Adding Fuel Injection on a 454

[Jeff Stevens]

I'm going to put TBI on a Chevy 454 in a 1989 Barth 22 footer. Does anyone have any recommendations? Looking for reliability, and possibly better mpg. Cost is not a big issue...performence is.Thanks for any advice.

[tmsnyder]

Holley sniper system?

[Elandan2]

I've been looking at this system. https://fitechefi.com/ 
Having the ability to use the factory fuel pump allows a much simpler system when you have more than one fuel tank.

[Eyez Open]

Changing up a fuel delivery system can be quite a bit of fun, and very interesting. With that being said going to tbi will not enhance fuel ecomony nor improve power over a well setup carb/HEI system. Now cold starts will be improved that is a given.

In your new system do you intend to go open loop or closed loop? One would guess the cost to run about 4/5000 grand...Does this barth have a overdrive transmission?

[Pargin4]

The best advice someone can give you is the usually hardest to hear: stick with the carb.
Using a GM TBI system doesn't gain much in terms of economy or performance. Sequential MPFI systems are pricey and some might have clearance issues in your rig. Aftermarket units have gotten to the point where they are easy to install (read Edelbrock Proflo, Holley Sniper/Terminator, Fastefi, FITech), but what a lot of people miss is that with most of these you lose the ability to just walk into a parts store and pick up a MAP sensor, O2 sensor, etc. The ones that do a better job of making more power also control spark advance so if that starts acting up, your ability to purchase ignition parts on the road can be affected too. That's fine with a restomod or something that doesn't get driven all over the continent, but with a home on wheels?

This is coming from someone who walked 3 miles to the nearest parts store last year. But when I got there I was able to get what I needed and only lost a few hours of road time on a week-long trip. Power and fuel economy are great, but enjoying your trips is best.

[Oz]

 Hm?  Very good points, Pat.

[tarifachris]

You can buy the Holley Sniper system refurbished from Holley direct for 799$. It is true to have better performance you are better to  control the distributor (+400$). If the stand alone EFI system without distributor control is not working, just screw your old Carburetor back on and use the 5 PSI fuel pressure regulator...

Actually there are EFI 60PSI electric fuel pumps on the market who replace our low PSI in tank fuel pumps. They used the in tank fuel pump system from the 5.7l GM efi system in the P30's after 1986 with the return fuel line.
You would need a different fuel regulator for EFI and remove the mechanical fuel pump. Most P30 RV's after 1986 have already
a fuel return line. So not a big problem to change to EFI if you have some change. If you use the refurbished Holley Sniper without
distributor control and replace the in tank fuel pump to EFI you can manage to have EFI under 1000$...

[Eyez Open]

I took a look at that Holley system, now that takes tinkering to a whole new level. I seem to be at a loss here, if you have this system up and running how does this system time a HEI? It cannot be done. It would seem it is a quasi self jetting electronic carb..perhaps?

[khantroll]

Eyez: You have to either swap the distributor for one that is preconfigured to interact with the system, or by parts that and modify the current distributor. At that point, the electronics on the Sniper system will control it.

Going the TBI route on the 454 will give you better reliability and a slight improvement on mpg. It's also bang cheap because a the non-consumable parts can be safely purchased used.

I might be biased though. I've had a good luck with TBI vehicles and bad luck with carbed vehicles my entire life.

[Eyez Open]

I do understand the bias part, you see I use to hotrod Marine TBI for many yrs. Yes, I am well aware of what it takes to operate an electronic fuel & ignition timing system using software. I can tell you it is a slow painful process with far from linear results.

I am now tinkering with carbs and find it fascinating to work on, i am finding there is nothing tbi offers that a carbed/hei system cannot do, actually, hei provides more flexibility and with less time and drama...Trying setting any efi system to 34 degrees advance @2500 rpm under a load then it instantly reverts to 45 degrees advance at cruise at the release of the throttle...LMAO. It would be a nightmare...HEI add a few springs, turn up the initial timing and poof your home...vacuum advance is at it best in these old engines.

Actually, I should mention these auto-tune systems give the user a very very crude tune to work with, just enough for the engine to run. To optimize the engine would require quite a bit of hands-on custom tuning. And a very expensive list of parts..very.

[khantroll]

I've heard the whole "flexibility of carburetors" point my whole life; my parents were stock car mechanics.

Here's the thing: it's a double edged sword. Yes, carbed systems are simple, but they slowly get out of calibration. Even on hotrods that don't see that much road time, or RVs that sit.

As for setting timing curves on EFI systems, yeah, highly configurable EFI systems are either complex or expensive or both. But modern EFI systems also aren't that hard to work with.

There are times when I think I'd love to switch mine over. But my 413 gets phenomenal mileage, so I'm loath to mess with anything, and if it ever needs to be replaced I'll most likely just do an engine swap.

