hello

I have a '86 monty SS  that is stock down to the fan belts...

nice car  but a tad slow  best et 15.87 

it's time to put the stock engine on a stand

and build another for it.. keep the stock engine stock incase these things are ever worth anything...

I'd like to install a 383  but also pass the sniffer

is the computer controlled carb on 305's and truck 350 the same or different..

if a 350 carb is needed ..what needs to be done to a computer controlled carb to flow enough fuel for a 383  and still pass the sniffer..

I plan  on  vortec heads and a mild cam...   how far can I do with a cam and still pass???

looking for a way to look stock and go faster......   cubic inches is a great way but unsure if the g.m. computer controlled carb can be made to work on a bigger engine than it was used for... and still interface with the cars computer...

You know I absolutly hate the computer controlled carb engines. It's a Mickey Mouse arraingement at best. You'd be much better off finding a doner Camaro or Firebird, dare I say Corvette, up to 1992 or 3 with either a 305 or if the Gods are smiling on you an L-98 350 and transplant the entire set up. It's way cheaper in the long run and is simpler to get past the SMOG police.

If you just have to stay with the diddle rod carb, you'll need to chip the computer from a custom chip house and make jet and metering rod changes. This can be a difficult exercise to dial in as metering is a lot dependent on where you live, altitude, weather, humidity, temperature, everyday stuff like that. You can spend a lot of money at a shop with emissions measuring equipment trying to dial all this in, where an earlier MAF TPI system will be just be spot on.

Trucks are different from cars and are not legal to put into cars. They probably won't SMOG without a lot of extra work.

You can't go with much cam on a diddle rod carb or a TBI and still SMOG about 200 degrees in the intake and 210 in the exhaust is about the upper limit. A MAF TPI (that's the kind that uses a heated wire to sense air flow) can be pushed quite a bit further up into the 220 degree mark and still SMOG.

I wouldn't worry about the Monty becoming valuable, it'll take another 20 to 30 years at least.

Bogie

o k  so  a tpi  from the last of the 350tpi's before the change to LT1

vette would be easier cause the ecu is in engine compartment...

if I went this route...  I'd need intake work to make it work on a 383...

port the lower/upper intake or leave it alone...  

350 injectors big enough for a 383 to 5200 rpm?

  but will a tpi pass in a car that never came from the factory that way..?

I know it be cleaner  but  logic isn't part of the testing system(smog)

TPI from a pre reverse coolant LT1 is easier because it 's using OBD I protocalls which are easier and way cheaper to diagnose problems and replace chips. The TPI of these engines isn't sequential, but its very effective at holding the line on emissions. It doesn't matter where the computer is mounted other than you'll need to get into it to replace the chip, so it's good to know where it is.

The 350 injectors should be up to feeding a 383 with a new chip that sequences them on longer. If your car doesn't have TPI, you'll need the fuel system from one as the line pressure is considerably higher than for a carb or a TBI.

If your car has a TBI engine (ie 305) this system can be adapted to a 383, but you need a bigger TBI from a 454 or Holleys 502-7 either of which flow about 670 CFM where the stock SBC unit is only good for about 400 CFM. This also will require a new chip. You'll be cam duration limited to about 200 degrees with TBI beyond that the sensors aren't sensitive enough to measure the operating conditions to keep the fuel map tracking with what the engine needs. The same can be said if this has the computer controlled carb.

You'll probably want a larger throttle body. Porting the intakes will be beneficial.

I don't know where you live so I don't know exactly what they're testing for. But basically the law is set up to allow you to use the same year or newer system in your car. California checks for engineering and offers a certificate of registration for mods that pass configuration. Then you also have to pass a sniffer or if you put in an OBD II system they'll just download its condition from the computer. If you live where they just test the tail pipe, then you have to pass. These places have a no mans land where there is no provision in the law to replace an older engine with a newer design. So if you don't pass even at some point in the future as the engine ages, I suppose they could make you park it or return it to original. I know I'll have to face that with my S-15 someday as the LT1 is gradually creeping up on emissions.

Bogie

thank you for your time...

I'm in MA. and shops around here don't know whats legal  or not..

and that kinda a problem..

i'll just need to get the questions answered by the reg. of motor vic.

as they run it(for the state)

again thanks for u'r time...

maybe cheaper to dump a ls1/6 crate in there and pray for the 200r4..

Massachusetts and several of the surrounding states uses some version of California standards. Whether your state introduced a system such as California concerning engine changes I don't know. I live at the far west end of the Mass Pike in Seattle. Washington state uses, or rather allows to be used, California standards on a local option basis. So some locals require testing and others don't, where California applys the standards state wide.

Washington thought of that! It's illegal to register your personal vehicle to an address where you don't reside. They check on registrations at PO boxes and sue you for conformannce to emissions and for back taxes if you live in an area that appies local option taxes such as Seattle does to support mass transit projects. The minimum state standard for emissions is the federal requirement. The high population centers like Everett, Seattle, Tacoma, Olympia on I-5 and Spokane out on I-90 by the Idaho border require the stiffer California standard.

So like I previously said, if you live in a state that uses Calif. standards but doesn't provide for explicit testing and approval of engine changes, you live in a no man's land if the conversion ever fails a test somewhere in the future. The typical proviso for a "stock" vehicle that fails an emissions test is that you have to spend up to some amount of money at a state emissions certified shop for repairs. Then you have to retest and show proof that repairs were legally attempted. If the vehicle passes great, if not your granted an exemption that has to be renewed everytime you're required to retest for license renewal. The stickler under all this is the proviso "that the vehicle is unmodified" from what the factory built. So if you stuff an LS-1 into a 1992 Camaro and 2 years from now it fails an emissions test and you don't live in and posses a Calif. techncial sticker approving the modifications, where are you with the state?

Here's a couple links to California BAR which is pretty helpful info when contemplating a swap.

http://www.smogcheck.ca.gov/stdPAge.asp?Menu=/includes/Menu_GenInfo.htm&Body=/Geninfo/OtherInfo/OBDII_info.htm

http://www.smogcheck.ca.gov/StdPage.asp?Body=/geninfo/publications/Engine_Change_Guidelines-Jan_1994.htm

Bogie