I decided that it is time that my 283 grows up. I have a 327 .060 over or have just recently been offered to have "professionally" build 383 lower end. I am keeping the TBI fuel injection from 1989, stepping up to a bigger throttle body and a nice spacer plate. Computer programming is a area that I must figure out to do either choice correctly. I am not looking for 500 horse out of this either. A nice dependable daily driver that get the grocieries quickly!
Any ideas on the A/C box that is in the way? What all has to be done to remove it and what and were do I find parts that go in its place?

 

The 327 is a wonderful engine, but is noticeably less torquey than a 350. Still, probably noticeably stronger than your 283 though.

Stroking a 327 to a 383 is probably possible, but what a jump! It also depends on if you have a small or large journal 327 block. You wouldn't be able to stroke the small journal block.

You could easily convert a large journal block to a 350, and that is a nice all around compromise between torque and economy. A 383 is a big jump in torque, and is probably the ticket if you want to get groceries quickly but not be the king of the hill, necessarily.
The difference between the 383 and your 283 might feel like an amazing change for you. You'll really love it.

But I might suggest trading in your TBI for a tuned port. Way stronger torque, albiet not real high-revving. But that's okay. Lower rpms stress the engine less, and you won't miss the lower operating range either, with all that torque.

 

What does the AC box get in the way of? A 327/350/383/400/434 are externally the same dimensions as the 283.

A large journal 327 block bored .060" over should be approached with suspecion. Earlier blocks would go that much over without much trouble, but in the later years the factory started getting stingy with their wall thicknesses. Before you do anything, you need to have that block sonic checked.

If the 327 is small journal, you need to stay with the 3.25" stroke. A special 3.75" stroke crank could be built for you, but they aren't "standard" by any means. Cutting down the main journals of a standard 350 main stroker crank to the small journal size probably wouldn't be a very good idea.

 

While TPI makes for a good street engine, I wouldn't use it unless its what you already have, simply because any big bore, heavy breathing engine like a 327 or 350 (or especially a 383) will just not get up to its full potential with it, its just too restrictive.

I say upgrade the TBI to a 454 throttle body and maybe an aftermarket manifold for it, or swap to a carb.

 

Since you have the option to do either, go with the 383. The 327 sounds like its mostly used up, being .060 over. Also, the more cubes the more potential for power. Even if you arent looking for a 10 sec 1/4, more power is always better. Or you can look at it as more potential power down the road. If the 327 block is OK, and has Large journals, you could use it for a stroker. Got the same 4 in bore, well in your case a 4.060 bore, but you get the idea.

 

You could sleeve the motor. If it's done properly, that would work on the street.

I kind of disagree that the TPI doesn't make a good induction system for a 350. Most of the problem with L98's in my opinion is the tiny cam that is used. Yes, some of the problem is that the tuned port's pipes are optimized for lower rpms than most people like on their engines. But I'm pulling 5000 rpm and making very strong power and torque with a stock TPI. I've done a couple of things, like port the blockage behind the throttle body and port the base plenum.

In comparison, this exact engine was in my '68 Corvette with a Wieand Action Plus dual plane manifold, a 650 Holley double pumper, and full length Hooker Competition headers with 2.25" dual exhaust. Compression was 10:1, the heads were pocket ported with a good 3-angle, and the cam was an Isky 270 Mega-cam hydraulic flat tappet. Rear end gears were 3.36 through a Muncie M21 close ratio 4-speed.
This motor was respectable but I didn't feel it had enough torque for a 3200 pound Corvette, and I was frustrated by the 5500 rpm limit on this cam. But midrange was pretty strong.

