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pres589
pres589 SuperDork
6/20/13 9:33 a.m.

In reply to jstand:

The 302 is cool. It is not a truck engine. It wasn't looked at as great on the street at the time. I want an undersquare engine for better tumble & swirl into the combustion chamber, and for less area away from the sparkplug for fuel to hide and get left out of the combustion process. Torque at low RPM and fuel economy, basically. The same reason the 307 was built in the first place, why it wasn't used in Trans-Am where as the 302 was. A more modern head that flows well with a smaller valve setup ala the Vortec heads of the 90's will wake the thing up and still preserve some of the intrinsic characteristics of the 307.

That's my reasoning anyway. This is a truck, let's suggest something that works well in trucks.

Rob_Mopar
Rob_Mopar SuperDork
6/20/13 9:42 a.m.

Matt, how do you use the truck? As a truck or a toy? How soon do you want it back on the road?

I think you are more than capable of getting multiport fuel injection running in an older vehicle. I'd go with the used 4.8 and forget any of the 307 ideas. If you need more torque, pony up for the 5.3.

pres589
pres589 SuperDork
6/20/13 9:45 a.m.

I honestly wouldn't build the 307 either unless a lot of this hardware was lying around. Like... all of it already around or very cheaply available.

jstand
jstand Reader
6/20/13 12:07 p.m.
pres589 wrote: In reply to jstand: This is a truck, let's suggest something that works well in trucks.

In that case, I'd weld up the block, get a new carb and call it a day. What option in the best choice really depends on how it's used.

For something cost effective, simple, reliable, and balances fun and work, it would be hard to beat the 350 that is already there. Electronics, accessories, driveline, and mounts already work with that engine.

Even if you start fresh with a bare block parts are plentiful, internals are cheaper than the same part for any other displacement (unless the same part number can be used). Tuning can be anwhere from tow vehicle to race car depending on components selected during the build.

Installation, maintenance, and repairs are also simple since there is no debate on whether to get the part for the donor or current vehicle.

Vigo
Vigo UltraDork
6/20/13 12:17 p.m.
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.

I've just realized that i completely forgot to use context clues to the judge the knowledge level of who i was talking to... whoops.

Well, to be less snarky and more detailed, i simply fail to see that the tbi ecu has any particular advantage for any app other than driving a tbi setup, because i would have to spend at least a little bit of money getting it and some of it's associated wiring/pigtails and effort socketing the board and building a (simple) harness, and if i were picking up an ecu setup with the intent of running a multiport setup, i think i would put that money/effort towards something else. In my given example, even a cheap, used fuel-only MS1 setup running off the tach out of the edelbrock spark box and the stock map and tps would be more easily tunable for not a whole lot more money. The same MAY be true of running the tbi unit off an MS but i am unsure of the existence of any 2-injector base tunes or how much time i would put into getting it to run even as well as the 4.8 would on a 5.0/5.7 tbi tune.

As for the tbi on a carb manifold, i am a big believer in 'good enough' and i feel confident that it would be good enough. On a stock, n/a 4.8 i doubt fuel distribution would be far enough out of whack to cause misfire or piston melting issues, and in a 2500lb truck, even a stock 4.8 that lost 30hp to its induction setup and having a few mis-fueled cylinders would probably still run 12s in the 1/4 mile.

MadScientistMatt
MadScientistMatt UltraDork
6/20/13 12:21 p.m.

It would probably be good enough - but it sounds like some minor wiring changes to make a TBI wiring harness connect to multiport injectors would be cheaper than buying a new intake manifold and adapter. The spark control is readily available on its own.

Vigo
Vigo UltraDork
6/20/13 12:23 p.m.

I am curious about other spark control options but dont want to hijack here, unless this whole 4.8 swap thing is sufficiently relevant to the OP's truck (maybe it is?).

MadScientistMatt
MadScientistMatt UltraDork
6/20/13 12:58 p.m.

I'm strongly leaning towards an LSx of some sort now. The spark box - which I don't plan to use myself - is an MSD 6LS. Used to have a lot of customers use a 6LS for spark and an MS1 for fuel, until MegaSquirt spark control for the LS series caught up.

pilotbraden
pilotbraden SuperDork
6/20/13 1:04 p.m.

A 292 cubic inch 6 cylinder with a Megasquirt?

Vigo
Vigo UltraDork
6/20/13 1:55 p.m.
MadScientistMatt wrote: I'm strongly leaning towards an LSx of some sort now. The spark box - which I don't plan to use myself - is an MSD 6LS. Used to have a lot of customers use a 6LS for spark and an MS1 for fuel, until MegaSquirt spark control for the LS series caught up.

In that case, i am more interested than ever in how this ends up.. Im always looking for smart people to copy.

patgizz
patgizz GRM+ Memberand UberDork
6/20/13 10:34 p.m.

http://cleveland.craigslist.org/cto/3874960772.html

4.8/5 speed donor

benzbaronDaryn
benzbaronDaryn Dork
6/21/13 12:02 p.m.

I am ignorant about chevy engines but what I can tell you is when I was in San Diego they had a drag night on fridays. One of the cars running was a primer gray C10 with a long bed. The engine was described as a big block and that truck flew. I think it would be a hell of a ringer for drag race betting. I thought it was cool how fast that old primer gray pickup was.

MadScientistMatt
MadScientistMatt UltraDork
6/21/13 1:44 p.m.

On the hunt for a suitable LS series truck motor now...

Vigo
Vigo UltraDork
6/21/13 4:30 p.m.
The engine was described as a big block and that truck flew. I think it would be a hell of a ringer for drag race betting. I thought it was cool how fast that old primer gray pickup was.

