DILYSI Dave
DILYSI Dave SuperDork
12/23/08 11:18 p.m.

So, I need to know what's involved in building a Challenge worthy Chevy drive train. The build vehicle has a 4.3 Vortec, so I should be able to use the accessories, serpentine system,etc. from that, right? I imagine I can't get into the LSx engines on a challenge budget. Valid assumption? If so, then what? LT1? Old School SBC? I'm even considering a carbed engine, tough I admit that scares me a bit. I'd like to see 300 HP minimum naturally aspirated, with the ability to add nitrous for the strip. I'm also considering turbocharging the 4.3, but I really think I'd rather have a V8.

The trans is a 700R4. I've heard from the automatic defenders (I'm looking at you Vetters) about how good automatics can be with a shift kit and a couple of tweaks. Teach me.

ReverendDexter
ReverendDexter Reader
12/23/08 11:25 p.m.

I thought you could get all the parts for an LS1 swap (ie, engine, wiring harness, ecu) for somewhere in the $1500 range, so I'm not really sure that that idea should be tossed out so quickly.

LT1s should be dirt cheap, and they're much better motors than people seem to think, but the aftermarket flocked to the LS1, so you'll have more issue finding aftermarket parts (read: still easier to find mods for than any Ford engine :angryface: )

AngryCorvair
AngryCorvair Dork
12/23/08 11:28 p.m.

i've got a roller-cam vortec-head 5.7L in my garage that's already got an edelbrock performer intake and 600cfm carb on it. i'll throw in an HEI and an aluminum water pump (NIB) and you can have the whole package for $500. from there, swap in a slightly larger cam (max lift .480 without changing springs and retainers) and you've got a pretty bulletproof combo that'll run like stink and handle some spray if you wanna go that route. it was supposed to go in the '08 challenge V8 944 but i fell behind on that project and didn't have time to complete the swap. i've still got the flex plate for it, and a reman ACDelco starter, all part of the deal.

like i told you the other day, i've got a friend that builds torque converters and automatic transmissions. we can hook up whatever you want, on a challenge budget.

AngryCorvair
AngryCorvair Dork
12/23/08 11:30 p.m.

or you could do the L33 aluminum block and heads 5.3L LSx family engine, which can usually be found through LKQ and similar for under a grand with computer harness and accessories. it gives up 24 cubic inches but comes with a much lower price tag compared to LS1. and the LS6 intake and cam slip right in.

DILYSI Dave
DILYSI Dave SuperDork
12/23/08 11:37 p.m.
AngryCorvair wrote: i've got a roller-cam vortec-head 5.7L in my garage that's already got an edelbrock performer intake and 600cfm carb on it. i'll throw in an HEI and an aluminum water pump (NIB) and you can have the whole package for $500. from there, swap in a slightly larger cam (max lift .480 without changing springs and retainers) and you've got a pretty bulletproof combo that'll run like stink and handle some spray if you wanna go that route. it was supposed to go in the '08 challenge V8 944 but i fell behind on that project and didn't have time to complete the swap. i've still got the flex plate for it, and a reman ACDelco starter, all part of the deal. like i told you the other day, i've got a friend that builds torque converters and automatic transmissions. we can hook up whatever you want, on a challenge budget.

If I don't have a solution by the time you get to Greenville this might work.

Appleseed
Appleseed New Reader
12/24/08 12:41 a.m.

If you want cheap, I'd stay away from the LT1. Way too much electronics. You can spend a small fortune replacing sensors. (Ask me how I know.) But if it can be heard running and all the peripheral stuff like fuel pump, ECU, etc... are with it, only then would I say yes. The classic small block runs on dog water, and anything short of building it is space has been done with it.

DILYSI Dave
DILYSI Dave SuperDork
12/24/08 8:15 a.m.
Appleseed wrote: If you want cheap, I'd stay away from the LT1. Way too much electronics. You can spend a small fortune replacing sensors. (Ask me how I know.) But if it can be heard running and all the peripheral stuff like fuel pump, ECU, etc... are with it, only then would I say yes. The classic small block runs on dog water, and anything short of building it is space has been done with it.

The classic SBC was my first thought, and you can pick up 4 bolt truck motors all day long for $200. OTOH, my power goals seem like a breeze for the later model stuff, but the crap from the 70's and 80's seem challenged to hit it. Now, I know that there have been 1000HP SBC's since the dawn of man, but I don't know what is involved. Is a POS $200 truck motor a set of High CR pistons away from being a hot rod?

Trans_Maro
Trans_Maro New Reader
12/24/08 9:06 a.m.

L98's are cheap now and made decent power in their day.

The LQ9 is supposed to be pretty good, it comes in the trucks (Escalades and such) and is supposedly an iron-block version of the LS1

Shawn

Travis_K
Travis_K Reader
12/24/08 4:46 p.m.

