Mathius

Ok, I read the stickies/faqs, and did a search, so I hope I'm not asking anything that's been asked before.

I have a '305 from a '76 Chevelle, it has the stock 2-bbl (rochester), HEI coil-in-cap distributor. The EGR has been blocked off and most of the smog components removed. It has headers with no provision for an o/2 sensor.

I have a TPI setup from an '85 IROC. It's missing the MAF and a few sensors need replaced, but it looks servicable. I have a couple of questions though...

1. I remember reading somewhere or hearing from someone that the coil-in-cap HEI setup won't work with TPI. Is this true? What distributor/ignition's are ok then?

2. I also remember reading there was something undesirable about the MAF from '85 years only. Is this true? Can I use a MAF from any non-speed-density setup then, or do I need a matching ECM?

3. Can I just use one of those weld-in o/2 bungs from Summit? I'm a certified welder, so installation doesn't intimidate me, I just want to make sure that it'll work.

4. Last question... will any pre-87 parts work with TPI or are their certain things I should stay away from? I noticed Edelbrock likes to list very specific applications for their products but even they don't list anything for TPI, pre-87. Summit has a whole section devoted to TPI,LT1, & LS1 to compete with Mustang owners, but they don't list a set of TPI specific heads or cam.

Thanks,
Mathius

Vader

TPIs from 1985-86 used the HEI Coil-in-Cap version, although the distributor was different to accomodate a slightly lower and slightly wider cap. The clearance was to allow the installation of the TPI trim extension.




The 1985 TPIs used a digital (frequency modulated) output from the MAF. Subsequent years used the analog (voltage) output MAF. V-6 engines continued to use the FM MAF, and are not compatible. The ECM used in 1985 models was old, slow, and barely capable. Any '86-89 ECM (1227165) will work fine, and they are more plentiful.


Yes. Just get it as close to the head end of the collector as possible. Watch the orientation for underbody clearance.

1986 was the last year for SBC perimeter bolt (valve cover) heads. The blocks used up through '86 were also flat tappet cammed. '87 and later years used roller cams, centerbolt (valve cover) heads with self-aligning rockers instead of guided push rods. These heads had the center two intake bolts drilled at a 72° angle instead of perpendicular to the intake flange. Intakes can be mixed and matched with a little machining, but it is easier to stay with one series or the other. Either will bolt to your '76 vintage block.

Mathius

Bumping this thread from the dead... I never did get around to this swap. I want to try and do it this summer.

Again, it's a '76 engine out of a Chevy Malibu. Engine is a 305 carb (2GC). I believe the transmission is a TH-350. The engine has had the EGR plate blocked off, and most of the emissions stuff removed. The stove pipe is gone going to the air cleaner. I've added headers, removed the catalytic converter, and installed true duals, as well as installed this camshaft: http://store.summitracing.com/partde...part=SUM-K1102 last summer.

The TPI unit is supposedly an '85 from a firebird, not an iroc. The computer reads: The computer reads: Service Number 1226870 and below that there is a bar code with the numbers 1226870255

I don't know what those numbers mean.

I intend to go with an inline fuel pump and get rid of the old mechanical. I guess I'm gonna pickup another distributor to fit under the TPI unit.

I'm still not sure if I'm better off finding a MAF or getting a MAP and going speed density. I used to know the pros and cons, but I've been too long out of the third gen scene.

Right now while it's still winter out, I intend to bring the TPI parts in from storage and get them cleaned up, as well as take a look at the wiring harness and see what kind of shape its in.

So with Headers, no cat, no Emissions, and that camshaft, I'm most likely going to get a custom prom then, right? What's the cheapest way about going about this? Can I send away the cam and engine specs and have someone do it relatively cheap?

Mathius

Mathius

Should I have just started a new thread?

rgarcia63

Seems you're hell bent on building a non-emissions TPI, care to share why?

Mathius

No, it's just that the motor already has the emissions taken off, and all of these changes done, and I'm just trying to find out if that's going to cause me to have to have some work done to the CPU.

I have the motor, I have the TPI setup... I have to get an inline fuel pump and run a new fuel line on the one side (copper line is there now, I don't trust it for EFI). I don't want to spend more money than I have to. But if I need something done to the CPU to make this work, I will.

Mathius

rgarcia63

I would take some time to determine what would cost the most, completing the emissions removal and reprogramming the EPROM, or reinstalling it and use a stock EPROM, or if it's about the same for both.

Mathius

Either I'm not understanding you correctly, or you're not following me well.

The emissions are already gone. The '76 was one of the early years of emissions and it had a restrictive butterfly valve below the exhaust manifolds, an EGR, a few extra vacuum lines in the thermostat housing and a vapor canister.

Everything except the canister has already been removed from the engine.

A set of headers and a new cam have been added to the engine.

What I need to know is, will a stock CPU work with this setup, or will I need to get one burned.

It is possible that the TPI setup I got came with an EGR. I have not looked.

Mathius

rgarcia63

Maybe I'm not following you. This is what I'm hearing.
'76 engine with no emissions with some new parts.
You want to put the TPI top end on the '76 block leaving it in the Monte Carlo is that correct?

Mathius

The motor is out of a Chevelle, but the rest of what you said is right. So do I need a new CPU or Prom burnt? Because that's my main question right now. I would assume yes, but I don't want to just start assuming things. But I'm guessing a new cam, heaers, and no catylatic converter is enough major changes to the flow of the engine to mean I'd need a prom burnt.

And do you still think it'd be cheaper to swap in some emissions than to have a prom burnt?

I'm not swapping the cam back out no matter what. Too much work and cost. I suppose I could get a set of stock manifolds in place of the headers, but I'd rather not if I don't have to.

Thanks for helping.

Mathius

rgarcia63

If your leaving it in the Chevelle you'll need the TPI harness from the ECM to the engine, the ALDL diagnostic connector, and the relay assembly behind the brake booster as well.
To keep from reprogramming the PROM install the emissions which, yes is cheaper.
if you don't have the funds to pay for reprogramming, or for buying what you need to do it yourself then I would suggest installing the emissions stuff until you can get rid of it properly. The smog pump can be left off, but the difficulty is with which belt drive you're using V, or serpentine.
If you eliminate the smog pump you won't need stock manifolds, just weld in a bung for the O2 sensor on the driver's side.

flaming-ford

iTrader: (7)

what garcia said just run an egr valve they are all the same from around the same era i do beleive so grab 1 and throw it on. other than that these cars had no imperaitives emissions equipment that would truly affect the computer or even an emissions sniffer test honestly...... a good cat and egr and a clean running car will still pass without error

Mathius

I don't have to pass inspection here, so that's not an issue, I just want it to run good.

So I need a cat and an EGR, and I'm good? Can't get away without the cat?

Mathius

rgarcia63

You don't need the cat
FYI - EGR valves come in 2 flavors positive and negative backpressure you need the one for the car the ECM/EPROM combination is from.

Mathius

Cool. I'll try to pull the TPI setup from storage this week and start cleaning it up and seeing what I've got. It was supposed to come with a full wiring harness as well. I bought it from a guy off the forums here, so I'm probably in good shape. I know the runners had some dents in them I wanted to try and work out as well.

Might try that frozen water trick if nothing else works.

I'm not forgetting anything for the swap, am I? TPI manifolds, wiring harness, EGR, provisions for an efi fuel pump... I'm gonna try to grab a serpentine setup as well, but cash it tight right now after Xmas and from what I understand that's not strictly necessary.

Thanks again,

Mathius