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84 Mod or Engine Swap

 
Old 03-12-2019, 10:42 PM
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James C4
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Default 84 Mod or Engine Swap

Is it worth trying to mod the '84 to high 300 low 400 horsepower range? I'm in high school and don't have a ton of money so I don't want to spend money on the crossfire, be disappointed, and then do an engine swap. I'd rather leave it slow and save up with a job during college for a nice crate motor. I did a lot of research on the forums and selected about $2,000 in parts that I would like to save up for, but a lot of people said it would just get to 300 hp if I was lucky. I'm looking at anything from an engine like this to one like this 383 if I were to do an engine swap. The first one is significantly cheaper but I'm not sure if either of them would work in the '84. For some reason the second one goes to eBay and not Summit but it's BluePrint Engines GM 383 C.I.D. 430 HP Stroker Base Long Blocks w/Aluminum Heads BP38313CT1 on Summit.

If I did an engine swap, would it be worth buying a Renegade and trying to keep the ceasefire, or would it be better to switch to EFI? If I went EFI, what other modifications would be required to accommodate the different computer and fuel delivery as well as the crate motor itself? I'm not even looking at an LS because I figured a normal SBC would be cheaper and easier. Also, these crate motors have higher hp and torque ratings than a stock LS1 which I consider enough.

Any and all info would be greatly appreciated. I don't want to spend much more than $4,000 on the engine and would prefer to spend less. None of this is happening anytime soon. I'm just trying to decide what I'm going to do in the future to avoid wasting money. Finally, I don't know why some random words have links now that take you to eBay. I tried to unlink them and nothing happened. Sorry about that.

Thanks,
James

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Old 03-12-2019, 11:18 PM
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IBVETN2
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I would probably ditch the 84 motor and go with something that is factory roller cam. There are a couple ways you can go and would have to figure the costs of every thing involved and go from there. First you can just start with a shortblock, either a new one or rebuild one, and add some decent heads and go from there. Or you can go with the crate 383 with an aluminum head already installed. Either way, I would go with a self teaching FI setup, and do away with the stock computer.
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Old 03-12-2019, 11:20 PM
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It will depend on your ability and a place to work on it. Building a sbc to meet your goals shouldn't be difficult or expensive. Renegade has some QA issues with runner alignment on lower intake. The stock lower intake could be reworked , it would be time with a grinder vs laying cash out. You could go the carb route if you are stuck during tuning.
A concern is the 700r4 in 84 wasn't the best. It wouldn't be until 88 for them to be reliable. So you may find you need to have transmission upgraded for the new engine.
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Old 03-13-2019, 06:26 AM
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If you drop 4k om building an engine you can very easily exceed what you'd get in a crate engine. That being said, save the money now and do the little trick mods. Bump the fuel pressure, check throttlebody alignment etc. If you want to do a mild hand port go for it. The hand port will get you something like 15 horsepower but almost 1000 more rpms.

It gets expensive really quick and you gotta pay to play. Once you build the motor than everything behind it needs to be beefed up too. Just saying... enjoy it the way it is for now.
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Old 03-13-2019, 07:09 AM
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The 84 is a great car and if that's what you have to work with, you will be spending quite a bit in machining to have the engine bored and rebuilt, stroker parts installed, cam, headers, aluminum heads, renegade intake etc. You can get quite a bit of power out of an L83, but you're going to spend a bit of money to do it. Why not just start with an LT1 car or an L98? Don't get me wrong, I'm a huge fan of the 84's, but I know that without spending a lot of money, the power output is not going to see anywhere close to between 00 and 400 horsepower.

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Old 03-13-2019, 10:36 AM
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@IBVETN2 That's what I was leaning towards but how would the EFI computer work with the old computer in determining the speed, rpm, and the overdrive unit?

@Kevova Do you think it would be more cost efficient to build my own or buy a crate? Also, I have the 4+3 with the Dana 36 so I don't know how much power it could hold.

@84 4+3 I don't have a lot of experience so I don't know if I would trust myself to build the whole motor but I guess my lack of knowledge is why I'm here. I'm fully aware that it will cost a lot of money, I'm just trying to spend the least when I spend a lot.