When I bought my IROC, it had 3.36 gears too, but with the 700R4. (In case you're wondering, the 350 was balanced for an automatic but was used in a manual and was slightly out of balance). All I did was to pull off the dual plane and carb, and bolt on the TPI after doing some porting work. I had to trade the full length Comp headers for Hooker shorty headers, but built a custom 2.5" mandrel bent dual exhaust with X-crossover. Otherwise, nothing changed on the engine. I didn't even change the PROM or the injectors! I raised the stall speed to 2200 and installed a B&M Megashifter.
In comparison, this exact same engine is EXTREMELY torquey, noticeably more than with the Holley carb. Although I've lost 3 or 400 rpm on the top, I've more than made up for it in the midrange. It pulls very hard all the way to 5000 rpm, maybe because of the higher compression and the bigger Isky cam. I don't miss it, it's a worthwhile trade off.

For whatever reason, the combination is now perfect and I'm a lot happier with this engine. I read about people yanking off the TPI and going carbureted and I can't believe it! I'll take TPI anyday over a carb for a street application.

 

Perhaps it needed more tuning when it had the carb on it? Dont take that the wrong way either, I am not trying to flame.

I have seen people pull the TPI off of a car and go to carb and gain .5 sec on the 1/4. Thats a lot. Big time gain can come from the carb. The TPI has its limits. Once you cross a certain threshold, TPI just keep up. I would never consider it on a performance engine, personally.

 

The 327 is a small journal engine. The 383 that I am concidering would be internally balanced. The thing with the A/C box..... The A/C does not work on the car, so I am thinking why have it there. I have seen pictures and one car wthout the A/C box and I think that it looks much better! I know that everything that I do to an engine has limits on what it can do. I do have a budget that I have to work in. Nice thing about collecting stuff over the years os that I now have somethings that are getting harder to find and it is great bartering material. The TBI will be changed to one from a 454, unles Santa Clause is really nice and a new one falls under the tree!!

 

Knowing the "why" of the AC box would have been helpful. Sounded like you thought it wouldn't work with the larger engine originally. Try searching on that topic.

I'm not sure if aftermarket stroker cranks can be cut down to the main small journal size. I know you can't with factory 400 cranks. I'd guess that the engine would be best kept a 327.

Budget - don't we all?

 

using 2 different blocks! was not going to use the 327 block to make a 383.

 

why oh why are you going with this??? this is the worst injection ever, especially for a 383.

get a stock TPI set up from the classified section for about 150$, get a fuel pump from Summitracing, i have the catalog here,

pin# HLY-12-912 its rated 255lph and is 79$

you wont be sorry that you went with a proper fuel injection.

doing it right the 1st time saves you the hassel and money of correcting something you did wrong.

by the way, tuning a TBI computer is a bastard, especially since you are upping to a 454 model.

 

I dont know that TBI is any worse than TPI, once you ditch the swirl port heads and crappy cam that is standard with it. I dont think I would build a 383 and put TPI on it either. It chokes a 305, why put it on a 383? TPI is a serious power limiter.

 

you honestly think a TBI equally as bad as TPI???

hmm.. dont agree on that one, not by a long shot.

i do agree about the 383, but not the 350 or 305..

now are there better things to run? yes of course, will it do the job and produce awesome low end street torque.. hell yes..

depends on what he is using the car for.

 

stock to stock i wouldnt take tpi or tbi they both suck ...if it were my choice id go carb...and a 383
awsome torque and topend with the carb will make it run like it should

 

I was exaggerating a little bit, I was just trying to make my point that in a performance build, neither really has its place there. Not unless your state requires it (damn emmisions ****'s).

Why limit yourself to what TPI has to offer, go aftermarket if you want FI on your performance engine.

 

Okay!! From what I see here TBI and TPI are both very unpopular. I have givin thought about going to TPI, but I didn't want to mess with the headache of re doing the whole fuel system. Thought about the carb option. That is looking like it could happen. I have the nice fuel pressure regulator already just stitting on a shelf in the garage collecting dust. Many options that are available. I know that tunning a TBI is a real pain! That is why I can't find anyone near where I live for this. I look at this as a minor limitation!! I have decided to go with the 383!! Now I have a 327 small journal for sale!! I don't want to sit on parts that I will not use.

