Author Topic: New engine plans  (Read 3830 times)

Offline werewolfx13

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New engine plans
« on: June 11, 2008, 11:46:02 PM »
In my last set of plans, I had intended to build a motor with a good torque curve for towing. Thats changed, since I no longer use this truck to pull anything heavier than 6,000 lbs. The very long term plan is to convert the truck to a 5 speed TKO-500, (.68 overdrive 5th gear), 3.08 rear end, and run 237/75/r15 tires. Should be like 1700 rpm at 70 MPH in 5th..I think..With that setup in mind, heres what I want it to do: I want to see 15-17 mpg at 70 mph, run on 87 or 89 octane gas,  run a holley commander 950 TBI kit for a carb intake manifold (its laptop tuneable, and summit carries 650 cfm, 700 cfm, and 900 cfm versions, and it claims to handle a hotter cam). The main purpose will be my daily driver (20k-30k miles per year), but it needs to be able to take care of business when I want it to.  ;)
N20 is a possibility, probably a 150hp shot, figure on using it a couple times a week depending on the availability of the n20 locally, so, forged internals neccessary or no?

I have a '73 350 block, haven't pulled the pan off to see if its 2 or 4 bolt main. I'd really like to run a roller cam and lifters, what additional machine work, if any, is needed? I'll probably buy heads, i have the 993 casting heads off the '73 engine, but they would need new valves, seats, springs, etc..I'd like to keep the total cost for the engine (TBI kit and n20 system excluded) under $2000 if possible, with a hard cap of $2500. I don't mind starting with a crate short block IF it would save money..Emissions aren't a problem, I do have to have cats though, or rather, I need things in the vague shape of cats installed somplace in my exhaust....they don't have to have anything in them though. Headers are part of the plan, as is new exhaust using dual 2.5" flowmaster original 40 series. I'll be doing all the engine assembly work myself, except for any head work..I've got a haynes engine rebuilding book to refer to, and will probably buy most of the specialty tools I need but don't have..

Input and suggestions?
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.

Offline Captkaos

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Re: New engine plans
« Reply #1 on: June 12, 2008, 12:05:17 PM »
Yeah, I have some input.  You want good MPG, EFI and power all for under $2500 (minus the EFI/Power)  Skip the pre-GenIII motors and get a LS 5.3L, you can pick one of these up around here for about $800 with the accessories, computer, harness.  For $1500 you get the transmission.  Generally they have less then 25K miles on them and they make 295hp stock...  I would check you local salvage yards for them

Offline choptop

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Re: New engine plans
« Reply #2 on: June 12, 2008, 01:03:20 PM »
+ 1, Im looking for that myself.
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
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Offline Captkaos

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Re: New engine plans
« Reply #3 on: June 12, 2008, 01:05:22 PM »
Chop, you being in TX you should be tripping over pulled 5.3L's  :D

Offline SUX2BU99

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Re: New engine plans
« Reply #4 on: June 12, 2008, 01:38:26 PM »
Yeah the LS series of engines are just more efficient and a better design all the way around. Having the original SBC around for 50 years to ponder how it can be better I guess has paid off  lol   

And it's about time they did figure out how to make a better SBC. I remember when my buddy's dad bought a new 96 1/2-ton 4x4 ex-cab with the Vortech-head 350. 255 HP and it got TERRIBLE gas mileage. Like 12 mpg maybe. It was bad.  My 03 Tahoe Z71 with the 5.3 is much better on gas, and it has a 3.73 rear end. It still revs lower on the freeway than does my 2.82 rear end 05 Magnum R/T. Go figure.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline choptop

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Re: New engine plans
« Reply #5 on: June 12, 2008, 04:58:54 PM »
Chop, you being in TX you should be tripping over pulled 5.3L's  :D
You would think so, but the ones I find are $2000-$3000. I had a lead on some old worn out ( and I mean abused and worn out) work trucks, but they all went for $2500-$3000, and all the trucks had 220,000 miles or better. I didn't care about the mileage, because I plan on rebuilding it anyway, but the rest of the trucks were junk. Not a straight panel anywhere, so couldn't even sell the leftovers to recoup some of the cost. They guy who bought them hauls them to Mexico, that happens alot here. I will find one though, just gotta be patient. The big seller on them in this area is that most of the mileage is highway, so they still want a premium for them. I am going to start checking some other wrecking yards and see if I can get lucky. I really want a 6.0 for my extended cab, maybe I'll find an 8.1 for my choptop. We'll see.
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
86 C30 extended crewcab

Offline Fordeatinz71

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Re: New engine plans
« Reply #6 on: June 12, 2008, 05:05:06 PM »
well, i'm lookin too Chop, so if i find a couple i'll let ya know as we aren't THAT far apart...
1991 Chevy Silverado K1500 ECSB, 350, 700R4 w/shift kit, 3.42's, exhaust work...
1983 GMC Sierra K1500 SWB-sold :(

Offline Blue 82

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Re: New engine plans
« Reply #7 on: June 12, 2008, 05:09:43 PM »
The LS option is a good one

How much are those Holley systems anyway?
Looks like they are close to $3000 with a wideband O2
so even with a $2000 rebuild you are at approx $5k

With that kind of budget I would consider one of these
http://www.sdparts.com/catalog/crateengines/GMPerformanceParts350ci350hpRamJetEngine.aspx



82 stepside 2wd 355/th350/3.08 posi

Offline werewolfx13

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Re: New engine plans
« Reply #8 on: June 12, 2008, 11:28:00 PM »
My $2k budget is for the intake manifold down, the holley commander 950 systems run about $1500-$1700. As for the 5.3 swap, its out of the question but I appreciate the suggestion..I'm not putting a used motor in this truck unless the one thats in it now has a catastrophic failure that demands I replace it sooner than I'd like..
I prioritized the list:

