New year, new setup. Built 6G74 and Billet 20Ts

**DocWalt** · 06-17-2015, 11:22 AM

Not that I really have much in the ring regarding the 6G engines anymore... but 20w50 is used for good reason on engines that are built a bit looser, especially when they get hot. 15psi isn't that terrible though for a loose engine, IMO.

**Chris@Rvengeperformance** · 06-17-2015, 11:29 AM

20w50 is fine, but that is pretty bad oil pressure for 10w40. I'm running 24-26 at 800 RPM hot on 10w40 and 70+ PSI at 2500.

35 PSI at 2500 would scare me. You really ought to see 20 PSI per 1000 until you start getting over 70 PSI when the relief starts to open. You also shouldn't really see any smoke on a new motor built right. I've never had any smoke from mile 1. Is your tune okay? Wideband reading okay?

I wish we had a better definition of loose than you have .002 is "loose" to me and could still make a good street engine, but if an engine builder thinks .003 is nice and loose for a street motor you are going to have low oil pressure.

**murphys_law** · 06-17-2015, 11:31 AM

.002 here.

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**Chris@Rvengeperformance** · 06-17-2015, 11:34 AM

FYI Ray has mentioned to me several times that a motor making 100+ PSI at high rpm pretty much won't blow up. He likes to see the most pressure possible to keep the oil film layer the strongest and keep the crank from flexing. That's why he likes 20w50 so much.

**Uniuno** · 06-17-2015, 11:46 AM

20-50 it is then. Thanks for the tips guys.

That reminds me, I need to get a hold of the guy I got the engine from and see if he used a turbo oil relief spring. I know he replaced the oil pump, so hopefully it was for a turbo model. I imagine it would be, but being a 74 engine I'm not sure. My last 74 engine had an NA spring in the pump. I'll also ask him if he has a build sheet or anything for it.

I'd like to throw a catch can in it. I know some people swear by them and others don't even use them. I don't think Ray does on his red car.

**Uniuno** · 06-18-2015, 09:50 AM

I picked up some 20-50 VR1 last night and then started ripping into it to see where the oil is coming from.

Charge pipes and throttle body were bone dry. I pulled the intake and found the lower intake runners soaked in oil. #3 and #5 seemed worse than the rest. I pulled the plugs and found #1 was black and wet. Did a compression test and it was 180 across the board except for #3 which was only hitting 165. I put a little squirt of oil in it and it came up to 180.

I made a PVC Home Depot catch can to see if maybe it's the PCV system causing the oil. It seem like there is a direct oil feed to the lower intake, it is very wet.

Could PCV cause the VSS to leak that bad? The valve covers still have baffles so I don't see that much oil getting through the PCV valve. When I pulled the hose off the PCV it was dry.

**Uniuno** · 06-18-2015, 10:48 PM

Well, the car isn't going to be on the road again any time soon. The catch can idea was fruitless. I had an engine building buddy of mine come over to get a second opinion. He pulled the oil cap off and there was a lot of blow by coming out. We stuck a boroscope down the cylinders and of course they are just soaked with oil. There is no amount of finagling the PCV system to take care of the amount of oil it goes through.

Besides all this, there is a substantial amount of noise developing in the lower end. It's going to have to come apart.

I can't tell you how many times I've said "Part-out" over the last few days. I'm tired of throwing good money after bad on this car. I guess it won't cost anything to take it apart and see what's going on, but this is very depressing.

**DocWalt** · 06-18-2015, 11:13 PM

Originally Posted by Uniuno

Well, the car isn't going to be on the road again any time soon. The catch can idea was fruitless. I had an engine building buddy of mine come over to get a second opinion. He pulled the oil cap off and there was a lot of blow by coming out. We stuck a boroscope down the cylinders and of course they are just soaked with oil. There is no amount of finagling the PCV system to take care of the amount of oil it goes through.

Besides all this, there is a substantial amount of noise developing in the lower end. It's going to have to come apart.

I can't tell you how many times I've said "Part-out" over the last few days. I'm tired of throwing good money after bad on this car. I guess it won't cost anything to take it apart and see what's going on, but this is very depressing.

I've been there, dude.

Sorry to hear the issues