rkreigh

I have a bunch of 4.8 engines I'm trying to build

a couple of questions

where can I find a reasonably priced rod for the stock 6.28 length and stock .945 pin. all the after market rods seem to be shorter and have a .928 pin

are the stock 4.8 rods out of a gen IV strong enough to stay with a stock rod? just upgrade the bolts? I have one block with some nice wiseco pistons but the rods look suspect and I'd like to replace them with an after market rod if it's needed and not too expensive

I'm looking for something less than 600 with the goal of a 800+ at the tire turbo engine. I already have wiseco forged pistons with the stock pins and the bores look really good.

on another combo, separate engine

I'm looking for good deals on either wiseco or maybe diamond pistons with pins and rings. like to know who would be a good reputable source with good prices!!!

also looking for a short 4.8 stock stroke forged crank for a max effort build.

I'm thinking the turbo engines would respond well to a short stroke

last but not least,

what do you all think is a wise "upper liimit" for the L33 alum block

I have a few iron blocks around, but I'm running a TTix kit in a C5 corvette and would like to stay with the alum block but I'm afraid to push the LS6 block I have now much past 800 at the tire and want a bit stronger block without going LSX or Superdeck

the superdeck stuff is nice but beyond my means.

thanks!

DavidBoren

I checked eagle, scat, callies, howard's cams, oliver, and K1... Negative on an off the shelf forged 6.275" rod.

Best bet is to shot-peen (sp?) and cyro a set of stock rods, assembled and balanced with ARP hardware.

For where to buy the wiseco or diamond piston/rings, many of the vendors on here will hook you up with a good deal.

Searched many of the above listed companies for a forged 3.27" crank, but no luck for an off the shelf unit.

If a shot-peened and cyro'ed stock crank isn't going to cut it, then call callies. They have the programs up and loaded, all you have to do is specify the stroke, give them your money, and wait.

The L33 block probably isn't going to split before the heads blow off, so the ability to keep the heads clamped to the block is more of a limiting factor than the block itself.

Lots of stock 4.8 parts are surviving 700+rwhp, and that's probably why nobody bothers offering direct replacement forged parts.

I think a well prepped L33 aluminum block and a stock rotating assembly, that's been shot-peened and cyro'ed and very well balanced, will work perfectly fine in all of your proposed builds.

DavidBoren

PS. Define your idea of a max effort build involving a 4.8, please.

Because people are pushing junkyard builds over 20psi/800rwhp... How much more do you want or need? And might you be able to achieve those goals, whatever they may be, more cheaply by increasing displacement, rather than getting custom forged parts for the 4.8L motor?

You can buy an off the shelf, fully forged rotating assembly with a K1 4" crank, K1 6.125" rods, and wiseco 3.78" pistons... Making a 359ci/6.0L engine... for cheaper than the cost of a custom order 3.27" forged crank.

rkreigh

I have 3 blocks I'm building. one already has wiseco pistons with the stock stroke and a .945 pin bore. I did find aftermarket 6.3 rods but that would put the piston up out of the bore. I've never heard of shot peening powdered rods, will that work the same as a forged rod?

for the other engine, I have a lunati 4.0 crank, and rods, and wiseco stroker pistons so that block will be bored out to fit the pistons.

last engine I'll likely just build it stock or part it out, not sure yet.

for goals. the forged piston engine with late model stock rods I'll stick to around 800 hp.

for the 4.0 forged crank engine with forged lunati rods and wiseco pistons I'm looking to run about 1000 hp at the crank on E85

one engine is going in my old 68 resto mod corvette (if it doesn't sell as is) and the other big daddy is going in a TTiX C5 Z06 (already at 800 at the tire).

like to hear thoughts on the upper limit of the L33 "thick liner" alum block.

I'd like to keep the weight down on the C5, but don't really trust the LS6 block to live long at 1000 hp.

you are probably right I don't NEED 1000 hp, I'm going with a haltech with traction control and boost by speed and I want to try my hand at some flying mile runs down the road so I need a fairly durable engine to do that.

DavidBoren

I haven't seen or heard of one splitting yet.

I would worry more about the mains walking and allowing the crank to flex at 1000+hp, more than the liner cracking. I would worry more about the studs pulling free of the block before I worried about the liners.

However, you said that you are overboring the forged motor. How much?

If you bore it out to LS1 bore size, then you no longer have the benefits of the thicker cylinder sleeves.

Forcefed86

iTrader: (4)

The factory gen4 rod is very stout. Get a decent forged piston, mount it to the GEN4 rod, and go to town. Keep the majority of the power above 5k rpm, and they will handle 1000 crank and 7500rpm easily IMO.

Because I have the parts laying around I was planning a short rod/stroke LS. Using the shorter 5.3/6.0 6.098” gen4 rod with the 4.8 crank. This gives you the added strength of the shorter gen4 rod and the better bore/stroke ratio with the piston .178” in the hole.

Basically a wheezy 7.6:1 4.8 with short(stronger) rods. Run a 4k stall and a little nitrous to get up on boost. Once the turbo lights off the lack of compression isn’t even noticed. You’ll have the ability to run TON of boost with the low compression and have a very stout bottom end capable of high RPM.

rkreigh

interesting stuff haven't heard of folks going that low on compression but with nitrous out of the hole and plenty of cfm on top no reason it can't work

thanks for the feedback, these littl3 4.8s are pretty stout!!

svslow

There is some information here that may help.

https://ls1tech.com/forums/generatio...l#post19113084