 

if you still want a fuel injection on that 383, do it the easy/cost effective way and go with an LT1 intake.

or you can go with a stealth ram

carb is the easy route of course.


good luck

 

Still the same issue is there again. I would have to "upgrade" the fuel system to allow multi port injection. May not be a bad idea. Lots to think about and try to figure out!! One thing is for sure., no more 283!!! Good idea, just not enough torque for me!

 

"TPI is a serious power limiter" depends on your definition of power. If you mean top end power, yes, it does limit top end. But horsepower is torque times rpm divided by a constant. In other words, if your idea of power is torque, then the TPI is a thing of beauty. If it's revving to 6500 and pulling harder the higher it goes, then the TPI is not for you.

I didn't know if I wanted the TPI either when I bolted it on, but I really just got lucky with the combination. I've got just the right cam to stretch that thing out 800 rpm more than a stock cam would allow, AND the cam's powerful region matches the TPI's powerful region perfectly. That and the improvements made in the heads, almost ideal 0.040" quench, and better compression make this engine a lot more satisfying in the IROC than it ever was in the Corvette.

My 465 Firebird has a torque and power band very similar to the response of my TPI engine. Redline is 5600 rpm, and midrange torque is very strong. But try to tell me that it isn't powerful, and I'll show you a car that can disappear in its own tire smoke, and flat out destroy C5 Corvettes. It's that strong.

The TPI 355 in my IROC is like that too. But not quite as powerful. Still really powerful. Try to imagine an IROC that'll drift sideways all the way down the block.

It's like they say, it's really all in the combination.
If anyone wants to donate their TPI to me, I'd love to take it!

 

Where would TBI fit in? I am not looking at spinning more than 6,000. I would too take TPI donations as well!! That is never happened yet, so I am making due with what I have and what I can afford to do! It will still kill most anything in the area that I live in.

 

Another question...........
Why are so many people against TBI?

 

Because in stock form, it blows. Its worse than TPI. Don't get me wrong, they both work great, but they both suck for making power without serious modifications.

 

That wasn't clear from what you said.

 

TPI makes great low end power, and has a good feel coming off the line. But all the low end power in the world doesnt help, when you get spanked by someone. Or by lots of people. TPI lets a car feel really powerful down low, while taking away its real performance. An old drag racing guru here in my town always says it "RPM's win Races."

 

You don't really need to rev past 5,600-5,800 in a street race. My car will pull tremendously from 3,800 - 7,000. Its really a kick in the pants. But with the 3.23 gears that come with it, it is hobbled. Low gears are better for low end power and fuel economy. With 4.10 gears my car would come alive in the top end because it would get there quicker. Street use would be compromised. With great low end you can make much better use of your gears. The high end pull is for strip cars with crazy gears.

For a street driven car a modified tpi running to near six grand is plenty.

Modified TPI drivers, what speed does your car pull to? If you can pull to 100-120 thats all you really need for a street car unless you want a highway monster.

 

Whats your point? TPI doesnt pull to 6k, thats the problem. The best way to get it to that point, is to take the TPI off and replace it with any other intake.

Racing is racing, and TPI isnt optimal.

 

Okay fine. To you, spinning to 6000 rpm is your idea of power. In your opinion, TPI's aren't performance set ups.
I dunno, maybe you don't know how to properly set up a TPI, or you're more the horsepower type rather than torque type.

But you know what? There are very few street cars out there that'll beat me. The WRX STi is probably one of the few that can. I've run a few of them. One beat me by a car length because he caught me with my pants down. The next 3 went down hard, by 4 to 5 car lengths, because I don't give them a chance anymore.
I raced an LS1 4th gen Camaro and beat him by 3 carlengths twice in a row.
And despite my high 5800 ft altitude, the car will smoke the tires for an entire city block without any problem. Usually fishtailing or completely sideways.
My TPI will probably smoke your car, 6000 rpm notwithstanding.
Come out to Denver sometime, we'll run at Bandemere. Loser buys the beer. (I like Hazed and Infused)

Actually, you probably don't think my 5600 rpm Firebird with its 500 horse, 600 lb-ft engine is powerful either. It runs solid 12's at high altitude. But it doesn't rev to 6000 so its not powerful.
Hmmm.
Sorry you have had such bad experiences with TPI, but there are fast TPI cars out there...I'm sure several members here will agree. They own them.

