Danny Richie

It was recommended that I post this over here too where the experts on forced induction hang out.

We have a 2004 Convertable that we've made a few modifications to. We've been running a Procharger for a while now (about 60,000 miles), a blower profiled cam, headers... running 9.5 pounds of boost. And we recently added a little nitrous. This motor also has nearly 130,000 miles on it and it's a stock bottom end. We have raced the car quite a bit too.

Well that last shot of nitrous was a little much for it. We hurt two pistons, and cracked the block slightly. The heads took a few dings but they are all small. It's all fixable, but is it worth fixing?

We'd like to rebuild it a lot stronger and make more power this time around. We can't help it we love drag racing.

But should we just ditch the LS-1 and start with an LS-3? Any issues with dropping in an LS-3 into a C5?

Should we go with a lower compression motor and just add more boost? And we'll go with a much bigger cam this time. So a good deal on a long block would be great.

Any opinions, options, recommendations, or deals that anyone has on something would be welcome.

Further notes, we have dropped the rear end gear to a 3.42 and we are running a 3,200 rpm stall converter from FTI.

zdeckich

I say go with the LS3.

SquatchMachining

My advice would be to stick with a Gen III block so that you do not have to relocate your knock sensors. They never seem to work right when you do that in my opinion.


That leaves you with a few options. Get a new LS1/6 Block, a Iron 6.0 block, or a Iron 5.3 block that can easily be bored out to be a Iron 5.7. The cheapest option would be to bore out a 5.3 iron block as they are cheap as hell and they will hold the same amount of power as any of the other options. Spend the coin on a decent crank, rods, and pistons setup, get the best you can afford as its the backbone of your build. I would keep the compression between 9.8-10.2. Just my $.02

RU_VVET

Aluminum 4th gen L33 truck block. Best stock motor for boost hands down.

Travis_C

Thompson forged LS1 short block. Be back up and running in a few days.

SquatchMachining

Take one apart, measure it, and see if you still recommend them..

Travis_C

Details?

SquatchMachining

Of the three I have taken apart I have seen out of round cylinders with excessive piston to wall clearance, bad line hone and inconsistent bearing clearances. Sure they are cheap, but when you mass produce engines you are going to give up a certain level of quality control. In my opinion its a bad buy and one of those "you get what you pay for" type deals..

Forcedvert

See my post in other thread on sdpc long block, came recommended to me by a very reputable tuner along with, texas speed and lingenfelter, as good builders.

Ther is less traffic over here but very good advice from these guys.

SBCGENII

The amount of time it takes to put an engine together I don't know how some people can sell them so cheap. Also big differences between assembling and surviving some passes at the drag strip vs drag strip and going 100k on the street.

Rkreigh

If interested I have a fresh iron 4.8 block (Gen 3) with factory crank, factory gen 4 rods, and wiseco forged pistons.

I have 1200 just in the machine work and new bearings, rings, balance ect... lots more than that of course in the block and parts.

2k plus shipping (I'm in Alex VA). Need to sell this thing, decided to go with an L33 block instead and I need the $ to build it.

I'll pop the add to the top if interested.

RU_VVET

+1 for the L33. Best bang for the buck

blackmachdown

Same boat as you, I decided on doing an iron 6.0 with forged everything and ARP hardware

MVP'S ZO6

How many cubic inches are you going with?

MVP'S ZO6

How much out of Round? How much excessive piston to wall clearence? (What Pistons were being used and exactly how much power were these things making?) how inconsistent were the bearing clearances? Same question for the main housing bores? Are we talking more than a half a thou on the aforementioned cylinders?

I'm in no way affiliated with these guys. I'm not against them or for them. I'm simply curious? You can post here or PM if you'd like.

I saw another big name company who builds some pretty serious very large cubic inch engines out of factory (non GMPP) blocks that had a POS linehone too.

I don't agree that you have to give up quality control with mass production. I think complacency gets in the way of quality control especially when building a bunch of the same exact stuff.

Danny Richie

Looks like we're headed that way. We just picked up an iron 6.0 block.