Anyway to run compression on engine without starter etc?

[LAC_STS]

I am going to be bringing my old engine back to my house sometime soon. I should have run compression on it before I took it out. I knew it was something major and long story short I decided to spend a little extra money and get a new engine so I knew what I had.

Right now the engine is without a starter, alt, and dist.

The intake manifold, carb, flywheel, manifolds, and risers are still on there though.

What happened was that the engine was slowly leaking oil and when driving it oil pressure went to 0, overheated, I shut the engine down, checked oil, was 1 - 1 1/2 qt short, added the oil and started it up and it was knocking from the bottom of the engine.

So Im thinking maybe spun bearing or bent rod, or something.

But either way I would like to run compression on it if its possible.


Any way to do this?


Thanks

 

[JustJason]

Re: Anyway to run compression on engine without starter etc?

You cant do a compression test without a starter, but you can certainly do a leakdown test.

 

[whitney]

Re: Anyway to run compression on engine without starter etc?

You spun at least one rod bearing. Been there done that on several automotive engines (racing).

You can do a leakdown test -- http://en.wikipedia.org/wiki/Leak-down_tester with no starter. However, you will be removing at least one piston to replace or repair the rod end due to the spun bearing. You will need a new camshaft or have the old one ground and use oversize bearings. If you are going to go through the trouble of a rebuild, re-ring all the pistons and check the bores with a bore gauge. And get the head(s) rebuilt.

So in effect, your current compression doesn't matter. Take care of everything which could affect compression while the motor's apart. Disassemble, clean, inspect, and organize everything as you go. Use lots of light. If you haven't done it before it's a great learning experience, just be patient and look for good resources.

 

[HT32BSX115]

Re: Anyway to run compression on engine without starter etc?

So Im thinking maybe spun bearing or bent rod, or something.

But either way I would like to run compression on it if its possible.

So I am sort of at a loss here........


If you spun a bearing, why do you care about compression?

 

[LAC_STS]

Re: Anyway to run compression on engine without starter etc?

Thanks everyone.

So I am sort of at a loss here........


If you spun a bearing, why do you care about compression?

I am not sure of what I did yet. Just figured a compression test would be a good thing.

All I know right now is what happened and what is was doing when I decided to pull and replace it.

I had a friend who works on diesels come look / listen to it and he said that it definatly wasn't lifters or anything from the top of the engine.

He said it was for sure from the bottom and told me it was probably a spun bearing and/or rod.



I'm still undecided what I want to do with the engine. Rebuild and sell it, part it and sell whats good, rebuild and keep as a spare, rebuild and find a small boat to throw it into with a SEI drive I dunno

Wonder how much I could get for it rebuilt, or for the long block rebuilt, or parted out? I guess the main question would be how much would it cost me for each of those options. I know how much rebuilt long blocks, and semi complete engines go for. So... I dunno. Decisions

But I would like to rebuild it for the learning experience alone.

Guess I wont know all of the answers until I tear into it. I'm gonna go pick up an engine stand sometime this week hopefully and get it to my house.

 

[Alpheus]

Re: Anyway to run compression on engine without starter etc?

Not much. You can get remans with a 3 year warranty for 1150 bucks.

You cant rebuild one for that. The machine shop bill alone would be close to that if you did it the right way...

 

[Howard Sterndrive]

Re: Anyway to run compression on engine without starter etc?

someone around your neighbourhood has a chevy starter or five laying around.

taking the pan off would probably be more telling.

 

[LAC_STS]

Re: Anyway to run compression on engine without starter etc?

Not much. You can get remans with a 3 year warranty for 1150 bucks.

You cant rebuild one for that. The machine shop bill alone would be close to that if you did it the right way...

Thats what I have no clue about is how much the machine shop costs would be.

But can you really get a reman marine long blocks for $1150? Heads and all?

Cheapest I found was Rapido which was $1450. Either way though I guess with the machine shop bill and the other parts required it still wouldnt be worth it to just rebuild and sell the long block. Maybe if I could sell the other parts if they are still in good condition. But then again if I could break even or even make a little bit it would be worth it just for the learning experience.

someone around your neighbourhood has a chevy starter or five laying around.

taking the pan off would probably be more telling.

I was thinking that would be my first step. I have an oil drain pan that has a screen on it so I could drain the oil and see what it catches, I imagine that the particles would be small enough to slip through though.




So if I got this right, best case scenario just to fix it if its a spun bearing I would still have to have the camshaft ground or replaced, and reaplce the bearing. Is it a for sure on the cam shaft? Could it be possible that I would just need to replace the bearing(s)?

