iamdub
Full Access Member
Been a while, welcome back. How ya been?
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I just went back and re-read your original post and noticed you talk about a "dimple on the larger of the two gears"- please explain. Are you talking about your timing gears? That's the only thing I can think of that matches what you're talking about, since there's nothing on the oil pump itself that you can turn around backwards. And if so, I don't see how you could have got the timing correct if you didn't have dots to line up on the upper and lower timing gears. But... if you did install the upper timing gear inside out, that's most likely your problem. My Cloyes timing set came with a camshaft thrust washer and it needed to be installed correctly or "it will cause a severe wear issue". I'm not sure of what would happen if you reinstalled the stock upper timing gear inside out but I don't think it's a good thing at all.
Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.It was the oil pump I was referring to. If you look it up, on the gerotors, there are dimples, you dont really see them, at least I didnt at first, there is no reference to them in the instructions I found while doing this work. I found it while looking for reasons why my oil pressure is low at running temperature AFTER doing all this work. the timing chain was fine, inspected by a neighbor who has rebuilt many small blocks.
Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.
I've never seen anyone disassemble an oil pump to install it like in that video. That's a new one on me. I love how they say disassembling the pump voids the warranty. There is a simpler way to center the pump, and I've never heard of a problem doing it the normal way. But now I see what you were talking about. Thanks. Your problem is worrisome to me though since the NBS GMT 800's normally have 40 psi at idle and 60 at higher RPM's. Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.
Doing good, you?Been a while, welcome back. How ya been?
Doing good, you?