1995 LT1 oil

[RHALL]

Recently bought a 1995 Z28 with a modified LT1. Builder says it's putting out 450-500 horsepower. It has a 502/510 lift roller cam, .030 over forged replacement pistons, high pressure oil pump, 52 mm throttle body, ported heads, and probably some things I'm forgetting. The engine builder/shop also installed 3.73 gears.

It's been many years since I've owned anything with this much power, and I'd appreciate recommendations on the best oil to use. Engine has right at 1000 miles on it, and I'll make an oil change soon.

 

[spasm3]

I'd ask the builder, since he knows the main bearing clearances. I'd probably run a 5w40 like rotella.

 

[Mr Nice]

Rotella or Motorcraft HDEO. Both can be found at Walmart.

 

[Duffyjr]

VR 1 20w50 would be a good one.

https://sharena21.springcm.com/Publ...bd3/8213a6c1-0cbd-e711-9c12-ac162d889bd1

 

[skyactiv]

It's my opinion diesel oils don't have the same high tech beneficial anti wear additives which wont show up on a VOA or UOA as modern PCMO does. The only reason people like diesel oils is because they typically have more zinc and phosphorous.
And the herd response of "I'd ask the builder" is getting old. A safe recommendation is to use anything which is Porsche A40 approved.
Modern 4 cylinder engines have more HP per liter than your built engine and don't need a thick oil to live 200K.
Use https://www.amazon.com/Pennzoil-Platinum-Synthetic-1-Quart-Single-Pack/dp/B00JMCCBRW?th=1 or Kendall Euro 5W40 https://petroleumservicecompany.com/kendall-gt-1-euro-fs-5w-40-12-32-ounce-bottles/

 

[ka9mnx]

Originally Posted by spasm3
I'd ask the builder, since he knows the main bearing clearances.

Yep. Any replies on here is just guessing.

 

[4WD]

Sure … roller cam and already broke in …

 

[spasm3]

Originally Posted by skyactiv

And the herd response of "I'd ask the builder" is getting old. A safe recommendation is to use anything which is Porsche A40 approved.
Modern 4 cylinder engines have more HP per liter than your built engine and don't need a thick oil to live 200K.


Those 4 cylinders do make more power per liter. They do it with VVT and 4 valves per cylinder. The builder of the V-8 knows the valve spring pressures and the main and rod clearances. That is what you need to know to determine the oil viscosity.

 

[Randy_R]

Howbout maybe Driven LS30? I just read today about some of its' attributes here on BITOG. I know an LT is not an LS but it still might be good for you. Maybe a 0W-40 spec'ed for Hemi, maybe not Euro spec. Pennzoil, Schaeffer, etc. Or just ask the engine builder.

 

[IMSA_Racing_Fan]

Moble1 10W-30 synthetic

 

[Dinoburner]

Just curious, is this the first OC after rebuilding? If so I`d cut open the filter and inspect. As to oil it depends on how this thing will be driven etc. I use 10/40 syn in modified engines with no problems even tho the big block in my sig gets hot suppers quite frequently.

 

[IMSA_Racing_Fan]

Commonly .002" for rod bearings 0025" mains 1-4, .0027 to .0030 main #5 for thrust and seal oiling. You have more leakage on a LT1 than a Euro/Asian/modern US engine which potentially drops oil pressure. Unless you're racing and looking for an extra 1-5 HP gain and rebuilding after every event I would not use a 5W- weight. That is my opinion, what I would do, and only that.

 

[RHALL]

Engine was built four years ago, and was broken in by a friend of mine, the previous owner. The car developed electrical problems and was stored. I've talked with the builder and he said the rod and main journals were fine, so they're standard. Cam is a Comp Cams roller with matching springs. Engine was balanced, and had head porting.. After four years I'm glad he remembered that much.

 

[Linctex]

I used to run a twin-turbo 351W in a drag Mustang making right about 600 RWHP, and I used common Shell Rotella 15W-40 with excellent results.

 

[userfriendly]

Yep. Maybe an SAE 30 if you can't find 15w40. Or what spasm3 said (5w40 HDEO).
Roller valve trains don't need breaking in, or high Zn.

 

[GMBoy]

Redline 10W/30 would be an excellent choice. Followed by Valvoline Vr1 Syn. Off the shelf Mobil 1 HM 10W/30 or 40 is a good option too. I run Mobil 1 HM 10W/30 in my 94 Corvette LT1 which is only mildly built with the LT4 kit, exhaust and programming.

 

[Scuder]

Some hydraulic roller lifters spec a certain grade of oil. I don't know if your rollers are hydraulic, or if Comp does spec a grade, but it would be worth looking into.

 

[DGXR]

I was also thinking a 10w40 for the OP's built LT1, maybe a HM version.

 

[tblt44]

When I saw the title it reminded me of my 1995 Vette I sold 8 years ago.
Ran good stock. I'll bet yours screams.
Oil No idea since its modified