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pres589
pres589 SuperDork
6/18/13 8:43 a.m.

I would think that the LT1 isn't very desirable because of the somewhat costly ignition parts it probably needs now or in the near future.

The 4.8 is looking really nice at this point if $300 or less will get you something with a lot of life left in it. Wonder what it costs to get the ECU and the engine bay wiring to facilitate a swap.

rob_lewis
rob_lewis SuperDork
6/18/13 9:04 a.m.
MadScientistMatt wrote:
rob_lewis wrote: What's the goal for the truck? Unless it's serious towing, you could probably pick up a 4.8L LS motor for next to nothing and just do the swap that way. The 4.8 isn't as torquey as the bigger brothers, but is still a decent option. -Rob
Playing around with the LKQ parts locator, and the 4.8 appears to be the cheapest Chevy V8 they have for sale! Prices look like this: - 4.8 LSX: $245-285 - 5.3 LSX: $545 - TBI 350: $635 - Corvette LT1: $650 - Vortec 350: $935 - 4.2 Atlas: $935 - 6.0 LSX: $1335 - Corvette TPI motor: $2120 Couldn't find any 8100s on their site, and it was interesting to see some of the outliers in pricing. I guess there's just zero demand for 4.8s - they get passed up by hot rodders, and they don't wear out enough for their owners to need a replacement (or maybe they just upgrade to 5.3s when the motors die). Also noteworthy: A Corvette LT1 appears to count as a cheap 350. Interesting...

They were the standard engine and yes, most people want to upgrade to the 5.3 or 6.0. However, it's a very stout little motor and most of the standard stuff bolts on.

HotRod pushed one to 1100+ HP before it finally died.... http://www.hotrod.com/techarticles/hrdp_1109_stock_gm_ls_engine_big_bang_theory/

After eclipsing 1,200 hp, we kept going. Raising the boost beyond 27 psi resulted in what we suspect was an ignition failure. The motor was still in perfect shape internally and worked well up to 26 psi, but unfortunately we were out of available dyno time. The motor survived more than 60 runs, the majority of them more than 1,000 hp. We hammered this motor like we stole it, with repeated back-to-back pulls, but the little LS never missed a beat and was ready for more. Then something dawned on us after pulling it off the dyno: 5.3s don't come with flat-top pistons (we know the few exceptions). Combine this with the fact that this combination produced peak power at 7,000 rpm, and we started to suspect that it might not be a 5.3 after all. Off came the oil pan and sure enough, connected to those flat-tops was set of 121 connecting rods and a crank that featured a casting number of 12553482. That's right, this 1,203hp 5.3 was actually a 4.8L. That's just 294 ci for a stunning 4.09 hp/ci. The longevity of the combination is still in question, but having survived about 60 pulls under big boost means it could easily run a full season at the strip, making at least 1,000 hp. It might lose ring seal and drop power, but you can simply replace the rings. If the whole motor grenades in spectacular fashion, replace it with another $500 takeout. We'd caution that eventually you might drive over the crank at the drags and get oil under the tires, but as a detuned 700 or 800 streeter, this little sucker will be amazing.

-Rob

Strike_Zero
Strike_Zero SuperDork
6/18/13 9:06 a.m.
MadScientistMatt wrote:
rob_lewis wrote: What's the goal for the truck? Unless it's serious towing, you could probably pick up a 4.8L LS motor for next to nothing and just do the swap that way. The 4.8 isn't as torquey as the bigger brothers, but is still a decent option. -Rob
Playing around with the LKQ parts locator, and the 4.8 appears to be the cheapest Chevy V8 they have for sale! Prices look like this: - 4.8 LSX: $245-285 - 5.3 LSX: $545 - TBI 350: $635 - Corvette LT1: $650 - Vortec 350: $935 - 4.2 Atlas: $935 - 6.0 LSX: $1335 - Corvette TPI motor: $2120 Couldn't find any 8100s on their site, and it was interesting to see some of the outliers in pricing. I guess there's just zero demand for 4.8s - they get passed up by hot rodders, and they don't wear out enough for their owners to need a replacement (or maybe they just upgrade to 5.3s when the motors die). Also noteworthy: A Corvette LT1 appears to count as a cheap 350. Interesting...

4.8 . . . 4.8 . . . 4.8

I paid right at 300 with all the accessories for mine, with 101k on the clock. Got to hear it run before they dismantled the truck.

Everyone told me, at the time, "get the 5.3, it cost the same as 4.8". I couldn't find a complete + accessories for less than $600

fidelity101
fidelity101 Dork
6/18/13 9:10 a.m.

