I'm thinking about a future engine swap and the beginning of the parts collection beforehand. I figure if I space the parts collection over a long period of time I can both afford the swap and be ready when my 3.4l fails (Probably 60k away; it has 42k).
I want to do a 4.3l V6 swap. These engine are EVERYWHERE. A small local yard has 16 of them. Not one is from engine failure either, which impressed me very much about reliability. I also don't think the world needs another 3800SC Fiero. Not to dump on the 3800 AT ALL, as I know it's an impressive swap, but there are so many of them. There are 9 THAT I KNOW OF within 50 miles of Indianapolis, and that's not much because there are no other major cities within that. That's a lot! I want something people are surprised to hear about...even the common Joe's and guys at parts stores around here know about 3800 Fieros most of the time, and even with my 4.9l they had never heard of that swap before.
The 4.3l seems to be a MUCH easier to fit SBC. You need an adapter plate for it, but what else? Any serious swap issues I should expect?
Here is what I plan to do. There is a marine version of the 4.3l that has an all forged bottom end. Crank, rods, pistons...everything is built with extremely tough parts. That is because the engine is built to run at 4,500RPM plus CONSTANTLY in a boat. I found all this out talking to a boat mechanic. He thinks they're the strongest stock American engine there is, which may or may not be true, I have no idea. Then I thought of the stock turbo charged GMC Syclone and Typhoon trucks. These are STRUCKS and they run in the 13's bone stock. They also produce over 315HP and TQ bone stock, and they make that power very quickly and from a low RPM.The engines are not much improved over the N/A versions from my understanding. They run about 13 PSI stock.
So, a marine bottom end mated to turbo 4.3l automotive heads should be able to make over 400HP on 27 PSI boost with stock heads and a slightly bigger turbo. They would make over 300HP at 3.5k by my math, and that would be absolutely astounding compared to even a very well built 3800SC. Do you guys think the marine block would hold 27 PSI....or more?
I KNOW the heads will be a direct bolt-on to the marine 4.3l, because the carbed intake from the marine unit is a popular bolt on swap for trucks since it makes more power and can deliver more fuel.
My question is, do you guys think the bolt pattern/etc are the same? Knowing GM I can almost bet they would be, but I'm not sure.
------------------ 86GT Modded 3.4l V6/Getrag with Trueleo - 210WHP 1972 Honda CB350 Motorcycle For Sale - 80% NOS
PM Me if you need: Interior/Exterior Parts Stock Switches/Bezels Gauge Clusters Body Panels Fiero Rotor Hubs for Brake Swaps Or custom fabricated parts! My prices are very low.
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08:35 PM
PFF
System Bot
fieroguy123 Member
Posts: 1523 From: Indianapolis Registered: Sep 2009
gm 4.3 v6 have the same bellhousing bolt pattern and offset as a sbc 350 v8. so a archie sbc v8 kit would work with it. but if your going to that much trouble why not use a 350? my .02
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12:04 AM
litespd Member
Posts: 8127 From: No where you want to be Registered: Aug 99
Check the direction of rotation of the crankshaft. I'm not sure about the 4.3 marine engine (although I should, I had one in my boat), but some of the marine engines turn in the opposite direction of their automotive counterparts.
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12:06 AM
jscott1 Member
Posts: 21676 From: Houston, TX , USA Registered: Dec 2001
dont get me wrong the 4.3 is a good engine in my humble opinion. and likely a good choice in a fiero. but i personally would stick a stock 350 v8 with tpi or tbi injection in it and would be very very reliable. stock tbi is about 230hp. stock tpi is about 260hp. and both can be greatly increased in hp and tq. anyhow ill quit. its your car and a 4.3 is a good little motor. happy motoring. my .02 mike in oklahoma
You can throw 27 PSI at any engine if you really wanted to. Will it take it? If it's built for it, yeah it should take it for a while at least.
Will you get 27 PSI through the engine, and not be overkill on an engine that might not flow very well.. Well thats another story. How well can you get those heads to flow? Do they make aluminum performance models or do you have to modify stock heads? You can only do so much with stock cast heads.
[This message has been edited by Custom2M4 (edited 06-05-2010).]
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03:24 AM
R Runner Member
Posts: 3678 From: Scottsville, KY Registered: Feb 2003
If you are going to do a 4.3 swap, the real advantage is the shorter block. That means you could run it longitudinally with a porsche transmission. Should be able to do it without stretching the chassis. Personally I think this would be the ultimate swap for performance, durability and balance.
