heres the deal:
my uncle has that 400 SBC. he will swap me it for my 305... its only for his beach truck, and he doesnt need a 400.... catch is, i need to drive to north carolina and swap motors... in otherwords, put his motor in my car. and give him my 305..... prob is, i still have TBI....


now first question... will it run? i have no idea what cam is in there, athough i do know it is REALLY mild. esp for a 400..



i know that if i can find someone with a TBI running a 400, i can ask them for a copy of their BIN, have a chip made, and when i do the swap, pop in teh chip for the drive home....... but who has a chip for a STOCK tbi with a 400 under it?!

otherwise, id be trying to drive a 400 on 305 programming




what can i do to make it work just to drive me home.......??

 

ps: home is roughly a 470mile drive.


keep in mind, i can tweak everything when i get home and i will eventually put TPI and a aftermarket manifold on it.....

 

Get some 75 pph injectors, install them when you switch the engine. You'll get it good enough with those, FP adjustments, and timing for the trip home. See my sig, and you'll see waht I've done w/NO PROM tuning.

Edit: why in the world would you put TPI on a 400 ??!

 

where can i get 75# TBI injectors????

prefably used and cheap.... since this is only a temp thing..

 

I got mine off ebay. They were $90 for the pair, brand new.

Or go to a salvage yard and get some from a TBI 454.

 

off a 454 TBI? any years to look for or are they all the same?


ive swapped injectors for new ones before, im assuming the 454 ones drop in the exact same way right?

 

oh as for your TPI comment:


its not TPI.

im just getting sick of explaining my entire scheme:

TPI harness
730 ECM
sheetmetal intake made by me
LT1 throttle body
30# injectors

once sheetmetal intake is done, im going to work on the ultimate intake... basicly, im making the airflow passages by shaping foam, then im going to overlay them with carbon fiber... and when thats done, bond it to some alum flanges and be done.


all that on my 400... 400 will either have a large solid roller cam, or a large hyd roller with a rev kit.

big cam and alum heads dont go on until i do the T56 swap.



but thats like 3 years of work... its being done in stages... stage one is, get car running for now.



edit:

obviously, im planning on burning some chips too...

 

did a lil searchy searchy since i knew i was looking for bigger injectors now..

from http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm

mmk, so i need pre '94 454TBI injectors... the blue/black ones

 

Well that's good! All the TBI injectors, from the little 2.8, up to the 7.4, are mechanically interchangeable. Direct bolt in's.

 

do you think i can get away with just swapping the injectors and not touching the fuel pressure or anything else?

 

Probably, if the injectors you happen to get are close. But it'll run much better if you spend a little time fiddling with it.

Honestly, you could probably make the stock injectors work if you just crank the FP up high, for the trip you're doing.

When I first put the 400 in my car, it had the same combo as listed above, MINUS, the injectors, ported intake, bored TB's and it had a weak fuel pump that couldn't muster over 9 PSI. Yet it still ran fine. I actually thought it was pretty great...until I took it to the track.

But daily driving it was fine. So you could get some bigger injectors just to be safe, but I think you could just boost up the FP to about 15 and you'll be fine, considering the mild cam you mentioned.

 

are the fuel pressure regulators in the 454TBIs the same as the one on my car?



cause if they are, i can modify that regulator instead of my stock one (and if i mess it up, no worries)....

i'll snag the regulator when i get the injectors if they're the same..

 

They're the same.

 

The 454 reg is a little different!! I saw a post on here the other day with pics. For one the spring is a lot stiffer, and the part you drill out is different. This guy swapped the 305 reg onto the 454 TB so that he could adjust it. Not sure what forum this was in, you might try some kind of search. Bobby

 

Uh-oh. Another thread, same story.

The regulator IS basically the same. It will bolt on. In some applications the spring is to stiff, and it won't work. Others it will. Either way, check it compared to yours when you get it. It will bolt on though. How do I know? I actually I did it.

 

its not that big of a deal to reuse the spring that i currently have.



as long as i can still "convert" it into being externally adjustable, and it bolts on, im happy.