For cheap, a carbed 350 is probably the best. The main things that make power are cam, heads and compression. I knew someone that was running 12s in the 1/4 mile with a fullsize chevy truck with a basicly stock 350 other than the heads, cam and carb (plus alot of nitrous) and it lasted a whole season and didnt blow up. He finally stopped using it cause he switched to a big block I think.

patgizz
patgizz Dork
12/24/08 6:13 p.m.

dave,

a late model roller cam 350 with a mild cheap gm performance parts crate motor takeout cam and stock L31 vortec heads is good for 330hp. or buy a $200 350 from a TBI truck and swap on the vortec heads and a good cam, same deal but the roller stuff is just easier because no break in time like a flat tappet cam.

you can use the 4.3's water pump and accessories on a normal small block.

you'll be hard pressed to make an LSx challenge feasible yet - not saying it cannot be done but it'd be tight budget wise with leaving cash for the rest of the build.

i built a hypereutectic piston vortec head roller cam 350 for the belair that will run a 13.9 quarter in a brick of a car with a 2.73 on htr-z's and occasionally i throw nitrous at it.

honestly i'd take up angry on his motor - it's your solution and a great deal at that.

what year is this vehicle? the newer 700r4's are great, and with a shift kit work very well. i towed alot with my 92, then at 171k i put in a v8 and beat on it another 20k then sold it and it is still going. i'll sell you a b&m 700r4 shift kit on the challenge friendly cheap.

noisycricket
noisycricket Reader
12/24/08 6:42 p.m.

Why you should not consider an LT1:

http://www.bacomatic.org/~dw/engine/lt1/lt1.htm

Relevant quotes:

"I thought, "yeah, a Chevy V8, all the V6 stuff will bolt right up." Sometimes I'm a moron."

"Remember, Chevy stuff all interchanges, and they're easy to work on... "

wheels777
wheels777 HalfDork
12/24/08 8:44 p.m.
DILYSI Dave wrote: I'd like to see 300 HP minimum naturally aspirated, with the ability to add nitrous for the strip.

Stock 350 with headers and any decent 4 bbl will do that.

neon4891
neon4891 SuperDork
12/24/08 8:59 p.m.
wheels777 wrote:
DILYSI Dave wrote: I'd like to see 300 HP minimum naturally aspirated, with the ability to add nitrous for the strip.
Stock 350 with headers and any decent 4 bbl will do that.

throw in a good cam/intake/carb combo, 300 is easy, and a simple rebuild wont be too exspensive... i was raised on V8s and treated jegs and summit like the bible, FWIW

Trans_Maro
Trans_Maro New Reader
12/24/08 10:35 p.m.

Jegs and Summit are pricey..

Shop where the racers shop: www.speedwaymotors.com

The prices on their Chevy engine parts are amazing. Stroker kits are a good price too (under $700 for a complete rotating assy). Downside is they only have parts for the old fashioned small block so an LT-1 is out.

I'm not affiliated with these guys but I've had great service from them in the past.

Shawn

curtis73
curtis73 Reader
12/25/08 1:50 a.m.

Wait... y'all are forgetting that the rotating assembly from an LT1 is the same as any 1-piece-rear SBC.

But... an LT1 is nothing special. The aluminum heads are basically a step above L98 heads. The LT1 iron heads are what they used to make Vortecs, so stock LT1s are basically upgraded TPIs or a Vortec SBC. No reason for the specialty intakes and higher prices to use the LT1 when it is functionally a duplicate of other stock SBCs.

Vortec heads (casting numbers end with 062 or 906) are super cheap stock castings that will do 400 hp easy. Valve lift should be kept under .470" unless you do one of the many aftermarket spring/retainer kits that allow .550".

The rest of the recipe is easy: Flat tops give about 9.5:1, good for up to about 224 degrees of intake duration. Set total timing to 32 degrees, initial to about 10-12, burn 87 octane all day and enjoy 375-400 hp. Small domes (don't mill Vortec heads much, they have thin decks) will give you 10:1. Pocket port the heads at home, up the cam a touch, and enjoy 450 hp or more on 91 octane.

Of course, headers and proper intake are necessary. Pick up a used Ebay Performer RPM for $100 and a Qjet for $20. Rebuild/tune it yourself and spend another $35 on a rebuild kit. Find an HEI from a junkyard for $25 and buy an $18 HEI recurve kit.

