De-Stroked aluminum 5.3

[Steve1968LS2]

As a possibility to power my Track Rat project...


I was Turn Key Engines building the 427 LS engine for the Project American Heros Camaro and saw they have PALLETS of 5.3 ALUMINUM blocks. Litterally dozens of them.

So we started chatting and decided it would be cool if we could come up with a budget minded high-reving 302ish displacement engine.

Would be super lightweight and to keep the cost down would use all GM stuff except maybe the pistons (since we would bore the block).
4.8 crank and rods then top it off with an LS6 intake. If we choose the cam right I'm thinking 500hp isn't out of the question.

I've been considering a 5.3 but hated the idea of the heavy iron block.

Thoughts?

[skeeters65]

Are most 5.3 blocks steel or aluminum??

Which cars came with which??

Thanks

[WS6]

Not bad. There way a company that built a 302 oh 8 years ago now. M something was their name and they put it in a 4th gen trans am racer.

I'd just build the snot out of the AL 5.3 since people don't think they can spin or make power. Modern 327 if you will. There is not reason a 5.3 won't spin to 7k or higher if you want to push it.

[PonchoJohn]

Interesting idea.
I'm not super knowledgable on the LSx stuff, but isn't the 4.8 crank stroke and rod length different than all the rest?
If so, wouldn't the piston be pretty TallxWide?

[WS6]

Are most 5.3 blocks steel or aluminum??

Which cars came with which??

Thanks

Most are cast iron but they started making aluminum ones in quantity with the Impala SS, Monte Carlo SS, Buick Rainier, and now trucks have aluminum 5.3s. I think those started in 05 or 06 though.

[WS6]

Interesting idea.
I'm not super knowledgable on the LSx stuff, but isn't the 4.8 crank stroke and rod length different than all the rest?
If so, wouldn't the piston be pretty TallxWide?

Correct 5.3, 5.7, and 6.0 all have the same rod and crank dimensions. 4.8 has smaller crank.

You could get out of hand and make the engine very over square (bigger piston than stroke length) but those engines love rev's. If the block and components can handle it, it's not a bad way to go.

[Steve1968LS2]

Not bad. There way a company that built a 302 oh 8 years ago now. M something was their name and they put it in a 4th gen trans am racer.

I'd just build the snot out of the AL 5.3 since people don't think they can spin or make power. Modern 327 if you will. There is not reason a 5.3 won't spin to 7k or higher if you want to push it.

Well a company in the midwest did it for GM called Westech. It was in a pewter 4th gen Camaro.

I know I could just do the 5.3 but I was trying to think of something different.

I will use the 5.3 aluminum block... the question is how.. hmmm

[Steve1968LS2]

A 4.8 crank, rods and pistons would make something like a 297cui if you went 60 over it would be around a 305-307

That's just off the top of my head, I would have to crunch numbers.

Excited now that I found some 5.3 alum blocks. I think budget wise it could be a real doable deal.

[WS6]

check it out Steve. I found this while googling info on the 302 Trans Am I mentioned.

http://www.pro-touring.com/forum/showthread.php?t=20495

[Van B]

Well a company in the midwest did it for GM called Westech. It was in a pewter 4th gen Camaro.

I know I could just do the 5.3 but I was trying to think of something different.

I will use the 5.3 aluminum block... the question is how.. hmmm

The "other" Westech, just down the road from me in Silver Lake, WI. I think they built it for Power Tour a number of years ago.

I like the 302 idea.

[compos mentis]

Andrew B and I suggested to you several months ago the 4.00" x 3.00" setup like the Daytona Prototype cars use.

Another forum member here knew I was interested in a high winding destroked LS motor. He was talking to Mast Motorsports about it and wrote me this.

'I just got off the phone with the guys over at Mast. There ECM offers a ton of stuff I've been looking for in the tuning setup, while maintaining almost all of the GM driver friendly gas mileage bits as well... The VVT is fully variable for the 62 degrees of camshaft movement. They've been focused on big power and flat torque arks with normal RPM's, but he told me they've never gotten a motor to use the full 62 degrees of adjustment in the camshaft. 10,000 RPM in a streetable LS motor ...'

[Gordz32]

Dooooo It. Theres nothing like a super high winding small block. There hasn't been much done by way of the LSX crowd and for you ( and your resources) It would def. be something different. Oh and maybe slap a turbo on on there for extra coolness.

[Steve1968LS2]

Yea, but I was having a hard time finding an alum 5.3 that wasn't stupid price. Now I have a plethora of virgin blocks, so the idea is once again alive.

[compos mentis]

Another guy who works with engine builders doing these smaller LS motors wrote me this.

"There are probably used (billet) cranks available for a reasonable price. They tend to use fresh rotating parts for the 24 hour race, even though I don't ever
recall hearing of a crank failure."

[slowcamaro]

my friend plans on doing similar for a CP autocross car where hes limited to 310 cubes(i think) before taking a weight penalty.

[andrewb70]

http://www.westechauto.com/

The 5.3L bores are just too small. Stephen, if you're going to do this, do it right. LS2 4" bore block, billet 3" stroker crank. This is a track car. The engine needs to live!

Andrew

P.S. Answer your PMs...LOL

[Damn True]

I like the idea.

Andrew, why is the bore such a factor?

[EFI69Cam]

I like the idea.

Andrew, why is the bore such a factor?

On the top end a bigger bore allows bigger valves and less turbulence from the air hitting the cylinder wall.
The over square concept that ws6 mentioned is when the bore/stroke ratio is >1 4/3 is the b/s for the orginal 302.
A shorter stroke is supposed to rev better as it allows a longer rod and less friction from piston movement.

With the deck height of the LS1 block easily allowing a 6.2 rod and modern connecting rods and cranks it is easy to build a shortblock were the rev limit on the reciprocating assembly is way higher than what the valvetrain can handle reliably. In other words you are leaving power on the table not putting in the longest stroke crank you can fit. Building a 302 would be cool from a nostalgia standpoint but fairly useless in terms of efficient use of build dollars.

[Tony_SS]

Steve I like the idea.. Doing more with less is always interesting.

Phil at BRP HotRods seems to know a great deal out the LS series - maybe he will chime in.

[WS6]

MMS, Morgan Motorsports was the company that built the 4th gen Trans Am racer that had a 302 in it that I was referring to. It just so happens that it was a white with single blue stripe Trans Am just like the 70-72 TA. I don't even know if MMS is around anymore.