 

His beach truck isnt gonna haul much with a 305 ....
and specially with the weight it carries ...

Anyhow.. A 400 cu.in convertible should be fun none the less ..
The intake project sounds like fun ...

good luck

 

I would go to the junkyard and get a carb intake, quadrajet, and Hei distributor. That would probably be the safest way of doing it. You will need a fuel pressure regulator though.

 

LOL. That's all he needs now, MINUS the intake, carb, and distibutor. And I'm sure a junkyard non CCC carb will be ready to go, AND have the proper jetting too. lol.

 

he lives on the outer banks of NC. the speed limit on the beach itself is about 15mph. the truck couldnt take a strong motor anyway.. like all things driven on the beach/saltwater, it rusts. i wouldnt trust it with the L03 floored if it was on pavement. he only drives it on the beach anyway.


ahh, but then not only am i buying stuff i wont use later, but 3 port regulators arnt cheap. not to mention, i probly should rebuild the carb before i plopped it on there. and im not hacking the stock harness, so im going to need to plug into the stock plug and make a lil connector to attach to the HEI... i agree that a carb conversion is probly safest though.


i should mention, this is my backup plan if i cant find another good running complete SBC to swap him...

 

If you grab a carb off a 454 it would run a little rich, but that is a good thing. The stock cast intake manifolds are a dime a dozen and so are the distributors. We are talking under a hundred for everything, but the regulator.
Now if he runs lean on the 305 setup because of programming and blows up his motor, what do you think will be cheaper?

 

I have a mallory 4309 3 port regulator. I will let you have it for 40 dollars and shipping. This is what I paid for it. You can put it on ebay and sell it easily after that.

As for the carb, sometimes you can get one off running engines at the junkyard. You can buy a good used carb off ebay for nothing also. Sometimes off the classifed section. A basic holley rebuild kit only cost 21 dollars from autzone btw.

 

Don't worry about hacking your harness or making a plug. All you need is a cheap relay and a little wire. Wire the relay so it comes on with the ignition and have it run battery voltage to the distributor. All a Vacuum advanced HEI needs is 12 volts and a ground.

 

He's not going to "blow up" a mild 400, cruising at highway speeds! Think.

And did you read my post above about MY 400? I didn't cause any damage to that, drivng it for months, and taking it to the track!

The SIMPLEST, CHEAPEST, reliable way for him to get that car home w/the 400 is to crank the FP, and maybe throw in some 350 injectors.

Not only will this work perfectly fine, I bet it'll actually run pretty darn well. Mine did.

 

The cam will play a large role in how well the setup runs.
If the cam LSA is less than 112*, you may need to consider changing the cam.
Best of luck.
S-D

 

Exactly, the cam and the compression ratio will affect how it reacts to the 305 programming. He could run the motor too lean depending on those factors.

Its like finding an edelbrock and just slapping it on your 454. You may luck out, you might run lean and damage your motor.

 

No ****. I'm not saying it's a "bolt-on" to the 400. He's going to need to ADJUST FP, and possibly change injectors (easy to do).

No, you won't damage a motor that is that mild, under light load (highway cruising), from running it lean. We're not talking about a dirt bike or snowmobile motor here, that makes 200 hp/liter. We're talking about a 6.6 liter that might be making 200 hp. You won't damage the motor under those conditions.

 

At the risk of stating the obvious:

old engine: 305 TBI, 51 lb/hr injectors

new engine: 400

Q. What size new injectors for the ride back:

A. displacement ratio is 400/305 = 1.31, so replacement injcetors should be 1.31*51 = 67 lb/hr assuming you retain the stock ECM to provide the same fuel vs rpm & load as the 305 had.

So you could use either the bbc TBI injectors of the 75 lb/hr size as has been suggested above, or, use copcar Caprice LO5 350 injectors (65 lb/hr). This shows, btw, why Tom400cfi had no problems by using the copcar injectors on his 400 -- they were perfectly and proportionately sized for a 400 upgrade.