TBI SBC is not a good idea.

yamaha
yamaha UberDork
6/18/13 10:02 a.m.
Fueled by Caffeine wrote: Or a 2 stroke Detroit 4 banger.

Did you ever see how much cutting it took to get a 4-53T in a similar vintage c-30? It was scary, plus the 4-53 weighs about 1200lbs.....

914Driver
914Driver MegaDork
6/18/13 10:06 a.m.

A nicely put together straight six could always turn my head.

Change intake to suit your needs.

Rupert
Rupert Reader
6/18/13 11:29 a.m.
914Driver wrote: A nicely put together straight six could always turn my head. Change intake to suit your needs.

Sell me either of those motors for $300 & I'll find a truck to put them in!

patgizz
patgizz GRM+ Memberand UberDork
6/18/13 9:40 p.m.
fidelity101 wrote: TBI SBC is not a good idea.

in a truck? it's a great idea. it's all low end and out of breath at 4200. who revs their truck that high?

81cpcamaro
81cpcamaro HalfDork
6/19/13 7:43 a.m.
patgizz wrote:
fidelity101 wrote: TBI SBC is not a good idea.
in a truck? it's a great idea. it's all low end and out of breath at 4200. who revs their truck that high?

I agree with Pat, the TPI was the best truck motor GM made, too bad they didn't put it in a truck. Plenty of power where needed for truck stuff.

MadScientistMatt
MadScientistMatt UltraDork
6/19/13 7:54 a.m.

TPI would be pretty good in the truck - a TBI motor isn't that much cheaper and I'm not especially impressed with the fuel distribution they have. A minor step up from a carb, but if I'm going to do an EFI swap, I see no reason to do this halfway.

mazdeuce
mazdeuce Dork
6/19/13 8:19 a.m.

It really depends on your long term thinking about the truck. Do you just want it to run, or is this something you're going to hold on to for a decade? If you just want it to run then let cost be your guide. If you really want to keep it, then LS seems to make the most sense. The support for LS motors is huge and the potential with them as well. The 4.8 would be my preference for a project like this. It's cheap and is probably enough motor for what you need. If you end up wanting more kick, a nice moderate single turbo and 500+ whp seems almost trivial to implement. Not that I've actually done it mind you, but I've thought a LOT about doing it to my 5.3 truck.

Vigo
Vigo UltraDork
6/19/13 10:35 a.m.

My personal plan, which everyone will think is stupid..

Is to get a 4.8, put an Edelbrock carb adapter intake on it with the included spark computer to run COP, and then pare an old tbi harness down to standalone basics and run an old gm TBI setup on top of it. Should cost just over 1k. And it goes in my 1980 Plymouth Arrow truck which weighs ~2500lb.

Dusterbd13
Dusterbd13 HalfDork
6/19/13 10:37 a.m.

sell the c10 to my best friend, then ill sell him the drivetrain from the elky and put a 4.8 in it.

on yours, honestly, id just shove another craigslist small bloick in ity and let it eat

MadScientistMatt
MadScientistMatt UltraDork
6/19/13 12:03 p.m.
Vigo wrote: My personal plan, which everyone will think is stupid.. Is to get a 4.8, put an Edelbrock carb adapter intake on it with the included spark computer to run COP, and then pare an old tbi harness down to standalone basics and run an old gm TBI setup on top of it. Should cost just over 1k. And it goes in my 1980 Plymouth Arrow truck which weighs ~2500lb.

I'd sooner use the TBI ECU on the factory multiport intake, unless you have a very good reason for wanting to do this.

pres589
pres589 SuperDork
6/19/13 2:26 p.m.

... And here I thought my previously un-mentined dual-TBI on an Edelbrock dual-quad Vortec Performer RPM intake / Vortec heads on a 307 idea was too crazy to bring to the table.

MadScientistMatt
MadScientistMatt UltraDork
6/19/13 2:45 p.m.
pres589 wrote: ... And here I thought my previously un-mentined dual-TBI on an Edelbrock dual-quad Vortec Performer RPM intake / Vortec heads on a 307 idea was too crazy to bring to the table.

I'd considered something very similar for my own truck before I realized the block was cracked.

pres589
pres589 SuperDork
6/19/13 2:46 p.m.