@mazdaverx7 When I bought the car I was an idiot and had it painted so I'm too far into it. With the loss I'd take selling it, I could buy a different motor. Also, I don't want to mess with the opti spark going out when it rains, which seems to be a problem with the LT cars, and it's my first car and my dad and I have spent a lot of time together working on it.
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Old 03-13-2019, 10:49 AM
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If you like your car dump the money into it. you never get it back anyways. Buccaneer is a memebr here and pioneered that piece he has a strong running 383 and knows all the ins and outs page him in the C3 tech section.
There is nothing performance oriented about the GM L83 engine period may as well start over with something all new.
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Old 03-13-2019, 11:12 AM
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Also, I have the 4+3 with the Dana 36 so I don't know how much power it could hold.
At some point you will want to be considering a Dana 44 swap. Add $1200 (minimum) to your build.
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Old 03-13-2019, 11:18 AM
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@cuisinartvette I noticed that @Buccaneer had mentioned switching to EFI over CFI if you were looking just for power. The only thing is I don't know what changes would need to be made in order to go to EFI and still have everything work with the stock cluster and overdrive unit. Hopefully someone could chime in on that. It looks like I'll work on preparing for more power but leave the engine alone until I have enough money to replace it.
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Old 03-13-2019, 11:21 AM
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@drcook this is when I wish I was smart enough when I bought my car to have bought an 85 or newer, but at least I've learned something.
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Old 03-13-2019, 11:57 AM
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I see that folks have mentioned the intake manifold. That should be your first mod before you do anything else. It's by far the most restrictive part of the 1984 engine. That engine won't really respond to other changes (cam, headers, etc.) with the stock manifold. The manifold is way too restrictive.

There are differing opinions on the Renegade manifold. If you get a good one, it's great. There's been some quality issues with that one lately, though. If you have lots of time on your hands and a good die grinder, porting your stock manifold is a good option as well. You can take a bunch of material off the top of the ports and work that back through the runners. Put a new intake gasket against the manifold ports and you'll see that about 1/3rd of the opening is blocked by metal on the manifold side. The gasket is almost a perfect match for the heads usually. That's a huge restriction and a big "step" in the intake air flow that causes even further flow issues.

AFTER you do something about the intake, you can start making other mods and the engine will respond as expected. If you ignore the intake issue, nothing else will seem to work, and you'll be one of the guys who thinks that engine is a total POS and nothing can be done to make power with it.
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Old 03-13-2019, 12:07 PM
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I was in the same place as you a few years ago with my 94 LT1. I wanted more power, and after really working out the TOTAL costs to pull motor and rebuild to add power, I quickly realized I could buy something already completed, that had a better body/interior/suspension then my car for what I could sell my car for + mods.

Is the car you have sentimental/really great condition? If not, there are plenty of people selling complete cars out there for reasonable prices. Just all depends on your end goals, but then you can test drive a car and know exactly what it is (power/performance wise) before spending thousands to build a car only to find out that it still doesnt have the power you want. I would suggest getting up to the LT1 era at least, and realistically you could get to basic C5, for what a C4 + mods would cost.
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Old 03-13-2019, 01:46 PM
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Originally Posted by James C4 View Post
@IBVETN2 That's what I was leaning towards but how would the EFI computer work with the old computer in determining the speed, rpm, and the overdrive unit?

@Kevova Do you think it would be more cost efficient to build my own or buy a crate? Also, I have the 4+3 with the Dana 36 so I don't know how much power it could hold.

@84 4+3 I don't have a lot of experience so I don't know if I would trust myself to build the whole motor but I guess my lack of knowledge is why I'm here. I'm fully aware that it will cost a lot of money, I'm just trying to spend the least when I spend a lot.

@mazdaverx7 When I bought the car I was an idiot and had it painted so I'm too far into it. With the loss I'd take selling it, I could buy a different motor. Also, I don't want to mess with the opti spark going out when it rains, which seems to be a problem with the LT cars, and it's my first car and my dad and I have spent a lot of time together working on it.
Even if you have a machine shop build it, for price paid vs what you get, you'll be ahead with the machine shop still I would bet. Plus they'll work with you to build something the way you want it optimized for the application. I like crate engines for stock replacement. Once you want to up the power they generally aren't as good an option because they are a lot of times geared towards carbed vehicles and more often than not the cam isn't a good choice for an efi engine imo.

