Winter 2020 (Now Spring 2023) 350 Fresh-Up Project

I’m no expert either and the person I knew that would have the answer is no longer with us. That being said here’s my 2¢. I think the pressure would remain the same, the pressure we’re measuring is the restrictions the pump faces on the other side. Removal of restrictions on the suction side would aid in volume.

 

Actually I don't think it change the volume or the pressure on the high side.

I think what it does is reduces the mechanical resistance of the turning pump. So less wear and tear on the cam gear/distribute gear and less wasted power turning the oil pump.

The rotational speed of the oil pump doesn't change due to mods to the oiling system. so the volume of oil pumped remains the same.

 

Probably, the range of the aftermarket sender is wrong, and I agree a mechanical gauge to verify real oil pressure.

 

Here's the two springs. It had a Stage 1 spring in it. It was pegging the gauge at anything above 1200 RPM when hot. With the same spring it ran prior to rebuild, it now almost pegs the gauge cold and holds half the gauge at hot idle. Revving up above 1200 RPM now is one notch below full on the factory gauge. I'll see how it does until I change oil the first time and maybe try a mechanical gauge then. I'll need to get a T fitting to make it work.

Original pre-rebuild spring on left, high pressure Stage 1 spring on right.

 

Pegging gauge or not, a mechanical gauge will tell you everything you need to know. The real deal oil pressure.
There are no numbers on factory gauge. You're guessing.

 

Exactly only a guess with dash gauge

 

I'm not going to jinx it and not changing anything else until after the GS Nats. It is still being broken in, rings and clutch.

 

I had a similar issue when swapping to the TA loaded cover (with oil pump and adjustable regulator) on my 400. 85 psi on cold start, 60+ hot idle. Anything over 1500 RPM when hot would get the oil pressure up to 100 psi or more. After a phone call to TA, they advised me to put the smaller spring in the regulator (came with it), and not to used the adjustable regulator to lower it. Worked out great. Now it's 65 psi cold, 25-30 psi hot idle, and tops out at about 65-70 psi when I'm on it.

Note that changing from 20W50 to 10W30 made a very negligible difference (3-5 psi cold). I'm currently running 10W30.

 

I'm going to try using 5W30 since I know it holds such good oil pressure cold. No reason to go nuts on oil pressure.

 

Soooooo, did you manage to make a few runs at the GS Nats???

 

No, it still only has 70 miles on it the rebuild. The engine needs a few more miles to make sure the rings are seated and the clutch has to take it easy for the first 500 miles.

To be honest, I'm not really the drag racer type any more. I got tired of breaking things. I just want a strong running 350.

 

Cal looks great Greg! Was good to see and talk to you a few times at the Nationals.

 

The first 100 miles are done. Am I safe in thinking that the cam is OK if it didn't eat itself in the first few miles?

Also, I've been doing blasts to 5,000 RPM in second gear and letting it engine brake back down to 1,500. I'm thinking that has the rings broken in.

The oil is a little discolored but I figure that is all the wear from the rings/cylinders, lifters/lobes, timing chain/gears getting acquainted with each other after a 2 year wait.

Still holding 1/2 on the stock gauge at hot idle with the non-Stage 1 pressure spring.

Now that the GS Nats are over, I need to pull the QJet off and fix the idle screw.

I also need to recheck the timing and probably bump it up a few degrees. I was running it low to make sure it didn't ping/detonate with 2-year-old gas in the tank.

 

I was tinkering with the car today and I really got into it hard. It didn't seem like it was pulling that strongly for being on the floor. I'm looking at it and decided the throttle bracket was bent up pretty good, probably because it had a Holley on it before. I tweaked it back into shape and it lengthened the throttle cable. I got it to about 5,000 RPM today at 110 miles since rebuild and it felt better than before. I'll have to get someone to floor it while I check the position of the throttle blades under the hood to be sure I'm getting WOT when it is on the floor.

 

OK, finally pulled the QJet off and spent FOUR HOURS drilling out the broke idle screw. It was in there good.

I cut it off with a dremel on both sides and drilled a hole all the way through it. An EZout just stripped away more material. I drilled it out to the next size and still nothing would come out.

I finally had it to the size for tapping to 10-32 and started tapping it. About 1/3 of the way in it hung up and I backed it out. There was a circle of the old screw on the tap. Knocked it off and started again. happened twice more before it was all the way through.

I put another screw back in it and it looks like it will be good.

Only, now, I find the clear powder coating was EVERYWHERE including in the plenum! It was bubbling up and pealing off. Here's praying it hasn't done anything already to the engine.

 

So the intake was powder coated clear and they didn't bother to block off the plenum?

 

Nope. It was bubbling up and had air under it. I stuffed the intake and scraped off what I could but some of it was already missing. Some days you can't win.

 

I think that stuff burns anyhow, so it might be ok.

 

Hoping so. Fresh rebuild with only a few 100 miles on it.

 

An update:

Finally did a bit more tuning after I got the carb able to idle down with the idle screw repair.

I had the timing way low since I wanted no chance of detonation until I got it running well. I now have it set to 30° total timing without vacuum advance as I zero in on the gas requirements it will have a 9:1 compression.

The 4-core brass radiator and clutch fan are doing an excellent job of keeping the temps where I want them.

I plan on working up to 32° if she doesn't ping on regular. My goal is to not have to run expensive gas if I can avoid it. I like the least common denominator fuel options.