In reply to MadScientistMatt:

I don't think a 307 block would be real popular. Should be cheap and commonly available, right?

novaderrik
novaderrik UberDork
6/19/13 2:54 p.m.
Vigo wrote: My personal plan, which everyone will think is stupid.. Is to get a 4.8, put an Edelbrock carb adapter intake on it with the included spark computer to run COP, and then pare an old tbi harness down to standalone basics and run an old gm TBI setup on top of it. Should cost just over 1k. And it goes in my 1980 Plymouth Arrow truck which weighs ~2500lb.

what's your solution to getting a distributor signal to the ecm?

MadScientistMatt
MadScientistMatt UltraDork
6/19/13 3:31 p.m.
pres589 wrote: In reply to MadScientistMatt: I don't think a 307 block would be real popular. Should be cheap and commonly available, right?

That was minus the 307; it would go on the (now broken) 350.

The 307 is basically a 327 crank in a 283 block. The small bore kind of holds it back compared to other engines - but it almost seams like putting a 283 crank in one might make sense.

pres589
pres589 SuperDork
6/19/13 4:02 p.m.

In reply to MadScientistMatt:

Picked for cost / commonality, torque production possibility, and economy. 307 should be a cheap rebuild with cast pistons, a modern flat-tappet cam, and Vortec heads with the money going to the intake and carb linkage required.

A good 350 short block wouldn't be a bad route either, obviously.

AutoXR
AutoXR HalfDork
6/19/13 4:08 p.m.

4.2 Atlas: $935

I have seen them for $300... this is the GM I6 correct

That and a big Single....

Fueled by Caffeine
Fueled by Caffeine MegaDork
6/19/13 4:46 p.m.
yamaha wrote:
Fueled by Caffeine wrote: Or a 2 stroke Detroit 4 banger.
Did you ever see how much cutting it took to get a 4-53T in a similar vintage c-30? It was scary, plus the 4-53 weighs about 1200lbs.....

Minor details. Screaming jimmy motors are awesome.

It don't look so bad. http://www.thedieselpageforums.com/tdpforum/showthread.php?t=27343

Vigo
Vigo UltraDork
6/19/13 5:16 p.m.
I'd sooner use the TBI ECU on the factory multiport intake, unless you have a very good reason for wanting to do this.

Yeah, the very good reason is that the stock multiport manifold is designed for dry air flow and bolting a TBI to the front of it is berkeleying stupid. Unless you were suggesting.. wiring all 8 injectors to the 2 tbi injector drivers?

what's your solution to getting a distributor signal to the ecm?

Which ECM? The edelbrock package comes with it's own spark computer that reads the factory reference sensors and triggers the factory coils. Spark timing is also sort of adjustable between a few presets. It almost certainly has a 'tach out' line that i could use on the tbi ecm if that's what you mean.

The idea here is to get something ALMOST as simple as a carb/hei setup on a $300 LS motor while actually being reliable and tunable in all the ways that a carb setup isnt. I already have all the stuff to socket/flash/tune a tbi ecu and i've never even owned one. I really like the simplicity of TBI setups. I understand that's not a popular thing.

MadScientistMatt
MadScientistMatt UltraDork
6/20/13 7:47 a.m.
Vigo wrote: Yeah, the very good reason is that the stock multiport manifold is designed for dry air flow and bolting a TBI to the front of it is berkeleying stupid. Unless you were suggesting.. wiring all 8 injectors to the 2 tbi injector drivers?

TBI injectors: 1.5 ohm resistance, 4 amp current draw each.

Stock LSx multiport injectors: 12 ohm or greater resistance, 1 amp current draw each.

You're not putting any more load on the drivers, and there's no problem running an LSx bank to bank. Or just use a TPI ECU if you're worried about things being too different.

And the experience I have with sticking a TBI on a carbed manifold is that they often don't have great fuel distribution, much like trying to use a manifold designed for one carb type with a different carb.

jstand
jstand Reader
6/20/13 9:10 a.m.
pres589 wrote: In reply to MadScientistMatt: Picked for cost / commonality, torque production possibility, and economy. 307 should be a cheap rebuild with cast pistons, a modern flat-tappet cam, and Vortec heads with the money going to the intake and carb linkage required. A good 350 short block wouldn't be a bad route either, obviously.

It your going to mix and match I would lean towards over square with the shorter stroke of the 283 with the 327/350 bore (in other words a 302) rather than going under square.

You can fit bigger valves and it will rev better. Just getting the bearings, block, rods, and pistons to work together may take some planning so journal sizes and wrist pin heights are correct.

Not necessarily a good truck motor, but not bad either, and will bolt right in.

HEI and a new Carb and you can have a very simple and reliable engine.

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