To the other dude that wanted to know how many revs I can get out of my modified tuned port engine, I pull hard to about 5200 rpm. That's with the small tubes. I hear you can get close to 6000 rpm if you get the large or siamesed tube set up for TPI.

But you've GOTTA set up your combination to see maximum benefit. Everythings got to work together perfectly. Any mismatch will be obvious, and usually I suspect, TPI issues are more cam-related in the stockers.

 

What are your mods?

 

I'm not gonna raise a BS flag, but 500hp out of a TPI? I find that hard to beleive.

The only way to get enough air through a TPI manifold to support 500hp is to either use a nitrous system, or to force-feed it with a blower or turbo(s).

I'm with Mike... I'm curious what you've done to the car to get 500hp out of it?

 

Sorry dude, I dont think you make 500hp N/A from TPI. Not happening. TPI is not a performance induction setup because of its limitations. Its not all about high RPM capabilities. Its also about raw power output. TPI cannot match a carb in that category.

No I am not into "torque." I dont build cars to "FEEL" fast. I build them to go fast. Yes I like torque, because HP is a function of torque, but I like to beat the guy next to me, not yell out, "yeah, well I got more torque below 4000 RPMS!" Who cares when you lose?


Actually, I have never had a bad experience with TPI. I think it is a good form of fuel injection for a daily driver. I have no problems working with it or tuning it. But, if you think its the best thing in the world for performance, then its you my friend that has a lot to learn.

 

if you have the 327 that has the small rods (opening on the crank end you can use them to make a 396 small block.

if you want to rev the crap out of your motor the 327 is the way to go ig going to use the tpi I would go 383 or 396 more power in the lower end because of displacement ==better for the tpi

just my 2 cents

later

and
GB

rk

 

Here we go again, I can already see where this argument is going. All things being equal (valve train wise) the 327 isnt going to rev any better than a 350. All of the debating and arguing in the world isnt going to change that. A 350 has just as much RPM capability as a comperable built 327.

Why put TPI on the bigger CI engine? All it will do is choke it even more. TPI does not belong on a performance engine, unless your goal is 350 hp. Then its perfect.

 

Quote:

Sorry dude, I dont think you make 500hp N/A from TPI. Not happening. TPI is not a performance induction setup because of its limitations. Its not all about high RPM capabilities. Its also about raw power output. TPI cannot match a carb in that category.


******************************************

YOU don't have good reading comprehension do you???????????
The 500 hp is on my 465 cubic inch 1968 Firebird...
NOT my tuned port!!!!!!!!!!



I am including my signature so you can see my other hotrods. My quickest hotrods are carbureted. The Firebird has a Holley on an Edelbrock Performer RPM and my Corvette had a Gold Claw on a single plane. But the high rpms and low torque on the 427 drove me nuts around town. It was too much all or nothing. So I'm backing off to an Edelbrock Air Gap RPM on that too, along with a smaller solid roller cam.

So you see, I am no stranger to carburetion. The TPI is simply my first venture into performance fuel injection.
Please read my posts FULLY before you fly off the handle. That's all I ask. Let me know if you ever pass through Denver, and we can have that friendly race day bet for beer. Kay???

 

Regarding the 327 revving better than a 350, try it. I've had both in my Corvette. The 327 revved a lot more eagerly than the 350, but the 350 was quicker because it had more torque. Yes, it's torque that gets you launched and it's horsepower that does the work down the track. And when you have enough torque, you end up having more horsepower as a result too.

hp = torque x rpm / 5252

You can't have horsepower without torque. Horsepower is the RESULT of torque, not the other way around. You like high rpm motors, so for you, a torque curve should be shifted higher in the rpm band. (You would have LOVED the 427 in my Corvette!)

But you definitely have to pay attention to rod/stroke ratio when you're going for higher rpm. Poor rod/stroke ratio engines are lazier revvers. But higher stroke engines are good torquers. You have to find the balance that works.