Its really simple. Just pick a recipe from this site and duplicate it: http://www.camaros.net/racing/SBCombo.html or here: http://www.chevelles.com/racing/SBCombo.html

There is another really good site with like 400+ combinations dyno tested, but I can't find it right now. EDIT: I found it... http://www.ryanscarpage.50megs.com/combos1.html

Concerning the 700r4, you won't hear me giving lots of love for them. They have a super deep 3.06 first and then a huge step to a 1.7x second. I used to autocross my Impala SS with the 4L60E (the electronic version of a 700r4) and it was a pain. Heavy throttle inputs leaving a turn it was reluctant to drop out of second so it bogged. Then when it did shift down to that 3.06 first, good luck not eating cones. In stock form they are pretty wimpy and have shift hunting issues... all of which are easily remedied, but not on challenge budgets. A good old fashioned TH350 is tried, true, better ratios, more reliable, and three gears is all you need for the challenge. You can buy a good used TH350 for $150 and add a shift kit yourself. Same basic strength/guts as the 700r4, but without the OD. Its also lighter :) Up to 1982 they were non-lockup TC. After 82 they were lockup. The lockups have some rare reliability issues where they don't unlock, but in a challenge situation where simplicity, cheapness, and only having what you need are key elements, I would stick with the older version. You won't need TC lockup anyway, so why add the teeny tiny risk of TC lockup failure and the potentially higher cost of the newer tranny? BUT, its what you have, so I suggest a shift kit and practice getting used to racing it with that big ratio change. That's cheaper than buying a whole different TH350 tranny and a longer driveshaft.

The 4.3 V6 is an SBC with two cylinders missing. All accessory drive bolt holes are the same, so any 4.3 or SBC belt drive will bolt on.

Travis_K
Travis_K Reader
12/25/08 9:55 a.m.

A set of used vortec heads is easily avaiable for under $100 ( I have passed on at least 3 or 4 sets already in the junkyard becasue they were in vans and i didnt want to pull them). You cant run a cam with really high lift with vortec heads, but you wouldnt have any problem making 350 hp. Old truck blocks are probably the strongest, and roller cams are $$$, so the old stuff is probably better. Cast or forged crank really doeant matter, you probably wont break either one. If you are running nistrous make sure you get the best pistons you can afford though. Remember that vortec heads need a special intake (or a modified stock one will kinda work)

curtis73
curtis73 Reader
12/25/08 10:50 a.m.
Travis_K wrote: and roller cams are $$$, so the old stuff is probably better. Cast or forged crank really doeant matter, you probably wont break either one.

I disagree with the first statement. If you have a roller block, roller cams are only a couple dollars more than a flat tappet cam, plus you can re-use the lifters which more than offsets the extra cost. You might be thinking of retrofit roller cams which can cost upwards of $1000 until you buy the retro lifters, dogbones, thrust button, distributor gear, etc. But if you start with a roller, its just as cheap as a flat. Old stuff also may have been cast thicker, but that doesn't make it stronger. Newer blocks are a few pounds lighter which indicates thinner castings, but alloy and casting technology has come a long way. Newer stuff is usually stronger despite its thinner casting.

The 96-99 (and later on some HD trucks) Vortec engines are an awesome place to start a build; roller blocks, 1-piece rear seal, Vortec heads already bolted on, latest SBC technology, strong mains. I see them regularly as running take-outs from wrecked trucks for $500. Try to negotiate the computer and wiring with the deal, then you'll have something to sell. Take the EFI intake, wiring, and computer off and that should pay for the aftermarket intake, HEI, and carb. Another option is to use an 87-up car 350 (non LT1) and swap to vortec heads. The blocks are basically the same deal, its just that the vortecs didn't come around until 96. If you hold out for a Vortec truck block the benefits are a pre-assembled engine, and a 1 in 10 chance that you'll get a 4-bolt main.block.

I do agree, though... no need to waste money on forged stuff at these power levels. Cast crank, stock rods (which are forged), and hypereutectic pistons will last forever. If you're careful with the nitrous, hyp pistons are fine. If you're just slapping it together, or using more than a 150 hp shot, I'd consider forged pistons.

Travis_K
Travis_K Reader
12/25/08 11:03 a.m.

Vortech block is fine, the older roller blocks are made from cheaper materials than the 70s truck blocks. It looks like for a decent roller cam it is about double the price of a flat tappet one, but yes, if there is room in the budget they are better.

curtis73
curtis73 Reader
12/26/08 12:45 a.m.

If you buy an aftermarket cam from someone like Comp or Crane, then yes, they are a bit more expensive... but contact a machine shop. They can set you up with a Melling, Blue Racer, Wolf, or other factory performance grind (or light performance grind) for under $80 per stick.

Just do your homework and find the duration you want that was available from the factory. F-body LT1s got up to 207 intake duration, Y-body got a bit more. LT4s had up to 212 duration, and the LT4 HOT cam (not a production grind) was 212/218 I think.

Anyway, exhaust your options from the Melling catalog first. MUCH cheaper.

neon4891
neon4891 SuperDork
12/26/08 10:02 a.m.

Curtis73 has a good point on the factory vortec heads, they are probly the best everyday stock head, and are better than some standard style aftermaket peices.

DILYSI Dave
DILYSI Dave SuperDork
12/26/08 10:30 a.m.
patgizz wrote: what year is this vehicle? the newer 700r4's are great, and with a shift kit work very well. i towed alot with my 92, then at 171k i put in a v8 and beat on it another 20k then sold it and it is still going. i'll sell you a b&m 700r4 shift kit on the challenge friendly cheap.

It's a '93. Drop me a line on the shift kit.

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