jbtautoman

Going out to 3.898, what can I expect in terms of wall thickness? Has anyone ever measured or sonic tested one? Both thrust and lateral numbers would be spectacular, but I realize information is hard to get. Thanks.

G Atsma

Aluminum or iron block?? Not sure there's a wall thickness difference, but in case anyone knows for sure....

LS1Formulation

iTrader: (13)

All iron 5.3 blocks can be bored to LS1 size and will end up with basically the same wall thickness as an LS1. Certain Gen 4 aluminum blocks can also be bored to LS1 size, and have the added benefit of siamesed bores. I just built one of those blocks myself. I didn't fully bore it out, there was no need, but there's a LOT of material left around the bore/sleeve. If you can find one of the really rare 4.8/5.3/6.0 designated iron blocks, I think those are around .375" wall thickness at LS1 bore size.

jbtautoman

Iron block. Gen 4 5.3

strutaeng

I'm curious as well. Seems like an iron block bored out to 5.7 would make a cool engine and decent power. Especially with the vast availability of 4.8/5.3 iron blocks out there. Should make a good, budget and robust build and wouldn't break the bank, no? Using stock internals.

LS1Formulation

iTrader: (13)

Chevy High Performance magazine had an article about just that some years back. Here's a recap: https://www.enginelabs.com/engine-te...scrapped-5-3l/

LilJayV10

iTrader: (39)

Thompson Motorsports(I'm about 99% sure it's them)engine of the month was an aluminum 5.7. Now I'm guessing they didn't find a warehouse of LS1 blocks, and are boring 5.3's out.

It was funny to see how many people asked what a 5.7 was on the FB thread. .

demonsmokr

This is what im currently debating right now. My engine has 275k, i think. Dash started getting funky in the 250s, now i always have 16mi on the odometer. Anyways, engine is on its way out and i have a free donor long block to use. I want to go with 5.7, but im stuck on which brand pistons i should get, then if i should swap heads or just rebuild the stock ones, and i dont know enough about camshafts to make a decision.

Just a 2005 4x4 1500. I dont want crazy power. Just a smooth ride with some oomph. Ive never done any performance mods on LS engines, theres so much out there i just get stuck being indecisive with all the options.

Anyways, glad to see there are more people considering rebuilding the 5.3 into a modest 5.7 truck engine.

Forcefed86

iTrader: (4)

I wouldn't sweat it much. You can run hyper 5.7 piston clones if you want cheap. Any of the basic "stage 1" truck cams the vendors sell pretty much do the same thing. I'd look at the towing cam line with the factory converter. I wouldn't want to give up any TQ down low on a daily with oem converter.

demonsmokr

Exactly. I want the same power curve, same drivability, reliability, just a little more power without having to swap out my transmission for a 4l80e.

Forcefed86

iTrader: (4)

Blocks are pretty disposable at this point. I’d def. bore it as big as possible. General consensus is 3.905. Might look at 6.125 rods w the pistons to match as long as your in there. Its not that much more.

Honestly building your motor is likely counterproductive cost/time wise. Might try to source a decent JY 6.0 and press on. Machine work for me has always meant tons of down time and they don’t always get it right. Not to mention the cost.

Could also consider a 5.3 and a decent set of heads, cam, and exhaust. It will give ya roughly the same gains.

I was picking up healthy 4.8’s for $350 here at one point. Less than $1000 on cheap china turbo kit @ 6-7lbs will out pull a OEM 6.0 any day.

Lots of ways to skin a cat!

strutaeng

I like this approach. I think previous poster can keep his 5.3 heads, no? (Which heads?) Or will that increase compression too much? I guess I would have to look at the static compression calculators online ...as I'm certainly no expert on heads.

So, order 5.7 LS1 piston stock replacements, send out block for boring and get rotating assembly balanced. Reuse connecting rods. Install "stage 1"/towing cam and do some mild tuning and off you go... Everything else is reused.

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demonsmokr

My current heads and heads on the donor block are 706. I found q bare pair of 243s for 150$, im just skeptical because that seems cheap. Dont know howvto spot cracks or overheating damage, just nitrous pits.

LS1Formulation

iTrader: (13)

Not too cheap, I have a set of disassembled 243's for sale for $300, but so far there are no takers. Might have to drop the price. 243's aren't the hot ticket they once were.

strutaeng

OP, I missed your question about thrust and lateral numbers?

What did you mean there? The crankshaft should not change at all (except for rebalancing), so thrust clearance is the same as any other LS engine family. I'm not following you... maybe I'm missing something? 🤔

LS1Formulation

iTrader: (13)

There's a "thrust" side of the cylinder wall in any engine. On an LS, it's the sides of the cylinders that are toward the passenger side of the car. When the piston moves downward under combustion, the angle of the rod actually applies more pressure to that side of the cylinder wall. It's nice to have the cylinders a bit thicker in that direction. Laterally means the wall thickness measured 90 degrees from the thrust side, so front and back of block, and between adjacent cylinders.