That's the way I see it. If you are in love with the car do what you want. I love mine and have too much attachment to it so I will do stupid things. But I need the extra cash, which I don't have at the moment. And any money I do have went into the 400 in the 67 after that blew up. Cars are fun.
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Old 03-13-2019, 01:51 PM
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Building vs buying depends on cash on hand on ability and place to do it. No place to work on car long term. No tools or equipment, no skills puts you in the drop it off and have crate engine installed. Since you in high school VoTech is an option depending school administrator. Some may allow it some not. Building with guidance from a qualified is a good experience whether stock or modified. The time and costs vary due condition of engine you are working with. "How to Hot Rod SBC" worth a look for information.
Transmission isn't going to take manual downshifting going into 1st. 4>3, 3>2 ok. 4>1 will break transmission. As noted earlier there were alot of improvements. In 1988-89 they much better.
The D36 should hold up for a while even with 400hp as long as you're not using slicks.
You could just drive it and do little things such as LT1 exhaust and long tube headers. Aluminum head's. Port the intake runners. 1.6 long slot rockers. The little things could be done on weekends. So could keep driving in car.
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Old 03-13-2019, 03:39 PM
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Originally Posted by C6_Racer_X View Post
I see that folks have mentioned the intake manifold. That should be your first mod before you do anything else. It's by far the most restrictive part of the 1984 engine. That engine won't really respond to other changes (cam, headers, etc.) with the stock manifold. The manifold is way too restrictive.

There are differing opinions on the Renegade manifold. If you get a good one, it's great. There's been some quality issues with that one lately, though. If you have lots of time on your hands and a good die grinder, porting your stock manifold is a good option as well. You can take a bunch of material off the top of the ports and work that back through the runners. Put a new intake gasket against the manifold ports and you'll see that about 1/3rd of the opening is blocked by metal on the manifold side. The gasket is almost a perfect match for the heads usually. That's a huge restriction and a big "step" in the intake air flow that causes even further flow issues.

AFTER you do something about the intake, you can start making other mods and the engine will respond as expected. If you ignore the intake issue, nothing else will seem to work, and you'll be one of the guys who thinks that engine is a total POS and nothing can be done to make power with it.

There is nothing wrong with the Renegade manifold. It is rather unfortunate that the company that is pouring/casting and another company doing the machining sometimes get it wrong, but there is nothing that we can do about that except pull our tooling. We can not control their business or quality in any way. When we were pouring and machining locally in AZ, we DID NOT have any issues that I am aware of since we could easily go to the companies and have a look to see what it going on if there was any issues. Unfortunately for us, the company doing the castings in the beginning raised their prices per casting to the point it wasn't profitable for us to continue with them any longer. As far as quality goes, I even hand stamped each and every manifold myself for the first 100 and gave them my personal touches, that again unfortunately doesn't happen anymore and have heard of complaints that the manifold doesn't look exactly like the picture first posted. Other than that the manifold performs as advertised.

ON TO OTHER STUFF...
The CFI to EFI is a project that I have started a while ago when DCS as still actively online, but I have gotten caught up in life and has taken a back seat for now. I do have some things done though on the project. Once I finish the current mods on my car, I will start the EFI project once again. Who knows, I may like enough to leave it on my motor. (grin) My new motor runs really strong and only has 600 miles on it. I'm doing some rear suspension mods right now and going completely through the brake system yet again and possibly another gear change with a trans mod. I also have been doing another website for another CFI business and not too far away with that. "Maybe" you will be able to purchase CF items again online, stay tuned for more on that...

As far as power goes with the 84, it really boils down to how deep are your pockets and do you love the car enough it spend the amount necessary to make it run the way you want it to with either L83 mods or motor swap, both will cost a fair amount to put you in the 400-460 range since you will have to a lot of other upgrades if you go LS. Think hard on what you want and do like the carpenters do, "measure twice and cut once".

Last edited by Buccaneer; 03-13-2019 at 03:42 PM.
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Old 03-13-2019, 04:32 PM
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Old 03-13-2019, 05:32 PM
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Originally Posted by Buccaneer View Post
There is nothing wrong with the Renegade manifold. It is rather unfortunate that the company that is pouring/casting and another company doing the machining sometimes get it wrong, but there is nothing that we can do about that except pull our tooling. We can not control their business or quality in any way. When we were pouring and machining locally in AZ, we DID NOT have any issues that I am aware of since we could easily go to the companies and have a look to see what it going on if there was any issues. Unfortunately for us, the company doing the castings in the beginning raised their prices per casting to the point it wasn't profitable for us to continue with them any longer. As far as quality goes, I even hand stamped each and every manifold myself for the first 100 and gave them my personal touches, that again unfortunately doesn't happen anymore and have heard of complaints that the manifold doesn't look exactly like the picture first posted. Other than that the manifold performs as advertised.

