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i can get my hands on a aluminum block 5.3 out of a GMC Envoy that was losing oil pressure it was rattling at lil bit at idle with low oil pressure but it still ran very strong(no smoking), is this a good block to rebuild vs a 5.3 or 6.0 iron block, im wondering because im looking to do a v8 swap in my 03 silverado...yall tell me what i should do with it...
If it's free, take it.
ok, ya its free, is it any better than a iron 5.3?? what s the diffrences just weight or is there a HP diff??
The aluminum 5.3 was rpo code L33, ask me how I know :lol:. It came with 799 casting heads, same as 241. It's better than your run of the mill iron 5.3, and it weighs less. I don't know what you're planning to do with it, but it would be a nice heads/cam drop in for any short wide.
How do you know?Quote:
Originally Posted by truckinL33
The 799 head is the same as a 243, not a 241. The L33 also has flat top pistons to gain back the compression lost with the 243s.
I ment 243, thank you for the correction. I know because my handle on here is truckinL33. Why is it L33? Because I have one in my truck. I'm actually surprised to hear that it came in Envoys factory, that's pretty badass.
I know that, but you said ask....Compliance is mandatory!Quote:
Originally Posted by truckinL33
If it is from a Envoy it is a LM4 or LH6 (AFM), not a L33.
there are several versions of the aluminum 5.3. the ones found in the trailblazers and etc are more prone to issues with the rought casting they have.
also in the GMT900s they have an aluminum version its a LC9 which has 243/799 on them
if its free then just do a refresh on it or add a 4" crank to it. However its not a capable motor or being bored out. You would have to have it reselved and at that point it could be a 427 if you wanted to spend enought money
ok thanks yall! i was wondering if it would be worth my time and money freshning this motor up or just buy a iron 5.3 or 6.0 thats ready to go, im goin to add a cam,LT's and a nelson tune to whatever motor i choose, so what yall think i should do with my money???
You'll actually lose weight using the L33 over the 4.3. So there's that benefit too. If I had the choice I'd go aluminum
Aluminum also dissipates heat faster. So an all aluminum motor will run a bit cooler.
That may be true, but it will still run at the same temp that is determined by the thermostat.Quote:
Originally Posted by IXLR8
I might be wrong but Im pretty sure the alum. 5.3s have iron sleeves. so boring might be possible if this is the case..
I like this idea. :DQuote:
Originally Posted by Quik
It definitely has iron sleeves, almost all aluminum engines do. The point was that you can't do a real heavy overbore on these 5.3's because there isn't enough sleeve material to maintain wall thickness. Not as bad as an LS1 (which can basically only tolerate a hone), but just not worth the hassle imoQuote:
Originally Posted by kyle.p12
I think you missed my point. An aluminum motor radiates heat better than a cast iron motor. It's like adding more cooling capacity, and will usually allow a tiny bit more timing and compression.Quote:
Originally Posted by PitchBlackC3
I know exactly what you are saying, but the cooling system is what determines operating temperature, not heat radiation from the block. It might cool slightly faster after shut down, but while the engine is running it won't affect it. If both engines have the same thermostat and cooling system, they will both run at the same temp.Quote:
Originally Posted by IXLR8
You're still missing the point. The heat transfers better which means fewer hot spots. This faster more uniform heat transfer is the reason you can usually run a tiny bit more compression and/or timing. It doesn't really have anything to do with the thermostat. Do you think the thermostat has total control of all the temperatures inside the motor? It doesn't. It just regulates the water temp.Quote:
Originally Posted by PitchBlackC3
If you've ever tried to weld aluminum you'd understand. The heat transfers more uniformly through the aluminum part which makes it more difficult to weld. If you aren't careful the whole part will melt. Instead of having a small easy to control weld puddle (as you do with steel), the whole aluminum part can melt and fall out because the heat transfers through the whole part faster than it does with steel. This is a perfect example of why you have fewer hot spots in an aluminum motor.
It also means the radiator doesn't have to work as hard to keep the motor cool. If you had a marginal cooling system on a very hot day, an aluminum motor would help keep the temperature under control.
This superior heat transfer also means that an aluminum head will make slightly less power than an equal cast iron head. But you can usually make up that difference with a little more compression and/or timing.
You can argue the benefits of aluminum versus iron untill the cows come home. I don't own cows, so I will not participate. As the thread starter stated, the engine in question is free. This should make the decision a piece of cake, take it! Put ported truck heads on it, and stick a 220 cam on a 114 in it. I think you'll like the outcome.
Quote:
Originally Posted by truckinL33
I agree!! and even though it doesn't have the sweet heads like the L33, itd still be fun to build and maybe make some money on!!