Everything LS3/L99 Oil Pumps

[ztsmith86]

Gentlemen & Beautiful Ladies,

First off Robert (The Melling Oil Pump Engineer) called me. For all you naughty camaro5 members who are calling him .... please stop. He called me at work and asked how I would like my work phone to ring off the hook all day. Ok on to business.
For those who don’t realize this GM (usually) only makes enough parts for production of their vehicles. They don’t make a bunch of extras (oil pumps being my example) that are sold as GM replacements parts. This is where a company such as Melling comes in and reverse engineers GM’s (Camaro being my example) oil pump. Melling then becomes the manufacturer who makes all the replacement oil pumps that will be needed for repair. They
I'm going to address 5 oil pumps in the following order:

1. M295 - This is the stock GM oil pump for the LS3 Engine.
a. I talked directly to one of the engineers as GM who was involved as a tech for this specific oil pump. It is the recommended oil pump for an LS3 engine regardless of performance upgrades. It has no more issues with failures than any other performance/stock oil pump that anyone will be able to find in the world. The pressure relief valve “sticking” can happen in any oil pump with a pressure relief valve.

2. 10295 - This is the high pressure Melling upgrade for the M295 oil pump.
a. This is a recommended REPLACEMENT oil pump if you are an LS3 engine. It has a 10% increase in pressure over the stock M295 GM oil pump.

3. 10296 - This is the high volume Melling Upgrade for the M295.
a. This is another recommended REPLACEMENT oil pump if you are an LS3 engine. It has an 18% increase in volume over the M295 & 10295 oil pumps. (Note I did find out direct from Melling that it cannot run your stock LS3 oil pan dry). I was wrong about this. This oil pump will also require modifications if you intend to use it with a double roller timing set.

4. M355 - This is the stock GM oil pump for the L99 engine.
a. This oil pump will come on the L99 engines because of the different valvetrain configuration (VOD). It has a much high pressure/volume than a M295 found on the LS3 engines and is ABSOLUTELY NOT recommended for an LS3 engine.

5. 10355 - This is the Melling high volume performance upgrade for the M355.
a. This is the M355 REPLACEMENT oil pump if you are an L99 engine. It has an 33% increase in volume over the M295 & 10295 oil pumps. (Note I did find out direct from Melling that it cannot run your stock L99 oil pan dry). I was wrong about this.
b. This is very interesting, but even though this is what GM has Melling manufacture as a replacement oil pump for the GM M355 oil pump, Melling does not recommend this oil pump in any LS3/L99 engine. Basically they say even though this is what GM puts in their car they don’t recommend anyone use it , yet they do manufacture it as a replacement part for GM in replacement of the M355 oil pump for the L99 engine.

6. This is what I recommend (If you must have “piece of mind at night”). Texas Speed & Performance takes a STOCK M295 oil pump and then ports it for about a 10% increase in volume over the stock M295 oil pump and then SHIMS the internal parts. This by far the best option if you are considering buying an aftermarket (performance oil pump for your LS3 engine).

7. My final thoughts. I spoke with Texas Speed & Performance and they will openly tell you that you never need to replace your oil pump when doing performance upgrades. You never need to increase your stock pressure or volume. It doesn’t hurt you, but gives you no real benefits. TSP said it’s a waste of money. Let’s all think about it. How could increasing pressure or volume help you? A stock oil pump will provide you the pressure you need to maintain lubrication in your system. If you’re going to worry about your engine your money would be much better spent of harmonically balancing your engine, making sure you always change your oil & properly maintain it, regular service intervals, knowing your performance modifications have been properly installed by reputable shops, & correctly choosing a system that “works” together.

Lastly I’m sure there will be members who are still skeptical of my write-up, but I insure I spoke with key people who are involved in the behind the scenes work of all of these pumps. From GM to Melling I spoke directly to the engineers who build and test these pumps. For anyone who is curious I run the plain stock M295 oil pump in my engine and have no plans to ever swap it unless I pass the GM mileage service schedule for the life of the pump. I’m sure no one has even come close to hitting this mark! Thanks for reading.

[mikeSS]

good info

[brantley847]

ok.. then what is recommended for an LS3 conversion from the L99?

[Cheesehead1]

10295

[bmbbl be]

i have the ls3 conversion and my oil pressure is the same as it was stocl L99

[RED DEMON SS]

Originally Posted by bmbbl be

i have the ls3 conversion and my oil pressure is the same as it was stocl L99

+1

[jeffny09]

Again, thank you for your time in getting this info

[ztsmith86]

Originally Posted by bmbbl be

i have the ls3 conversion and my oil pressure is the same as it was stocl L99

According to Melling that would be "VERY BAD"

[ztsmith86]

Originally Posted by brantley847

ok.. then what is recommended for an LS3 conversion from the L99?

I would recommend the TSP ported & shimmed M295, Melling would say you would be fine with a 10295 or 10296, but there are trade offs for those 2 pumps .... i.e. cost and noted items in my first post

[ztsmith86]

If it adds any "good" to my original post I hold 2 engineering degrees from MIT and design water/wastewater systems all over the country. I have very practical and design knowledge of almost ever valve you could ever imagine ..... i.e. pressure relief valves. I'm not a engine expert by any means ... I really only state this info about me to give credit to my ability to assemble details

[brantley847]

Originally Posted by ztsmith86

I would recommend the TSP ported & shimmed M295, Melling would say you would be fine with a 10295 or 10296, but there are trade offs for those 2 pumps .... i.e. cost and noted items in my first post

I believe I ordered the 10296 with my cam swap... hmmm

[ztsmith86]

I won't hurt anything to install it just understand what it changes for you and that it is not a necessary install for any reason. You won't be able to use a double roller timing chain with that oil pump without performing modifications.

[ztsmith86]

On a different note it would be really nice if someone would do a very detailed writeup about performance lifters for our engines. I'm considering doing it, but it takes so much time calling people and sifting through the details. Also there are a LOT of aftermarket lifters.

[ztsmith86]

Another thought to people looking to achieve better flows out of your oil pumps. You could just use a lighter weight oil, there would be some trade offs, but a lighter weight oil would give you better flow characteristics through any oil pump