Compression Tester????

8nsyes

Member
To any and all; What would you suggest to be a good compression tester? I've never used one and been looking and found many, many with all sorts of gadgets for them. I need to check my 1948 8n and figured that I would ask you all this question.

Thanks for this forum and you folks who make it truly a joy and great learning for such as me. I'm older than the hills but still want to learn. Thanks to all responses!!
Walt 8nsyes
 
Since there is limited clearance between the gas tank and the spark plug locations, you need one with a good, flexible hose, and not much length to the fitting that screws into the head. (IF you plan to check the compression with the hood/tank on.)

Some guys make up their own adapter with an elbow to facilitate this.

A search of the archives would probably turn up some photos.

What is the problem that you need to check compression?

Have you had it for a while and it is beginning to give trouble, or is it newly-adopted and hasn't been run, or run and worked for a while?
 
(quoted from post at 21:43:39 03/02/15) To any and all; What would you suggest to be a good compression tester? I've never used one and been looking and found many, many with all sorts of gadgets for them. I need to check my 1948 8n and figured that I would ask you all this question.
Can't remember if you have to make your own or look for it in the kit but you'll need to be sure you have 90° hook-ups because of the gas tank (or so I've heard). Seems like Bruce(VA) made his?
May be something to consider.
 
In answer to your question; My 1948 8n is blowing some (not too bad) black smoke after starting. Also it is hard to start on it's own. Pull it off and in just a few feet it will start. Uses about 1/2 quart of oil after two days light work. Also exhaust manifold is showing some black blow by or whatever you call it near one of the exhaust/intake holes.
walt
 
Son-in-law rigged up this adapter for me to check the compression without removing the hood.
a185123.jpg
 
Del I like that set-up. Before reading all of the forum responses I had not thought a whit about the distance being small between the tank and spark plugs. Great advise, Thanks :D
So I need to come up with a similar device to use.
 
(quoted from post at 20:04:53 03/02/15)
(quoted from post at 21:43:39 03/02/15) To any and all; What would you suggest to be a good compression tester? I've never used one and been looking and found many, many with all sorts of gadgets for them. I need to check my 1948 8n and figured that I would ask you all this question.
Can't remember if you have to make your own or look for it in the kit but you'll need to be sure you have 90° hook-ups because of the gas tank (or so I've heard). Seems like Bruce(VA) made his?
May be something to consider.
b:5db038fa57][i:5db038fa57]

I use this one, bought at my local auto parts store, to do my 2N, and have never had any problems with using it with the hood on!
Works easy and good due to the flexability of the hose, and quick dis-connect function. I think I paid under $20, for it 4 yrs ago!!


Gary[/i:5db038fa57][/b:5db038fa57]
 
Walt........I don't like the compression testers with the "cone" rubber tip. I can NEVER gitt itt tite enuff. I like the "screw-in" type with rubber hoze. You should see the "adaptor" you haffta use with the Chrysler "HEMI-V8". Sparkplug is in HOLE in the valve cover. My semi-race 1969 BMW 2002 needs an extension too ...or... the screw-in rubber hoze type.

BTW, yer N-Tractor specs: 90psi MIN, good runnin' N's are about 110psi. Brand new will test about 125psi. Compression testers will also identify burned EXHAUST valves or blown cylinder head gasket. (intakes never burn) ........HTH, Dell
 
Autozone will let you borrow one for a deposit. The one i had was just the threads on a tube, then the gauge, so it would fit in tight spots, worked great, took it back, they gave me my $47 back.
 
This is the one I bought. They're cheap enough i'd never rent one, plus saves me from renting one for every non running tractor I have. It works great, fits easily under the hood
Untitled URL Link
 
(quoted from post at 19:17:48 03/02/15) In answer to your question; My 1948 8n is blowing some (not too bad) black smoke after starting. Also it is hard to start on it's own. Pull it off and in just a few feet it will start. Uses about 1/2 quart of oil after two days light work. Also exhaust manifold is showing some black blow by or whatever you call it near one of the exhaust/intake holes.
walt

If you have evidence of your exhaust manifold leaking, I would not waste any time fixing it. The longer you let it go, the more chances you have of it eroding the mating surface of the block.
 
Caryc Thanks. I do have an exhaust leak and also have my gaskets ordered to be here in a couple of days! Appreciate the hot tip!!
walt
 
Gary
I found and bought a compression tester like the one in the picture you posted! Thanks
walt
 
(quoted from post at 20:31:19 03/03/15) Gary
I found and bought a compression tester like the one in the picture you posted! Thanks
walt
b:7e85f600f7][i:7e85f600f7]
You are quite welcome!! I think that will do the job for ya. Just put the right adapter on the end of the hose, then hand start that into the sparkie hole, while twisting the hose....tighten it up and install the guage, with the quick-disconnect attach. on the other hose end.....Compression test away!!!
At least three to four revs, on the engine for top comp. reading!!!!

Gary :wink: [/i:7e85f600f7][/b:7e85f600f7]
 

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