i just made a post on here about 10 minutes ago about my new plan, and it didn't show up.

anyways, i am gonna buy a 4.8 block and was wondering how far i could bore it and about how much it would cost. i figured i could go 4" since the 6.0 is 4". also i want forged pistons, what ones are the best for a good size cam and atleast 200 shot of n2o. what would be better, stock 6.0 crank with the forged connectins rods and pistons, or a 4" forged crank. i know the bigger crank would be better cuz of more cubes, but is the stock crank decent with other forged components for a big n2o shot. what length connecting rods would i need with the stock crank, and what length with a 4" crank. what are the best pistons for us. diamond? JE? what fuel system mods would i need to make with this setup. i figure on leaving it stock for a little while, but will upgrade eventually. thanks in advance for any help.

Matt

 

you can't bore a 4.8 to 4", not exactly why but the topic has come up before.

 

Matt - I wouldn't take the cylinders out past 3.905, especially with that much nitrous. With this bore, pistons would be easy to get and cheaper since its what most LS1 aftermarket pistons come in. With a 5.3/LS1/6.0 crank, you would have an iron block 5.7 liter.

The stock crank is fine. A stroker crank is better, but lots more $$$. You can probably get by with stock rods too, just use good rod bolts.

 

what kind of horsepower/torque difference would i be looking at between 3.905bore 4stroke, and just an iron 5.7 with good heads and cam. both having good heads and cam. i'm probably gonna start on this project pretty soon. what kind of cost should i expect on having the 4.8 block bored to 3.905?

Matt

 

BigTex and Parish are right. The 4.8 and 5.3L blocks can be taken out to around 3.9+/-. If your going to go out that far you might as well just get a LS1/LS6 aluminum block. They can take whatever you throw at them and weigh ~70-80lbs less than the iron block.

Diamond sells replacement 5.7L pistons that are setup for 6.125" or stock 6.098" rods and a 3.905" bore. Thunder Racing is a dealer.
http://www.thunderracing.com/index.c...yid=1114#T1574

The stock rods should be fine but, definately replace the rod bolts.

Fuel system wise you could probably get by with some 8.1L injectors and an add on inline pump. A 200 nitrous shot should be a wet setup so the injectors don't have to add the extra fuel.

John

<small>[ February 22, 2003, 11:14 PM: Message edited by: XLR8NSS ]</small>

 

get yourself a 6.0, they are cheap, your talking about geting the crank anyways.

to go from a 3.9" bore to a 4.03" bore you would gain 23ci, even on a prety mild set up you are going to be seeing 1hp per ci so a guestamaite would be 23+ hp diference.

 

rather than go 6.0, you're telling me it would be cheaper to get pistons for a 4.8 block with an ls1 bore? and then just go with the stock or 4" crank.RIGHT? seems easy enough. anyone know where i could get a 6.0 block cheap? i have an offer for a 4.8 block, crank, and all but one piston but if i can find a good deal on a 6.0 i might take it.

Matt

 

also, should i go with flat top pistons or what? i'm new to this, i know what i want to do i just don't know exactly what parts work best in all situations.

Matt

 

What type of pistons you run kinda depends on what compression ratio you want to run and what heads you'll be running.

Why don't you just buy a complete 6.0L replace the pistons and rod bolts. Then spray the shiznits out of it. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

John

 

it'll have stage 2 5.3 heads on it, prolly around the specs of the 220 cam i should be getting soon. truck intake manifold, 8.1 injectors,external pump. what type pistons would be best? flat top, or with some valve relieve or whatever it's called?

Matt