I've also been told that all other 92-93 Bcars using the non-police LO5 350 also use the 65 lb/hr injectors based on the injector constant buried within the EPROM. I'm sure that info is either on the DIY PROM forum here, or elsewhere on the web (if you search for it). So a 92-93 Roadmaster 350 sedan/wagon should also have the right injectors, and these plus the LO5 Caprice TBI copcar will be easier to find in a junkyard.

The torque and power rating for the 400 would also be, to first order, the 305 value(s) multiplied by the same 1.31 factor for the displacement increase, or 223 fwhp and 334 fw ftlbs. This assumes you do nothing else to the engine.... which for the 470 mile ride back is fine.

Finally, if you do the swap and drive home, drive conservatively. The 400 won't breath well at upper rpms into the factory Fcar exhaust even though the extra torque off idle will feed great, so you'll be risking the swap and the drive for nothing. Wait until you get home (with no breakdowns) and start modding the exhaust + intake. And those mods will absolutely demand larger injectors and/or an increase in fuel pressure AND probably ECM tuning ---- unless you get lucky as Tom400cfi did. Meanwhile, 350 or 454 injectors and the stock ECM should be just fine for the ride back. HTH.

 

That was very well articulated. Just wanted point that out.

 

the 400 is a 2 piece rear main seal engine.

it's also externally balanced.

you'll need another flywheel for this application if it's a manual. i know mcleod makes one. the 400 flywheel won't work with a t5.

if it's automatic, i'm not sure the turbo 400/turbo 350 flex plate will work with the f-body transmission. need to check into that.

also, before buying those injectors, why not go ahead and buy a 454 tbi? there's a guy in texas selling them with the correct linkages and throttle position sensors to bolt straight onto our cars. if you try to develop any power out of the 400, you'll need more air than the tbi unit you currently have can flow. you'll have to swap over at some point, so why not do it at the start and save the money on the injectors?

 

I would make every effort to find out what cam is in the engine. If the LSA is something low, like a 108*, that will need special consideration especially when driving that long distance on a computer. Lift will also have a huge impact on air and fuel requirements.
Kdrolts observations are good, but remember that cam and heads are probably not identical on the 305 and 400, which would throw off those calculations. They may or may not be on.

The above paragraph is why I'd be extremely cautious concerning running lean, particularly on an engine with siamese cylinders. Do you have the equipment to monitor engine function (WinALDL?). Will the engine run lean and burn up? Without knowing the cam specs, the only sure thing is that no one knows for sure. I'd do everything possible to make sure it has plenty of fuel.

The points on motor balancing and flywheel/flexplate are very important as well.

Will the manifolds swap? I thought some of the older camaro heads had a different intake pattern- not sure what year yours is. Also- what bin do you have?

As far as using a carb- that would take some work and adapter fittings and whatnot. Not sure if fuel can be pulled through the in-tank pump using a manual fuel pump.

Just a few more things to think about.

Good luck with your project-

S-D

 

Running lean will not hurt the engine at this LIGHT load! It may run lean (if he doesn't make the proper adustments), but it won't matter! You can run it lean to the point that it'll start miss-firing, then you'll want to richen it for the annoyance factor.

 

the intake pattern IS different.

you know, this seems to be going about things the hard way. rushing to do this swap so you can drive the car back is fraught with potential problems. here's a much simpler solution:

! pull the 305 out at home.

2. rent a pickup truck from uhaul.

3. place 305 in bed of pickup

4. drive pickup to uncle's house.

5. take 400 out of uncle's truck.

6. put 305 in uncle's truck

7. put 400 in bed of pickup truck

8. drive home.

9. install 400 in car at your leisure after carefully working out all parts configurations, etc.

just my 2 cents

 

Tom400cfi says this because in highway mode (on a computer-controlled engine like the TBI), the air:fuel ratio is designed to be lean (say around 16:1 air:fuel). It's when the engine gets LOADED (i.e. WOT blasts, or 4 passengers + full trunk, or towing an Airstream, or all of the above...) and you are running lean that bad things can happen.

That's why I advocated a conservative no-WOT drive back home... do not load the engine and the problem(s) of possibly going lean-under-load will be at a minimum. And perhaps it's a good idea to have your TBI (or a spare TBI already loaded with the extra injectors and a FPR that can be adjusted externally -- so you can tweak from the stock setting.