[Eyez Open]

A 413 is old-school engineering, actually well engineered would be a better description. Pre smog the combustion process was maximized to be efficient, i would be surprised if a recurve would aid that engine whatsoever...It was designed correctly right from the start..Impressive actually it belittles the 454..and oversquare, I'm sure it winds up fairly quickly.

1960
Engine Specifications: 413 V8 as used in Chrysler 300F ​   
Bore, Stroke, Compression   4.18 x 3.75; 10.1 to 1......
Max. BHP @ RPM   375 @ 5,000 (std) or 400 @ 5,200
Max. Torque @ RPM   495 @ 2,800 (std) or 465 @ 3,600.....
Firing Order   1, 8, 4, 3, 6, 5, 7, 2

[udidwht]

With TBI ones drive-ability will be the one thing noticed vs carb. A TBI unit will only give one the illusion of better MPG due to the fact that 99 percent of folks who slap a carb on do not spend time dialing the jetting in.

No carb is ever plug & play out of a box. Never.

Dial the jetting in on the carb and MPGs will be the same.

[78BraveGuy]

There was a gentleman that used to be on here named Frank who swapped TBI onto his motorhome and said that he went backwards in power compared to the quadrajet 4 barrel carb with mileage being about the same.  I actually had several conversations with him about doing an EFI swap on my motorhome a few years ago.  After all of his advice, I had the quadrajet rebuilt and am satisfied.  Adding OD if you have the torque would do more for fuel economy than fuel injection.  You can spend a lot of money chasing fuel economy, but remember that these beached whales aren't going to be easy on fuel no matter what you do.  I say if it isn't EFI already, just get the carb dialed in and enjoy driving a piece of great Americana.   

[eXodus]

If you go swap an engine in to go for fuel economy you need a diesel.

Going for power?   Depends,  either tune the carb or drop in a LS or LT engine. 

A stock 6.0 LS has the same power as 454 TBI and practical unlimited potential upwards.
Or go super modern (2014 and later)  with a 5.3L  LT already outpowering the 454.  Or crazy with a 6.2L LT.

[78BraveGuy]

I question whether an LS engine would be a good replacement for a 454 BBC in a motorhome.  We aren't talking about muscle cars or pickups here.  Sure they can make crazy HP and decent torque numbers, but at what RPM are they making their peak torque?  These motorhomes are heavy pigs and big blocks (and diesels) make their torque at a lot lower RPM than LS engines.  I believe peak torque for a 454 is going to be somewhere around 1600 RPM.  If replacing a 454, the only options would be going to an 8.1L or a diesel IMHO.  I have had pickups with 350's, 454's, 5.3's, and one with a 6.2.  The 350 would out pull the 5.3 because it is a longer stroke engine and made more bottom end torque.  Sure the 5.3 was peppier and had more high RPM power, but if I needed to pull something, the 5.3 was my last choice.  Nothing compares to a big block in the gas engine world when it comes to pulling a heavy load (and I would classify driving a motorhome in the same category as pulling a trailer).

[eXodus]

While that it is true that the 454 makes a more torque down low -  the LS torque gets above the level of the TBI version -  at around 2000-2200 rpm and gives you a 40 ft-lbs of torque more at around 3000rpm.
the 8.1L vortec has it's maximum torque around 3200rpm.

All the Box Trucks on Chevy Express basis have the 6.0LS or the the 6.2 LT   and those are really heavy bricks. Contractors load them up to the gills and they still get 200.000 miles out of those engines.

While the 454 in RVs are hardly ever see 6 digits and need some major rework somewhere before that.

I'm not saying LS/LT it's the right application for every 454 swap - but I would assume for the smaller and shorter RVs should be a decent upgrade-  not the 37ft tag axle ones.

[78BraveGuy]

Yeah, I would think a 6.0 would make a good swap for a smaller class C that had a small block in it to start with.

[eXodus]

The 6.0 is an Amazing Engine.
when you get one out of a Silverado or a Chevy Express HD. Those things make 360HP out of the Factory and got 380 lb.-ft. (515 Nm).

You add some headers (which you need anyhow during a swap)   get a tune for ECU and you are looking at
6.0L  400HP and 520 lb.-ft. @ 2500rpm 

compare this with the

TBI 454 255hp @ 4000rpm 405 lb/ft torque @ 2400 rpm

You can definitely build a big block, let it make more power,  but you are sacrificing the already not great longevity and drop the fuel economy even lower.


