I did a search for "L33" here, and didn't find any relevant information as to this subject.

I bought a 2005 L33 (aluminum block HO 5.3L motor from a wrecked Silverado) and will be putting it into a 3,000 pound RX7 convertible. I don't need to go overboard with this, but it appears that the heads (799 casting) are better flowing than the LM7 versions, and the cam is a little bigger.

The L33 is rated at 310 HP and the LM7 285~295 HP depending on the year.

I know the L33 is like 9.9:1 CR vs. 9.5:1 for the LM7.

I'm thinking I could make some good improvements w/o too much cost by doing a cam swap. I won't need much torque on the bottom end since:
1) I'm limited as to tire size, more than likely a best case of 275/50-17, and
2) The LSD I'm putting in is geared like 4.10:1

I'm limited (by budget and hood) as to the intake, so I'll use a stock LS1 F-body style. I have a set of 1&5/8 shorty headers leftover from the Supra swap and will use them if they fit.

At this point, it does not appear to be cost-effective to do a head swap, since the 799 casting appear to be good heads out of the box.

I'm looking for insight or advice on this for budget based bolt on performance mods, mainly some cam suggestions.

Thanks in advance.

 

I am using Comp Cams 216/220 .525/.532 114LSA in my 5.3L I have a BBK SSI intake and 80mm TB the exhaust is 1 5/8" short tubes a 2.5" Y-pipe and 3.5" single from there.

Here is the Dyno Graph on it. I Average about 28MPG on the HWY.

She Made 325HP and 327TQ to the tires cam only!

 

Since this is just a smaller disaplacement LS1, I would think you could follow the same cam choices msot of us make. Of course, the smaller displacement will make the cam seem "bigger" in your engine than the LS1/LS2 engines. Will you be using an LS1 or LS6 intake? Do you know the flow specs on the stock 799 heads? This will help determine if you need a cam that is a traditional or something like a reverse split which has more intake bias. Your best bet will be to get a cam that matches those flow characteristics as best as you can...

 

Thanks for the info, I have to get some more data on the 799 heads.

I will be using the LS1 intake, the truck one is too high (I now have two of them with FBW throttle bodies, maybe I can adapt them to the two Supra motors on my floor LOL) and the LS6 is too high dollar.

 

You'll likely encounter the standard accessory drive issues as with most LS1 to truck intake swap's. I'm not sure about the injectors on the L33, but I suspect you'll need to change them along with the electrical plugs on the harness to match the LS1 injectors. The L33 is a great motor; it would be nice not to have to mess with the intake.

Andy1

 

Andy,
Yes, I found that out about this the hard way with my Supra LM7 swap:
2003 LM7 motor
LS1 intake
LS1 rails
LS1 injectors
LS1 1998 Harness
LS1 1998 PCM

Also had to drill the extra hole in the block to mount the F-body alternator bracket, but I used the truck alternator.

Surplus truck water pump, surplus truck injectors, surplus truck intake, surplus truck oil pan...

Fortunately I was able to sell some of this stuff to offset the LS1 accessories & parts needed. I'll have more to sell as soon as I strip down the L33 .

I couldn't pass up the deal on this 20K mile motor for roughly 1/3 the price of 100K mile LS1 motors. Sounds like a cam swap should do the trick.

 

V8 Supra Builder,

I nearly pulled the triggger to buy an L33 with 17K miles on it for cheap. I went with an LS1 only because it was one less project to deal with for my particular swap. The truck motors are a super deal any way you cut it. There's a big truck yard locally that always has lots of motors to choose from.

Andy1

 

I have the same setup as well except for the headers.

 

As an added bonus, it turns out the L33 heads are LS6 parts, same part # on GM Parts Direct for an '05 L33 as a '04 Z06. The springs for the L33 do not have a part # online, so I am checking with a dealer to see what springs are in there.

 

The dealer advised the part numbers for the L33 springs are the same as a stock LS1, so they would need to be changed for a decent cam swap.

 

Is the ls1 cam bigger? I'm doing a mkIII swap any advice would b great.

 

Holy 5 years....

 

LOL. Hey.. at least he did a search.

 

LMFAO....but its true, doing a search will send you back in time without even knowing it.....

 

I wish I had known he was going back. I could have got him to tell me not to buy that GM crate motor I blew up!

 

Hope you can help me here. I have a2001 GMC with a tired LM7. What modifications if any would I need if I installed a L33?

 

How About 10 years.... total of 15