Running Johnson lifters

[morepowerjoe]

Maybe your sending unit is bad. When mine went out it was reading like 15 psi too low.

[Risingson05]

Apparently theirs two iterations of the melling 10355 there’s the 10355 then theirs the 10355hv both are upgrades to the gm (part # 12612289 which is the zl1 oil pump .. 10355 not the hv comes with a by pass spring of 43.5 .. and is standard volume but high pressure but offers 30% more volume than stock ..

Was a goof up with tsp , I had asked if that was the hv and was told yes .. guess we’re both at fault as I didn’t know there’s two iterations of it .. either I’ll change out spring for copo spring or change the oil pump but according to melling website this is also the correct pump

[Risingson05]

Got this off jegs

[acammer]

Originally Posted by Risingson05

Apparently theirs two iterations of the melling 10355 there’s the 10355 then theirs the 10355hv both are upgrades to the gm (part # 12612289 which is the zl1 oil pump .. 10355 not the hv comes with a by pass spring of 43.5 .. and is standard volume but high pressure but offers 30% more volume than stock ..

Was a goof up with tsp , I had asked if that was the hv and was told yes .. guess we’re both at fault as I didn’t know there’s two iterations of it .. either I’ll change out spring for copo spring or change the oil pump but according to melling website this is also the correct pump

You want a 10355 at most, not a 10355HV. The HV flows and absolutely insane volume of oil, and would only be suitable for engines with major oil demands, big coolers, turbos, vvt, and afm. The 10355 should be 10psi over stock, and 33% more volume than a stock ls3. The 10355 HV is 59% more volume than stock, way too much.

[acammer]

Originally Posted by Risingson05

Got this off jegs

I'd be careful with information off jegs, I'm not saying it's not always right, but it's not always right. Melling has some good information on their website, and they have a great video on their YouTube channel that talks about LS oil pumps and their attributes. That (and experience with our own builds in house) have been my source for the oil pump guide that I shared above.

[Risingson05]

Taking it for a drive , where I could put better eyes on it it actually bleeds back down to 45and jumps up to 52 to 55 when I let off throttle . It doesn’t stay there at 52-55 during the whole wot it looks like it’s fighting itself ..

I believe the copo is a 20% in pressure ? That translates to only 8.7 psi right ?

[Risingson05]

Talking. To melling they told me to jump to the HV but I think that guy was just trying to get me off the phone ..

I’m not doubting anything you post Andrew so please don’t take it like that it’s just I’m running into a lot of conflicting info and I’m just honestly wanting to be within the 10psi per 1k rpm deal I know that’s not the end all be all.. just figure it would keep motor more happy having that pressure there during wot.


I just feel that Jeff article is true on the pressure relief spring as my Denali acts in the same manner but it never bothered me as It doesnt rev as high, although I didn’t do the relief valve mod in the pan on. My truck as it’s still has vvt

[acammer]

Originally Posted by Risingson05

Talking. To melling they told me to jump to the HV but I think that guy was just trying to get me off the phone ..

I’m not doubting anything you post Andrew so please don’t take it like that it’s just I’m running into a lot of conflicting info and I’m just honestly wanting to be within the 10psi per 1k rpm deal I know that’s not the end all be all.. just figure it would keep motor more happy having that pressure there during wot.


I just feel that Jeff article is true on the pressure relief spring as my Denali acts in the same manner but it never bothered me as It doesnt rev as high, although I didn’t do the relief valve mod in the pan on. My truck as it’s still has vvt

I've been overlooking the fact that this is a ZL1 with an LSA - too many irons in too many fires I guess. That makes a difference! Piston oil squirters will consume a lot of oil volume and pressure. The 10355 would be the right stock replacement pump, and should see a 10psi increase in pressure. The 10355HV would be a high volume replacement, and has that same 10% pressure increase, but is probably more likely to actually see an increased pressure as it can fully meet/exceed the LSA's demand for major oil volume.

VVT on your Denali will eat through oil volume/pressure as well. VVT stuff and LSA should get a 10355 or more for a replacement. The pan relief is 55psi, unless that's plugged, you're not going to see pressure over that amount.

[Risingson05]

Originally Posted by acammer

I've been overlooking the fact that this is a ZL1 with an LSA - too many irons in too many fires I guess. That makes a difference! Piston oil squirters will consume a lot of oil volume and pressure. The 10355 would be the right stock replacement pump, and should see a 10psi increase in pressure. The 10355HV would be a high volume replacement, and has that same 10% pressure increase, but is probably more likely to actually see an increased pressure as it can fully meet/exceed the LSA's demand for major oil volume.

VVT on your Denali will eat through oil volume/pressure as well. VVT stuff and LSA should get a 10355 or more for a replacement. The pan relief is 55psi, unless that's plugged, you're not going to see pressure over that amount.

Thank you ! ,, so here lies the question do I try and mess with springs or jump to a 10355hv. My minds telling me to go for hv but if the copo spring can solve my issue why not . Better taking just the pan off instead of dampener and timing cover and such

[acammer]

Originally Posted by Risingson05

Thank you ! ,, so here lies the question do I try and mess with springs or jump to a 10355hv. My minds telling me to go for hv but if the copo spring can solve my issue why not . Better taking just the pan off instead of dampener and timing cover and such

Spring is a lot easier than the pump, if you're determined to try to add some pressure, that would be the path of least resistance and cost for a next step to try.

[morepowerjoe]

You got to remember though that higher pressure doesn't change idle pressure only the HV will doesn't that as far as I know. But I think that's what your after anyways correct wot pressure?

[acammer]

Originally Posted by Risingson05

Taking it for a drive , where I could put better eyes on it it actually bleeds back down to 45and jumps up to 52 to 55 when I let off throttle . It doesn’t stay there at 52-55 during the whole wot it looks like it’s fighting itself ..

I believe the copo is a 20% in pressure ? That translates to only 8.7 psi right ?

The oil squirters in an LSA have a check valve in them, which opens somewhere around 42psi. This is why you'll see the oil pressure come up, and then fall back some, those squirters dump a good amount of oil volume. All of a sudden remembered why this comment made sense as well.