electric waterpump and an aluminum flywheel will also help the 'bottom line'.

Comp Cams Pro Magnum Roller Rockers and measure for custom length pushrods.

 

Going by that, you got most of your stuff from the same place. That would be great, then there is no question that the stuff is meant to run together.

 

My tab went between $6-7K but I did a bunch of things you won't need or already have. The big ticket items:

Precison Porting Stage 3 heads, 286 cfm intake / 260 cfm exhaust
Matched, polished, coated intake
52 mm TB
EM LT headers, no cats
Comp Cams custom grind: 230* / 236* duration, 0.576 / 0.571 lift, 112 LSA +2* advance
Carolina Stage 3 clutch, aluminum flywheel
Electric WP
Rebuilt PS pump
PCMforless PROM
30# FMS injectors
New valves, springs, titanium retainers, pushrods, hyd lifters
1.6 RR
Canton 7qt baffled Oil pan
10% higher volume Oil pump

Lots of other stuff.

 

All of the parts of the valvetrain came from Comp cams. You can have them match everything together or take recommendations from whoever you have do your heads.

Bob was the guy at PP, he went ahead and ordered everything and Comp dropped shipped it to me. Made things a lot easier that way and everything went together well.

 

I agree with just about everything there except the cam requirements. 236* of duration is quite a bit more than what you need to get around 430FWHP...but it will get you there easily, just as long as you don't need to go through emissions.

When I did heads/cam on my car here's what I had;

-Ported LT4 heads and intake (I had an LT4 to start) flowed 280 intake 200 ex. 2.055 intake 1.60" exhaust valve sizes
-Cam specs 222/230 duration .542/.563 lift w 1.6 rr's 112CL
-TPIS Longtube headers 1 3/4" primaries (I would get the EM headers now though, but they weren't out when I did mine initially)
-Corsa cat-back
-Crower 1.6 rockers
-Stock 48mm throttlebody
-SVO 30# injectors
-Ed Wright program

This got me 365 RWHP, which if you go by the standard 15% drivetrain loss is 430HP at the crank

Now, if I was to do it again I would change the cam and get something bigger. Initially I had emissions to worry about when I chose that cam, but now I don't...and there is a really nice Comp grind out now that has 224/230 duration and .600/.600+ lift that's been putting out some really nice numbers.

An electric WP should add 5-7 RWHP, but I would buy two of them and keep one in the car as a spare...as I do now. In case the one you are running fails...but my car is my daily driver. Also, an electrip WP is so damn easy to change out compared to the stock mechanical pump...it only take about 20 minutes before you're filling the car back up with coolant.

The real question is at this point, what are your END goals for the car? You said you wanted to do a full rebuild at some point...well, when you do would you punch it out to a 383 then? If you EVER plan on going the 383 route I would get the parts NOW that you would run in the 383...it sucks paying for parts twice. At the very least, get the heads ported for a 383...you *may* lose a little power from having the larger heads but it will be negligable at best. And yes, you can certainly use stock LT1 castings on a 383 and make very good power, so you don't need to go with a big set of aftermarket heads.

I've rebuilt my engine a bunch of times now, and I really with I would have had a complete end goal in mind when I was doing it because I would have saved A LOT of cash! But I'm done now (well, mostly) and I'm happy...but I just like to point this out to people when they start their projects! Good Luck!

 

Zix
My goal is to get the car to run high 11's NA but I would be happy to see low 12's too. Not sure if I'll keep the N2O shot or not. It is fun that's for sure but a SC would be too. I think that when I do rebuld it I'll stay at the 350ci and not punch it out. I have punched out some of my bikes and sleds and it really knocks down the reliability of the motor. Ideally what I would love to see is a motor that is 450hp and I can still trust it to drive it from MI to the Cruise-in.

 

High 14's stock, and mid-13's now...looks like you're losing close to a full second somewhere. Compression problem?

I think I'd start by resolving this and move on from there.

BTW - I used your Tech Tip on Lowering last spring...saved me a bunch of time. Just wanted to say "Thanks!"

 

I'll add my two cents. I was about in your shoes with my 93 coupe M6 having done about the same bolt ons. 1.6 rockers, K&N, Bob Bailey LTCC ignition, canton 7qt pan+ balanced oil pump, hooker ceramic shorty headers. I would encourage you to get the heads ported. In Lingenfelter's SBC book he says he will take better breathing heads over a bigger cam, but it's important to match a cam to your heads.

I bought LT4 heads and had them ported by Bob@Precision. I had him add LS1 beehive valvesprings. I was also lucky to find a brand new LT1 4bolt shortblock so after this buildup I will truly have a brand new motor. I am staying 350 for now but plan on boring my old block to 383 for later. Adding EM long tube headers, Meziere HD electric pump, Jesel belt drive, Fidanza aluminum flywheel, Ford SVO 24lb injectors. I have a new LT4 hotcam in the box but am toying with a more agressive cam. The GM 846 (or is it GM 847? I forget) has also been suggested to me. My car is a daily driver in the summer. I am also toying with the idea of adding 1.7 rockers and keeping the hotcam. Maybe even using shaft rockers. I want to get at least .550 lift to take advantage of the ported heads, .600 is better. I'm not sure at what point the mechanical advantage is lost by using higher ratio rockers over larger cam profile. I also need to address the computer tune. I plan on getting an Osprey emulator from Craig Moates (www.moates.net) and tackling that myself. The porting was expensive part $3k plus I bought brand new heads, I am afraid to add everything up but I am in the ballpark of $5k for my setup.

I notice you are in Grand Rapids. I am down in Kalamazoo. We should hook up sometime when the snow clears.

 

To get a good power increase the 2 main things you need to do are, have heads ported, and change cams. There may be better cams, but the hotcam is hard to beat, exspecially if you need to keep the car emissions legal. Look at my signature, and you will see I am making pretty good power with the hotcam. Send your heads out and have a professional port them. At least,before you port match anything check with a pro about that. I believe it is not recommended on the LT-1 engines. The main gain is in bowl work on the heads.
Things that I have tried that have given me no performance results are, MSD 6al. The LT1 ignition works fine without it. The only advantage is the soft rev. limiter. Catback exhaust, the stock exhaust flows very well, change it for a better sound, but dont look to it for a good value in the performance dept. 52mm throttle bodies, I purchased one used and tried back to back runs at the track and can see no difference.
Things that did work, Heads, Cam kit, LT headers, professional custom tuning, and in my case the electric water pump. With it, along with a newer style opti conversion from http://www.samtaylor.com/en_US/ I was able to use the standard double roller timing set, (coyles 9-3145) and at the track you can cool the motor quicker between rounds. Of course for dragracing dont forget gears, converter , racing wheels and tires.

Edit to add, Its a good idea to use the Impalla head gasket, as they are about .020 thinner and give you a slight compression increase.