Inliners International Forums General Discussion Engines Fired up the rebuilt engine for the first time

Hooked up everything while on the engine stand and worked on getting it fired up. First I had the distributor out 180 degrees, fixed that. I left my rockers on the loose side because I didn't know if they tighten up when I got oil pressure...motor was spitting fuel up through the carb. It was late so I went to bed...worried.

Next morning I had all day off, so I brought the engine outside so I could do a proper cam break-in. She was still spitting and I was worried maybe I hadn't lined up the cam timing marks properly? I decided to tighten up the rockers more, so I lined up #1 and did all the ones I could and then I lined up #6 and did the others. I did the "tighten until zero lash is felt and then tighten 1/2 turn". I gotta admit, I'm not 100% sure I found zero lash correctly on all of them...basically I tightened until I felt some resistance while rotating the pushrods and called that zero lash. How exact does it need to be on a stock cam?

So anyway then I moved the distributor around a bit and finally I must have found a sweet spot because she jumped to life.

I immediately shut her down and proceeded to hook up a radiator and add water. I re-checked the oil and then got out my watch and ran her for 5 minutes, at a "high" rpm as defined by ear. I was shooting for 2000-2500 RPM (I had no tach).

I noticed that the engine was louder than I liked (I did have a muffler on). I was pretty worried because it sounded like a lot of ticking and what not was going on in there. I ran her for 5 minutes and she heated up really really quick. After about 5 minutes I was around 230 degrees water temp as measured in the cylinder head.

I shut her down again, checked the oil, and noticed a coolant leak at the water neck where it meets the block. I had used only hylomar there and it didn't seal properly. it wasn't a huge leak so I could continue on breaking in the cam, just adding water as needed.

I brought out my strongest electric fan and bungee'd it to the radiator. I let the motor cool down a little bit and took a break. Then I went back out and did another 5 minutes. Boy did she put out some heat - are 250s always hot like this? I had a hard time keeping my hand on the throttle at times.

So at the 10 minute mark I pulled off the oil filter and threw on a new one. I added another quart of Brad Penn straight 30wt and rechecked the oil. The oil filter was really really hot. Too hot to use bare hands to get it off without getting burned.

So I let her cool off again and then did the last 10 minutes. It did seem a bit quieter now, but maybe it was my imagination.

When cold at high rpm I had around 50 PSI oil pressure. When hot I had about 40-44 PSI. I never did let it idle, so I have no idea (yet) what my idle pressure is.

Would be great to have an engine run-in stand. If I was going to rebuild lots of engines, it would be worth the $$$ to buy or the time to build.

So hopefully I did everything "right" and this motor will provide years of service :-) I should find out some time in July, when I get the motor into the car.

Thanks guys for all the help and advice.


Dan

Did you check the water level?
Sometimes you will have an air lock.

Will Willis

It's finally in the vehicle and on the road, but it sounds like it has a knock. it's coming from the rear of the engine and it seems to get louder after it warms up. I have spent so much time on this engine I don't even know what to say...

Don't get discouraged... I recently had a similar problem with mine and everything now seems fine. I ended taking mine apart to double check everything and found nothing. Eventually found the problem was an eternal part. I wish I had taken time to go over everything carefully before I took it apart.
Start by making sure everything is tight. Standard or automatic? Could it be something loose on the back of the engine like a flex plate...or something slightly out of line? How about crankshaft end play? Try your best to locate where the noise is coming from. And if you have to open it up again, it's a pain, but it's not the end of the world. In that case check all your clearances again. You put it together the first time, you can do it again.
Good luck.. Others will have suggestions as well.

x2 on flexplate and other noises. I rebuilt a v8 recently, took half the engine back apart (oil pan & 1 cylinder head) just to find that the "rod knock" was the TIMING POINTER banging against a high spot on the damper. UGH!

My engine stand is just one of those car-tire-dollies (they hold >1000lb and roll easy) with 2x4's to build a cradle. Cheep. Then, I leave the crane bolted to the engine so its ready to lift into the car IF things go well.....this is plenty stable even with a big cam. FLexplate, starter, muffler (so you can hear noises), radiator & hoses and youre ready to start. I added an alternator/regulator setup but that's optional.
And LOTS of gages:
* Oil Press
* Vacuum
* Tach
* Water Temp
* Timing Light
Then I record the what-what every couple minutes for reference later.

While building, what were your clearances, mains/rods/pistons/ring gaps/side-clearance/crank-end-play? Gotta know that stuff.

What torq did it take to spin the crank over (hopefully about zero)?
How bout with the pistons/rings in?
How bout with the cam in too?
I record all that stuff. If something is REALLY hard to turn over its a message.

You can pull the plugs out now and check that tho its harder to read the steady-state torq on a beam wrench when its in the car.

Will the pan come off in the car without major surgery?
If so youre lucky again, not so bad to pull that & check in there.

Good luck it is always a tense time with a new engine, doesn't seem to get any easier, I've done many.

I disconnected the torque converter and it still made the noise. I took the car back to the engine machine shop to get their opinion, they listened with a stethoscope and thought the noise was coming higher up than the crank area and recommended that I re-adjust the valves. I re-adjusted the valves and I learned that you if you quickly tighten the rockers the engine will run rough until the lifter bleeds down, and if you keep going you will eventually get to the point where there is no more bleed down (so at least I learned something).

The flexplate is a brand new napa unit and the flexplate bolts are brand new ARPs.

I think the most telling part is this:

The engine was originally running straight 30 wt oil. Today I changed the oil to Valvoline straight 60 wt racing oil. The knocking got louder, and not just after I restarted the engine for the first time - but literally the entire time it was running. It also sounded more like a rod knock (or maybe a secondary knock).