It takes a HELL of a lot more money to make an old big block fast, than an LS motor. Generally speaking.

Kenny_McCormic
Kenny_McCormic Dork
6/21/13 5:00 p.m.
Vigo wrote:
The engine was described as a big block and that truck flew. I think it would be a hell of a ringer for drag race betting. I thought it was cool how fast that old primer gray pickup was.
It takes a HELL of a lot more money to make an old big block fast, than an LS motor. Generally speaking.

A BBC core worth rebuilding will cost almost as much as the whole turbo LS setup. Last I checked people routinely get 500 WHP out of a dead stock $300 junkyard 4.8 longblock with a turbo system made out of the stock exhaust manifolds. With HCI, you can put 800-900 to the wheels before rods bend.

Travis_K
Travis_K UltraDork
6/21/13 5:56 p.m.

Where are people getting $300 longblocks? Just from pick and pull in California a Subaru ej22 long block (no intake, accessories, etc) was $300, and over $1k for a complete vw tdi+transmisson. As far as big blocks go, unless you get an older one(like a 396 from a car), the heads flow so badly that I think a stock 350 powered truck might beat a stock 454 in a drag race. If both trucks were pulling a heavy trailer that would be a different story though of course.

Kenny_McCormic
Kenny_McCormic Dork
6/21/13 6:49 p.m.

In reply to Travis_K:

Move out of the PRC, though Subaru and modern VW stuff pulls a premium everywhere. In the Detroit metro area, a 4.8/5.3 is ~$450 from a salvage yard tested as good. At the big picknpull(3 locations), parts galore, $346.25 for any complete V8 minus accessories with a warranty. And Ive seen LS truck engines in there more than once.

Vigo
Vigo UltraDork
6/21/13 7:33 p.m.
over $1k for a complete vw tdi+transmisson

That's actually cheap.

the heads flow so badly that I think a stock 350 powered truck might beat a stock 454 in a drag race. If both trucks were pulling a heavy trailer that would be a different story though of course.

In a long enough race the one with the highest HP will win regardless of how much weight you put behind them. Even if it's a 1.0 w/ 300 hp vs an 8.0 w/ 250.

patgizz
patgizz GRM+ Memberand UberDork
6/21/13 8:48 p.m.
patgizz wrote: http://cleveland.craigslist.org/cto/3874960772.html 4.8/5 speed donor

seriously. $800 obo claims 80k miles. truck probably rusting around drivetrain. i swear if none of you do i'm going to buy it in the morning.

novaderrik
novaderrik UberDork
6/21/13 9:05 p.m.
Kenny_McCormic wrote: In reply to Travis_K: Move out of the PRC, though Subaru and modern VW stuff pulls a premium everywhere. In the Detroit metro area, a 4.8/5.3 is ~$450 from a salvage yard tested as good. At the big picknpull(3 locations), parts galore, $346.25 for any complete V8 minus accessories with a warranty. And Ive seen LS truck engines in there more than once.

look on www.car-part.com and you will find complete 5.3 long blocks without accessories and ecm for about $400 on average, at least around here. a 4.8 is about $350, and a 6.0 is usually around $1k.. i've never called a yard to ask, but i can't see them wanting more than $150 or so for everything else that you'd need to get the engine in something and running..

Vigo
Vigo UltraDork
6/21/13 10:12 p.m.
but i can't see them wanting more than $150 or so for everything else that you'd need to get the engine in something and running..

Good luck with that! If you ever plan to attempt such a purchase, call ahead and check so that you dont show up without enough money.

Travis_K
Travis_K UltraDork
6/22/13 1:13 a.m.

I know that's cheap for a tdi, but that's the same price for any 4 cylinder complete enough for a swap, or it goes in the crusher, they dont much care one way or the other.

By a drag race between a 350 and 454 powered truck I was thinking like actual 1/4 mile time, id be quite surprised if a 70s 454 truck was any faster than a 350 powered one.

novaderrik
novaderrik UberDork
6/22/13 2:06 a.m.
Vigo wrote:
but i can't see them wanting more than $150 or so for everything else that you'd need to get the engine in something and running..
Good luck with that! If you ever plan to attempt such a purchase, call ahead and check so that you dont show up without enough money.

some places leave the accessories on the engines for the lowball price- i've seen 5.3's advertised by junkyards on CL for $500 with the ecm, harness, and all accessories.. yeah, you will probably pay more if you buy it separate, but buying it all with the engine is less labor for them...

MadScientistMatt
MadScientistMatt UltraDork
6/22/13 8:11 a.m.
novaderrik wrote: some places leave the accessories on the engines for the lowball price- i've seen 5.3's advertised by junkyards on CL for $500 with the ecm, harness, and all accessories.. yeah, you will probably pay more if you buy it separate, but buying it all with the engine is less labor for them...

Found a guy in Decatur offering complete 4.8s with all accessories at that price - looks like 5.3s go for a little more here. I am thinking at this point I'll go with the 4.8. The truck is mostly used for errands and hauling yard waste / landscaping stuff and other light loads, so it doesn't need a huge amount of power. And if I change my mind on that point, I can always turbo it later and have more power than the chassis and drivetrain can handle.

Vigo
Vigo UltraDork
6/22/13 10:57 a.m.
I know that's cheap for a tdi, but that's the same price for any 4 cylinder complete enough for a swap,

Oh, well thats a E36 M3 price for most other 4 cyls!

I personally really like the feel of 4.8s anyway. Enough low-rpm torque to be satisfying, but more entertaining in high rpms vs the 5.3. They just have a more progressive powerband that i like.

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