It's a money and time game,  you can get a used Chevy Express (3500 + cutaway) van with a 6.0L and a 4L80E  for probably $3-4K

Get the whole drivetrain out of that - almost perfectly bolts into a P30 RV chassis. 
Also a bunch of spare parts - the hydroboost fits,  Steeringbox etc. Could reuse the transmission and powersteering coolers.
Heck I think even the steering wheel bolts on

[Eyez Open]

While the newer engines are more efficient, make no mistakes the old 454 can be made much more efficient with far less cost and labor. What GM did to these old SMOG motors is beyond the pale by today's standards. A simple comparison woul be hooking up a 1/4" hose to a 1" hose and watering one's lawn.

The simplicity of resurrecting the 454 is in the induction/exhaust system, a fully functional Quadra jet rebuilt by a pro, a slightly larger cam shaft exhaust headers and the elimination of the AIR system will net one around 400 hp and over 500 ft lbs of tourqe...well below 4000 rpm. Much more than that and one would grenade the existing transmission.

Push rod motors excell in heavy towing, the cost is by far less and I do believe the economy would be more more efficient. Now as to reliability, that as always depends on the care of maintenance and the abuse the motor received...200,000 miles is not a stretch in a well maintained 454 by any means.

As to the emmisson system, always follow state guidelines with that being said unless the old AIR system is fully functional the engine is a super polluter.

[udidwht]

I question whether an LS engine would be a good replacement for a 454 BBC in a motorhome.  We aren't talking about muscle cars or pickups here.  Sure they can make crazy HP and decent torque numbers, but at what RPM are they making their peak torque?  These motorhomes are heavy pigs and big blocks (and diesels) make their torque at a lot lower RPM than LS engines.  I believe peak torque for a 454 is going to be somewhere around 1600 RPM.  If replacing a 454, the only options would be going to an 8.1L or a diesel IMHO.  I have had pickups with 350's, 454's, 5.3's, and one with a 6.2.  The 350 would out pull the 5.3 because it is a longer stroke engine and made more bottom end torque.  Sure the 5.3 was peppier and had more high RPM power, but if I needed to pull something, the 5.3 was my last choice.  Nothing compares to a big block in the gas engine world when it comes to pulling a heavy load (and I would classify driving a motorhome in the same category as pulling a trailer).

Peak torque on the 454 in these RV's starts at ~1600rpm and stays pretty flat until roughly 2500rpm or so  then starts to drop rather quick. On my 1994 454 TBI w/4L80E trans when cruising at 60mph (US) the rpm is at roughly 26XX. That is right at the point of diminished return. Any more throttle and your only wasting fuel for faster hotter speed. This was at a time when the national highway speed limits were still 55mph. It is how the chassis manufactures built them gearing wise.

1994 454 385lb ft @ 1600rpm

Horsepower peaks (230) at ~3600rpm but your torque at that would be 330lb ft or so vs peak 385lb ft

[eXodus]

That's why I recommend a 6.0LS with a newer 4L80E  or even a 6L80E
The gearing is not for 55mph but for 70mph.

GM puts the 6.0L into  Isuzu NPR Medium Duty Trucks. Those have a GCWR up to 20.000LBS.
IF you got a super heavy vintage RV - like a 36FT Tag Axle - I would get myself a 8.1 Vortec.  But everything below that - the 6.0L should do just fine.

Like I said before - sure you can build 454 to do that. But how much money +time are you going to throw at it?

[Eyez Open]

For those that might contemplate a EFI conversion In a RV. This guy does a great job of laying it all out. He gets to the truth of the matter towards the end...without being to harsh.


https://youtu.be/basZ13N9OBg

[Oz]

Good video! 

[Rschieck]

I swapped a 6.0L LY6 (from a 2010 Yukon) and a 6L90 (from an 2010 police interceptor) into my 1976 D21. I think I'm just over 400 for hp and tq.

It has a 4.88 rear end. Rpm is about 2500 at 100 kph (60mph). It has a very comfortable amount of power, easily goes up steep hills shifting to 5 or 4, and doesn't need to shift up slight or intermediate grades. And it pulls away from the line too fast. Best of all (maybe not best of all, but really great), it is now quite quiet ( ) in the cab while driving.

I had the stock rad re-cored to suit an LS and a 1/4" port added for a steam line. I made new motor mounts and swapped an existing crossmember (in the way of the new trans) for a custom crossmember/trans support. And, had to have the front of the drive shaft changed to suit the yoke (u-joint) from the 6L90. And a custom bracket for the stock gear shift cable.

I used a plastic fuel tank from a 2015 f550 (I think) which was 190L (50 gal), and a fuel pump out of a 2012 flex fuel van.

I'm still planning to swap the vac brake booster for a hydraulic brake booster, and to hopefully try out 4.11 gears to see how it drives with those and get me under 2000 rpm at 100 kph.

All in all, it's very fun to drive now vs. The turd 360 and 3-speed that was in it.