RSsleepr

First I'll start off with what I'm working with and then I'll volley the questions. Should be easy for the most of you who frequent the boards here.

- 89 Camaro RS, Daily Driver

-Pertinent Engine/Drivetrain Data- 350 cid engine. Bored .030 over, 10:1 compression w/ 64cc heads (stock Vortech currently), Performer intake, Speed Demon 750cfm w/vacuum secondaries, 1/2" phenolic spacer, Summit distributor w/vacuum advance, MSD-6AL, cam profile unknown aside from hydraulic NON-roller, 3/4" primary/full length headers, open exhaust aside from collector baffles (Sooned to be muffled and possibly cat'ed again).

Dyno sheet included with engine advertised 351hp @6000rpm, 380~ft/lb @ 4200~rpm. (w/Stock 64cc Heads[?], Performer RPM intake, Holley 750cfm, and Large Tube Headers- not included, engine bought as shortblock)

T-5 tranny, 3.73:1 final, and 25.9" diameter wheels.

-With current configuration I've ran a best of 14.3 @ 97mph. Ambient temp was 74*F, no wind, sea level (roughly). I tuned the engine myself, so professional tuning should yield a moderate increase in power.

Questions:
1. I plan on porting the heads, port matching heads/intake, and machining for larger valves (2.02/1.60) and springs. I'm keeping the Vortech heads, but would like advice on an intake/cam combo to compliment the heads. I'm using an ASCD Ram Air hood (like the 4th Gen SS) and would like to retain the phenolic spacer to keep heat out of my carb. So a Performer RPM would be near the upper limit on intake height. I do use this car as a daily driver but have very little restrictions for drivability, ie as long as it idles and does not stall under moderate deceleration I'm fine with it. (I'm prepared to use a vacuum reservoir if necessary) What would you recommend to achieve 400+hp @ 6000 rpm or below?

2. Anyone know of a capable and reliable engine tuner in the Charlotte, Raleigh, Fayetteville, NC area?

Thanks for any advice offered!

kmook

General engine buildup questions and discussion should be in a generation spacific forum. Moving to 3rd Gen Tech.

Thank you.

Sitting Bull

Your current combo should have you well into the 13s through the quarter mile. What is the altitude of your local drag strip? There is a standard NHRA correction formula that will give you your true 1/4 mile time at sea level. With what you have I'd guess it must already be in the 13s.

Look here: http://www.prestage.com/carmath/NHRA...on_Factors.asp

Blownyellow

I am not a big supporter of the vortech heads but make sure that if you are having them ported, that the time is spent on the exhaust side and not the intake.

It is of course fine to do a minor clean up of the intake ports, but the only true benefit of porting the vortechs lies in the exhaust.

Marc 85Z28

I'd HIGHLY recommend Comp Cam's Xtreme Energy 274H grind. There are several guys on other sites with the Performer RPM, stock Vortec head, and XE274 running well into the 12s, some hitting high 11's. The cam is docile enough to drive everyday, has an optimum shift point (with above mentioned components) in the 5800-6200 range, makes decent low end torque and NO ILL MANNERS! Nice sound too, but not too radical.

Several magazines have tested the above combo and every single one made just a little over 400HP around 5800-6000 RPM with a strong torque band.

I have this cam in my engine and am running World Products heads that flow a little less than the Vortecs. It works great!

One other note: If you do decide to get them ported, make sure you use someone with experience with these heads. One of the local shops around here (who's know for good work) failed with the first few sets. They ended up flowing less after a good bit of work. He eventually figured the secrets and advertises flow numbers in the 265/200 range...

Rage

Sounds like a nice car man, but 14.3's??? I run a 14.8x(sea level) in my car in the sig. You've either got some problems or you havent got really good at driving it. Good luck on that man. Sounds like a really nice set up tho

RSsleepr

Thanks for the replies.

Sitting Bull, the above ET and Trap Speed was at 240ft above sealevel, but I have had to resort to tuning my current setup on my own. I suppose I should have mentioned I have 17x9.5 rims with 285/40's, so I don't get great launches. I too was surprised (read disappointed) when I made my first pass (15.2 @ 95 mph) using a set of 3.08 gears in the stock open differential. The 3.73's and posi got me to 14.4, and the MSD shaved another tenth off to get me where I am now. I FEEL that this configuration tuned properly could get me into the 13's but I have yet to find someone I trust to do the tuning.

Blownyellow, I've read before what you're saying and I agree with you. I'm more interested in a bowl blend and polishing the combustion chambers- regarding an article I read a while back pitting the LT4 aluminum (bone stock) heads against a cleaned up Vortech pair. I believe the Vortech's ended up pumping somewhere near 50 more HP than the LT4.

Marc, I think I've read about that cam profile/combo somewhere. I assumed then it was a bit mild for what I was wanting to achieve. Looking at its stats now though it seems to be right on. Thanks for the post!

Rage, yes I would considered myself a rookie when it comes to the dragstrip. I have maybe a dozen passes under my belt. I keep trying something new with each run seeing what will get me gains so it's only a matter of time before I see better ET's but as it is I've ran 14.3's the last three passes.

So another question creeps into my mind: Has anyone had experience with the new conical springs on the market? I know the stock Vortech heads have a lift limitation in the .480- .500 range (not real sure, but close). If I run 1.6 rockers with the above mentioned cam (lift specs- .487/.490) I know I'll need to either machine for bigger springs or opt for the conical springs. Anyone see a reason not to use 1.6's with the Comp Cam's XE274H?

Thanks again guys and girls!

Marc 85Z28

The stock Vortec heads have interference issues right around .480" lift. Anything close to that lift and I wouldn't try it. Have the heads machined for the larger cam profile. And while I haven't had a chance to use the new "beehive" springs all the magazines are raving about them. One of the techs in my shop put a set on his reworked 355, but hasn't run the motor yet. He was told by a reputable engine builder they work as well as everyone claims.

Sure you can use 1.6's. However, you'll most likely have to elongate the pushrod slots in the heads, and custom length pushrods may be needed. Also take into consideration that the lift will be raised to around .520" with the XE274. They work well with my engine, but everyone's car/engine combo reacts differently.

Sitting Bull

I agree. Don't run a cam with more than about .460 lift with Vortecs unless you machine them for a taller, stouter spring set.