ON TO OTHER STUFF...
The CFI to EFI is a project that I have started a while ago when DCS as still actively online, but I have gotten caught up in life and has taken a back seat for now. I do have some things done though on the project. Once I finish the current mods on my car, I will start the EFI project once again. Who knows, I may like enough to leave it on my motor. (grin) My new motor runs really strong and only has 600 miles on it. I'm doing some rear suspension mods right now and going completely through the brake system yet again and possibly another gear change with a trans mod. I also have been doing another website for another CFI business and not too far away with that. "Maybe" you will be able to purchase CF items again online, stay tuned for more on that...

As far as power goes with the 84, it really boils down to how deep are your pockets and do you love the car enough it spend the amount necessary to make it run the way you want it to with either L83 mods or motor swap, both will cost a fair amount to put you in the 400-460 range since you will have to a lot of other upgrades if you go LS. Think hard on what you want and do like the carpenters do, "measure twice and cut once".
I just happened to get a particularly crappy manifold and then dealt with an equally crappy company to no resolve... so right now I have a ~500$ doorstop that looks really nice. That being said I've gotten some really bad things from summit and they atleast msds it right. I could probably hand trim a set of intake gaskets and have the port mating surface milled flat on the intake and it would probably work fine... but for the ease of aggravation of others I reccomend the port the stocker first.

Don't get me wrong, it did exactly what it was supposed to but the casting and machining were... well particularly crappy. Every complaint you've heard on the machining... mine had every single defect. That's generally my luck though lol. And I will pony up another 500 when I have coin to blow to buy another one when I do build the new engine. So there, I still liked it!

BTW, thanks for the board again.
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Old 03-13-2019, 07:06 PM
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@C6_Racer_X I was originally planning on a Renegade intake and a chip this summer but if the CFI engine can't get to 350 hp then I'm not going to try because it would be a waste of money and I'd be left unsatisfied.
@Rexracer77 I don't want to sell it because it's my first car and I already have enough in it that I could have bought a low end C5 because I didn't know anything about cars when I bought it.
@84 4+3 Looking at dressed crate motors it seems that none of them come with EFI. I know EFI is a lot more expensive than a carb but it also tunes itself and gets better fuel economy so there's that.
@Kevova I have time, tools, and space, but no one in my family is really into cars. Our school buses kids to a nearby town for VoTech but I'm already a senior and didn't do it because I couldn't fit it in my schedule with my online college classes. Also, I definitely won't be on slicks and I just finished installing Melrose long tube headers about a month ago. That's the most work I've ever done on a car.
@Buccaneer Isn't CFI in some ways just like a two barrel throttle body EFI? Also, I said in my original that I don't want to go LS. I figured that a 350 or 383 could get me to 360-400 hp and I'd still get to use the Melrose headers I just installed a couple months ago as well as stock motor mounts.
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Old 03-13-2019, 09:18 PM
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Yes cfi is basically a tbi setup. I found great gains just by putting on a truck tbi unit and holley tbi intake. The factory wiring & ecm will run it just fine. If I had to do it over I'd use a vortec 350 and put a dual plane intake and tbi on it. The throttle body you want is for 87-89 Chevy trucks.
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Old 03-14-2019, 12:11 AM
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Originally Posted by 84 4+3 View Post
I just happened to get a particularly crappy manifold and then dealt with an equally crappy company to no resolve... so right now I have a ~500$ doorstop that looks really nice. That being said I've gotten some really bad things from summit and they atleast msds it right. I could probably hand trim a set of intake gaskets and have the port mating surface milled flat on the intake and it would probably work fine... but for the ease of aggravation of others I reccomend the port the stocker first.

Don't get me wrong, it did exactly what it was supposed to but the casting and machining were... well particularly crappy. Every complaint you've heard on the machining... mine had every single defect. That's generally my luck though lol. And I will pony up another 500 when I have coin to blow to buy another one when I do build the new engine. So there, I still liked it!

BTW, thanks for the board again.
Yeah, I'm sorry you also got a bad machined manifold and I feel your pain. We NEVER had an issue with machining when done locally. I still use our local machinist for a lot of jobs and he is spot on with his work. I feel that we should pull our tooling from Eddie Motorsports in CA since they not only seem to have issues doing it right for some unknown reason and makes us look bad, but I have heard that their customer service is not the greatest either. Hopefully down the road you will give it another shot or something. Did you buy it from EMS or Summit? Either or, I would demand your money back and if you paid with a credit card, call the card company and file a compliant, they should refund your money and deal with the seller. I wish I could help you out more, but it's out of my hands unfortunately.
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