A little back story first:

I am running routine errands one day and as I pull through a drive through the temp climbs on the coolant side. It only gets to around 220 so I think nothing of it. Normal for just sitting.

Next day I am driving to the local parts store and the car starts to overheat. At around 250 I pull into the parking lot and pop the hood. Coolant is spraying out as a fine mist at a high rate of speed from the front left freeze plug. Luckily I was in a Wal-Mart parking lot and go grab a gallon of coolant. I let the engine cool and then fill her up. The leak has stopped but I know once the engine warms it will start again. So i promptly start her up and get her back to the house (less than a mile away).

The water pump is shot, the freeze plug is cracked and the thermo-housing gaskets ruptured too. So i need to pull the engine and since it had 160,000 miles on it without a rebuild or tune-up since 30k. I figure i might as well put another engine in a rebuild it.

Here's where the problems come in. The only fresh engine I have is in my 1987 Firebird. Thing is the engine originally came from a 1984 Vette that had been raced prepped prior to catching fire and dying. Some might remember the pics i had posted of said "dead vette".

We get old engine out and the new one in. The new engine was setup for carberation so my only option right now is to put the stock TPI system on it. Keep in mind this is my daily driver.

After a few hick-ups with timing and fuel we get her running and running steady. But now I have a fully built, race prepped motor in the Vette but it seems to be lacking power. I know this motor is capable of 600+ with a carb and with the 250 shot we had on her in the white vette she topped out just over 900. But this engine is actually SLOWER than the stocker. Any suggestions as to why this may be?

New Engine Specs:
383 bored .030 over
forged 11.5:1 pistons
Trickflow Kenny Duttweiler Heads (ported and polished w/ CNC chambers)
Agressive street cam (unknown specs)
Full 3" ceramic exhaust w/o cats

I have no idea why a 600hp engine is pulling like a 150hp engine. Timing can't be the only issue.

 

So you're running it with the stock TPI setup?

 

Did you keep the stock tune and injectors with that engine?

 

Answer right there.
Should pull awresome to 4k before it strangles

 

WoW Why would you put the TPI on THAT Motor??? DD or Not..What a Waste Of HP...Take that crap off and carb it and make it breath...Ya had to know what you built....

 

Because of the add'l cubes, you need to have the ECM re-programmed, along with larger injectors for starts.

You really need to know what the cam specs are because the ECM re-programming will depend a lot on the cam duration and lobe separation angle.

Jake

 

Because I had 2 days to get it running so i could make it to work. And I still wanted some kind of decent mileage.

That is what i will be doing tomorrow until i can get a decent intake fabbed. As far as "knowing what i built"... how would that be possible unless I built the engine? I merely purchased the 84. i didn't build it.

 

I agree with Jake, non stock engine with stock programming equals disaster. I'm surprised its even able to get you back and forth to work like that. I'm all for the carb as well, sure your gas mileage will go down a bit but gas isnt too expensive right now anyway until you can find a solution to your EFI woes. Good luck

 

Cam, intake and ECM miss match.....woes for showoes!

 

with all

Bad combo that's all. With the TPI and original program the motor is starving

 

It's a wonder it runs at all, stock tune , stock TPI with what gears and what converter to go with this 600chp stroker ?

 

With original detonation concerns I retarded the ignition about 20 degrees, well with the computer controlled timing it also retarded it so i was running near 50 degrees retarded, making a $500 set of ceramic headers glow bright red. We adjusted the timing to standard, 10 degrees advance and that allowed to ECM to adjust it to around 20 retard. That coupled with 93 octane gas means no detonation but the engine still runs hot due to the compression and lack of cooling air.

I have a single plane, 750 carb and MSD dizzy I will put in once I can find my damned pressure regulator. We used a pump with built in regulator for the car it came out of. So that isn't really an option.

Otherwise she runs strong just limited by the coffee straw of an intake that is on it.

I will be fabbing up a SuperRam style intake for the rebuilt motor. Depending on reliability, I may offer it to any one who wishes to purchase it. But no promises on time frame. With all the major events coming up soon and other projects I have to get out of my garage, it won't be for atleast six months before work starts on the factory 350.

She is actually running quite rich. Extremely rich at this point. I don't have a wideband on her but I am willing to guess just by the smell I am some where around 12:1 or lower for the A/F ratio. I believe that mainly has to do with the retarded ignition and lack of cats on this exhaust. Yes I will be putting cats back on this car. Just unbolting the stock exhaust sheard 3 of the 4 studs on the manifolds.

 

Common problem with any tune with big cam.
Big overlap on cam fools stock O2 sensor into thinking engine is lean so it just keeps dropping more fuel in .