So, I know this is all guesses and I will not know get to looking at it but tell me if Im right on this.

If I take it apart and it is a spun bearing I could just replace the bearing and if needed have the cam done or replaced. Or if it is a piston I could just replace it.

OR

If I get into it and there is a considerable amount of damage or something worse than just a bearing I might as well just rebuild the entire engine.

Sound right?


Thanks

 

[a70eliminator]

Re: Anyway to run compression on engine without starter etc?

I can't believe 1-1/2 quarts of oil low low would cause a 0 oil pressure, maybe pump cavitated if you were running WOT, I think something else happened but until you take down the motor it's all speculation, could be disrtibutor oil pump shaft stripped or broke, you really have to know what your looking at.

 

[Bondo]

Re: Anyway to run compression on engine without starter etc?

OR

If I get into it and there is a considerable amount of damage or something worse than just a bearing I might as well just rebuild the entire engine.

Ayuh,.... It'll be the Crankshaft, not the cam shaft....

That motor is worth about $20. in Scrap Iron...
To fix it or rebuild it means a COMPLETE tear-down, just to clean all the metal filings out of it...
The Cost to fix it, in Any reliable form will exceed the cost of a Rapido motor....

 

[LAC_STS]

Re: Anyway to run compression on engine without starter etc?

Thats what I thought.

What happened exactly was that I saw it was leaking oil slowly. I called the PO and asked him what kind of oil he used and if he knew where it was leaking from. He said he used Mobile 1 10-30 and gave me some bs story about it not leaking oil.

I was planning on changing the oil over to straight 30 anyways but for the time being I bought 2 qts of what he said he had in there now.

I checked the dipstick before we went out and it was just a little under so I topped it off. We went out for about 3 hours and on the way back doing about 3/4 throttle was when I looked down and saw the oil pressure was 0 and the temp was creeping up to about 180.

I threw it in N and cut it off. Checked the oil and it was low. I started putting more in and it only help 1 1/2 qts. After this it would not start for about 5 mins.

It sounded like the battery was dead. But then I let it sit for about 5 mins and it fired right up but it was knocking. I think maybe it was too hot and someone told me some engines have something (solenoid maybe) that's prevents them from starting when they are too hot.

The temp never got over 200 though. I checked the oil when we got back to the dock several times and there was no water in it at all.

At idle you can barely hear the knocking but if you give it some gas (not alot maybe over 1500 RPM you can hear it pretty loud.

 

[Bondo]

Re: Anyway to run compression on engine without starter etc?

At idle you can barely hear the knocking but if you give it some gas (not alot maybe over 1500 RPM you can hear it pretty loud.

Ayuh,... Regardless How it got there, it's now pretty much Junk....

 

[HT32BSX115]

Re: Anyway to run compression on engine without starter etc?

Ayuh,... Regardless How it got there, it's now pretty much Junk....

Yeah. It's now a "core"

What happened exactly was that I saw it was leaking oil slowly. I called the PO and asked him what kind of oil he used and if he knew where it was leaking from. He said he used Mobile 1 10-30 and gave me some bs story about it not leaking oil.

AND........I guess if this were an oil thread .......we could conclude that this guy ran Mobil 1 10W30 and ACTUALLY HAD a problem!!!

 

[whitney]

Re: Anyway to run compression on engine without starter etc?

So if I got this right, best case scenario just to fix it if its a spun bearing I would still have to have the camshaft ground or replaced, and reaplce the bearing. Is it a for sure on the cam shaft? Could it be possible that I would just need to replace the bearing(s)?

I'm unfortunate enough to have spun rod bearings on three race car motors so I'll try to shed some light.

89 BMW, was going around a hard turn and saw the oil pressure light *briefly* flicker. Once. Cruised into the pits, towed it home, pulled the pan and caps off, and had a barely spun rod bearing. No noise or knocking, no indications that anything was wrong. This still required remachining of the rod end which was toast. Crank was slightly blued but not too damaged so I used some emery cloth and put it all back together. Best case scenario, but again no audible noise or indication of a problem.

In both Honda motors we've spun bearings in due to low oil, the knock was slight at idle but loud off idle like yours. Crank was junk in both cases.

FYI what you thought was a slow starter/bad battery was actually the extremely high engine friction caused by the oil+metal slurry that's now circulating around everywhere.

For $1450, it's a no-brainer, unless you want to learn to rebuild an engine. I think you could DIY for less. It's a lot of work and requires a good shop and skills.