Engine test

Is there any way to tell if an engine is in good condition as is without tearing it down or taking it to a machine shop??? Can you do a leak down test on an uninstalled engine.

I picked up a 360 last weekend and sure would love to just drop it in without tearing it completely down. However, I don't want to install an engine that needs to be rebuilt. I need some help from you engine builder types.

High5

 

you know, btdt and I know kinda how you must feel. But I would like to know the history of the motor from someone I could put stock in or hear it run. If it were mine, and it's not I think I'd want to crack it open and if I didn't do anything but a valve job and put rings and inserts in it I'd feel a lot better about what I had. And that way you can clean it up and out a bit and know a bit about it anyway. Not much money and time for a little peace of mind. 2c hth ymmv

 

I'm not the engine builder type really... at least yet. But you can do a compression test really easy. Just get a compression tester at the auto part store and take each spark plug out one at a time and check to see what the compression is against the books. Some reduction in compression is to be expected with an old engine but you don't want them to be too uneven. Maybe someone else on this forum can enlighten us further with some numbers



oh! my bad, Its not installed is it?! If you can crank it over somehow you can test compression. Might be difficult if it's not installed.

 

Gasket kits are not that expensive id pull the heads off and the pan. it would take less time then in installing the engine then pulling it if it is bad. At least take a look at the oil pump the amc v8s have problems with them wearing quickly.

 

Oil pressure. Compression test.

If you can't run it to test oil pressure, Plastigage the main and rod bearings and the oil pump gear clearance.

I'd advise you replace the rear main seal before you install the engine - much easier out of the car. Check the timing chain tension too, and replace the timing set if needed.

 

How would you run a compression test with the engine not installed? Are you talking about a leak down test where you put compressed air in the cylinders and check to see how much pressure is lost???

I think I will take it down to a short block and check things out. I will definitely need to read up on AMC 360 specs before that. I have a guy who knows a ton about engines, Chevy not AMC, but at least he can help with rings and bearings. It probably would be smart to have a valve job done prior to install as well.
I've looked at Bulltear.com and they seem to have everything you could ever want for a AMC V8. They have an oiling kit that includes a new timing cover, oil pump gears, timing set I think, and something else. 300 bones though.
Even used engines aren't cheap to install

I'm still trying to get the final two bolts out of the exhaust manifold. Sure as hell don't want to break them so I just keep coating them with well WD 40 now since I ran out of PB blaster.

This is going to be a long term project since I don't need a replacement engine right now. I plan on doing mainly Edelbrock parts so I probably will do a cam when the time comes as well.

High5

 

Don't forget the bees-wax tip from another thread on those last two bolts. I have used it before and believe it or not, it does work. You just heat the stubborn nut/bolt then melt the wax onto the threads, the wax seems to wick into the threads and before you know it, they will break loose.
As for the rest of the motor, listen to everyone else, not me.
(Although that 383 hi-po in my J4000 went together well, ran so strong I broke my bell-housing! )

 

If you want to test the motor you can do a clt test on a stand/floor that will tell you how well the ring valves and head gaskets are. But you still wont know about the brg.
Hear is my 2 cents if you need the motor now and have limited cash do clt test if good put the motor in my thought is good rings and valves probly good brgs.
If you are looking for a motor not to have to pull agin and have some time and money pull it down and ck it out.

 

Well,
I have time and of course I'm working on the money. Trying to sell the trans, transfer case, and all the other stuff I don't need or want.

I think I will take my time with it and have a valve job done and probably do rings and bearings with help from a friend. I don't want to pull it again because I didn't take proper precautions.

High5

 

I haven't done it, but I'd think you could crank the engine on the shop floor with its starter. This would allow a compression check. No need to start it.

 

At school we would have to start every engine that was disassembled and reassembled, we would set them on a wood pallet, wire them to the pallet with bailing wire around the exhaust manifold to the pallet, hook-up the fuel, CHECK OIL!, hook-up a battery, and fire away. Don't run very long without coolant, but we also had that option, it was just a couple of flex hoses to a container of water, worked fine. It always fun starting a motor with nothing but exhaust manifolds.
I guess what I am saying, you could test compression, see if it runs, don't know if you will be able to see if it smokes without proper warm-up, but give you an idea of what you have.

Greg

 

Excellent idea! I've also had a similar problem with a Dodge slant six, got one from a junk yard swinging from the back of a wrecker, and when it was dropped a bunch of water poured out of the carb and exhaust, after six drained and recharged batteries it fired up!
Had only 10 psi oil press. for the following 8 yrs I beat the h€ll outa it but never let me sit. Rudementary test's are a good idea but sometimes you need to to just go for it and hope for the best. Good Luck!

 

id throw new rings and bearings in the motor. lap the valves lightly and install new timing chain. at least when you install the motor, youll know that its decent. (of course this could get pricey as you find things out when you open it) i just cant see installing a used motor and hoping that it runs good. i know sometimes that $$$ is a big issue, but id rather play it safe.

 

Lap the what now???:? :?

Would this be involved with having a "valve job" done??

High5

 

Yep, lapping compound smeared on the valve seat, rotate the valve with light pressure, cleans the seat up and valve face up (you hope) or shows you if you really need a valve job.

John

 

Well, I had some time to work on the Jeep tonight after work. I got the transmission taken off the 360 as well as the flexplate and torque converter. I also turned the engine by hand. Was not stuck at all. This makes me happy. I now need to get it on the stand and do a compression test. I have a guy coming to buy the transmission and QT and hopefully the flexplate and torque converter. Then I can get my little trailer out of the garage and have some space again.

One question, what can one expect to pay for a valve job on a V8???? I notice there is a set of remanufactured heads on Ebay right now for 250 plus shipping. That a good deal???

Thanks

High5

 

I had a machine shop on the north side of Des Moines do a set of 304 heads when I lived out there. Depending on what all needs to be done, if valves or springs need to be replaced, I think it was only about $125 for both heads, and you know when they are done that they are not cracked. Unlike buying sight unseen heads.

 

Mmm, yeah. Definitely find a local place to do the heads, if needed. Also, don't spend a lot of money to fix a 360 head - junk it and get another one instead. They are plentiful and cores should be cheap.

Also, I'd throw the converter and flex plate away. No way I would reuse either of those... well, I might reuse the convertor if I knew the history, but not the flexplate.