Edelbrock MPI conversion for 5.7

Hmmm not a single person.

So you really think the TBI intake is ok for all these mods?

I currently have a dumped Borla catback, borla headers, chip, 160 degree thermo and shift kit (K&N air filter is pointless on this vehicle... unless changing the whole air box, that is, with it going all the way to the fender sucking in cold air).

But anyways, if I were to switch out the heads, would I really see that much of a difference? I have heard the intake is really what is terrible on these motors.

the TBI's limiter is the heads by a far margin. GM went waaaaay overboard when they designed them for max torque. the vortec's got the first decent iron non-vette heads in about 20 years. personally, I'd put a stock thermostat back in, those 160's make the engine run much richer than they were intended to.

-Bret

My Edelbrock heads did some real waking up of my 350. No other mods were done.

Sam

I would also put the 190 F thermostat back in, I had the 160, nothing put problems. Unless you have had the chip made up for 160. My gas mileage was much better when the 190 went back in, also can not do much for the O2 senor. My understanding is that the TBI will take a lot of mods. As I had said before, I put Hypertech chip 6 yrs ago before I did anything, then the Cam, that was designed for that engine, 1987 to 1995. Then the shorty headers, then the K+N. The exhaust work. The last thing will be the Aluminum heads, I think I will be find with the current chip. My friend has a highly modified TBI engine, running the stock TBI . I see a big change with these mods, going up hills, and the A/C on. Seems to me I read in a posting that the stock TBI is about 570 CFM.

I do have the stage 2 hypertech chip programmed to use the 160 degree.

I also forgot to mention that I have electric fans as well. Those made a HUGE difference in my opinion.

Course, they are on 80 percent of the time during the summer. I usually leave the windows down no matter how hot it is anyways, so the AC never requires the fans as well.

BTW what heads would you guys recommend?

if money were no issue I'd use the Edelbrock E-Tec heads with the GMPP TBI for Vortec manifold. if money is an issue, I'd use the standard port heads that Edelbrock recommends for the TBI power package.

-Bret

How does the thermostat affect the mixture of the engine?

I have a '87 truck 7.4L and it definately has mixture problems. When I changed the upper radiator hose the other day, I noticed that it has no thermostat at all.

Roger

The T-stat doesn't affect mixture.

WHen you put those lousy Hypertech chips in your truck and a new cold T-stat what you are doing is keeping the engine cooler which allows you to atomize more gas in the mixture. More gas under an altered spark advance curve will give you a little more power without pinging your engine to shit.

Of course, you're now running colder, running more fuel into your cylinders, increasing oil washdown and wearing out combustion chamber parts faster...but at least you have a little more power, right?

Roger, if your truck has no T-stat, your engine won't reach operating temperature in a proper amount of time, which can make the computer think your truck is freezing cold...which leads to a richening of the mixture.

Put a proper replacement T-stat in it.

Sam

Let me re-state that:

THe T-stat only indirectly affects mixture. THe Stat keeps water in the block, or lets water pass to regulate temperature. The CTS(Coolant temp. sensor), sends a signal to the ECM Re: the temperature of the water and that's how you get mixture changes.

See what hapens when you respond to usenet articles at 2:30 AM? :-]

Thanks for the info., Sam. I'm going to get the radiator rodded out this weekend, it's clogged up pretty bad, then I'll drop in a new thermostat. I had to drive home with the heater on, not a good thing in Texas!

Roger

Hell no! Not a good thing here in San Jose, either!

Sam