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07:51 AM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
If I remember correctly, the "Super Duty" V6 used in some of the racing Fieros was a 4.3. And they produced somewhere around 400 HP... naturally aspirated.
Originally posted by MadDanceSkillz: I want to do a 4.3l V6 swap....
Here is what I plan to do. There is a marine version of the 4.3l that has an all forged bottom end. Crank, rods, pistons...everything is built with extremely tough parts. That is because the engine is built to run at 4,500RPM plus CONSTANTLY in a boat. I found all this out talking to a boat mechanic. He thinks they're the strongest stock American engine there is, which may or may not be true, I have no idea. Then I thought of the stock turbo charged GMC Syclone and Typhoon trucks. These are STRUCKS and they run in the 13's bone stock. They also produce over 315HP and TQ bone stock, and they make that power very quickly and from a low RPM.The engines are not much improved over the N/A versions from my understanding. They run about 13 PSI stock.
So, a marine bottom end mated to turbo 4.3l automotive heads should be able to make over 400HP on 27 PSI boost....or more.
I was doing fine following the reasoning behind your interest in swapping a 4.3L into your Fiero (e.g., a 4.3L is an uncommon swap, but it's also a reliable engine) --- until I got to the part about running 27 pounds of boost in it, or more. That certainly would make your 4.3L swap even more uncommon, but interesting as that might be, I'd be concerned about the reliability of the engine because my 2¢ is the application you're talking about isn't exactly a "plug `n play" operation with that much boost.
Of course, if you are an accomplished tuner (and maybe you are), or you know someone who is, I suppose almost anything is possible with enough expertise and money.
Good luck to you with that swap, MadDanceSkillz.
In any case, regardless of whether or not you even pull off that swap successfully --- trying to get a highly-boosted 4.3L tuned to run well on the street without grenading the engine shortly thereafter --- I think yours would make for a very interesting build thread.
Why I'm not going with a V8...I've already had one. Not a 350, mind you, but I don't want an engine that takes up my entire engine bay and gets no more than 20MPG on the highway. Sure, maybe some of you LT1 and LS guys can beat 20MPG, but I can't even afford those motors, let alone do heavy frame and cradle mods. The 4.3l is exactly what I want...a V6 capable of netting good MPG and producing massive torque. I'm not a top end high winding kind of guy...I want an engine that throws be back in my seat.
I was shooting in the dark with 27 PSI...the Syclones ran 13.5 with a mostly stock bottom end...since the marine engine is built to run at a constant RPM and there probably isn't one non-forged and strengthened part in the bottom end.
In regards to head flow, newer 4.3l engines have very good heads and I was hoping to use a set of those, but even the olde rones still flow better than the 4.9l, and people have turbo-charged those with success.
Has anyone here besides Bobby ridden in a Syclone or Typhoon? If so, then you know why I forgot all about the 3800 when I rode in one.
I mean...a *truck* running high 13's STOCK? What does that mean in a Fiero? I'm not expecting 10's or anything, but I have a feeling it would run low 13's. the truck weighs well over 1,000 pounds more than the Fiero does.
EDIT: Actually, just corrected myself...Sport Truck (October 1990) tested the Syclone in purely stock form and obtained a 0-60 mph in 4.8 seconds and a quarter-mile run in 13.08 sec @ 100.44 mph"
Honestly, I'd probably be more than satisfied with the 4.3l with a stock turbo or one of similar sizing after some research. I don't need more than 360 ft/lb of TQ in my car.
Even if I went with the stock turbo, the marine engine still sounds like a good idea. Using a marine block with stock sized turbo should make an extremely reliable engines. After some reading, I've concluded an N/A marine 4.3l would last until hell froze over, so even that might not be out of the question.
Now I just seem to be blathering. Basically....I love the 4.3l motor, and I don't want to do a 3800 swap because I don't like how the powerband works...I want something that makes big power without having to wind up. Even though the 3800SC is a very torque heavy motor, it still can't measure up to a turbo 4.3l. I suppose a turbo 3800 could, but I think the 4.3l is always going to have a power band I like more,
And by the way, I received the name "MadDanceSkillz" for moonwalking at a church camp when I was 16 and the name never died. That group of friends still calls me MDS. Haha.
