dizwiz24

Ive seen this mistake repeat itself over and over on here.

guys will spend $10k to get a 383 motor built/installled to end up making 380 rwhp or something like that at best. They will them go around saying that its ‘all motor’ and ‘no power adder’

I mean they will spend $800 on a radiator. $1000 on an intake.

i have long championed you should spend more on your top end vs. bottom end.

A user on here took a very novel approach. A $200 bottom end with a forced induction top end making > 500 rwhp. While I wish dearly it was SBC (it was a 4.8 iron lsx truck motor), this approach is a super interesting concept.

Those bottom ends are known to be stout. But if you make a mistake And it blows up, oh well, you buy another one for a couple hundred bucks

Polo Vert

Depends on the engine. Try that approach with a big block of just about any make and it gets very expensive very fast. I'd rather overbuild the bottom end and know it's going to stay together. I can always upgrade the top end later. A great top end on a sketchy bottom risks scattering the whole thing and starting over. Would you put a weak foundation under a new house you were building? I've read that iron LS engine bottom ends will hold 2000hp. That's great but not something you would try with anything else.

Tom400CFI

You can have a LOT of fun for very little money with bone yard bottom ends, IMO.

$99.00 for a short block from PICK 'N PULL. Hard to beat.

JoeNova

I would be willing to bet that a $160 ebay GT45 turbo on a bone stock L98 would outperform 99% of all N/A setups on here.

dizwiz24

Another example is a guy i met at the dragstrip.

he has a dodge omni charger than runs 13’s on the stock 4 banger bottom end. Ive seen him beat stock c5’s. The car looks stock. Its a sleeper

boost is turned way up.

he says every once in awhile he will break a ring land/crack a piston.

He says its no problem - it will still drive like that and he drives it home / spends 2-3 hours replacing the damaged piston and he’s back in action

JoeNova

Ring lands crack from excess heat, not power.
The key to getting stock engines to survive with boost is to run extremely low timing and do everything you can to prevent heat.

I'd be willing to bet a stock L98 with a $160 ebay GT45 and less than $1000 total in oiling, hotside/coldside would do 500 at the wheels indefinitely.

383vett

A lot depends on what the car is being used for. A marginal bottom end can survive an occasional strip run or dyno pull and survive on the street. If a car is going to see hundreds of runs during a season, the motor needs to be stout.

pologreen1

I agree, and the average guy paying those prices for a 383 probably barely gets on it too much. I say it over and over that most here have them because they are a Corvette.

Kevova

Building a strong bottom end usually allow increased durability. Forged metal bends and flexes, cast breaks. It does depend on intent and driver.
For those who believe in run it till it blows, and get another one it's a no win argument. 4-7k short block vs 100-300 junkyard specials....that's alot of junkyard short blocks. The day it kicks a rod breaks the cam, and a piston bends a valve ruining a high dollar head. Then maybe.
The get a junkyard ls + turbo with lots of boost = racer; has become a popular theme for grudge and bracket racers. Just pick a roller that easy to change engines, because you will.

FAUEE

Yup. A lot of guys run stock too ends too. They just swap out engines like crazy. It's not AT ALL a reliable setup. You may make 500whp, but it does that only once.

Tom400CFI

I think it has more to do with the RPM. Like JoeNova is saying, boost an L98 and run it below 5k...it'd make good power forever, IMO.

Run it up over 6k and it won't last too long, I don't think.


.

JoeNova

Don't spend money on heads or cam with boost. Problem solved. Keep RPM below 6 grand, and get a turbo with just enough of a turbine to keep peak tq down.
It'll live MUCH longer than anyone gives it credit.

aklim

If you are trying to save a few bucks for a "claimer" race, sure. If not, what exactly is the point of the exercise? To save a few bucks here so I can spend more of my time doing an R&R of the motor? Wouldn't time be better spent on doing it once and doing it right? Assuming that the bottom end simply gives and does it quietly without destroying anything else, that is.

JoeNova

No wonder the C4 guys are stuck at 360whp

You guys have zero faith in your engines.

Tom400CFI

High fun value. Big fun, for small money. That is the point.


Totally depends on the circumstances; the car, the goals, the owner, etc.

cv67

Ive cheaped out on bottom ends....and have to worry every time that tach swings, not worth it.

Dont be fooled on the big power ls stuff, they arent slapping it together without having lots of issues and the eventual failure.

Stock/cheap bottom ends have their place but if ones chasing power/rpm its only a matter of time before it lets loose and takes out that nice head. At that point what money is saved??

C409

..... For drag racers it has to be consistent all the way to the final round …..

383vett

I've never had a motor failure, but it must suck to have it happen on the final money round.

FAUEE

I have a friend with a junkyard swapped LS turbo truck. It's been running for MAYBE 2 weeks total on the 3 years I've known him, and he had been working on it for 2 years before that. Its ALWAYS got some sort of problem. It's not reliable enough for him to drive 15 to 20 miles to work. And he has had the benefit of a lot of free hand me down nice quality parts

You want cheap fun? Buy an R53 stick shift Mini Cooper S. Fast? No. Fun? Incredibly.

aklim

If you are looking to spend big bucks on the upper end and cheap out on the lower end, it is "small money" ONLY IF the bottom end doesn't do something bad to the upper end and your time isn't worth much when you R&R it again and again like suggested when it breaks. Like I said, if you are building a "claimer" car, sure. Spending more on the upper end and a junkyard bottom end doesn't sound like much fun when it breaks. Sure, everything breaks but cheap stuff is more likely to break than well built stuff.