I think something internally is decreasing oil flow. I have no idea where the blockage would be, or if this is even likely. But all of the online information I have read said that a thicker oil should decrease the knocking sound if it's a rod or main (perhaps it would be louder right after startup but then quiet down.).

I don't know how the oil flows through the 250...I do know that the oil pressure gauge port has good pressure because 2 different gauges show pressure.

I also noticed that when I adjusted the valves I expected major oil splash (30wt oil at this point) - I did have good oil flow over the rockers and down the springs, but at idle I had no squirting over the head and my exhaust manifold stayed completely dry (I was on a relatively flat surface). So maybe this was normal? The oil pump is a new standard volume unit, the pickup is also new.

I've changed the oil filter 3 times now; the engine has about 300 miles on it. I changed the filter after the first 20 minutes, then again after about 50 miles, and then again today (with the new Valvoline VR1 60wt.).

Tomorrow I think I'll put some 5w-20 in it and see what it sounds like. Luckily I can re-use the filter and 60wt oil in my towing rig (I didn't drive on it, just idled).

What are the most likely cause of oil starvation in part of the engine? Are there any other places on the engine where I can check oil pressure?


Any other thoughts?

Thanks,


Dan

I am a bit worried about your engine.

I have seen the cam bearings fail on new rebuilds. What brand bearing did you use?
They will mash out on the bottom and smear babbit material over the oil holes that lube the cam.

You say there is little oil flow up above. What is the idle oil pressure? Hot.

At this point you need to cut the oil filter open and roll out and inspect the paper element inside of it. If it's full of debris and your scarred by what you see, you need to just pull the engine back apart, and the noise should be obvious once you do. You'll need a hacksaw to separate the element from the internal structure that it's attached to on the inside, but cut it up high where the threaded portion is that spins on the block. Oil goes to the inside center of the filter first, so once you get it rolled out, inspect the inside of the paper first. But it might be so full of trash without doing that that it will indicate an obvious internal problem. Take pics of it and post them.

Could the screw in plug in the front oil galley be blocking flow?

Don't fret over cam bearing brand. No matter what color the box they came in is about 90% of the cam bearings sold in the US are made by Dura-Bond in Carson City, Nevada. The rest are probably made in China and Taiwan.

And there is such a thing as too high a viscosity in an engine. The 60w is very likely too high. I think it would be a good idea to go back to 30w. Try the 5w20 if you like but you should not need 60w in a brand new engine. You have tight clearances and running heavy oil isn't helping circulation. And do cut the filter open and check it.

Seeing that no one has asked I have to. When you had the cam gear installed was it heated? Or just Pressed on? If it was only pressed on it could have walked. And Now the cam is doing the same. ( walking front to back ) And this could be giving you the knock that you are hearing.

Hey guys,

Oil pressure hot at idle is around 20-25 psi (car not in gear).

I am pretty sure the cam bearings were durabond - I'd have to try to find the box they came in.

I haven't had a chance yet to cut the filter apart, but will soon.

I don't specifically remember the front screw in oil gallery plug, I'll have to check when I pull the motor.

I think 60wt is also too much, but I had been hearing "thicker oil will quiet it down", which is why I tried.

About the cam gear - I don't know. The machine shop installed it.

I'm really bummed, the engine runs so nice. The car is really pleasant to drive. Winter is getting close and it's hard for me to get time to work on it (and it's supposed to be one of my main cars).

To make this even worse, after I've invested all of this time and money I may get relocated to California. The car is a 1979 Olds Delta 88 that originally came with a Pontiac 301 engine. I have the EGR, vacuum canister, and PCV all hooked up but its an engine swap and the engine doesn't match the under hood sticker. I don't think I can pass a visual inspection on a California smog test :-(

You can ask Hank but I think they only hold you to the grindstone on this if its newer than 25 years old. Older than that I think its exempt from some of the more strict emission criteria.

Cut the filter open first, and see how it looks. You might be able to start with just pulling the pan and doing a visual as you slowly rotate the engine by hand and see if you can detect anything hitting. Just start with the easy stuff before diving in to a complete teardown.

You may be SOL if you leave the USA and come to Cali.
As I recall the rules:
* Cars newer than 1974 have to endure smog. I think they did the cutoff here when catalytic converters started, and there was not much objection from the collector community after that.
* We brought a couple USA cars into Cali years ago:
* If the cars were first sold in the USA they don't have to meet CA smog, they only have to meet USA smog standards.
* They don't have to have original engine type.
* However, they have to have an engine that was offered in that car that year, or you can swap in a newer engine but then you have to meet smog for that newer year.
* You may end up at the State Test Center, there are some pretty cool Car Guys there, not bad guys or nit picky, they will be as loose as they can but cant change the rules. I had a 204-214-112 cam in one of my rigs (and headers), they sensed the cam and asked, but didn't care. It passed visual & tailpipe so I was done.
* Since the 250-i6 was not offered in any 1979 Olds you might be kinda stuck shoving another motor in there, or sell the car in the USA before you come to Cali.
* Good luck you have a lot of good advice here!

And they say Nevada is not a border state. $%^& California and the horse it rode in on!

https://www.dmv.ca.gov/vr/smog.htm

Does my vehicle qualify for a smog exemption?

Smog inspections are required unless your vehicle is:
• Hybrid
• Gasoline powered 1975 year model or older
• Diesel powered 1997 year model and older or with a Gross Vehicle Weight rating (GVWR) of more than 14,000 lbs
• Electric
• Natural gas powered with a GVWR rating of more than 14,000 lbs.
• Motorcycle

MBHD