1. runs on 87 or 89 octane pump gas
2. everything but the bare block has to be 0 miles, never been used.
3. makes 300+ hp, 350+ lb/ft of torque with a 3-5k powerband
4. EFI, MUST be laptop tuneable
5. roller cam and lifters required (I plan on running either castrol syntec, mobil 1, or amsoil synthetic oil and don't want to use a zinc additive)
6. 15-17 highway MPG with overdrive (no trans swap is going to happen unless its to an overdrive 5 or 6 speed)

If it comes down to insufficient budget, I'll build a low buck, warm cam, carbed 350 out of this block and wait til I have $5-6k to spend on the engine. I'm not into digging through wrecked trucks that are sitting in soupy mud at the salvage yards for parts that may or may not work, that also require significant modification to fit.
 I appreciate the input, keep it coming..
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.

Offline choptop

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Re: New engine plans
« Reply #9 on: June 13, 2008, 08:01:01 AM »
well, i'm lookin too Chop, so if i find a couple i'll let ya know as we aren't THAT far apart...

Gotcha, I'll do the same on this end.
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
86 C30 extended crewcab

Offline Captkaos

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Re: New engine plans
« Reply #10 on: June 13, 2008, 03:30:28 PM »
You really are selling youself short by skipping the LS as it will give you all of that and more.  I will NEVER build another SBC again.  Stock LS motors can last upwards to 350K miles.  A tech buddy of mine said he has seen 99's come in with 400K and the truck was trashed and rusting..

It is "used" but....

Offline werewolfx13

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Re: New engine plans
« Reply #11 on: June 14, 2008, 06:15:57 PM »
I might have found an LS I'd actually run..it has less than 100 miles on the drivetrain..its in a 2002 tahoe that was wrecked WHILE leaving the car lot..Going to call about the price Monday. With the number of places my money has to go, and the cutback on my hours, I may end up doing a used motor swap first (if the low mileage engine/trans is too pricey) and then going back and redoing everything with fresh rebuilds on the drive train, maybe an 8.1 swap at that time...My goal was to get everything together, rebuild the truck with as many new mechanical parts as I could, and install a dakota digital dash and have a "brand new" '83  ;D

I'll still build the '73 block, if for no other reason than the person that gave it to me insisted I promise to actually rebuild it..hmm..Maybe I should build it a little wild and buy a 4x4 project truck in need of a motor..
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.

Offline werewolfx13

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Re: New engine plans
« Reply #12 on: June 16, 2008, 09:09:10 PM »
Well, after further consideration, any LS swap is going to be placed on hold, even one with 0 miles..My truck is my sole means of transportation, and unless something major changes, like getting my car not only drivable, but setup mostly the way I want it, I can't afford to take the truck off the road for more than a day or two..and the potential to have to troubleshoot the LS during installation is higher than a carbed SBC. Ideally, I'll put a wild 383 or something in this truck down the road to make it a street truck and get a crew cab long bed 4x4 and go for a 6.0 swap for something to drive more regularly and beat on a little bit..

So, that brings me to this point..I'm thinking about buying something similar to this http://store.summitracing.com/partdetail.asp?part=NAL%2D10067353&autoview=sku
bolting on an aftermarket intake, distributor, and my carb and driving the truck for awhile with that engine and saving the '73 block for a 383..that should stay within my $2500 peak budget (even with a new water pump, fuel pump, plugs, wires, distributor, and intake), probably give me an increase in hp and torque, and the mileage shouldn't change much for the worse, if at all (a mild 250 hp 350 shouldn't do worse than 8 mpg city/13 mpg highway at 55 mph), AND it wont leak/burn a quart of oil every 300-500 miles....plus that crate motor can probably handle a small shot of N20 fairly regularly if I feel the need...
Chris
'83 Chevy c10 Silverado SWB
'76 Chevy k20 LWB 6.5'x8' Flatbed
I know that you believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant.

Offline lowbucktruck

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Re: New engine plans
« Reply #13 on: June 16, 2008, 09:22:46 PM »
Chop, you being in TX you should be tripping over pulled 5.3L's  :D
You would think so, but the ones I find are $2000-$3000. I had a lead on some old worn out ( and I mean abused and worn out) work trucks, but they all went for $2500-$3000, and all the trucks had 220,000 miles or better. I didn't care about the mileage, because I plan on rebuilding it anyway, but the rest of the trucks were junk. Not a straight panel anywhere, so couldn't even sell the leftovers to recoup some of the cost. They guy who bought them hauls them to Mexico, that happens alot here. I will find one though, just gotta be patient. The big seller on them in this area is that most of the mileage is highway, so they still want a premium for them. I am going to start checking some other wrecking yards and see if I can get lucky. I really want a 6.0 for my extended cab, maybe I'll find an 8.1 for my choptop. We'll see.

The LS1 5.3 is definitely worth considering as a reliable powerplant.  I'm not finding any good deals on those engines here in California, the last quote I got was for a 5.3L LS1 out of a 2000 Chevy truck with less than 80k miles on it for $1100 (that was complete, wiring harness and computer included).  I agree with you about that vintage '73 350 block, keep it for a future rebuild.  I have a 1972-vintage 350 motor that came out of a '72 C10 (I know because I pulled it) and it is worn out.  The rebuild quote I got locally was $2000.  So the 5.3L Gen III motor really has me thinking hard for my C20 project truck. 

Problem is, a motor swap is going to take you more than one day.  You might need to get a loaner car for your temporary daily driver (or a cheapo beater import) while you're replacing your truck's powerplant. 
"Two rules get you through life: If it's stuck and it's not supposed to be, WD-40 it. If it's not stuck and it's supposed to be, duct tape it."