Ls motor question

[Northernregal]

Making it live is alot easier than you think - it's in the tune. If you're content with 600HP, then it's really a snap. The issue with boost is that 'boost is addictive'. I'm sure you've heard it a bajillion times, but it's the truth. There is a mile of difference between 600HP on a safe tune and an unsafe tune. We run on the street, daily driving, a tune that has 4 degrees pulled from it and is at 10.8-11.1:1 when over 3 psi. That tune leave 80-100hp on the table at 10 psi, but the car made it over 5000 miles this summer without a failure. You need to keep your street tune 'away from the cliff's edge'.

Regarding Engine Masters, don't subscribe or succumb to that rubbish. The most recent episode ended it for me (Ford AFR head comparison.) I hate to say it, TV is TV and those guys are all about TV. With that said, I can't blame them, but they need some real world material. Who in their right mind compares heads with an intake that won't keep up with head flow and claims that it's the head's size that is the issue?

My grandaddy told me many times - 'believe half of what you see and none of what you hear' - it applies to Engine Masters.

p.s - I wish you were local.

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motorheadmike - we were posting at the same time. You keep your AFR readings secret? I'll keep some things secret (cam design, piston design, rotating weight, but AFR readings save motors - they are no secret.
.

You make a great point. It is essentially a TV production.

HOWEVER. They are doing some pretty good myth busting. This is a good article, in my opinion, of what is possible. They always take off all accessories and run the coolant with an electric pump so you are gonna be 45ish hp shy of a realist real world number. If anything that you should walk away from these videos is that great potential exists past the old ways of thinking.

My personal build is an LSA clone on a 6.0 LQ4. I just learned that the LSA used cast pistons. Stock. You just don’t need to spend the big forged dollars like you used to. The engineering is just that much better.

http://www.hotrod.com/articles/hrdp-1104-594hp-53l-gen-iii-small-block-for-3252/

I wish I lived closer to a lot of the people here. I’d be single but I’d have cool friends. Haha

 

[Turbolq4]

I'd propose that stock pistons are one of the LS based engines weakest points. Took this out of my 5.3 yesterday. Still ran great, dusted a procharged 04 Mustang while being gentle to my car because I knew it was hurt. Lots of crankcase blow-by was the only real clue. Didn't cause any damage to the bore either.

 

[Northernregal]

I'd propose that stock pistons are one of the LS based engines weakest points. Took this out of my 5.3 yesterday. Still ran great, dusted a procharged 04 Mustang while being gentle to my car because I knew it was hurt. Lots of crankcase blow-by was the only real clue. Didn't cause any damage to the bore either. View attachment 79049

Just out of curiosity, what are you pushing on those pistons? Have you bent rods or anything else on the bottom end?

 

[ctownracing]

Jim, I have to agree...it's never enough power!!! My old 355 when carbed put out 430 crank hp, I got used to it and wanted more. Then did the EFI upgrade and bumped the hp up a little which was cool. Honestly, if that motor didn't die I would've been ok with the power.
Annnnnd that's why I'm building the 5.3 now that will have twins when done! I'm shooting for 500+hp on a conservative tune with 8-10lbs of boost to start. Once I get adjusted to the turbo's I will begin turning it up, and might begin building a bigger cubed, stronger LS! The addiction is real lol!

To the OP, do your research. I research damn near every part before a purchase to make sure the combo will be right! This hobby we have cost too much $$$ to guess at stuff, be unhappy, and have to buy more to fix what could have been prevented.

Scott

With your 355 did you use a 350th trans? If so what size stall converter 2800? did you use? Cause I just got a 355 built for my 82 regal I have a 12 bolt rear with 456 gears. Any help would be great? Thanks

 

[Injectedcutty]

With your 355 did you use a 350th trans? If so what size stall converter 2800? did you use? Cause I just got a 355 built for my 82 regal I have a 12 bolt rear with 456 gears. Any help would be great? Thanks

I was running a TCI streetfighter TH350 with a roughly 2200 stall. The TC was too small for the cam, it was a dog out of the hole until I hit around 3k rpm then it came alive!!!! I have a 8.5" out back with 3.73's in it. My Cutlass was, and still is a street car, but really needed a 2800-3000 stall. With the LS swap, it will have a 2800 stall at the minimum.

 

[Turbolq4]

Just out of curiosity, what are you pushing on those pistons? Have you bent rods or anything else on the bottom end?

14psi, 14* timing, AFRs are 10.5-11 in boost. This engine has gen 4 rods in it and they still look good. Last one I had in the car ran great, swapped cams and pushed a cam bearing out. After I pulled the pan to put it on the current engine I noticed two bent rods in that one. So it's riding the ragged edge of the 91 octane fuel available here. I'm going to take timing out of the tune.

 

[Turbolq4]

 

[Northernregal]

Hubba hubba! I bet that gets snakey! Hahaha.

And that’s on a factory bottom end essentially!?! That’s having a good time!

 

[64nailhead]

I'd propose that stock pistons are one of the LS based engines weakest points. Took this out of my 5.3 yesterday. Still ran great, dusted a procharged 04 Mustang while being gentle to my car because I knew it was hurt. Lots of crankcase blow-by was the only real clue. Didn't cause any damage to the bore either. View attachment 79049

That looks like the rings butted when the piston was somewhat warm. Where are your gaps?

14 degrees at 14 psi on 91 octane? That's too much timing without some race gas or water injection if you want to keep your rods straight and head gaskets sealed IMHO. This of course is only a concern if you want the motor to stay together for any amount of time. But with no love or money invested in the motor, then that rod looks just right .

All kidding aside, you might be fine at the drag strip with 14 at 14, but street driving (hotter coolant, oil and intake temps) or a bad tank of gas will cause both of your attached pics. A controlled environment (drag strip) allows for a hotter tune.

I run 4 degrees less and 5-8% more fuel on the street tune after 6psi.

My two cents

 

[Turbolq4]

Bad fuel. Yeah it's tuned to the edge of sanity for sure. The internet says that's a safe level for the stock short block. I have two of them that say otherwise!! Stock ring gaps, one gen3 with curvy rods, gen4 with broken pistons. I'm a proud GM durability testing engineer!!