A 350 doesn't rev quite as well as a 327, but because the torque is so much better, it results in a little better horsepower as well. Same with a 383. The additional stroke makes it quite a bit torquier than a 350, and if you design it right, you can place that torque higher up the rpm scale which will result in better horsepower.

...And this is where I agree with you on tuned port induction. It will not allow that higher rpm band. You pretty much have to design a TPI as a torque motor. They still perform pretty well though...for a street car.

 

I dont need you te explain torque and horsepower to me, I understand it fully.

I didagree with you on the 327 argument. If you built the two engines identical, with the same valvetrain, the 327 would rev no better than the 350. Valvetrain is the real limiter of a street driven SBC, not the stroke. That argument is debated time and again, and probably will be forever.

Also, dont insult someones reading comprehension, I was not the only one to say that, you were not clear in what you claimed.

 

I don't see where reading comprehension has anything to do with this. I have read your previous post about 9 times now. No where do I see any noting about having mulitiple vehicles. You go straight from talking about TPI engines to talking about a 500 hp engine, to talking about a Firebird that houses this motor, right back to talking about TPI. Nowhere do I see reference about mulitiple engines or multiple vehicles. So, common mans reading comprehension, and given the fact that this is thirdgen.org, one would be led to make the assumption that this is a third generation firebird you reference, and it is powered by a tuned port induction system. Next time, do everyone a favor and make a direct reference.

Also, compare apples to apples. Your 456 ci engine has over 100 more cubic inches to work with. Cubic inches = power. That's a proven fact. If and when you race, race him with your small block. Either that or go find someone with a big block to settle your disputes with. Trying to prove your case with a big cubic inch engine versus a little tuned port is dumb.

An engines ability to rev is dependant upon its ablity to move air in and out, assuming the all components are up to snuff. And yes, in a street race (not some little light to light), horsepower will make the winner. What makes trap speeds? Torque or horsepower? Torque gets you your ET's, yes. it's fine and dandy when you're doing a little light to light shootout. But when you find some open road to open it up, horsepower is what takes you.

And for reference, its 5252, not 3232.

And damn, LJ got to it before me.

 

Im glad i wasnt the only one that thought his post was confusing on car to car and engine to engine...LOL

 

the same cam in a 327 brings in the power at a higher rpm than it dose on a 350--I have a cam that they say iproduces power in a 350 from 3000 rpm to 7600 rpms, but in the 327 I haveno usible power untill 4200 rpms withthat cam--so I mis spoke this would be with the heads being equal



HAHAHAHAHAHAHAHAHAHAHA

thanks

for the insite

 

ljnowell


Yea you where right as I fogot to say It depends on where you want your power at camrelated to motor size it where I should have went with that

later
and
GB



Rick

 

Correction: Divide by 5252.

 

The peak power will come at a higher RPM with the smaller cubic inch engine. This however has no bearing whatsoever on an engines ability to "rev". That is strictly limited by the valvetrain components. Period.

 

yes that is correct

later and have a great day--I guess i was not celar on that after i reread the post

sorry for the highjack


later and

GB

 

The good thing is, that people are reading and giving input!!! What more could we ask for?? Thanks for the ideas and input that was given. I am sure that this is far from being done! Bottom line...............Aren't we all after more power as cheap as possible, yet trying to be different about getting there? Maybe that is just me!! I have to be different. Don't like the stereotype of copycat. Just me.

 

Nothing wrong with being different, we all like to be different. Just do yourself a favor, make sure you dont screw yourself for the sake of being different. I have seen all to many people say "I want to build a 305 cause its different" or " I want to build a 335, cause its different". Those are not $$ per HP savvy builds. Make sure you get the most bang for your buck. The best way to do this is to stay away from the Mcdonalds parking lot monkey spank(thanks to RB83L69 for that one!) about high rev short stroke magical number type of BS.

 

Yes, thank you. I edited my post to reflect 5252 for the constant, rather than 3232. Sorry about that.