As far as the flow of the 400 heads -- I doubt it was very good stock, so the fuel demand based on proportional displacement increase is reasonable. IIRC the 400, during the gross hp era (circa 1971), was rated at 255 gross hp, so that's probably around 200 hp net (modern) rating. That's close enough to a TBI 350 copcar engine using the 65 lb/hr injectors, so the rule-of-thumb used here for injector sizing is still reasonable.

BTW, good comments on the mechanical issues (flywheel, rear main seal). If would be evn etter if your relative had an internet connection and a computer so that if/when you get stuck during the swap you can post questions to the board. HTH.

 

i'll be monitoring the O2 sensor as best i can with a multimeter.... i dont have a laptop.. wish i did so i could monitor it..


the external parts (other then the accessorys, im keeping the surp system) are all being swapped.. his 400 is set for his 700r4, mine is setup for a 700r4.


i think i will slowly be crusing home. no WOT for me



athough he says he will be waiting another month before the swap..... just in time too... im going to try to swap a TPI system onto my car first if i can ( i have otherthings going on myself)

if im still TBI come deadline, im going to pop some 454 injectors in there.... my uncle even has a set right there.. lol

if im TPI, i can run the stock chip since i know he did when he ran TPI on this a year ago... he has since taken it off and put the TPI on his 400SBC/T56 240Z car...(fuggin cool)


i'll be sure to snap a few pics of teh Zcar too.. just cause its cool



after poking around, and looking at my stock fuel maps and some other stuffs, im pretty convinced that this sucker will be running RICH when i put thoes injectors in. it may be a 400, but i know its not flowing alot of air right now.

 

You got it backwards there, FYI.

As to the subject of driving a 400sbc 400+ miles with a stock rochester 220 on top, with a stock L03 ECM: keep out of PE (this occurs at roughly 50% throttle on most calibrations) and keep the RPMs down if possible. The stock ECM is able to add an additional 17-25% of fuel (in closed loop/learn mode) over the stock 305 setup via long term fuel trim. Staying out of PE (WOT - also open loop) will prevent, or at least reduce, the risk of engine damage/failure. Keeping the RPMs down also reduces the chance of running out of injector (topping out at 100% duty cycle). Increasing the fuel pressure could go a long way toward helping the injector issue.

Now I don't know about the rest of you, but I'd find it REALLY hard to avoid PE and high rpms over the course of a really long drive like that, so I find babying it for THAT long a distance pretty unrealistic. Perhaps you have more self control than I do...good luck with that.

 

you're talkin to the guy that managed over 30MPG on a tank (avg overall was 24mpg) between Dallas texas and Charleston SC (roughly 1300miles)


i dont need self control... i have cruise control.

 

If you have any access to anyone that can burn a chip or if you have burning equipment you could always burn a prom in which it doesn't go into PE mode until a higher percentage of throttle is reached. ie if it goes into PE at 50% you could change that to say 75% or so.

 

true..... but i think i can have self control for one day


id probly do somthing like that if i had direct access to a prom burner... closest i have is a friend with it... id have to use snail mail to get the chip...

 

What if you have to pass? What if you have a semi bearing down on you? What if you have to stomp the gas to keep someone from rear ending you? A thousand things could happen to cause you to risk your engine.

TPI would be a bad choice for a performance set up, unless its stealth ram or similar. TPI suffers on even the 350, it was designed for a 305. Spend the extra money for the safety. SDPC sells remanufactured Holley's and Demons. Do it the right way, or don't do it at all.

 

you obviously have not read the entire thread if you are telling me about TPI.


i think i'll do better at half throttle in the camaro then in the old 4 cyl toyota corolla. not to mention that i wont be lean in open loop but REALLY RICH.




and if you still think not touching more then half throttle is crazy, call me a wild man living on the edge.

PS: i try to stay out of the way of semi trucks, even when i can go WOT.

 

Nevermind, that is the last thing I have to say. Enjoy your 400CI.