Had a dealer install the crate engine described belowTransferred most of the engine parts from the L98, A/C, waterpump, starter, etc.,although I purchased a Edelbrock intake, for the TPI.
Question: 52cc TB better or am I okay with stockTB, need headers, what kind and where plus exhaust, is the stock distributer okay. The car runs good after 3500 rpms slow off the line until I reach 3500 rpms.Hopefully TB, and exhaust (better breathing) will help, any help would be appreciated.



DESCRIPTION: ENG-330HP HO BASE
Our lowest priced crate engine, the 330 horsepower 350 HO doesn't sacrifice power or durability, it just pumps up the value. With its four bolt main block, nodular iron crankshaft, powerded metal steel connecting rods and light but strong cast aluminum pistons, this engine screams durability. Add to the strong foundation a pair of 64cc Vortec cast iron cylinder heads and a dual pattern camshaft with just a bit of a "lumpy" idle, and you've got the muscle car small block that you've been looking for. Dressed to impress with chrome valve covers and timing cover, this engine will look great between the fenders of your favorite street rod, muscle car or grass roots racer. The cylinder heads on this great little performer use 1.94" intake and 1.50" exhaust valves that are sprung with 5.7 Liter L31 valve springs. The 64cc chambers yield a healthy, but streetable 9.1 to 1 compression ratio. The cam is a modern dual pattern interpretation of the old '65 to '67 Corvette 327 cam. But with more lift and duration on the exhaust side, it does a better job of clearing exhaust from the combustion chamber. We also decreased duration and lift ever so slightly on the intake side to build more cylinder pressure. The result is a cam that makes great torque and horsepower with the 350 HO's compression ratio. This manifold has four bolts, not six, to attach it to the cylinder head. Older six-bolt manifolds will not fit the new Vortec heads.

 

I think that he stock throttle body should be fine for this engine.You may want to install large tube runners to complement the manifold that you have. what seems odd to me is your lack of power/torque early on.I would think that if everything were installed and adjusted properly,that this set up would have lots of grunt early on.Hopefully others more knowledgeable that I will chime in and give us some further insight into this problem.

 

considering the stock tune was for a ~230hp motor, and this one obviously uses more agressive parts...

did you order a chip or have someone tune the car before driving it?

 

One other thought on mods,I( think that you could benefit from a set of 1.6 roller rockers.

 

Actually the 1990 L98 was rated at 245 hp and 340 lb torque, and yes the chip was re-programed. I am having a guy dyno the car next week
hopefully he can make adjustments to the chip.

Thanks for the info........just looking for HP

 

Most all performance parts that make more HP, do so by raising the torque to a higher RPM range. HP ~ Tq x RPMs. Better breathing such as a larger TB or a freer, exhaust will not improve matters below 3500 RPMS. "The car runs good after 3500 rpms slow off the line until I reach 3500 rpms.Hopefully TB, and exhaust (better breathing) will help,". That low compression ratio and mild cam could probably stand a more aggressive ignition timing curve.

 

Thanks for reminding me, apparently the car (ECM) calls for +10* and
the new engine calls for 0* so the mechanic split the difference and set the timing at 5*. Is this a distributer issue or will re-programming the ECM fix the problem? Or do I have the timing set at 0*?

Thanks in advance for the help

 

Edelbrock makes a Vortec TPI Intake??? You've added pounds with those cast iron heads so that may suck up any gains. Might not be a bad idea to compare cam specs or share them with a tuner. Like most crates, yours was made for a carb. Scoggins Dickey is the only vendor I know of offering a full ready to run Vortec TPI motor (at least they did, they may be back to just offering an intake).

 

Start with the base timing (EST disconnected) set at 6* BTDC, the spec for the timing curve that is programmed into your stock prom. Make a 1/4 mile pass and then advance the base timing by 2*. Keep making the 2* additions after each run until the 1/4 mile MPH numbers quit improving. You will probably end up with 10* to 12* base timing with that engine.

PS. Be sure to reconnect the EST and clear the code after setting the timing, each time.

 

SDPC Edelbrock part #E3860 $349.99

 

With a good tune that car will run great. If your dyno guy is real good, you will be happy. No tuners around here. It took a few tries to get a good mail order chip for my car. The tune makes it or breaks it.

 

This car just needs proper timing and tuning, but its still not gonna make anything like the rated power.

Stock dist. should be more than adequate, dont spend money there.

Save for headers and exhaust, then intake mods. Read my website.

 

That's not a Vortec bolt pattern so I don't know how it works with those heads unless someone redrilled it.

 

i diagree with vader a tpi that is modified can make up to around 360 hp, i,ve seen it done before.

 

Did he replace the base with a Vortec style.

 

I didnt say you cant make the rated power, I said it wont once you slap a stock intake on it without headers.

Once you start changing the TPI intake through porting or replacement, you can easily make 350hp. This engine can do that if he modifies the intake, the cam and heads are not mismatched to TPI.

 

"Did he replace the base with a Vortec style"

Unless he did, I don't know how any of this works. Hopefully his mechanic didn't run off with a new set of Vortec Heads, but if he swapped them out for the 113's, that might explain why it's crapping out at 3500 rpms, especially with the Big Mouth Manifold and the stock runners.

 

You read it backwards. It doesn't "crap out" at 3500 RPMs. It isn't until 3500 RPMs that it wakes up. No bottom end.

 

Ok - but what combo of parts is being used here? The manifold he bought won't bolt up. If it were mine, I'd go out see what heads are on it - the combo doesn't make any sense.

 

No swapping of heads by the mechanic, the Vortech's are in tact. So my understand after the various conversations I should do the following;
1.) Timing
2.) Re-program the ECM
3.) Fuel rails & 24lb injectors
4.) Headers and exhaust

This will probably be a two stage process 1 & 2 first then at some time later 3 & 4. Once 4 is completed re-program the ECM again.

Once completed I may add additional componets to tweek the new GM engine. Thanks for all your help