------------------ 86GT Modded 3.4l V6/Getrag with Trueleo - 210WHP 1972 Honda CB350 Motorcycle For Sale - 80% NOS
PM Me if you need: Interior/Exterior Parts Stock Switches/Bezels Gauge Clusters Body Panels Fiero Rotor Hubs for Brake Swaps Or custom fabricated parts! My prices are very low.
[This message has been edited by MadDanceSkillz (edited 06-05-2010).]
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02:41 PM
Pete Matos Member
Posts: 2291 From: Port St. Lucie, Florida Registered: Jan 2010
Raydar, that was something I had forgotten to point out. The 4.3l has HUGE aftermarket support. There are 9 different supercharging kits that I know of, countless cam options, piston options, crank options, etc.
'm not too worried about the bottom end as I won't be changing anything. The marine cam turns the right direction and produces a lot of power at a low RPM. I *don't care* about going past 4,500 RPM. I want my power sooner than that so my car feels fast without punching the gas and winding high. I really miss that about my 4.9l...the marine cam is making big power at 2,700 RPM. With a 1.3k supercharger kit and a marine cam some of the boat guys were getting over 200HP BEFORE 3k RPM. That is exactly what I'm after. Big low end power without a big fuel bill, but more aftermarket support and potential than the 4.9l. The 4.3l just seems like the logical choice. But I guess I could be wrong...
------------------ 86GT Modded 3.4l V6/Getrag with Trueleo - 210WHP 1972 Honda CB350 Motorcycle For Sale - 80% NOS
PM Me if you need: Interior/Exterior Parts Stock Switches/Bezels Gauge Clusters Body Panels Fiero Rotor Hubs for Brake Swaps Or custom fabricated parts! My prices are very low.
A 4.3 in a Fiero can be very quick. I have seen one run in the mid 12s with my own eyes. It was normally aspirated too. But it was a little 84 coupe that had been stripped to the bone to make it really light.
the other cool thing about the 4.3 is the parts that are out there for it. Brodex heads and intakes GM racing parts, heads etc the whole Syclone development angle.... there are lots of 400 to 600 hp turboed 4.3s out there running pump gas and stock cams one thing that ppl keep forgetting is the torque these engine put out naturally aspirated... that alone is a huge bonus
------------------
87 Fiero GT 5sp with Vortec L35 4300 Turbocharged V6 Bully Stage 2 clutch Syclone intake manifold and engine management with Moates adapter and chip burner Air/water intercooler and Devil's Own progressive water/alky injection 50lb injectors, 3 bar map sensor, Walboro fuel pump and Jabasco Intercooler pump LM1 wideband on custom manifolds and 3" stainless exhaust system T31/T04B H3 turbo and a S10 caliper conversion. Murphy's Constant Matter will be damaged in direct proportion to its value Murphy's Law of Thermodynamics Things get worse under pressure. Arthur C. Clarke "Any significantly advanced technology is indistinguishable from magic"
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10:29 AM
m0sh_man Member
Posts: 8460 From: south charleston WV 25309 Registered: Feb 2002
our bone stock 05 chevy with 4.3L v6 was 200HP and 260ft/lbs stock, thats pretty much on par with a 4.9L v8 and the 4.3L has a crap ton more aftermarket.
im not real sure that 27PSI is a real good thing for any motor that you want reliability out of, there's a reason why the stock turbo imports dont run that much boost in their engines that are built for boost.
i would say a mildly built 4.3L with good parts, some 8.5-9:1 compression pistons and 12-15PSI should net around 300-350HP providing you put in a good cam and intake system.
keep in mind your probably going to want a redline of atleast 6,000 RPM like a stock fiero, providing your probably going to use a stock fiero manual transmission, you dont want to be changing gears every second if your peak power is at 4500 RPM, keep all that in mind, if you use a properly geared auto, 4500 RPM peak power would be fine.
It's been almost a week since I logged on to the forum and now I see that I almost missed this interesting discussion.
The 4.3 is a good little engine and don't let anyone change your mind by saying "why don't you just put in a 350SBC instead". If you go by that then why use a 3800, or a 3.4, or a 2.2 Ecotec, or any other swap.
I swapped in a 4.3, so I am biased in my opinion, but there are several good reasons why this is a good swap.
