4.8 vs. 5.3 Scammed
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
4.8 vs. 5.3 Scammed So I was sold an engine being told that it is a 5.3. On the back of the block neither the 5.3 or 4.8 were highlighted. So I get it home and break it down to find out it is a 4.8. It has the 4.8 pistons (flat) and crank with casting number verified as 4.8.
Obviously the guy who sold it told me to get lost so now I am trying to figure out what to do with it...
Is it worth my time to replace the crank/pistons to turn it into a 5.3 or should I just sell it for what it is and find a new engine? I have the entire accessory drive/harness/ecm that I paid $800 for.
Thoughts?
Obviously the guy who sold it told me to get lost so now I am trying to figure out what to do with it...
Is it worth my time to replace the crank/pistons to turn it into a 5.3 or should I just sell it for what it is and find a new engine? I have the entire accessory drive/harness/ecm that I paid $800 for.
Thoughts?
So I was sold an engine being told that it is a 5.3. On the back of the block neither the 5.3 or 4.8 were highlighted. So I get it home and break it down to find out it is a 4.8. It has the 4.8 pistons (flat) and crank with casting number verified as 4.8.
Obviously the guy who sold it told me to get lost so now I am trying to figure out what to do with it...
Is it worth my time to replace the crank/pistons to turn it into a 5.3 or should I just sell it for what it is and find a new engine? I have the entire accessory drive/harness/ecm that I paid $800 for.
Thoughts?
Obviously the guy who sold it told me to get lost so now I am trying to figure out what to do with it...
Is it worth my time to replace the crank/pistons to turn it into a 5.3 or should I just sell it for what it is and find a new engine? I have the entire accessory drive/harness/ecm that I paid $800 for.
Thoughts?
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
Not sure what JY build is (Junk yard??) but my goal is to have a fairly strong but very driveable engine for my 65 Nova. My original plan was just to change the cam/seals/intake and just drive it.
Any ideas on how much it would cost to bore it out to a 5.7 and get the needed crank/pistons/piston rods? How well would the stock vortec heads work with this. The 4.8 and 5.3 use the same heads correct?
PS this is a 2002 gen III engine.
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
Is their enough meat on the block to bore to a 5.7 and still have it being durable? And do the stock heads breath well enough with a cam upgrade to work?
Last edited by 65ChevyIINova; Jul 20, 2013 at 04:12 PM.
Launching!
Joined: May 2012
Posts: 249
Likes: 0
From: North Dakota
Look up the magazine article either hot rod or car craft where they buy a junkyard 4.8 and 5.3 and put the same parts on both and there was only like a 10-15 hp and 15 TA difference between the two engines...it's not that big of a difference so to me it wouldn't be worth losing money on the 4.8 to get 5.3...just put good heads and a cam and you won't know the difference...
Trending Topics
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
What about the stock heads? How well will they breath with a high lift cam?
Would a cam with around 220 duration at .050" on the intake/exhaust and around .550 lift on intake/exhaust be a good combo?
http://www.summitracing.com/parts/cca-54-424-11
Would a cam with around 220 duration at .050" on the intake/exhaust and around .550 lift on intake/exhaust be a good combo?
http://www.summitracing.com/parts/cca-54-424-11
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Buy a 5.3 crank, LS1 heads and Z06 camshaft. Makes a great 5.3HO. The parts are cheap and you end up with 350+ hp. Have one in my 72 Chevelle and its a great running and performing motor. May have to balance the crank though but you would do that with an overbore anyway. Yes you can bore the block to 5.7L.
The Z06 camshaft has .550/,550 lift but less duration. You can buy them on eBay for less than $100. Used crank are around $100 shipped and a used set of LS1 heads are around $200. I actually have a nice used pair if interested.
Here's a link to my motor build.
https://ls1tech.com/forums/16235381-post7.html
The Z06 camshaft has .550/,550 lift but less duration. You can buy them on eBay for less than $100. Used crank are around $100 shipped and a used set of LS1 heads are around $200. I actually have a nice used pair if interested.
Here's a link to my motor build.
https://ls1tech.com/forums/16235381-post7.html
Last edited by fox12303; Jul 20, 2013 at 04:41 PM.
I'd just keep it. Its not worth the few extra cubes to lose money.
See what they guys on performance trucks are running in their cam-only 4.8s. Maybe see what works in a 5.3 and go a little smaller.
The heads are the same as the 5.3 heads. Maybe get them polished up and milled (if you want to stay NA) while you have them off.
4.8s seem to love boost. If there's room, I'd do an LS6 cam/springs and budget turbo build.
See what they guys on performance trucks are running in their cam-only 4.8s. Maybe see what works in a 5.3 and go a little smaller.
The heads are the same as the 5.3 heads. Maybe get them polished up and milled (if you want to stay NA) while you have them off.
4.8s seem to love boost. If there's room, I'd do an LS6 cam/springs and budget turbo build.
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
Any idea on how the extra compression from only changing the internals will effect the engine? It would take it from around 9.5:1 to around 11:1 based on some quick online calculations.
Launching!
Joined: May 2012
Posts: 207
Likes: 1
From: ny 14845
On The Tree
Joined: Sep 2012
Posts: 103
Likes: 2
From: SoCal
seems to me the 4.8 would do what your asking sounds like you should just do the few mods to it and roll with it you have the option to get into the engine after you get it running and put some miles on it
5.3 and 5.7 cranks are dimensionally the same but the 5.7 LS1 crank is gun drilled to lighten it a bit. Be sure to balance the rotating assembly if you do some mix and matching. 11:1 is high but can be done if built properly running premium gas. Piston to head clearance(quench distance) should be .035-.045" to prevent detonation. This means more machine work possibly or more expensive heads gaskets.
Rather than doing that, get a pair of LS1 heads. They have larger combustion chambers and will lower the compression ratio to a safer 10:1 level. Upgrade the springs and trunnions in the rocker arms. Spend your money wisely and you will have a very nice 327.
Rather than doing that, get a pair of LS1 heads. They have larger combustion chambers and will lower the compression ratio to a safer 10:1 level. Upgrade the springs and trunnions in the rocker arms. Spend your money wisely and you will have a very nice 327.
Thread Starter
Staging Lane
Joined: May 2013
Posts: 72
Likes: 0
From: Dayton OH
So a cheap route I have found is a new crank/rods for about $80. This does not include the pistons but basically this combination is what is used for the L33 (minus the heads).
This would give a compression ratio of 10.4:1 (with the 61cc heads vs the L33's 64 cc heads).
Thoughts?
This would give a compression ratio of 10.4:1 (with the 61cc heads vs the L33's 64 cc heads).
Thoughts?
So a cheap route I have found is a new crank/rods for about $80. This does not include the pistons but basically this combination is what is used for the L33 (minus the heads).
This would give a compression ratio of 10.4:1 (with the 61cc heads vs the L33's 64 cc heads).
Thoughts?
This would give a compression ratio of 10.4:1 (with the 61cc heads vs the L33's 64 cc heads).
Thoughts?