1. You can check my build thread to see that you can use the stock water pump and a serpentine belt after rearranging the AC and alternator positions without changing the frame or fender well. 2. Kit Car magazine ran a dyno test on the 4.3 starting with the old 150 hp engine. They dynoed the engine after each modification to see how much difference it made to horsepower and torque. They changed the cam a couple of times, tried it with different headers, swapped intakes and carbs, and even tried two different heads (they didn't use the vortec heads). All the results were recorded in a table. Their conclusion was that a stock 150 hp 4.3 could be built with BOLT-ON ad-ons, naturally aspirated to 300 hp, no work to the block(other than the cam change) and raise the rpm from 4800 to 6200. This is without turbo or supercharge. 3. It's lighter than the SBC but heavier than the 3.8 or 4.9. 4. It's unusual in this crowd.
I'm at work, so I can't post any pictures right now, but you can look up the build thread: A little different 4.3 swap.
Don't let anyone talk you out of doing the swap if you want it just because it isn't the norm.
Good luck, Egor
------------------ ____________________________________________ "Of all the things I have lost during my lifetime, I miss my mind the most."
Originally posted by MadDanceSkillz: I mean...a *truck* running high 13's STOCK? What does that mean in a Fiero? I'm not expecting 10's or anything, but I have a feeling it would run low 13's. the truck weighs well over 1,000 pounds more than the Fiero does.
EDIT: Actually, just corrected myself...Sport Truck (October 1990) tested the Syclone in purely stock form and obtained a 0-60 mph in 4.8 seconds and a quarter-mile run in 13.08 sec @ 100.44 mph"
True, but there also 4wd... Duno if you would be able to put the power to the ground w/ street tires...
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10:35 AM
Hockaday Member
Posts: 2165 From: Clifton Park, New York, The States. Registered: Sep 2009
27 PSI is a LOT of boost. I mean, saturn 1.9 DOHC on garret T4's on 25 PSI would make 380-420 WHP. I would imagine that a 4.3 with 27 PSI would be making north of 500 HP.
I've also read of stock 3400's and 3500's making around 400 HP on 10 PSI.
I love boost, it is my friend, but you really don't need 27 PSI. Start with like 6-8 for the love of pete.
to be clear, I'm sure the engine can handle 27 PSI, I just don't see the need unless you are shooting for 500+++++
-Brandon
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11:05 PM
cooguyfish Member
Posts: 2658 From: Hamilton, OH, USA Registered: Mar 2002
Originally posted by m0sh_man: some 8.5-9:1 compression pistons
I cut this up a lot to make this point, lowering compression is 1980's style thinking with boost. This is 2010, where people have run some cars at 11.5 compression with over 20 PSI.
I have a 95 BMW 325i with factory 10.5 compression and I was told that I could run 10 PSI and make 300 WHP on a 2.5 liter. Emphasis on the 10.5 compression
Higher compression = better fuel mileage BTW. You would have to do some research and very good tuning but you should be able to run 10+ compression with boost.
I like the idea of better MPG/Power and still N/A...maybe I'll go with high compression pistons or something. Upping compression is not something I'm very familiar with.
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02:00 AM
cooguyfish Member
Posts: 2658 From: Hamilton, OH, USA Registered: Mar 2002
Upping compression will yield more power and better fuel mileage simultaneously. I have heard of people running as high as 13.5 on pump gas and a good tune. Good tune is an extremely key phrase, and you will be running 93-94 octane minimum BTW.
There was a time when I was big into saturns and someone told me on that forum that upping compression x was equal to y PSI, I don't remember what that relationship was, but if you went with 10.5-11.5, possibly even 12.5 it would make a big difference.
Also, since you are getting that marine bottom end, know that the heads are where power is made. Find a set that flows extremely well, and has the powerband you want. Make sure you store that bottom end covered up and grease the cylinder walls if it doesn't have heads, the cylinder walls will rust overnight in the right conditions.
-Brandon
Edited to add;
BTW, now you have me thinking about 4.3's. Not for fieros, but for my trucks for my grass business. I'm all about fuel mileage and low end power with my business and was thinking about going ford with the 4.9 inline 6. But I know the 4.3 is a stout engine, will run for quite a while, and is a 350 with 2 pistons missing.
That last part is important because if I need something with more than a v6 I can build a SBC V8 and it will have parts interchange and be similar to the 4.3. In other words, I am trying to make it so everything mechanically I deal with will be similar so it's easier to maintain them.
[This message has been edited by cooguyfish (edited 06-11-2010).]
